Okay all, I now need to work out belt reduction ratio's for my table.

[Apples]

Hi everyone.

I am now at the stage where I have bought my stepper motors and stepper motor drives. I am using one 1200 oz/in stepper for the long axis (gantry weighs, at the moment 100lbs), and one 270 oz/in stepper for the shorter axis that rides on the long axis.

My stepper motor drives are the new Gecko G202's.

Can someone please work out, or show me the the mathamatics to work out what speed my table will move with direct drive. For example if I use a 1.5" pinion direct to the rack( not to sure what type of rack to use, ie 14.5 or 20 degrees etc), how fast will the gantry move.

I don't know what rpm I should use use to work it out. What rpm should I use for the 1200 and what rpm should I use for the 270 motor for working out the calculations. I will want to be able to cut with my plasma as slow as 20ipm and as fast as 300ipm, (the same as plasmacam) and if possible even cut at 1000ipm for thin gauge galvanised tin for HVAC ducting etc. Although 100ipm is not needed if it is not possible to acheive, something under that will still be okay.

I would rather have a belt reduction, as it is more accurate and I think that I can still get pretty quick speeds out of belt reduction. It will also be better for when the gantry is rushing along and then stops suddenly, as because it is geared down it will have more stopping/holding power/torque.

What size pulley will I need for the one that goes on the motor shaft(including number of teeth and width of belt), and what size pulley will I need for going at the other end(including number of teeth)?

Like I said I do not know what reduction ratio to use, I am thinking around 3:1 or 4:1.

Can some one tell me what I need to buy?

Cheers

Learning allways!

Peter

[Splint]

Apples, do a search for posts by me and you should find a spreadsheet with ratio calculation formulas in it. I cant recall the name of the thread but if you see it you should realise which one it is.

Cheers
Splint