Friday, December 11, 2020

Friction Gears?

I made the first gear for my Catican Cotton Gin Mark II last night. The inner circle is smaller and the teeth are thinner, so hopefully that will solve the problem of the gears not meshing consistently as they rotate. Still, when I was done, I hated the look of the it.

I drilled out the voids and used a jigsaw for the teeth and blah blah blah. It's all very clever, but it doesn't work well.

Just look at that horrible, misshapen thing. Meh.

Look, the whole point of the gears is to get the two rollers to counterrotate together, right? Well, couldn't you do the same thing with simple friction? Why not take some coarse sandpaper and glue it to the ends of the rollers so they act sort of like Velcro and grip each other as they spin? I'd have to sand the ends of the rollers down to make up for the height of the sandpaper and that might be a giant hassle. I don't know.

I wish I had a lathe.

Boston Gears makes metal gears that would do the trick, assuming I could lathe the ends of the rollers down and form a key on them so the gears' inner holes would fit on them. Again, I don't have the tools to do the job right. A bandsaw would help with the wooden gears and I saw a YouTube video showing how to make a bandsaw from a jigsaw, mounted upside down on some plywood. That sounds like a serious injury waiting to happen.

Hmm: I wonder if my Dremel could clean out the spaces between the teeth in those gears. I might be able to salvage those toads yet.

Semi off-topic: Wife kitteh and I are still looking for a different house, one with an acre or so of property. If we could find that, I could build a workshop and have room for all the tools I'd like.

Insane Idea Update: What if instead of using coarse sandpaper on the ends of the rollers, I used very fine sandpaper along their entire length? The rollers would then be their own gears. Kind of like being their own grandpas. Or something like that. The risk would be that grit would get into the lint or the lint would stick to the sandpaper.

Experiments will have to be run.

Next Day Update: My second set of gears were horrible. I need much more precision. Here's a good set of tips, although I don't own a drill press. However, I have a friend with one ...

Good Lord This Is Brilliant Update: All you need to do is cut wooden circles and glue on a stepper motor belt and you have perfect gears. Unreal.


Ohioan@Heart said...

Legos and K*Nex both have nice plastic gears (there is a $19.99 LEGO gears set on Amazon).

Have you thought about having your gears 3-D printed?

Or you could try a router. I’d be happy to loan you mine.

Truthfully, what you need is a scroll saw ( has one for $69.99).

Mostly Nothing said...

I have a lathe. Inherited from my Dad. 25 years now. I think I tried using it once. It is a table top model.

I think sandpaper on the entire roller would collect the cotton.

What is the thickness of 80 grit, maybe 1/64 inch? I bet that wouldnt make a difference.

I agree with Ohioan a scroll saw. I first thought of my bandsaw, but the blade is too thick.

K T Cat said...

Ohioan is right, the scroll saw would do the trick. However, even with one of those, I'm not sure it would work. I just tried another pair of gears and they came out horribly. I think I'm going to go with the Boston Gears gears. Then my problem reduces to affixing them to the rollers.