Coil winders

[hallkbrdz]

Anyone know of an automated winder that can:

Wind coils on rectangular bobbins (good magnetic tension assembly)
Wind orthocyclic coil layouts using offset layers

I need to wind small coils with 28ga wire, 18 layers deep, on a bobbin 9mm wide, with a 11.6x27.5mm base. Winding orthocyclic coils with rather small wire (for my eyes) with a high number of layers is... very difficult by hand if you want to keep it nice and neat. First I looked at the ukcnc mk6 mini winder, which is pretty much close to what I need with small bobbins. I wrote them and they said they could modify the code for orthocycle, but they said it probably wouldn't work with that "large" of a wire gauge (pickups apparently use REALLY fine wire). I then found eguitarplans.com pickup coil winder. I actually like this physical design better with the magnetic tensioner, but I would rather use a servo motor for the rotation, and direct programming control vs the gcode method he chose. So, very much a DIY project as there really doesn't seem to be much out there for less than large industrial use. But if someone has their own design that would fit, I'm open to it.

 

[harrisonpatm]

Got a 3d printer? There's a few DIY projects out there, some by hand assisted by a printed structure to keep it tidy. Some automated.

This one looked pretty sweet:

Printables

www.printables.com

 

[floydr]

An old sewing machine with bobbin winder might work.
Later floyd

 

[hallkbrdz]

Got a 3d printer? There's a few DIY projects out there, some by hand assisted by a printed structure to keep it tidy. Some automated.

This one looked pretty sweet:

Printables

www.printables.com

Thanks, although this leaves a lot to be desired in precision, at least based on the video referenced. The layers need to have evenly spaced turns so that alternating layers stack well (14 layers is my target). Using a feed tube drilled just slightly larger than the wire is what I plan to use. In this case, a 0.35ish od wire so a 0.38mm hole seems reasonable.

For the rotating motor a 360 servo with a built-in encoder seems reasonable. One I'm looking at peaks at 140 RPM, so it's not fast, but accuracy is more important for this application to get the layer shift at exactly the right rotational location.

I'll may use a linear rail for the carriage movement like this one, but mount it on the bottom plate to reduce twist and vertical deformation. I'd like to get at least 0.0875mm accuracy in horizontal movement though, so a screw may be better - still need to research that more. I've also looked at having a stepper or servo on the carriage itself to move the feed inward and outward as the coil layers are wound around the bobbin to keep the distance MOL constant, but that may be overkill.

Bryan

 

[hallkbrdz]

Update: Finding no good off-the-shelf solutions, I decided to build my own using an OpenBuilds C-Beam® XLarge Linear Actuator Bundle for the X axis with a standard 1.8 degree stepper motor, onto which is mounted the bobbin motor with another 1.8 degree stepper motor. These are driven with two Stepperonline DM542T units, controlled with (for development) a Raspberry Pi 3B with a 5v signal converter board. Stepper motor power is supplied by a Mean Well 48v power supply, and wire tension is controlled with a MT-800 magnetic tensioner. Code is currently written in python and directly controls the steppers after inputs for the wire diameter, number of turns per layer, and number of layers.

Here's a short video of the first orthocyclic coil wind, and a picture of the so-so 9 layer result. Goal is 19 layers without any errors, but that will take some code and tension adjustments to get there. Then I'll slowly up the speed until it fails. Either way, it's still much better than my hand wound efforts with this 0.35mm 28awg wire.

View attachment 07ml7adbxp6c1.webp

 

[hallkbrdz]

FYI, if you are interested, I'm documenting the evolution of this build on a reddit channel here:

https://www.reddit.com/r/Coil_Winders/

 

[hallkbrdz]

Winding good quality orthocycle coils on a rectangular form isn't easy, but I'm getting there...