I have been playing around with making an overhead gantry design for a while now.
This will be belt driven on the Y, X axis, leadscrew on the Z.
Any ideas how to make this better without spending tons more $$$$ on it? Attached files

 

Hummm. Any idea on how much tension those beslts can handel?
For instance that will tell you how much force can be applied to your tooling which will give a good idea on what you can feed it. So really the question is what do you plan to cut with it?

 

I haven't looked into what belts/pulleys i will need as of yet.
I plan to cut any/all wood with it.
No metal at all.
Acme rods are expensive at these lengths and belts are much cheaper.
I do have it drawn up with Acme rods also.

 

The plans look pretty well thought out. What do you plan to cut on this machine?

 

Wood signs mostly, some small light ply also, no matter what i try on my phlatty it just skews all over the place

 

You can cut lite ply on your phlatty... very slowly though. Use the milling macro in mach3 and mill out a piece of FFF to lay your ply onto. The FFF will serve as a carrier and keep the wood from skewing all over the place.

For lite ply you need to cut slowly, around 4 to 8 ipm. You might even want to do it in multiple passes. Make a cnc file with 1/16" cut first then double it 1/8" and run the file a second pass without opening the lid.

 

Ok, made some mods on it already, set it up for Leadscrews.

Attached files

 

Would it be possible to setup some type of reduction gear / belt setup to drive the leadscrew? In other words, if it were me, I would stay away from a 1:1 drive system to get more torque from a cheaper stepper. But again you must account for the reactive force, so you don't want any streatch. Perhaps a roller chain system would be the way to go? But then you will need a way to deal with any backlash. But, you might need that anyhow with harder materials.

Just some ideas.

 

that would be easy, I looked at a machine for sale at a local shop and they used a short belt setup to drive a rack and pinion gear.
Of course I would have to go with a bearing on the belt side instead of just a bushing to take the added leadscrew loading that the belt would place on it.
P.S. no, I won't draw a proper gear and make a belt Attached files