A DIY Progressive/Universal RF Coil Winder

This is a mostly 3D printed all-mechanical coil winder that I designed to wind some coils needed for a Moog Melodia theremin. It is based in part on the Morris Coilmaster design that can create Universal or Honeycomb winding patterns, but I added the mechanism to provide a transverse movement that creates what is known as a Progressive/Universal winding pattern.
The purpose of this winder is to create high frequency RF inductors with low inter-winding capacitance. It does this by feeding wire in a criss-cross reciprocating manner so that adjacent turns of the coil rarely run parallel to one another.
For a detailed description of operation go to:
technitoys.com/a-homemade-pro...
Note: This is not a build tutorial and the files for the printed parts will not be available. It is intended to give ideas to adapt to your own capabilities and needs.

[@RODALCO2007]

A very nice coil winder you have built there.

[@rsz90182]

Wow man that is amazing!!! Just looking at it work gives you a chill down your spine!!!

[@pentachronic]

You have a very impressive machine there!! Kudos to you!

[@presentalinkwalterbak2426]

OK. This is the awesomest DIY project I have seen in a long time! :)

[@sosayweall1952]

I actually have one of the old winders from your article. I got it at a market a few years back. Sadly it has only the one set of cams and gears. I'll have to find an mechanical engineer who can make me the missing ones.

[@brys555]

Even tho I'm not a fan of 3D prints I must say this is one of the most interesting designs on youtube now. Currently I'm looking for inspiration before I make my own winder. Sill don't know if I should go into two stepper motors and micro controller or try some old school mechanical solution. Your video puts some hope in mechanics. I really like the lever system for stroke adjustment and magnets holding the feed arm.

[@julio3000]

Muy buen proyecto es una máquina impresionante un saludo

[@agush8082]

mechanically fantastic...

[@OIE82]

Beautiful.

[@fasted8468]

Ohhhhh youre that guy :) loved the ave maria

[@Reciclandoideiasoficial]

top parabéns ótimo projeto

[@SpinStar1956]

Really neat project and excellent build-quality. Amazing the precision you got out of your 3-D design. I would like to make a coil-winder for myself as I'm always needing 1-2.5mH coils. Not sure what you would use the big long coil for or how the universal wind helps when applied linearly along the form? Anyway, hats of to you and thanks for sharing your video! 73...

[@pitts8rh]

Thanks for your comments. The purpose of the universal portion of the winder as you know is to minimize inter-winding capacitance to keep the self-resonant frequency as high as possible. Adding in the progressive movement on top of the universal wind allows you to achieve more turns and higher inductance while keeping the ends of the coil well separated so that the end-to-end capacitance doesn't become too significant or even worse start dominating. For a high inductance RF coil with a high SRF you need to first prevent adjacent turns from lying directly adjacent and parallel to one another, and second you have keep the two ends of the coil separated otherwise the shunt C can negate the benefit of the universal winding. See my website listed in the info for a more detailed description of the operation.

[@Stelios.Posantzis]

Very impressive. Can you make the chuck holding the former more precise so that it wobbles less or is it simply poorly adjusted in the video?

[@pitts8rh]

Thanks for your comment. Actually the chucks are more than adequate for this type of application, but the core you see here was not very cylindrical. The form I was winding on was just a scrap of a thin-walled extruded plastic shipping tube that some fragile metal capillaries were delivered in. This tube was not very round and that's why you see a wobble. I could have used something better for a demo, but I like using these plastic tubes because I can slide a ferrite rod into the core afterwards. Also sometimes the tape and the starting end of the wire are clamped under one chuck jaw which throws it a little off center as well.

[@_wave64_]

What is the gear ratio of the bevel gears? I assume it has to be a very odd number in order for the zigzagging to progressively go around the coil form.

[@pitts8rh]

I don't remember the ratios in the video but I currently have 39:40 (crank :chuck spindle), although I have several other gears available. You are right that for honeycomb coils there is generally an odd gear in there to prevent the wire from falling directly on itself with each revolution. But for the progressive winding in the video you don't really need the odd number ratio because the form is constantly moving laterally and this prevents the wire from trying to stack on itself. For the progressive winding you pick a gear ratio that puts the number of turns you need in the length you need, without worrying about the wire piling up. A repetitive pattern develops in the winding that is hard to predict without actually modeling it out. I'm sure there is a lot more science to it than I have considered, but it worked for me and my project needs are over :).

[@jaygrote3557]

How do you take it off of the glass tube and adhesive?

[@pitts8rh]

I didn't remove it. The tube is plastic and was only used for experimenting by sliding different ferrite cores inside. The final coils were wound either directly on the ferrite or on a phenolic tube with an adjustable ferrite inside.

[@SLU2MOVIES]

Hey, mind if I reverse engineer everything and make myself a a guitar pickup winder ? Based on this design ? Greetings from Poland

[@pitts8rh]

Feel free, although I think you could probably find something better for that specific purpose if you look around a little. When I was looking for information it seemed that I ran across a few of these.

[@SLU2MOVIES]

@@pitts8rh Oh yeah, i've seen them as well, most off them are super simple and are motor driven, for me is a no no. Your design on the other hand, is a little more complex, but hey it's has adjustable "winds". Most guitar pickups are tightly winded, other some custom ones are "scattered wind" then, they are hand winded. All off these can sound different with the same magnet and the same resistance on the same guitar. Inner capacitance and canceling electromagnetic fields are the cause off it. Yes I could make a stepper motor one, but I'm not good at programing, I would rather have it mechanical. I've came across this desing when I started searching for UKF coils winders

[@pitts8rh]

@@SLU2MOVIES Okay, I see that you are working toward the same high SRF goal as an RF coil (except much lower frequency). One of the things to consider in your adaptation is to try to make a wire feeder that can get right down into the bobbin or coil form to feed the wire directly onto the surface without touching the sided of the form. This may be a very narrow "v" bent piano wire or something like the eye of a needle that can ride right on the surface of the coil without damaging the previous winds. Wire fed from above (as you know if you have hand-wound coils) has to have exaggerated lateral movements to lead the wire to the edges of the bobbin (for example, 0.2" lateral movement will not give a 0.2" wide coil if fed from some distance). I've found that getting wire to the very edges of a bobbin can be a challenge and certainly can't be done with the plastic feeder that I use, which requires that there be no bobbin walls. Good luck with your project!

[@mr_mack_indenver7807]

You could sell these; I'd buy one!

[@home_Grown_studio]

So much going on at the same time I can't make heads or tails out of any of it

[@brunociro5447]

Hello! If you don't want to share, sell the design. I'm interested.

[@pitts8rh]

It's not that I don't want to share, but I don't really keep track of the files that I end up using and therefore I don't really have a refined file set that will work for others. The iterative process that goes on in making the final prints involves a lot of tweaking and I don't keep track of the file versions along the way. Kind of a shame, but that's how I operate. Sorry.