My first successful homemade powered winder is finally built!

[shawnl]

I've been frequenting this forum for some time now getting loads of useful bits which have helped me iron out a bunch kinks. I went through several tests and rebuilt the drive train system at least twice, comparing the performance of a gear drive system with a belt drive. I finally settled on the belt drive for several reasons: It ran smoother at higher rpms, required less voltage, was more forgiving of slight wobbles in the pulleys, and was easier to disassemble for maintenance and repairs.

My prototype currently uses a mechanical revolution counter and I'm considering switching this out for a digital when I can get around to actually finding one. A small spinning wheel mounted to the edge of a flywheel pushes against a lever on the counter which registers as a completed revolution. The problem with this is that it can get loud. It sounds like a small engine. Secondly, I can't use full throttle on the speed control because it will overwhelm the counter resulting in a jam up that will toast the counter. This isn't a huge deal because I don't ever see myself winding at such a high speed regardless. It will take about 1000 rpms before bad things happen.

In terms of power, I'm using a generic hobby motor with a range of 4v to 12v. It's powered by a radio shack multipurpose wall wart with switchable volts. I find I only need about 6v to operate. Speed is controlled by a DC pulse width modulated speed controller I bought online from carl electronics. It was quite easy to wire and install.

I was undecided about including an automatic traverse system so I thought I would try something that I could still move manually but wouldn't have to control the tension. I build a mechanism that slides over a traditional traverse rod. The angle at which it pivots can be adjusted while a tensioning head holds two small plates that clamp over the coil wire as it comes off the spool. It essentially mimics how you would hold the wire between your index and thumb. The whole unit is removable for the moments when you do want to freehand it.

Please tell me what you think.

front | Flickr - Photo Sharing!
back | Flickr - Photo Sharing!
side | Flickr - Photo Sharing!

[Chris Turner]

Looks great! Very clean and professionally done. Can you post a close-up of the tensioning system?

I'm working on building a more automated system than what I currently have, using 2 stepper motors, one for the winding and one for the traverse. But I'm not set on how I'm going to set up my tensioning system. If you're willing to share, I'd love to see how you're doing it.

[shawnl]

Thanks for the comments! I'd love to swap notes or ideas on the subject. However, I don't want to mislead you on thinking that I've worked out the perfect system for the tensioner system. In fact I've tried to run some wire through it and it's still a little loose. Regardless, the basic idea for how the mechanism slides back and forth is there. The basic idea is that tensioner head has two sides. One side clamps onto the other with a small bolt that runs through both sides and a nut of some kind to hold it in place and adjust how tight the two parts squeeze together. Each side is lined with felt. I think I need to make the tensioner head longer. As it stands, I don't think there's enough surface area to create enough resistance to tighten the wire. Also, I think the tensioner head needs to rest higher than the guide rod. Right now it's just a tad under.


tensioner_close_up | Flickr - Photo Sharing!

[shawnl]

Ok, after having thought about how I've built the sliding tensioner head mechanism, I've concluded that as it stands right now, it won't be enough to control tension. I'm planning on adding a separate module that attaches to the base midway between the spool of wire and the sliding mechanism. This module will contain a series of spindles that the wire will feed through much like Jason Lollar's tensioning device. This unit will be stationary.The sliding mechanism can still stay where it is but will act as the final guide and not as the sole tensioner.

[Chris Turner]

What about using another set of felt pads as a pre-tensioner?

I was thinking of doing something along this line of using one set close to the spool as a pre-tensioner, and then another closer to the traverse. On the one close to the traverse, you could attach a guitar knob with the numbers on it to the tightening screw as a guide to the amount of tension being applied. It might help with consistency. Don't know though, as I've yet to even put the thing together.

[shawnl]

So I thought I'd share the changes I put into place with my winder. I did manage to build and install a better tensioning system that actually appears to be working. As I mentioned before the tension needed to be controlled in several places in order to work consistently. Chris, I took your advice and put in a second pair of felt pads to use as a pre-tensioner. As a stand alone device I can't confirm if this is all you would need. I got carried away because I like to tinker and mess with moving parts and added a bunch of extra things. Furthermore, based the experiences of many others I've moved the wire spool to the floor and feed it through the pulley system I've created. Altogether the wire tension can be controlled by 3 adjustments. 1) the pre-tensioner felt pad which really just keeps the initial feed in place. 2) by moving a pivoting arm that contains a final guide wheel up or down. 3) by tightening the two felt lined sides together at the sliding guide head mechanism. To further clarifty, I've included a labeled photo in the follow:

tensioner_unit | Flickr - Photo Sharing!
side_view_fully_assembled | Flickr - Photo Sharing!

hope this helps.

[Stratz]

Thats pretty sharp Shawn. Next thing you need is an auto felt squasher.

[shawnl]

Next thing you need is an auto felt squasher.

not sure what you mean by an auto felt squasher.

[Stratz]

not sure what you mean by an auto felt squasher.

I was just joking about the squasher name Shawn.
I was referring to a device that would allow for the felt to be tightened automatically as it wears from the wire running through it over time.
It wasn't meant to offend you, I think you did a fantastic job with the tension system.
Rob.

[shawnl]

Oh no I wasn't offended or even thought you meant anything by it. I was just curious. I thought perhaps you were referring to some sort automated system in which I'd love to know about!

[Chris Turner]

I was just joking about the squasher name Shawn.
I was referring to a device that would allow for the felt to be tightened automatically as it wears from the wire running through it over time.
It wasn't meant to offend you, I think you did a fantastic job with the tension system.
Rob.

How long does it take before the wear has a noticeable effect on the tension?

[shawnl]

I've never even thought about the wear aspect until now. I'm hoping that because the felt pre-tensioner isn't the only thing putting pressure on the wire, it won't wear as quickly. Even so it's just going to have to be one of those things that are routinely maintained.