CNC oxy profile cutter

[HelicalCut]

First post

Does not seem to be much interest in CNC oxy fuel profile cutters, anyway I have been collecting motion control stuff for years and decided it was about time to build a simple X/Y gantry to carry an oxy cutter and maybe a plasma when I aquire one. I plan on making a small stiff steel framed gantry unit with steppers and open loop position control, don't want to waste AC or DC servos on this. I am thinking of using 2 belt drive for the gantry with a single belt for the cross axis. Judging by what others have done with routers this appears to be a good choice. Positioning accuracy needs to be +/- 0.5mm, axis travel 600mm x 1250mm, it needs to fit a 4' wide sheet under the gantry as this is standard width for steel here. Traverse speed 40 ipm or less, heavy cutting might drop to 6 ipm. Plan on using EMC2, the linux environment is more appealing than windows and my programming skills are OK. Will probably add a Z axis once the machine is working to get a clean pierce and to account for different material like hot rolled sections.

Current stage is aquiring the missing bits, computer, interface hardware, stepper drivers belts and pulleys.

Has anybody made one of these machines? Will a 220 oz/in stepper accellerate a 15Kg gantry to 40 IPM OK, I know I should go and do the math myself

[massajamesb]

I built a chain driven oxy fuel unit originally, and was happy with it until I went to upgrade it, then I have not looked back since.
I wouldn't recommend belted drivelines for a oxy unit, might not last as long as needed.
With the proper gearing, voltage, etc. you should be able to get 40 IPM out of that small stepper, as long as your bearing slides move smoothly.

[HelicalCut]

I actually have enough chain and sprockets to do the job (photo minilabs are great machines to wreck) I was worried about dirt pickup on the chain but That bicycle dry lube may work OK. Slides are no problem I have some low end linear bearing track which travels nice and free. I'll try the steppers and if the one moving the heavy carriage can't keep up, I be looking for an encoder inteface board so I can run a servo.

Massajamesb you mention that your current machine is better than the chain driven one, what are you using now?

[massajamesb]

I am currently using spur gear and gear rack.