Spur gear cutting

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Spur gear cutting

Postby circuit » Wed Aug 27, 2008 10:37 pm

Hello everyone,

I'm working on this hexapod project and I will need some gears in it. One of those look like this:

The problem is, this pinion is very small (diameters are in milimeters). There are several companies with laser/water cutting CNCs in my country, but no one of them can cut with this precision. Please, what can you recommend to resolve this problem?

I think it would be easier to make them from plastic. As far as I know, best plastic for cutting by laser is acrylic. I've found on internet, that it is very brittle. Would it hold?
Or I need to use other technology?
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Re: Spur gear cutting

Postby Matt Denton » Wed Aug 27, 2008 11:22 pm


That's a really small gear!, I would always try and find an off the shelf solutions to gears, before you try cutting your own, but I presume you have tried this?

Well delrin or Acetal POM is a very good material for gears, its strong, slef lubricating and easy to machine. I think I could machine this on my CNC router, but you would need a cutter small enough to fit the inner radius between each tooth, I'm guessing from the drawing this is about 0.4mm? I don't see why a laser cutter couldn't handle this.
Matt Denton
AKA: Winchy_Matt

micromagic systems ltd
Matt Denton
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Re: Spur gear cutting

Postby circuit » Fri Aug 29, 2008 9:09 pm

Hi Matt,

I have searched some RC-modeling e-shops and eBay for gears, but haven't find ones that may fit my application. Also I will need some very strange looking pinions. Maybe you could recommend a place to buy some cheap pinions?

Have you worked with those materials you have mentioned? How do they react to laser? I have only tried to cut a plastic called "HIPS". No idea if this is a material or brand name. That plastic just went melting all around laser beam and nothing useful left from it.
Also, where could I cheaply obtain a small amount of those materials? 200x300mm would be fine. I have checked smallparts.com and some other e-shops, but all of them have huge problems with sane shipping prices to my country (Lithuania, EU).

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Joined: Thu Jun 12, 2008 4:50 pm

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