Help with Pickup Winder Counter Please

[classic.rocker978]

Well I built my own pickup winder from an older sewing machine utilizing the foot controls. It is awesome. The only problem is I dont have any way of counting the number of wraps of wire on the pickup bobbin.

Everyone mentions reed switches and proximity switches and optical switches or a mechanical counter that is belt driven. Etc...etc...

Can someone tell me the most accurate method of counting turns for around $50? I really appreciate the help, I've learned so much already from this wonderful forum. I'm not very technologically literate so if you can dumb it down for me that would be awesome. A lot of these switch terms and definitions are completely new to me.

[mondo]

Ebay has a whole whack of digital and mechanical counters available from 10 bucks to hundreds of dollars. If you want to save your money like I do you may want to go for an LED digital counter with at least 4 digits. Make sure it has a reset button and will add because some only work as timers. You should be able to find a chinese one for less than 20 bucks with shipping included. They usually come without a back so you'll need to mount it into something or improvise. Reed switches will work if you get the round ones for windows and door alarms. They come with the magnet that sends the pulse. I got mine for one red penny plus a couple dollars for shipping. So my turns counter cost less than 25 bucks but I had to wait about 3 weeks for the stuff to arrive. You may be able to get faster delivery if you buy from something closer but it will likely cost more too. Good luck!

[classic.rocker978]

Well I got the little white reed switch that is used for door alarms but it seems it cannot go over about 350 rpm before completely losing count. I have it wired to a calculator to trigger the = button for counting. Could this limitation be because of the calculator or the reed switch?

[mondo]

That sounds like the problem. The counter needs to be able to handle more pulses per second. I have heard that adjusting the distance between the reed switch and the magnet will help. I'm having simmilar problems with a counter that I pulled off an excercise machine. It has numerous settings and will take your pulse but it doesn't seem to like counting above 3-400 rpm. It also made a really irritating beep with each count until I discoed the chirping device and reconnected the circuit.

[David King]

The calculator is easy to test, start hitting the = button as fast as you can with your finger and see what happens.

Reed switches will probably require a magnetic armature that lengthens the pulse. You need a couple of 1/2 round, heavy gauge plates (saw a round electrical cover in half), get a 1/4" tall, neo, disc magnet 1/2 or 3/4" in dia. Attach the two 1/2 discs with the magnet and glue them somehow to (or screw them to each side of a 1/4" wide collar on) your spindle shaft so that the plates are exactly perpendicular to the shaft and the plates will spin on either side of your reed magnet. The damned thing will need a counter weight opposite the discs or your winder will be bouncing all over the bench.

The guy who came up with the calculator idea really ought to be dope-slapped for all the thousands of posts they caused trying to make the stupid thing work. If you can't afford a proper counter how the hell are you going to buy magnet wire and magnets? It make no sense to me.
Pickup winding is an expensive and mostly useless hobby unless you live on a desert island and can only communicate to the outside world via electric guitar. (Which for some reason has no pickup??)

[Joe Gwinn]

Reed switches will probably require a magnetic armature that lengthens the pulse. You need a couple of 1/2 round, heavy gauge plates (saw a round electrical cover in half), get a 1/4" tall, neo, disc magnet 1/2 or 3/4" in dia. Attach the two 1/2 discs with the magnet and glue them somehow to (or screw them to each side of a 1/4" wide collar on) your spindle shaft so that the plates are exactly perpendicular to the shaft and the plates will spin on either side of your reed magnet. The damned thing will need a counter weight opposite the discs or your winder will be bouncing all over the bench.

I would turn this inside out. Make the plates and reed switch stationary, and have a neo magnet swinging (with a slug on the opposite side of the axle for balance). The plates conduct flux from the flying magnet to the reed switch only while the magnet is between the plates. The plates need not be half-circles. The magnetic field of the neo magnet is parallel to the bobbin axle, the steel plates are perpendicular, the neo flys between the two plates, and the reed switch bridges the two plates..

I suggested this approach some time ago, but never got around to making a drawing.

[David King]

Smart, I'd read through your old explanation but hadn't realized that the plates were to be stationary. Won't you be setting up a very strong pulse-breaking action as the neo leaves the vicinity of the plates?

Not to mention monster eddy currents in the plates with no where to go...

[Joe Gwinn]

Smart, I'd read through your old explanation but hadn't realized that the plates were to be stationary. Won't you be setting up a very strong pulse-breaking action as the neo leaves the vicinity of the plates?

Not to mention monster eddy currents in the plates with no where to go...

Flux cutoff will be rapid, but the reed switch won't mind.

There will be eddy currents in the plates. By definition, eddy currents always go in circles, so yes, they always do have someplace to go.

Hard to say how much trouble the eddy currents will be without experimentation. If they are a problem, some radial cuts in the plates will suppress the currents. The radial cuts point at the reed switch, so they don't affect carriage of flux to reed switch

[classic.rocker978]

Well, I'm feeling incredibly dense right now... For whatever reason I cannot comprehend the idea about the steel plates and reed switch.

If I need to purchase a digital counter in place of the calculator then I will. I just cant tell if the reed switch or my calculator is the limiting factor at this point. I cannot press the calculator button 400 times+ per minute to test if the calculator is the issue. I have heard a lot about the Cub counters.. are they pretty decent?

I ordered a long 3 inch neo magnet that is 1x1 thick. I will tape it to the shaft, this should be more than powerful enough. I'm using a door alarm style reed switch.

I'm winding pickups because it will be far cheaper in the long run to build my own instead of buying vintage correct boutique pickups. Maybe someday I'll even sell my own.

Any and all help is greatly appreciated, I respect each of you here and want to learn as much as possible. How many RPM's is a reed switch like mine good for?

[David King]

CR978, that's a huge neo for this job and it will probably cause more problems than it will solve. I'd suggest a line of tiny button magnets, 1/4" dia x 1/8" at the most. Glue these buttons with all the same polarity up and all touching one another about 1/2 way around a wooden wheel, facing out (like a bike tire). As Joe mentioned you can fill the other half with non magnetic slugs to balance things up as necessary. Harbor freight sells 10 of these little neos in all their stores for $1.99.

Keep the 1x1x3 for magnetizing your alnicos. I hear you about wanting to make your own pickups, that's why i got into it too.
The Cubs are fine but Red Lion (Omron and others too) make some much nicer counters you can pick up as used surplus on ebay for a fraction of their original cost. Read some of the other counter discussions. It's an endless topic of conversation here.

[classic.rocker978]

I tried gluing a bunch of magnets around it but this causes the reed switch to rapidly trigger in between each of the magnets. I had them touching. Should I try it with slightly stronger magnets?

Would square or circular magnets be better at this?

Also can you recommend me a counter for under $30 used or new? Need to count at least 1,500 rpm accurately.

[David King]

CR978,
I was afraid that might happen with the button mags. I would check the polarity of the the magnets and then wrap a strip of steel over them to even out the field. This may move the field over to the edges of the steel strip.

Here's a counter http://cgi.ebay.com/PEPPERL-FUCHS-PR...-/390280564433
there were 3 pages of "preset counters" on ebay. Prices seem high these days but you can search low to high and see what's in your price-range.

If you don't want a preset counter then you'll save some.

[classic.rocker978]

I'm going to look for some thin steel and try to machine a C shape to wrap over the mags. Hopefully that fixes the problem.

[David King]

Let us know how that works. If you cut up a can you might need 2 layers to get enough iron where you need it.

[SkinnyWire]

A slot type photointerruptor works nicely for counting turns.