Rack & Pinion vs Lead Screw

[ger21]

Larry, belt drive is virtually the same as rack and pinion. If you need to gear one, you'd need to gear both of them. There's no difference if using a pinion with a 1" pitch diameter on a gear rack vs a pulley with a 1" pitch diameter on a belt. Belt drive would be slightly more expensive because belts cost more than gear rack, and pulleys a little more than pinion gears.

[SimjetAU]

Hi
I have most of my gear to ready to convert my chinese mill to CNC. A local here has done it to his mill which is the same as mine. I am in the process of replacing the acme threads on my mill and have been searching for ball csrews but in doing that I came accross this site

http://www.nexengroup.com/rps/
its very interesting...wait for the video to load

Attached is a couple of pics of his mill

[rsmurphy2]

Originally Posted by CNCAddict Carbon Fiber? I was aware of kevlar and nylon, but not carbon. Carbon is not very tough and I would think a bad choice for belting. Can you point me to some specs on carbon reinforced belts?? David B. http://www.axxustech.com/Axxus4x8/axxus_4x8.htm

Carbon makes great sense for precision belt design. Carbon fiber has a modulus of elasticity of 77,000 KSI and Tensile strength of around 820 KSI and weighs next to nothing!

Gates manufactures their new Poly Chain GT belts with carbon in place of aramid fibers, check it out:

http://www.gatesprograms.com/ptsavin...nothingtougher

I've been looking into a belt drive solution for a filament winding design I've been working on and will most likely settle for something cheaper than this but if I had the money I'd go with carbon belts for sure!

Thanks for all the info people!

[Zathras]

If you'd be prepared to DIY, why not consider something like this linear cam drive?

http://www.cim.mcgill.ca/~rmsl/Index...pers/slide.pdf