Coil winder Ideas and traverse devices

[Woodenspoke]

OK so I just spent about an hour reading through the coil winding Idea section and got a headache about page four. I have a cnc mill and still I was getting weary.

I kept hearing about using a heart shaped cam rather than the reversible drive belt mentioned. I did a search but could not find a drawing of a typical heart shaped cam.

I don't want to make this a long rehash of that coil winder post I am just interested in the cam design.

I personally believe a cam would be easier overall even with a CNC solution since you can vary the rate at which the cam spins thus changing the traverse speed. OF course if your coils are different widths then that may be an issue and require more than one sized cam or the movement of the transverse arm forward or backward from the pivot point.

Reversing steppers has always been an issue and unless you can go to a high end servo system I like the cam idea as a starting point better than using a belt driven reversing stepper.

I got the heart shaped cam theory but for some reason I cannot bring myself to put two and two together as to which part of the cam is driving the wire on what part of the wind, if this makes sense.

I guess if it made sense to me, or if I could picture it I wouldn't be asking. A picture, a link or a long explanation would be appreciated.

[David Schwab]

Check this page out Coil Winder (http://nervoussquirrel.com/pickup%20winder%201.html)

Go to the fourth, six and seventh and pages and see a heart shaped cam.

This winder spins the wire around a stationary bobbin. I've never quite figured out how that works. :confused:

[Woodenspoke]

David;

Wow just reread my original post, sorry I sound like an idiot???

Even though your pictures and links make some sense it seems like someone has reinvented the wheel or just likes to add lots of complicated parts. For something that complex you might as well program a CNC machine to do the work without all the little additional cams. Or buy that CNC winder from China for 2.5K I have seen on ebay. which incorporates all the standard winding features you would ever need to make straight neat coils.

My thought was a straight piece of aluminum bar with a set pivot point. Below the Pivot point a motor driven cam would push the bar out and a spring would keep the bar against the cam. The spring would allow the bar to ride along the cam creating a clean transverse winding motion. I realize the trick is is in the reverse motion. It has to be quick enough so the wire will not build up on the bobbin edges. bottom line a fast change of direction

The question I think is at what point in the movement along the heart shaped cam does this quick change of direction take place. Is it in the V at the top of the heart or the outer V point at the bottom?

I can picture the quick wire change of direction where the wire drops into that V portion at the top of the heart but why is it not the same at the opposite end? This is where my confusion comes in.

Here is a rough sketch of my design so this all makes sense. The only thing missing is a spring (not hard to figure that one out) and the motor may have to move along with the cam contact point or horizontal rather than vertical as drawn, I am not sure at this point. Again a rough sketch of a possible quick and dirty design. Now if I can only figure out the cam the design would come together much faster.

http://img.villagephotos.com/p/2006-11/1224497/MAVJL-CamDesign.jpg

[wilser]

I recently got a small DC motor that has a ball screw and nut attached from an electronics surplus store. I'm just waiting for a small linear bearing to complete my auto-traverse! getting guide bearings small enough for 42/43AWG wire was a challenge! Anyway, the motor will change directions by flipping the polarity with a DPDT relay that's driven by a simple flip/flop circuit. The circuit will be triggered by small push buttons (wired for set/reset on the flip/flop) that will be adjustable in position. I hope to have this ready by the time I start making the pickups for a few of the basses I have on order, otherwise I'll have to scatterwind them (which is getting tiresome!). I'll post pics and more detailed specs when I have it working.

[Woodenspoke]

My feeling is if you add switches and other electrical reversing solutions you may add in an unwanted delay. This delay would be the time the switch is actuated until the time the motor changes direction and would be enough to cause build up of wire on the coil edges. I am assuming the bobbin motor is running at a constant speed.

All things equal I believed keeping the transverse motor going in the same direction and having a cam do the rapid movements off the edges would eliminate the possibility of any directional delays. I will also probably experiment with different cams to create a scatter wound type motion as others have done.

Still would like to see some info on the heart shaped cam in action.

[Sam Lee Guy]

Just look at a real old treadle or hand crank sewing machine - one with a cotton bobbin winder on the side that you can engage with the main wheel and you'll see exactly how a heart shaped cam works.

[Woodenspoke]

I'll look for some old sewing machine pictures but why is it so hard to describe its operation in words?

Hopefully I can find something that makes sense, since I cant remember any cams on any sewing machine I have seen others use in my life time. maybe I was not looking too hard.

[Woodenspoke]

I really didn't find anything that stood out in bobbin winding from any sewing machine web page.

I did however set up a computer test using Adobe Illustrator where I took a guitar pick (heart shape) and set up several different points of rotation from center to top edge of the heart all of which rode along the edge of the rod. This shape created weird winding patterns where one fast wind across the bobbin was followed by one slow even wind. Moving the cam pivot point away from the edge made it even worse.

Then I though maybe it would be easier just to use a circle and offset the Pivot point to one side. In this model the rod moved cleanly back and fourth at a steady speed which would result in an even wind in both directions.

I also realized that the point of contact should be the rod and not some pin on the top. But I am still working on a theory about changing the movement to accommodate different bobbin sizes without changing the cam size. So a pin that moves is not out of the question yet but that may be wishful thinking.

With a round cam then you can start making different surface features which could mimic scatter wound pickups but still have smooth traverse motion between the two bobbin ends.


If anyone believes this to be wrong speak up before I wind up wasting time making parts.

Hopefully this makes sense

[John_H]

I really didn't find anything that stood out in bobbin winding from any sewing machine web page.

I did however set up a computer test using Adobe Illustrator where I took a guitar pick (heart shape) and set up several different points of rotation from center to top edge of the heart all of which rode along the edge of the rod. This shape created weird winding patterns where one fast wind across the bobbin was followed by one slow even wind. Moving the cam pivot point away from the edge made it even worse.

Then I though maybe it would be easier just to use a circle and offset the Pivot point to one side. In this model the rod moved cleanly back and fourth at a steady speed which would result in an even wind in both directions.

I also realized that the point of contact should be the rod and not some pin on the top. But I am still working on a theory about changing the movement to accommodate different bobbin sizes without changing the cam size. So a pin that moves is not out of the question yet but that may be wishful thinking.

With a round cam then you can start making different surface features which could mimic scatter wound pickups but still have smooth traverse motion between the two bobbin ends.


If anyone believes this to be wrong speak up before I wind up wasting time making parts.

Hopefully this makes sense

The oblong cam like you describe wont work. It would wind very lopsided coils. A heart shaped cam guides the follower at a smooth uniform velocity, and doesn't dwell at one end or the other.

To me it seems the most difficult part of making a mechanical traverse would be controlling your turns per layer, and being able to easily vary it. Without that all you have is a back, and forth thingy.

[Woodenspoke]

The oblong cam like you describe wont work. It would wind very lopsided coils. A heart shaped cam guides the follower at a smooth uniform velocity, and doesn't dwell at one end or the other.

To me it seems the most difficult part of making a mechanical traverse would be controlling your turns per layer, and being able to easily vary it. Without that all you have is a back, and forth thingy.

Thanks for the picture since at at least you have given me a starting point. I now see heart shaped means sort of heart shaped. It is actually a cross between the guitar pick and round offset cam I ran on paper.

Now I assume this rides along a small pin given the dip at the top of the heart is not that big. You also have it running from a drive gear and I want to mount mine directly to the shaft of the drive motor.

My only question and it might seem stupid at what two points on that cam does the left and right bobbin change of direction occur. This will help me with the location of the shaft position. I see this is also offset a certain distance from center.

Unless someone has a DXF file of a working cam they are willing to part with. Any info I can get will help speed up the process.

Thanks again for the picture you made my day.

[John_H]

Now I assume this rides along a small pin given the dip at the top of the heart is not that big. You also have it running from a drive gear and I want to mount mine directly to the shaft of the drive motor.

My only question and it might seem stupid at what two points on that cam does the left and right bobbin change of direction occur. This will help me with the location of the shaft position. I see this is also offset a certain distance from center.

A follower rides on the cam. It's L shaped, and the other end is the wire guide. The distance of travel can be controlled by the length of the rocker.


The change of direction occurs at the most extreme outward, and inward points. One revolution of the cam moves the lever across, and back.

You say you want to mount a cam to the drive motor. This wont work without some kind of mechanical reduction of the speed of the cam. For example, if you were winding strat single coils and wanted a level wind the bobbin is 7/16 tall (.4375) The wire dia. is approx .0026. That equals 168 turns. At that rate the cam would have to revolve once for every 336 turns of the coil. A different solution is required for every type of coil you would wind. Traverse length, and turns per layer both. I have ideas about how to achieve this rather simply, but would have to build another winder to implement them. Until then I'll continue to hand wind, and learn as much as I can about making good sounding pickups.

[Woodenspoke]

I think what you describe is what I envisioned. However I have not gotten the part of the inner V to outer movement as coming off the bobbin in the opposite direction of where you want the wire to go. I will have to do some building and see first hand.

I planned on changing motor speed to account for the width and bobbin speed. To do the two with equal precision will require some experimentation. or a cnc program and two servos. I also have a mill with the fourth servo in reserve and could create a program which would change the the speed of the motor to match the bobbin. Then just make whitness lines on the bobbin winder motor as to needed speed.

I did get the L shape but the rocker I didn't figure out where that is in relation to the L shaped piece. My picture may be an over design.


I have rushed this reply since I am going out the door but your explanation of the rocker would be appreciated.

[John_H]

I think what you describe is what I envisioned. However I have not gotten the part of the inner V to outer movement as coming off the bobbin in the opposite direction of where you want the wire to go. I will have to do some building and see first hand.

I planned on changing motor speed to account for the width and bobbin speed. To do the two with equal precision will require some experimentation. or a cnc program and two servos. I also have a mill with the fourth servo in reserve and could create a program which would change the the speed of the motor to match the bobbin. Then just make whitness lines on the bobbin winder motor as to needed speed.

I did get the L shape but the rocker I didn't figure out where that is in relation to the L shaped piece. My picture may be an over design.


I have rushed this reply since I am going out the door but your explanation of the rocker would be appreciated.

I should have said rocker arm in the earlier post. Sorry 'bout that. I was referring to the arm that actually guides the wire. Adjusting the traverse length could be done by attaching the wire guide at different points on the arm.

[Woodenspoke]

I kinda thought thats what you were referring too. I see that there is no 1:2 ratio on the cam as you stated. Unless you make a new cam for each coil size or change the speed of the cam it is an issue. I can see why you are hand winding

I wanted to just hand wind at first but then thought about just starting and stopping the process without sitting in front of the machine guiding the wire.

back to the drawing board for now to mill over all the information you have provided.

Thnaks again

[Wrnchbndr]

Hi, this is my first post to this forum. Lots of great info and talented folks here. My spin on this heart shape is to imagine that you need a cam to deliver a linear movement that travels the same distance for every degree of rotation of cam driveshaft. Using just an offset circle won't work because if you start at the high point of the cam, it is comparatively flat per degree of rotation and tranverse travel will be slow. Maximum travel will occur at 90 degrees of rotatation but will slow down again the closer the cam gets toward the 180 point and totally stop while it passes over 180 and then speed up again as it heads toward another 90 degrees. This will cause build up of windings at each side of the bobbin. The solution is to start with a circle. At the zero point (0 degrees, designate the maximum radius. At the 180 degree point designate minimum radius which will be a difference of the intended stroke. Consider that the rotation rate is constant. You divide the difference between maximum and minimum by 180 and you'll acquire a figure that indicates how much less than the maximum radius of material needs to be cutaway from the circle per every degree of rotation. 180 degrees is only half of the circle. The other half will be the exact opposite form for the opposite direction or stroke. The resulting cam will have a heart shape and if you do the math and calculate the radius by ever degree, the resulting transverse motion will yield an even build up of wire.

[Woodenspoke]

I do understand the theory behind your math unfortunately my math is not up to the challenge. A DXF file of a proper cam would be my ideal answer. From that I could make several dozen different sizes using a CNC mill and some 1/4" aluminum plate. I will assume the cam only changes in size not shape for a given distance. This also many not be true.I think there is one factor though missing from your math and that is the thickness of the magnet wire including the coating. Probably why John H is still holding that cam in his hands and hand winding. Now I am assuming this has to be added to the calculations since a thicker wire will require a smaller cam. This is because the wire will lay down faster at larger sizes given everything is a constant and the reverse will be true when going from lets say a 42 to a 43 wire. Again this is all assumptions I am making from posts on this thread.

But you did explain why the v shape at the top will work I think the correct figure is .5:1 for each wind layer. I think the 1:2 which is also correct had thrown me off. Sometimes I have to be hit on the head a few times before it sinks in. Cam makes 1/2 turn per coil rotation but I kept seeing 1 full turn per rotation of the coil.

I guess if I could devise a winder that rotated the cam 1/2 a turn for every turn of the bobbin all I would need is a different cam for each pickup and wire size. A mechanical reduction should be easily, the cam design for me is the hard part.

I have thought about using my small CNC mill as the bobbing winder and cam and programing the z axis to change direction at the proper time. But the CNC does not have auto motor speed control so this would be much harder to do using a manual speed knob. The the ideal situation would be to kill the motor at a certain count again another thing which is missing.

I have ordered some basic parts to start building a winder since the CNC winder is a good idea but has too many variables for now and I am not ready to start putting in motor and rotational count controls since they may exceed the cost of building a winder from scratch. I also like the idea it can me small enough to be put away until needed.

Well again thanks for putting the cam into perspective for me I finally have the operation down just my math skills are not up to the task. If there is a formula handy that may help me.

[Wrnchbndr]

I think you are thinking too hard and you don't need to really calculate every degree. Lets say your desired stroke is 0.5". There are 180 degrees in half a circle. 0.5"180=0.00277... . To cut out a heart shaped cam you could probably get away with just plotting out ever ten degrees around your circle and then connect the dots. 10x.0027=about .03 so for every ten degrees around the circle you'd decrease the radius by 0.030 or 30 thousanths of an inch until you get to the opposite side and then you reverse the process.

[Woodenspoke]

Sounds easier now. But I go back to my original question about the thickness of the magnet wire. Should you deduct the full thickness from your calculations given you are looking to end the wind 1/2 the thickness of the wire gage away from the end of the bobbin. I am using the word bobbin to include flatwork.

Just off the cuff I believe AWG 42 is about .0056 or.006 inches wide with a coating but if this is wrong this does not matter just the principle about deducting this dimension from your calculations. EX: .5 - .006 = 0.494/180=.00274 then 10 x .00274= .274. OK so I can do some basic math.

I should be able to do this arch in Solidworks down to .027 without rounding it off and export a dxf file. Yes you can duplicate one half mirror it and combine the two ends. From what you are showing with the math I can just resize the finished cam to accommodate wider bobbins. Make one 101% and another 102% and so on untill you get tired of making duplicates.

I am surprised no one has posted any dxf files for this cam if the math is so simple. Somehow it seems too easy to be true or is it just the big secret no one will reveal. I am going to wait and see what other people have to add to this discussion before I start my work.

[John_H]

I do understand the theory behind your math unfortunately my math is not up to the challenge. A DXF file of a proper cam would be my ideal answer. From that I could make several dozen different sizes using a CNC mill and some 1/4" aluminum plate. I will assume the cam only changes in size not shape for a given distance. This also many not be true.I think there is one factor though missing from your math and that is the thickness of the magnet wire including the coating. Probably why John H is still holding that cam in his hands and hand winding. Now I am assuming this has to be added to the calculations since a thicker wire will require a smaller cam. This is because the wire will lay down faster at larger sizes given everything is a constant and the reverse will be true when going from lets say a 42 to a 43 wire. Again this is all assumptions I am making from posts on this thread.

But you did explain why the v shape at the top will work I think the correct figure is .5:1 for each wind layer. I think the 1:2 which is also correct had thrown me off. Sometimes I have to be hit on the head a few times before it sinks in. Cam makes 1/2 turn per coil rotation but I kept seeing 1 full turn per rotation of the coil.

I guess if I could devise a winder that rotated the cam 1/2 a turn for every turn of the bobbin all I would need is a different cam for each pickup and wire size. A mechanical reduction should be easily, the cam design for me is the hard part.

I have thought about using my small CNC mill as the bobbing winder and cam and programing the z axis to change direction at the proper time. But the CNC does not have auto motor speed control so this would be much harder to do using a manual speed knob. The the ideal situation would be to kill the motor at a certain count again another thing which is missing.

I have ordered some basic parts to start building a winder since the CNC winder is a good idea but has too many variables for now and I am not ready to start putting in motor and rotational count controls since they may exceed the cost of building a winder from scratch. I also like the idea it can me small enough to be put away until needed.

Well again thanks for putting the cam into perspective for me I finally have the operation down just my math skills are not up to the task. If there is a formula handy that may help me.

I'm just a dumb old carpenter, but I think you're making things too difficult.

I re-read my original post. Although it was hypothetical situation that would make for a poor strat pickup the math works.

I was trying to illustrate the ratio of the cam speed to the bobbin speed. A full rotation of the cam will guide the wire back and forth (two layers). The ratio was 336:1 from the bobbin to the cam. 180 degrees cam rotation = 168 turns = 1 layer of wire. If you wanted 100TPL The ratio would be 200:1 .

I could easily enough build another winder with a mechanically driven auto traverse, and maybe someday will. It's just not very high on the list.

Good luck with your winder. Post some pictures when you get something together.




wrench; That was a great description on the cam.

[Wrnchbndr]

My spin on the magnetwire is to just do a number of physical measurement of the wire itself with a micrometer. Remember that there is an actual thickness to the insulation and the average thickness will change by manuacturer because of the different processes they may employ to apply the lacquer or enamel. I'd take the largest of these measurements. You'll have a bobbin width measurement to use based on your bobbin design or existing pickup. If your wire is for example .0028 (bare clean 43 gauge is .0024) and your intended bobbin is 0.55", You divide .55 by .0028 and get 196. This means that your transverse device needs to do one stroke in one direction for every 196 rotations of the bobbin. If you're using this heart-shaped cam, it will yield a a full back on forth movement in one complete revolution which is actually two layers of wire -- one layer to the right and another to the left as it returns to the starting point. Two layers is 2x196 widths of wire so the ratio is 392 revolutions of the bobbing to 1 complete revolution of the transverse cam. Its the max and minimum radius of your heart shaped cam that needs to match the width of your bobbin. What is unfortunate is that this whole concept limits you to doing the same bobbin width if you're concerned about laying the wire neatly side by side. Not only do you need a cam of the proper size but you'll need to change the ration to other bobbins of different width. This is something that I did not understand until I though about your question. For another size pickup, if you maintain the ratio and only change the size of the cam the wire will not lay properly.

[Woodenspoke]

Sounds like I should have just kept to my original idea to hand wind. First I was thinking of only using one wire size AWG 42 and single poly coating and doing three different pickups. All of which will be a different width. So if a coated wire is for argument sake is .006 then we divide by the distance between the width to get an even coil wrap lets say 1/2 " so .5 /.006 = 83 wraps per layer.

OK I got that part and getting the shape of the arch math; now where do you combine the two???

Then we (royal we) have spoken of an L shaped wire guide which is adjustable. It will also change the distance and speed at which the arm moves and thus the wrap count depending on where the follower for the cam pivot's on this wire guide. Assuming this guide has a fixed or adjustable pivot point. Just theorizing here since we all by now I have no clue.

My quick story is I have been a woodworker for 30 years and over the past three years added metal working tools to my shop. When I was young even worked with a few top builders but decided it was better as a hobby than as a career of you like eating (this was in NYC in the 70's). So now I am selling parts for guitars on eBay as well as doing some manufacturing for one of the two major guitar parts suppliers trying to slowly build up a business. So I have been around the block way too many times to just give up on automation just yet.

Now I will build a winder and hand wind for my first go round but I find I pickup things easily so I expect to wind less garbage than one may expect from a newbie. But adding any automation has been the most difficult concept. I figured someone had a preset formula which takes in all these variables, but it does not look that way. If there is something out there its a closely guarded secret. Or using a cam is really a stop gap before spending the 10K plus on a dedicated CNC machine. I have also seen the homemade winder pages as has everyone else has but no secrets are provided. Besides it seems they are more interested in the winder build than the pickup, but I am sure I am wrong as I have been so far.

Honestly it was easier to retrofit a small mill for CNC than to design this seemingly simple device. But I will keep going maybe someone who has lived this retrofit will chime in here and let everyone know how these issues were overcome. Math and design. I could go the experimental route but I really don't have that kind of time frame to tinker.

[John_H]

I'd take the largest of these measurements.

I'd take the smaller. Depending on how tight you wind the wire does get thinner under tension.

[John_H]

Then we (royal we) have spoken of an L shaped wire guide which is adjustable. It will also change the distance and speed at which the arm moves and thus the wrap count depending on where the follower for the cam pivot's on this wire guide. Assuming this guide has a fixed or adjustable pivot point. Just theorizing here since we all by now I have no clue.

I'm not sure of what you mean by "(royal we)", but I'll take it in stride. If I came off as condescending in an earlier post it was unintentional, and I'm sorry. I was trying to help. That being said maybe this will help.

Changing the length of the rocker arm that guides the wire will change the distance, and speed that the wire travels. The only way to change the wrap count is to change the ratio from the bobbin to the cam. I tried to illustrate that in an earlier post. The example I gave you was for a level even wind which is probably not where you'll find your best tone.

After some experimentation you'll figure out how many turns per layer sounds best to you on a 42g 8k humbucker. When you factor in all of the variables such as magnet type, wire insulation type/build, wire tension, baseplate, keeper bar, stagger, slug material, and pole screw material the possibilities are exponential in number. That is what differentiates one builders sound from another That's only one pickup design.

Some of the guys that contribute on this board who by the way are among the best in the world have built countless prototypes, and they know what works for them be it vintage replicas, or contemporary designs. That's info that won't be thrown freely about. Most of the good info you'll find will be in the form of a subtle hint, or someone will tell you right out when something wont work, and why.

I like yourself am pretty new to all of this. I started winding only six months ago. The six months previous to that I was reading all that I could absorb on the subject. It was only after I started winding that many things actually became clear to me.

Now I will build a winder and hand wind for my first go round but I find I pickup things easily so I expect to wind less garbage than one may expect from a newbie. But adding any automation has been the most difficult concept. I figured someone had a preset formula which takes in all these variables, but it does not look that way. If there is something out there its a closely guarded secret.

When I first started I built a couple from SM kits. After that I asked friends if they had junk pickups that I could have. Those that were worth rewinding usually ended up back in the hands of the donors rebuilt for feedback. It doesn't take too long to get the hang of it.

No secrets here. I'd be happy to share my ideas with you. It seemed you were pointed in the direction of a CNC solution so I didn't expand.

[Woodenspoke]

Royal we explanation: I rebuild a room top to bottom with no help from anyone and my wife comes in with a friend and says look at what we did. "The royal we" I call it. Doesn't translate well. Your idea not mine is what it means.

Again the CNC is limited without additional modifications to run cutter head motor speed and shutoff. The program can count winds and kill the motor and adjust the speed if I had the modifications for the mill, even scatter wind a particular pattern. I think right now its cheaper to spend $100 and build a manual winder than modify my CNC machine. Besides I do use it to manufacture items so I rather not screw it up just yet.

If I do get it right as we all hope we will; the additional money right now would be better spent prototyping than buying equipment. I have come to realize the endless variations available with materials and winding techniques as you stated. It can be pretty daunting when you start searching the web for metals which are better gauss conductors. I will just start off with something basic and see where it goes. I expect the same learning curve on pickups but compressed into a much shorter time frame than the 20 or so years it took to become a good woodworker.

The cam idea would be minimal cost and I always have scraps of 1/4" aluminum in my shop, so other than adding a cam drive system, my other costs are zero, Plus cutting them on a cnc mill would be what I am set up for cutting now. So it seemed at the time like it was going to be an easy thing to do since we have forums and I'll just ask how they did it??? ha

I guess I have joined the ranks of the pickup obsessed. I also ordered two kits from SM and I do have some old pickups to play with. I have an old velvet Hammer Red rodes which is in need of a rewind and an unknowm humbucker which can be canabilized. First I have to build the winder.

[R.G.]

Check this page out Coil Winder (http://nervoussquirrel.com/pickup%20winder%201.html)

Go to the fourth, six and seventh and pages and see a heart shaped cam.

This winder spins the wire around a stationary bobbin. I've never quite figured out how that works. :confused:
It took a minute. the wire comes into the center of the wire distribution arm, goes out to the end of the arm, and is let out of the end of the arm toward the bobbin. The end of the arm plays out wire around the bobbin. The bobbin is not fixed. It moves in and out along its axis, but does not spin.

The motion is the same as if you held a bobbin in your left hand and wound wire onto it with your right hand.

That diagram of various cams to get various degrees of scatter, the complicated machinery, and the picture of the cam being machined is one of the strongest arguments I have seen yet for doing an all-software winder.

[David Schwab]

The bobbin is not fixed. It moves in and out along its axis, but does not spin.

That part I figured out.

The motion is the same as if you held a bobbin in your left hand and wound wire onto it with your right hand.

I can't figure out how the wire doesn't wrap around the axel that the wire distribution arm is spinning on. That's the part I can't visualize.

That diagram of various cams to get various degrees of scatter, the complicated machinery, and the picture of the cam being machined is one of the strongest arguments I have seen yet for doing an all-software winder.

I agree. It's an amazing machine, but way too complex. I'd think it would be hard to change it's winding pattern.

[R.G.]

That part I figured out.
I can't figure out how the wire doesn't wrap around the axel that the wire distribution arm is spinning on. That's the part I can't visualize.
Ah. The axle is hollow. The wire goes down the hollow center of the axle for the wire arm.

[Woodenspoke]

Here is that Chinese CNC winder off ebay http://cgi.ebay.com/Fully-Automatic-coil-Transformer-CNC-Winding-Machine_W0QQitemZ180209345339QQihZ008QQcategoryZ92081QQs sPageNameZWDVWQQrdZ1QQcmdZViewItem

Says only 40 gage minimum and looks to be of little use trying to program in any kind of pattern. But they did mention tension programing for the wind. The bobbin is stationary in a lathe style setup and the wire moves which is what you would expect, see the video. Just try returning it??????

Eureka
Light bulb just went off: I have a servo motor which I bought as a spare. I can mount the servo on the main mill head (or stationary using the rear column) with the servo axis forward toward you, throw on a bobbin attachment and you have a programmable motor for counting turns and auto stop capabilities. Forget about the main motor that was a bad idea. Then I can use the Y axis on the mill bed to move the wire. The 4th servo will drive the bobbin at no additional cost and I have an unused 4th axis on my controller card. Anyone have any gcode for mach3 LOL. I would also need some kind of stationary tension device to mount on the mill bed. I am trying but right now this seems like the solution to mechanical auto winding. Not that I have seen any indication there is a good mechanical solution.

I am still going to build that hand winder first and learn to wind bobbins but I have a backup plan now that is not too far fetched; Yippee. Still interested in seeing where this thread goes.

[David Schwab]

Ah. The axle is hollow. The wire goes down the hollow center of the axle for the wire arm.

Ah ha! That was simple... :o

Thanks for clearing that up.. was driving me crazy! :p

[Ampclutz]

Woodenspoke,

If you have a cnc machine you probably have a CAD program to do your drawings... If so, you can make almost any cam you need in just a few minutes. Don't let anyone convince you cams are difficult because they aren't difficult. Your cnc machine gives you a true advantage. You can probably make a cam from start to finish in less than an hour. That's about 10 minutes to machine it and 50 minutes to draw it! If you are quick with the drawing part make that 10 minutes to draw. That's about what it took me to make my cam.

AC

[R.G.]

Woodenspoke,
If you have a cnc machine you probably have a CAD program to do your drawings... If so, you can make almost any cam you need in just a few minutes. Don't let anyone convince you cams are difficult because they aren't difficult. Your cnc machine gives you a true advantage. You can probably make a cam from start to finish in less than an hour. That's about 10 minutes to machine it and 50 minutes to draw it! If you are quick with the drawing part make that 10 minutes to draw. That's about what it took me to make my cam.
AC

Ya know, that's absolutely true! IF you have a CNC machining center available to you, you can make most mechanical parts quickly and easily. What does that CNC machine cost, either in dollars or your time and money to CNC a basic lathe or mill? Last time I checked, the great preponderance of private house garages do not come standard with a CNC machining center in them.

Given that it may be possible to skip the CNC machining center in favor of going directly from CAD to wound bobbin by using a programmable coil winder instead of a programmable machine tool to make the cams that make the winding machine work the way you want, as well as being able to do things that cams can't, might it not be useful to look in to programmable - i.e. CNC - coil winders? :)

[Ampclutz]

RG,

You're absolutely right! But in this particular case Woodenspoke, who started this thread, says he has a CNC and scrap aluminum sitting around. I'm not too sure about his drawing and CAM software because he hasn't actually mentioned being able to get all the way from concept to drawing to tool path to finished part. He seems to be stuck on the concept and drawing part, not the manufacturing part.

My theory is if you have it feel free to use it. Woodenspoke seems to have it and just wants to be able to use it. CNC is definitely not for everybody.

Sooooo, I'm willing to help woodenspoke with his cam... Anyone else in?

AC

[Woodenspoke]

http://img.villagephotos.com/p/2006-11/1224497/5ProductionRun.jpg
http://img.villagephotos.com/p/2006-11/1224497/4BasePlate.jpg

I leave it up to you to guess who sells it, I'm not telling since its marketed under their name not mine. But I will say I did have a long email discussion with Frank Ford over design elements of the Fret bender. From Solidworks to sales.

A small manual mill is cheap and is as small as most band saws and if you look on the CNC zone forums many garages as you call it are setup for some serious work. My shop is in my home but 1000sq feet is limiting me right now as is a planned move to another state. I have already paid for the mill from sales in a fairly short time frame. I will just say you need some money in your pocket. However with Two servos and an old computer making a winder would be at least 1/4 the cost of a mill. I also did all the conversions thus saving about $700.

CNC'ed base plate from my small mill. Not much to rave about but its mine. The goal was one bit two holes and one slot 4 min between plates including removal and restart on the next plate. The bushing was added later. It is also milled on top of a 3/4 inch thick jig plate which was designed in Solidworks and milled on the same mini mill. I can send you those files if you need them (for the jig plate) since I don't sell it I don't care. I have not experimented because its setup to do this one job. But with this same setup I can cut cams so I don't have to play with it.

OK I showed the goods told all now show me yours, LOL

I believe this thread is about traverse mechanical design so lets get back to it. So far all I have is theory from everyone. has anyone gone from concept to design using a cam and can it be modified to Scatter wind ?

GB
Pennington Luthier Supply
PLS

[Ampclutz]

Woodenspoke,

Your drawing in post number 3 of this thread will work just fine if you use a sliding pivot point in the middle and a fixed point for the cam to ride on. The movable center pivot point will let you adjust the width of the wind to use different heights of bobbins with just one cam. The closer the pivot point to the cam the wider the scatter.

Your heart shaped cam is more of a traditional Valentine than a real heart shaped cam. It would work well on Valentine's Day, not at all for a winder. LOL!

My winder uses a cam with a .5 inch throw from minimum to maximum. The computer I drew it on took a very hard hit from lightning and is no longer among the living. The drawings are gone...

Can you draw radial lines, draw absolute points at specific points along those lines, select the points and draw a cubic spline, convert the cubic spline to an arc spline, draw a line offset from that arc spline and convert that to a tool path? Can you machine the result and then mount that to a stepper motor shaft somehow? If you can do that you are good to go! I can do that so this is not just theory. Damn lightning!

With a stepper or servo motor for the bobbin it will do anything you tell it to do... Except go faster than it can go!

BTW, Nice EBay store you have there. Do you want to sell these things?

AC

[David Schwab]

OK I showed the goods told all now show me yours, LOL

OK... ;)

http://www.sgd-lutherie.com/images/bender.jpg


They make those things out of aluminum now, huh?

Seriously though... very nice work. :)

[R.G.]

RG,
You're absolutely right! But in this particular case Woodenspoke, who started this thread, says he has a CNC and scrap aluminum sitting around. I'm not too sure about his drawing and CAM software because he hasn't actually mentioned being able to get all the way from concept to drawing to tool path to finished part. He seems to be stuck on the concept and drawing part, not the manufacturing part.

My theory is if you have it feel free to use it. Woodenspoke seems to have it and just wants to be able to use it. CNC is definitely not for everybody.

Sooooo, I'm willing to help woodenspoke with his cam... Anyone else in?
AC
OK. I agree. Let's help him understand.

Woodenspoke:
A cam is a device for forcing linear motion as a result of a wheel's rotation.

Imagine a perfectly round steel wheel with a lever arm bearing on its rim. As you rotate the wheel, the lever arm does... nothing. That's because the radius of a circle is constant. The lever is never moved. But now, let's offset the center of the wheel. Now as it spins, the wheel is eccentric - the lever is pressed further away from and allowed closer to the axle because the "radius" it sees at any instant is different.

If you think about it, you could imagine the linear motion that the wheel (which is about to be a cam) imparts to the lever is just the change in distance of the edge of the wheel from the center of the axle it spins on.

Generalizing to a cam, a cam is a rotating member on an axle; it has an edge that is a varying distance from the center of the axle as it rotates through an entire revolution. Although many cams are symmetrical, there is no need for it to be. All you need is for the variation in what would be radius for a circle, the distance of the edge from the center of the axle, to be the variation you want in the linear motion at the edge.

You want the amount that the edge is different from a true circle to be small compared to the total size of the cam. Probably the edge variation should be less than 1/5 of the average diameter of the cam; here's where my ME is weak. The closer it is to a true circle, the easier it is to drive the cam. That's why the cams illustrated at that coil winder site I was deriding were mostly circular, with little variations on the edges.

Literally, to get a cam to give you the correct motion, you decide what you want the linear mechanical motion to be for each degree of rotation of the cam. That's the edge profile. You add to that a base radius that makes the edge profile easy to turn, probably five to ten times the min to max on the linear motion. When that's done, you have a desciption of the cam in terms of distance from center for each degree of rotation.

[R.G.]

I believe this thread is about traverse mechanical design so lets get back to it. So far all I have is theory from everyone. has anyone gone from concept to design using a cam and can it be modified to Scatter wind ?
Sure.
But you won't like it.

A cam is a translater of rotation to reciprocating linear motion. Most coil winders have the motion of the cam rotationally locked to the rotation of the bobbin of the coil being wound so the cam moves the wire laterally on the bobbin by a fixed amount per turn of the bobbin.

However, there is no particular reason that the cam and bobbin have to be rigidly geared together. If you rotate the cam at speeds other than the necessary fixed speed to give you even layer winds, the wire is spread out or piled up in un-neat turns.

At the "perfect" speed for layer winds, the cam rotates just enough so that the wire always lies right next to the previous turn. If you spin the cam slower than that, the wire moves too little to lie side by side, and it piles up in untidly little piles as it goes. If you spin the cam faster than the perfect speed for the wire diameter, the wire is spaced out laterally, with space between adjacent turns. Finally, you ... could... drive the cam with an average speed appropriate for layer winding, but with random variations around that average, and get amounts of scatter appropriate to the degree of variation from even layers.

So when do you plan to start marketing your winder?

[Woodenspoke]

RG

Sorry but I think got a better reply from John H. I had also mentioned offset circular cams and that was dismissed due to the shape so I don't see where you have connected all the dots or helped me out. I was expecting more from your "lets help him out" like you had some plan to follow not dummying it down teaching me how a cam works. This is where I start singing "the wheels on the Bus go round and round". I said I was clueless not an idiot.


What I have learned so far:
Most of the transverse devices I have seen built are based on a linear switching mechanism requiring at least a one axis controller and servo. Hit the switch make the direction change. But I opted for old school from another post here where they mentioned different cams for different patterns. Switches will not work for anything other than a straight wind pattern so why bother.

I also realized from others that by adding additional speed changes to the bobbin VS the cam made no sense since you are making 1/2 a cam revolution per wind no matter what the wind or distance traveled. It was easier to change the cam using the same 1/2 rotation ratio to single bobbin turn for different pickups and adding to that some sort of adjustable arm feed for the wire, also mention by another poster here.

I can visualize with the correctly shaped cam you can force the movement from a nice even stroke to a more varied pattern it will not be pretty but as long as when you reach the end of the bobbin you can make that quick change of direction again bringing us back to the same 1/2 turn ratio. But you need only design 1/2 a cam since the opposite is just a mirror of the one side unless you want a different wind pattern on the second pass.

Also the math provided places the hole in the center of the cam and the shape creates the lateral motion of the arm thus heart shaped was the cam shape for a straight pattern wind. All of this was explained long ago on this post. Of course when you finish with the math and cut the cam the hole is no longer centered an therefore a true cam.

Thats it.

It is not my intention to beat on you over the head RG but that was pretty lame; you have not provided any additional info or even a picture of a cam operated winder or even a rough design. I can already take the theory others have graciously provided (note: without asking me to provide a reference of my work) and play with a design. But I would rather see a design that works makes it less of a playtime project and more of a recreation.

Just look at David's winder a perfect example of taking a proven design and recreating it (by the way love the engraving and work one of the best winders I have seem made by anyone). No one wants to reinvent the wheel nor do I want to start from scratch if its been done before. Besides its only a tool I thought the winding pattern and material choice was the big secret.

I have no desire to market a winder and this whole project started out as dislike for the pickups available in the retail market. So far I am going to take the motor, counter and reed switch I purchased on ebay and make a base and do some hand winding.

[Woodenspoke]

Woodenspoke,

BTW, Nice EBay store you have there. Do you want to sell these things?

AC

I am not sure what you mean about selling these things. Winders never, its too easy to make one from a drill. If I could actually make a good pickup maybe but that may take years. I have asked about vendors but so far I have come to realize I may just do it on the side for myself or helping friends out rewinding some junk they have. So its just another thing to have under my own control.

That design was just a sketch and was flawed from the start. I have a good idea where to start but after all this banter I feel I just want to start winding already by hand.

Thanks for the thumbs up on the store but I really want to go online and dump ebay but still provide a decent price point. But I have a house to sell and a move to make so it will be after that happens.

[David Schwab]

Just look at David's winder a perfect example of taking a proven design and recreating it (by the way love the engraving and work one of the best winders I have seem made by anyone).

I can take no credit for that fret bender, other than the monogram. That's a Stew-Mac bender, circa 1988. It's made with a steel plate and weighs a ton! I showed it because you showed the benders you made... obviously for S/M!

I had brought up a cam driven traverse here a while ago. What didn't occur to me was that an offset round cam will give a linear motion, and that will cause the wire to pile up on the outsides of the coil because it spends too much time there and not enough in the middle.

The "heart" shape causes the motion to be slower across the middle and faster on the ends.

If anyone here has a working solution, they aren't saying... so far it's been a lot of theory mostly involving stepper motors and stuff.

I for one would love to get my hand off the winder. :)

[Woodenspoke]

I can take no credit for that fret bender, other than the monogram. That's a Stew-Mac bender, circa 1988. It's made with a steel plate and weighs a ton! I showed it because you showed the benders you made... obviously for S/M!

I had brought up a cam driven traverse here a while ago. What didn't occur to me was that an offset round cam will give a linear motion, and that will cause the wire to pile up on the outsides of the coil because it spends too much time there and not enough in the middle.

The "heart" shape causes the motion to be slower across the middle and faster on the ends.

If anyone here has a working solution, they aren't saying... so far it's been a lot of theory mostly involving stepper motors and stuff.

I for one would love to get my hand off the winder. :)

Stewmac makes their own stuff its the other company. The Frank Fork email was a hint. Also Starts with an L. Anyway I know your pain in only a few weeks of posting here, but you have at least used a winder and understand why you don't want to be stuck feeding wire while you can be doing something else at the same time.

I find this fear now of giving away any design info in every forum because of the internet Luthier Market. Everyone keeps all their secrets close to them because someone else may profit from the information. Thats exactly why SM is so huge. No one will tell you how to make the tools yourself so you might as well just go out and buy it. I am old enough to remember no internet, no SM and everyone was happy to show off their stuff without fear, Haa those were the days. But you hand wound no CNC either at our level.

I don't think a winder is an item worth manufacturing anyway due to the limited number of people who actually use them and how easy it is to buy a motor and hand wind. Schatten has the winder for sale already but I bet they do not sell quite as many as you may think. If they sell 50 a year I would be surprised.

One good thing is if you ever need CNC support the CNC zone is very open. So when or if you make that plunge you can probably find some help programing the thing to wind. Plus It would not be an off the charts purchase either. Most of those forum members work in shops and have no fear about telling all and helping out. Completely different level of support they actually like to tell all, amazing.

[David Schwab]

Stewmac makes their own stuff its the other company. The Frank Fork email was a hint. Also Starts with an L.

Ah... yes I know that company well!

Anyway I know your pain in only a few weeks of posting here, but you have at least used a winder and understand why you don't want to be stuck feeding wire while you can be doing something else at the same time.

I get in my own way. I'd really rather have the winder do all the work.

I don't think a winder is an item worth manufacturing anyway due to the limited number of people who actually use them and how easy it is to buy a motor and hand wind. Schatten has the winder for sale already but I bet they do not sell quite as many as you may think. If they sell 50 a year I would be surprised.

I have a Schatten. It looks like it was a time consuming thing to build. That's where the high price comes in. The newer model has a plastic housing, which no doubt to keep costs down and make it easier to build.

It works OK but I'm already thinking of designs for a winder.... It got me started though.

[R.G.]

RG
Sorry but I think got a better reply from John H. I had also mentioned offset circular cams and that was dismissed due to the shape so I don't see where you have connected all the dots or helped me out. I was expecting more from your "lets help him out" like you had some plan to follow not dummying it down teaching me how a cam works. This is where I start singing "the wheels on the Bus go round and round". I said I was clueless not an idiot.
Sorry if I offended you. It's really quite difficult to really know how well informed a person is online. Maybe it's entirely my fault for not reading all of the postings closely enough. But no problem, we can rapidly un-dummy it back up.

What I have learned so far:
Most of the transverse devices I have seen built are based on a linear switching mechanism requiring at least a one axis controller and servo. Hit the switch make the direction change. But I opted for old school from another post here where they mentioned different cams for different patterns. Switches will not work for anything other than a straight wind pattern so why bother.
As long as you are limiting yourself to mechanical-only systems, yes, you're pretty much stuck with either a traverse and limit switches or a slew of cams, gears, and followers to program the motion mechanically.

I also realized from others that by adding additional speed changes to the bobbin VS the cam made no sense since you are making 1/2 a cam revolution per wind no matter what the wind or distance traveled. It was easier to change the cam using the same 1/2 rotation ratio to single bobbin turn for different pickups and adding to that some sort of adjustable arm feed for the wire, also mention by another poster here.

I believe this is incorrect. Why would a cam make 1/2 rotation per turn of the bobbin? If, for instance, you're doing a level wind of wire across a bobbin that's 0.25" wide. The wire is on the order of 0.003" diameter, so you need 0.25/0.003 = 166.667 turns per layer. That means that your cam turns one half turn that many turns of the bobbin.

Of course, level winds are the Great Satan, so you want to traverse faster than that. You can get fewer turns per layer by changing the number of bobbin turns per cam half rotation. At 1/2 cam turn per bobbin turn, the wire lies from one side of the bobbin space to the end of the bobbin in one turn, and while you might make a pretty neat progressive winding out of it, that isn't needed for pickups, isn't scatter winding, and isn't exactly random, either, although it might qualify as the wire lead is too great for the wire friction at any appreciable tension to hold itself in place.


I can visualize with the correctly shaped cam you can force the movement from a nice even stroke to a more varied pattern it will not be pretty but as long as when you reach the end of the bobbin you can make that quick change of direction again bringing us back to the same 1/2 turn ratio. But you need only design 1/2 a cam since the opposite is just a mirror of the one side unless you want a different wind pattern on the second pass.
OK, that part's correct.

Also the math provided places the hole in the center of the cam and the shape creates the lateral motion of the arm thus heart shaped was the cam shape for a straight pattern wind. All of this was explained long ago on this post. Of course when you finish with the math and cut the cam the hole is no longer centered an therefore a true cam.
Thats it.

Good, you're not clueless on cams.

It is not my intention to beat on you over the head RG but that was pretty lame; you have not provided any additional info or even a picture of a cam operated winder or even a rough design.
Actually, I have. I have sketches posted at Geofex. I just posted my idea of how to do a winder, which doesn't match your idea of how to do it. My preference is to make the mechanics as simple as possible by making all of the motion programmable. The bobbin is spun by a stepper motor. That sidesteps the whole issue of one axis of a servo by making rotations of the bobbin be X steps per rotation. The computer that runs this keeps the numbers in what serves it for a head.

The lateral motion of the wire across the bobbin is also done by a stepper motor, turning a lead screw. This gives a literally unlimited set of motions of the bobbin rotation versus the traverse across the bobbin. There are no limit switches - at least they're not needed for basic operation. This setup can spin the bobbin, move the wire across it, make the wire have intricate motion changes on the way and can do it with a different pattern per layer if needed. It has the potential to "memorize" a hand guided wind and replicate it, in addition to replacing the cam driven structure.

But if you think it's lame that I didn't sketch out for you how to make a cam operated traverse winder, I can only plead that I misunderstood your request. I didn't realize that you wanted me to do drawings for you for your preference of mechanisms. I did not understand that was what you wanted.

I can already take the theory others have graciously provided (note: without asking me to provide a reference of my work) and play with a design. But I would rather see a design that works makes it less of a playtime project and more of a recreation.
Note: I didn't ask you for a reference for your work. Check the posts.

There are designs on the web for coil winders; I believe some of the links are posted here.

Just look at David's winder a perfect example of taking a proven design and recreating it (by the way love the engraving and work one of the best winders I have seem made by anyone). No one wants to reinvent the wheel nor do I want to start from scratch if its been done before. Besides its only a tool I thought the winding pattern and material choice was the big secret.
I think that the winding pattern is being pumped as a big secret. I think that "hand winding" has to reduce to something less poetic in the end because no two hand windings are the same. Since changing the winding pattern quickly to match something else seems to be necessary, it seems laborious to cut a new cam each time, and wrongly or rightly I decided that making the computer do the heavy lifting to deal with the complexity was the better way to go. But that's just me. You go ahead with whatever seems easy to you.




I have no desire to market a winder
Sorry - I was confused by the references to an ebay shop, the note about Pennington Luthier's supply, and the pictures of a zillion identical fret benders out of your CNC setup. At least I'm not the only one who was confused, I see by the posts.

I do apologize for my lameness, my underestimation of your insight into winders, and my not knowing how you wanted your drawings done. I'll try to do better next time. :)

[Woodenspoke]

When I heard it was plastic thats when I decided not to follow my better judgment and tinker. Being a woodworker why use a metal housing when weight is an asset, So I will base my design on MDF. The other item to consider is should I build a two sided device? Do you use both sides or is it useless since you can always reverse the bobbin or reverse wire a coil wound in the same direction. I have a bit to learn on mounting but that I should be able to find info somewhere in this forum or online.

My asset on this project is my metal lathe which affords me the opportunity to make a platen or two with ease. yes its always nice to have the right tool. I also think a round platen will overcome some of the forces that will effect stability when turning an object that is not evenly weighted

To me this is not a big project. Just an interruption on other projects.

I have also had the notion of minimizing the whole design with no enclosure so I can hang it up with all the other instrument related jigs on my wall.

[John_H]

When I heard it was plastic thats when I decided not to follow my better judgment and tinker. Being a woodworker why use a metal housing when weight is an asset, So I will base my design on MDF. The other item to consider is should I build a two sided device? Do you use both sides or is it useless since you can always reverse the bobbin or reverse wire a coil wound in the same direction. I have a bit to learn on mounting but that I should be able to find info somewhere in this forum or online.

My asset on this project is my metal lathe which affords me the opportunity to make a platen or two with ease. yes its always nice to have the right tool. I also think a round platen will overcome some of the forces that will effect stability when turning an object that is not evenly weighted

To me this is not a big project. Just an interruption on other projects.

I have also had the notion of minimizing the whole design with no enclosure so I can hang it up with all the other instrument related jigs on my wall.

I used MDF for mine, as I do with most jigs etc.. I could've used nicer material, but why bother? I put the most time in designing it. I built it in just a few hours. It's not very sophisticated, but it was cheap and it works great.

It's an advantage to be able to wind from either side.

The shape of the platen is irrelevant as long as it balances. Mine are just a couple blocks of maple. I trued them up with a sanding block as the winder was running. No wobble, or run out. My main criteria was to keep it simple, and small.

[David Schwab]

When I heard it was plastic thats when I decided not to follow my better judgment and tinker. Being a woodworker why use a metal housing when weight is an asset, So I will base my design on MDF. The other item to consider is should I build a two sided device? Do you use both sides or is it useless since you can always reverse the bobbin or reverse wire a coil wound in the same direction. I have a bit to learn on mounting but that I should be able to find info somewhere in this forum or online.

In my case at the time I had no access to anything that resembled a work shop. I live in an apartment (in a house), with a wife, two kids and a cat. :) If I were alone I'd surely have a work bench somewhere... as it is I wind pickups on the kitchen table!

So for me the Shatten was the solution to winding with no place to wind, plus no place to make a winder. I do like that I can store it in its box when not needed, and it's potable and ready to go.

I think it was over priced, but as someone who makes things myself, I under stand it's the work of probably one man. It needed some small adjustments, such as squaring up the wire guide to the "winding tower" as they call it.

The particle board and melamine base is somewhat crudely made. The inkjet clear decal is also crude and the logo is bitmapped. The counter could be bigger, and the motor is just on the verge of being under powered. It's fairly easy to slow it down without breaking the wire!

But it works well for those that need a winder out of the box.

I never use the left side of the winder. I wind all my coils in the same direction. I did do one pickup with the coils reversed, but it's easy enough to turn the bobbin over in most cases.

[Woodenspoke]

RG I have a family, am in the middle of selling a house in a bad market, so I'm always in a mood these days really didn't mean to do that it just comes out. You only have so much time to think about what you said before you press that submit button.

Your last post included a tidbit if information that was helpful. These little morsels of information that slips out that makes your day.

After due consideration I have decided to leave the traverse motion part for another day. If I figure out the secret of a great pickups I will then get some help turning my small Mill into a CNC winder (programing help) since its a small additional mod to all the money I have put into it already.

David: I know your pain but I cant live without my shop. I don't live only for guitars so my tools are put to good use on other projects. Never a dull moment when you have clueless neighbors LOL.

John H. Its just as easy for me to use the lathe as any other tool. The chuck is very expensive an allows very high precision turning. I also have a large sheet of PVC which may be my best choice for the platen. But you do have a nice winder.

I guess we are onto building a winder now David said he only uses one side John says he uses both? Also David says the motor will stop on the Schatten at high tension. and John seems to have devised a drive based on friction rather than a belt which may also help to not break wire.

Winder Opinions
Two sided yes or no?
Make a solid winder drive which can break wire, or one that will slip under too much wire tension?

[Berman]

Hi Woodenspoke
Just my opinion
You need a two-sided winder only when the motor can't change the direction (as the often used sewingmachine-motors).
The power of the Motor is not so important. The Schatten-Winder has a real lowpowered powersupply (0.5A at 9 Volt).
I think with a stronger powersupply (1A, 9Volt) it will work better.

Just my 2 cents
Hermann

[Woodenspoke]

Already have a motor and variable speed control box but it will break wire. AC powered controler but looks like some weird stepper motor. Its ebay so no indicationss of reversability and only three wires, also shows direction arrow but that does not mean it will only turn one way just the correct way. Thanks for the info

[David Schwab]

You need a two-sided winder only when the motor can't change the direction (as the often used sewingmachine-motors).

You can mount the bobbin upside down... but really there's little reason to wind coils in reverse. Just wire them up backwards like with a humbucker.

[R.G.]

I have a family, am in the middle of selling a house in a bad market, so I'm always in a mood these days really didn't mean to do that it just comes out. You only have so much time to think about what you said before you press that submit button.

Your last post included a tidbit if information that was helpful. These little morsels of information that slips out that makes your day.
No foul. I have bad days too. I think I was having one when I read your reply, judging from what I wrote. No problem.
After due consideration I have decided to leave the traverse motion part for another day. If I figure out the secret of a great pickups I will then get some help turning my small Mill into a CNC winder (programing help) since its a small additional mod to all the money I have put into it already.
I think you might want to have a look at these:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95012
http://grizzly.com/products/G9247

They're great places to start in a coil winder build, as they are small(ish) and have the hard parts where precision is needed already done for you. Each is a complete manual winder if you will guide your wire on your own. Each only needs the addition of a traverse and tensioner to be a "dumb" mechanical winder, and the addition of some electronics smarts on the spindle motor and the traverse to be a CNC winder.

I like to find places where the - for me - hard parts of high mechanical accuracy has already been done, and what's needed is the guidance and control.



Two sided yes or no?
Make a solid winder drive which can break wire, or one that will slip under too much wire tension?

While it's possible to design a winder that would slip rather than break #43 copper wire, it's a challenge to make it do that reliably. The break tension on the wire is pretty low.

I took the other approach of designing a tensioner that would keep the wire tension limited to no more than X so that if the bobbin wanted wire, it got wire. I posted the sketches at GEO as well. Originally I wanted to use an electrically servo'ed tensioner, but a slip clutch works as well. What I came up with was three rubber-tired wheels; each in contact and the wire routed over/under/over them. A friction brake on one wheel with a spring-calibrated force on it supplies the slip tension limit, the other two wheels guide and press the wire against the friction wheel. Rubber rollers from an old printer work, as do tires from RC hobby autos and quad (4-wheel) roller skates.

[DrStrangelove]

Consider this wood lathe, too:
http://grizzly.com/products/VS-Wood-Lathe/G8690

This one has an inexpensive 4" face plate suitable for mounting pickups,
while the smaller G9247's is only 2" diameter.

-drh

[Woodenspoke]

I know you all love to convert things but in this case you will pay more to convert these machines into a CNC winder than building one yourself. The only complicated part is putting the traverse mechanism onto a rail or slot which keeps it from flopping in circles. Even two L shaped aluminum guides will work. You can modify some of the replacement parts from the Mini mill, lathe Line of tools which you can find at Littlemachineshop.com and turn them into parts for a winder.

Here is a simplified picture of an easy to build CNC winder. If you take away the cost of converting something like a mini lathe vs two servo motors costing $25+ each or less. You begin to see that a tool conversion makes no economical sense.
http://img.villagephotos.com/p/2006-11/1224497/Untitled-1copy.jpg

In fact if you read back to my eureka moment in this post I realized the Motor control conversion will cost you more money, time and effort getting a computer to drive it at the correct speed and count winds properly would be almost pointless. I am luckily enough to have a mill and spare servo motor to make the bobbin portion of a winder and use the mills Y axis already outfitted with précising ball screws for the traverse motion. My problem is programing. A Servo motor is made to do everything you would need at a low cost and functions with precision far beyond winding needs. I have gone through conversion of these devices to CNC. Its expensive. A pre CNCed mini mill is $2,500 and that does not include the computer and software add another $2000. Also you have to have a standard Parallel port which is not a standard item these days on new motherboards. USB will be the next of controller cards but I don't believe that has happened yet.

For metal turning or wood they are great, converting these to a winder even non CNC unless you use the basic tool for what it was designed for is a waste of money.

I have all my parts now and will whip up my winder in the next week or so.

RG I will look for your tension device sounds like a better plan

[Alabam]

I got lost in all the heart shaped cams solutions, etc, and came up with this traverse setup.
It took me a while to figure out how to mount the wheel that the wire passes through without the wire snagging on the wheel mountings.
This wheel has to be flanged on both sides, to hold it in, with holes drilled into the face, to match the height of the coil.
Shoot it down lads before i waste time building it.

[R.G.]

Shoot it down lads before i waste time building it.
OK. The side to side component of the wire motion is inconsistent. It has a sine wave velocity. As such, it dwells a long time at the outer ends of the traverse and runs across the middle of the bobbin much faster. So wire will pile up on the ends of the bobbing and there'll be a valley in the middle.

Of course, that may sound good, since the wire will pile and slide down the two half-hills at the ends of the traverse, and the resulting non-uniform winding may be random(ish), so it might be as good as some hand wound ones. But there is no reason to think it's a particularly good traverse. You'll have to manually pile up wire in the middle to fill it up to get a full bobbin.

[Alabam]

Thanks R.G, yes i can see your reasoning, that poses a problem.
Strangely enough, i replied a few days ago to a post in the Pickup Makers Forum regarding- "Winding a thin pickup".
In the reply i didn`t mention that i had no need to use a traverse device, the core depth was only 3/16th" and it wound perfectly, this is the pic i posted there.
Cheers.