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Permalink Reply by mojoatomic on June 24, 2014 at 7:13am

Forgot to post this pic of the wire guides... 

They're ball bearing races held in place by neo magnets on the winding rod because it's so much easier to reposition them mid wind this way instead of using set screws - 

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Permalink Reply by the anonymous pick on June 24, 2014 at 7:22am

nice!!  and  welcome  ;-)

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Permalink Reply by mojoatomic on June 24, 2014 at 9:20am

Thank you :-) 

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Permalink Reply by mojoatomic on June 24, 2014 at 9:21am

Thanks for the welcome!

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Permalink Reply by Richey Kay on June 24, 2014 at 7:08pm

Amazing work, and welcome to the Nation. I make pickups too... but my setup is much more humble! 

I, and I'm sure many others would love to see how you made this.

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Permalink Reply by mojoatomic on June 25, 2014 at 2:39am

Thanks for the welcome! Happy to share the design, let me get a post together. 

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Permalink Reply by mojoatomic on June 25, 2014 at 4:26am

I'm releasing this under the Creative Commons License - Attribution Non-Commercial Share Alike (CC BY-NC-SA) 

Basic idea and prices

I've wanted a new winder for awhile, and thought I could make better than I could buy, and do it for cheaper. I reused everything I could from the basic lathe and used off the shelf components to keep this simple and inexpensive. You just program the number of turns, press go and let it rip while you guide the wire. I don’t see the need for an auto traverse, so I didn’t make one; I like scatter wound PUP’s.

The lathe ships with a starting speed of 750 RPM's, so I modified that. It now starts at 0 RPM and goes to 3400; I also added a forward and reverse switch for CW and CCW operation so you don’t have to flip the pickup over to do a reverse wind – you can even wind stacked humbuckers without removing the pickup to switch direction between the upper and lower coils.

Here's the break down...
Lathe $120 - 20% coupon, think it was $104 after tax
Tach - $9.98
Programmable counter $33.00
DPDT center off switch - $5 (added forward and reverse)
Neon Lamp - $2
Opto interrupter - $5

 

Most parts can be sourced from Ebay or Amazon (Ebay turned out to be cheaper); just search these descriptions – 

Tachometer - 0.56" DIGITAL Red LED Frequency and Tachometer Rotate Speed Meter DC 7-12V

Preset Counter C3E-R-220 - 110V 220V 6 Preset Digital counter 10KPCS Relay
(get the 110v - 220v relay version, 12v - 24v version will require an additional 12v power supply)

From Radio Shack - DPDT center OFF switch
This source is just for convenience, just get a DPDT center off switch with spade logs.
Neon Lamp
Again, get what you want, 120V will be the easiest to use. 

The following parts are from www.sparkfun.com
Photo Interrupter GP1A57HRJ00F Breakout Board

Photo Interrupter GP1A57HRJ00F

Resistor 330 Ohm 1/6th Watt PTH

 

Opto Interrupter Disk

For those who would like to make the winder but might have trouble making the opto interrupter disk... here's the file in a format ponoko.com likes. Just upload it to them and they'll cut you one. 

Their current pricing to make if for you is $5.33, so not bad at all. Make sure to specify these options - 

Acrylic - Black
3.0 mm
P1 - 181.0 mm long x 181.0 mm wide
Making: $1.83
Material: $3.50
Total: $5.33

Schematic and control circuit - click top open the PDF

Theory of operation

My design relies on a latching circuit for basic operation – so here’s how that works…

Here’s an animation I did to illustrate the basics of a latching circuit – you’ll find that this is directly relatable to the schematic posted above. 

S1 is a momentary action switch, so it returns to it's original position after you press it, but while pressed, this is what the circuit looks like... S1 is pressed and latches the upper portion of the relay, both armatures move as one and the lower armature circuit completes the circuit between the motor and it's power supply, and the motor begins to run.

S1 is released, and through the nature of the circuit, the relay remains "Latched". The coil is still conducting and pulling both of the armatures into a closed condition and the motor and it's power supply are still bridged so the motor continues to run. 

The momentary switch labeled S2 in this schematic represents the "normally closed" outputs of the counter's relay. Imagine that you have the counter set to spin until it reaches 10,000 winds and it gets there. The Normally closed contacts on the counters relay open, thus breaking the electron flow through the coil, thereby releasing the armatures, severing the circuit between the motor and it's power supply and the motor stops spinning. The circuit is now in a rest state and "unlatched". The circuit is reset and made ready to run again when you press the reset key on the counter, thereby closing S2. 

 

As a bonus, this basic idea can be retrofitted to Schatten and most Schatten based designs as well… It will almost certainly retrofit most DIY winder designs with minimal tweaking. Why? Because all it has to do is interrupt the voltage going to your winder’s motor, either directly or through an inhibit signal.  Here’s what that schematic looks like –

Interfacing with the Harbor Freight lathe –

This is the motor control board for the Harbor Freight 8x12 wood lathe and probably several others..... 

Here's how everything works - 

DC out - motor for the lathe
AC in - AC input from wall (mains)
Potentiometer - (controls lathe min-max speed)

Inhibit - what we're using to stop the motor at the specified number of turns. Most commercial DC motor controllers have some variation on this theme... some provide braking and others, like this one, kill the DC voltage going to the motor. Other variations of lathes use this input for a type of safety circuit or to make sure chip guards are in place. 

For some unknown reason of applied goofiness in engineering, on this lathe, this line was attached to a momentary push button switch labeled "circuit breaker reset"... whatever.

*** In this design, it's now connected to the "Normally Open" outputs on the counter module - when those outputs close when the preset count is reached, the motor controller shuts off. ***


As for the High and low speed adjustments, they do exactly what they sound like :-) - adjust the lower one to have the motor start at 0 RPM's instead of a "really not appropriate for this application" 750 RPM.

 

Opto interrupter disk and opto interrupter for counting winds

Here's a view of the left side of the lathe with the plastic bell housing removed showing the opto interrupter disk I cut and the assembly steps –

Spindle assembly ready for optical interrupter instillation (remove the plastic bell housing and the outer most jam nut) - 

Place spacer on spindle shaft (I laser cut this spacer, but you could stack washers to achieve the same effect) -

Spindle assembly ready to go with the new opto interrupter disk and outer jam nut installed – you need 2 windows on the disk and it needs to be well balanced, 3000 RPM is unforgiving in this area.

Under power at 3200 RPM – smooth as silk.

This photo shows the opto interrupter on the top of the lathe – it just attaches with a magnet and hangs over the disk. I’ll take better pics of this area as soon as I get a chance.

Wire Guides and winding bar

Added a wire guide bar - 10mm (what I had on hand). 

This photo shows the opto interrupter on the top of the lathe – it just attaches with a magnet and hangs over the disk. I’ll take better pics of this area as soon as I get a chance. 

The wire guides are 10mm ID ball bearings held in place and adjusted by magnets (way easier to adjust position then using set screws). 

I've tried to be very detailed and I hope everything is as clear as mud :-) Happy to clear up any questions - 

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Permalink Reply by Richey Kay on June 25, 2014 at 4:32am

That's pretty amazing... please post this as a blog and tag it up so people can find it easily in future.

Good on you for sharing under CC.

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Permalink Reply by mojoatomic on June 25, 2014 at 4:42am

Thank you! The CC is the way to go.. it's way more fun when everyone can play and benefit. I did a blog post, not sure how to tag it though - 

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Permalink Reply by Richey Kay on June 25, 2014 at 4:45am

Yep, if only everyone thought like that...

You can add tags at the bottom of the blog post

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Permalink Reply by Suspect Device on June 25, 2014 at 5:52am

Whoa. This is lots of great info. Thanks for sharing this! Those little 3-string pups are pretty sharp too!

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Permalink Reply by mojoatomic on June 25, 2014 at 6:07am

Thank you; happy to share. Those 3 string PUP's were actually for a prototype 6 string split coil humbucker - my homebrew version of a Supro lapsteel string through design. Looks like a Coodercaster pickup. They'd work for a 3 string CBG as well I'd imagine. They're tele width, so fairly wide and each one has 11K winds.

You have to make a cleat to mount them on the lathe winder... I need to post up a pic of that setup. 

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