Geo Stevens 39AM

[Beef Coon]

For quick n dirty you can make a rectangular one or 2 out of polycarbonate. It machines easy and holds a thread.

print a template out on a laser printer, paste to the poly, cut, drill, tap and you're good to go. You can prototype cams with that stuff too.

[CheopisIV]

Thanks for the offer David, I might just take you up on that if my Brother in Law's lathe can't handle the blanks. He has a bench model and might not be big enough to work the 3" width.

Bob, that sounds like a great idea! I have a few interesting cam profiles and one is very, very close to humbucker bobbins but a touch too big on the swing. I was thinking of using aluminum or wood to prototype but Lexan should be a lot cheaper, easier and durable. I downloaded the Coil Winding book so have the TPL figures from the charts, now just have to sit down and figure out the math behind these heart shaped cams!

[David King]

My main lathe is a 9x20 bench model. I do have a 3" step collet for my Hardinge turret lathe as well but it's set up for other operations.

[CheopisIV]

Turns out my Brother in Law has a decent setup so I got to cutting some Aluminum yesterday! Turned out 2 of them.


I made a drilling template in Sketchup for the mounting holes.


Following the info here, I designed up a basic cam in Sketchup to fit my bobbins. More interesting designs to come if this works!


And here's where I sit while waiting for the upgraded Extruder for my 3D printer.


I'm thinking the ABS cam should be good for a bit of testing but not likely long term use. It should save a bunch of time in cutting other styles of templates though.

[CheopisIV]

I had a Mojotone Tele Bridge bobbin with ~1/2" gap in the pile so figured I'd hook up the 500 Cam and give a test wind. The cam is a tiny bit too big for the bobbin but close.

Here's the start of the wind, gearing set for 94 TPL, speed varies. Pretty excited to have it running without wire breakage!

Uploading the second vid of the finish. Tension still needs to be figured out, I think I have too much post Meteor tension in the felt clip. More testing to come.

[David King]

No dancer on the meteor? Low speed seems a little uneven during the initial turns - I bet there's a way to smooth that out with some lube.
Oh and nice work on the face plates.

[CheopisIV]

Thanks! The faceplates turned out really good until I tried to drill and tap for the mounting holes. I broke 3 bits off inside then a tap so have some ..errr.. 'weight relief' holes on the one I ended up with some holes that are a bit snug so can pressure mount a humbucker bobbin without issue, I'm using 2sided tape on these vids with the tele bobbins.

There's no dancer, but the back wheel jiggles about when I loosen the front felt tension. I had to add some tension on the rear of the fishing rod to keep the wire from just going crazy and was having it fly around the rod and snag/snap before adding the funnel. It all runs smooth right now but I still need to try some things on the tensioning as it seems quite tight. I'll snap some pics of the whole thing soon. I found the wire was laying down a bit crazy at first too, but there's a wheel on an arm near the bobbin and moving that closer gives a lot better control of the laydown. The bunching is most likely because my cam is 0.5" and the bobbin is 0.464" so there's a bit of dwell and overshoot on each side with this bobbin.

I found a Tele neck bobbin that's a lot closer to 0.5" so threw it on there today. I started getting bunching on one side so had to move the traverse wheel over a bit; it's threaded on the side so really easy to adjust on the fly too! After adjustment I was getting a really smooth layering.

[CheopisIV]

Here's vid #2 of the Tele Bridge Bobbin showing the finished wind. As stated, the bobbin is 0.464 and the cam was 0.500 so there's some buildup. I've been in touch with a guy who does CNC Acrylic cutting and am seeing if he can do up some test cams for me. I'm waiting for the 3D Printer Extruder to come from England so no clue when it's going to get here...

[CheopisIV]

Well now.... here's an interesting picture.


This actually makes more sense as far as the useage and tensioning vs the setup I'd assumed from the original auction pics. Does anyone else have any experience with a Meteor device?

[CheopisIV]

Been a while since I updated, but I've been busy trying different things.

1) Got my cams from the CNC guys (aerotex.ca) and they're perfect! Exactly as designed in Sketchup and a nice tight fit on the machine. Now to see how long Acrylic lasts!

2) Flipped the Meteor despooler/tensioner around and it now works much more efficiently. I was thinking of adding a second system to the machine and tracked down another Meteor 483 as well as a few Meteor 484s and they want $650 USD for ONE of the units.... seems I REALLY got a steal on this whole rig if that's the going price!! I think I can get rid of the fishing rod and other extraneous parts and feed the wire directly to the Meteor, but the 483 only goes up to 18G whereas I've read 42AWG needs ~42-45G tension. the Meteor 484 ranges from 10-300 so if I decide to drop $650 on something, Ill get that one. Here's another pic of one in use that I think confirms the setup;


3) My 3D Printer 'Hot End' replacement arrived so hopefully I can get it hacked in and print my own prototype cams for some interesting winds.

Here's a vid testing one of the Aerotex cams. It's a bit bigger around than the hand cut thing I was previously using so I had some bunching on the outer end before I adjusted in to the proper spot. Also adjustable on the fly so pretty versatile.

[David King]

Check your AWG 42 tension specs. I've never seen tension specs above 35g and have never needed to run wire beyond 15g. I typically run between 5 and 7g. I'd say 45g is just insane.
Re longevity of the acrylic cams you might want to put a layer of silicone grease to bring friction down. See if they can make you a second set out of Delrin/acetal.

[CheopisIV]

Oh! I was going by some old info in another thread here, let me see if I can find it again... May be recalling it incorrectly.
Here we go, I guess that's listed as max spec before stretching.

Oopps,

I misinterpreted how tension is defined and used. The max tension in grams provided by the manufacturer means the point where the wire will start to stretch and it doesn't mean the recommended amount of tension one should use when winding a coil. After some discussions and more research, I found that the actual recommended amount of tension should be between 50% to 80% of the max measurement. But this is not written in stone obviously. But it is a good baseline for research.

I also found some stuff on Seymour's site that may clear it up a bit too.

Tension: Is the measurement usually in grams that measures the maximum amount of tension that a wire can be drawn or pulled off a spool without stretching and causing higher coil readings.

What is the tension that should be used with magnet wire?
The maximum tension before the wire will stretch causing undesirable or high coil resistance.
42 Gauge is 45 grams
43 Gauge is 35 grams
44 Gauge is 29 grams

754. How do you determine the winding tension?
There are tension devices that measure the tension in grams when the coil is being wound. When hand winding you can usually feel the drag between your fingers and also the amount of heat that builds up if you are holding the wire to tight. If there is not enough tension on the coil, the magnet wire will flop all over the winding area and cause the coil to have loops and snags. I hold the wire between my thumb and index finger when hand winding. This allows me to control the shape of the coil. Leo Fender told me that he liked pickups hand wound because you would have better control over the tension of coils being wound.

I typically get the cantilever in the 8-10 range and loosen/tighten the felt clamp on the back of the Meteor so the wheel starts to jiggle, then up the tension with the gauge until the wheel jiggles less. I also have some drag on the back of the pole to get the wire going straight, it's pretty minimal and mostly for control through the eyelets.

[CheopisIV]

Finally figured out the Hot End and Firmware on the Makibox so first print... Cam!

It did not turn out very well as I needed to calibrate my X axis for less backlash but print 2 and 3 were a bit better. Still needs tweaking to get things right.

Here's the first print through the whole process. ~17 minutes worth.