Rack & Pinion OR belt/Chain drive?

[dopatrick1]

Im new to this plasma thing. My knowage cosists of, plug it in, hold gun close to metal, pull trigger. and draw...lol

Been studding the CNC plasma stuff now for about 1 year after my day job. Looked at hundreds of designs. I have a large background in contruction as well as electronics and im a master electrician and also metal fab so building one will be easy. I have bought the step motors and controllers needed and mach3. ive hooked them all up and they turn. NOW>>>>> the part i cant decide. the look........ but the most import part, THE Question.... should i use rack and pinions or belt/chain for my x/y axis? Im worried about performance and speed with accuracy. Is chain drive going to produce an accurate cut at faster speeds and is it as accurate as rack and pinion?

please help

[Kentuckyfarmer]

When i built my table a couple years ago, i had the same questions, along with a lot of others.
I went with gear racks mounted under the sides and have not regrreted it. They cost a little more than roller chain but all in all I think it was worth it.
Hope this helps.
Most advce is free, nd still over priced
Mike

[Stout]

Both of my commercial machine have rack and pinion drives. Any deflection in a chain is going to cause errors in the cutting process, so they would need to be very tight all the time. And inspected and adjusted on a regular basis. Chains stretch so you will get deflection over time. I believe ball screws would be the most accurate.

I've been wondering about the cogged drive belts like they use on HD motorcycles. They are installed super tight with almost no deflection, are light weight, inexpensive, and seem to last forever. Except on a Ferrari 355 engine, because they want $6k to change them every 15k miles. Bastards.

[dopatrick1]

OK, so rack and pinions are alot more accurate. NOW do i use a 20 tooth gear to fit right on my step motors ( 8mm hole i believe ) ????? i see these 2:1 belt gear ration reducers and whatever, do i need to be using them for performance or what are they used for?

Thanks for all the info guys, im trying to get all the info i can to build a long lasting quality machine..