Tig weld rack and pinion to cnc plasma frame?

[JAZZCNC]

think the pinions are 20t and was hoping to use a 60t for 3/1 gearing....as for resolution i havent a clue as of yet..have just been taking advice from a very nice fella locally and building it in stages..right at the start of my craving for cnc i was totally over whelmed so now im just doing stages and moving to the next part of the build....

Ok well lets work it out for you. I'll assume Mod1 pinion. So the Diametric pitch (basicly diameter) will be 20mm because Mod1 =1mm times the #teeth.
Apply \pi and the affective pitch is 62.832mm which is huge and why you need ratio. So then divided by the ratio to give pitch of 20.95mm per rev.

Working on motors full step value then Full step resolution will be 20.95/200=0.104mm per Step.

Now this is the smallest amount you'll move if the drives where set to Full step. Which you won't want to do otherwsie they'll run like bag of marbles. But take it thats your worst case scenerio.
In real use you'll have the drives set to something like 800 or 1600 micro steps. Going above this is pretty much wasted and just stress the system for very little gain.

So Best case will 20.95 / 1600 = 0.013mm thou don't get excited because you won't get that in reality but will fall some where between 0.1 and 0.01 which i'm sure you'll be pleased with.

But again don't too giddy because thats only resolution and it means nothing in accuracy terms if the machine bends like banana.!!

Now you'll want to know the speed you can expect.? So lets work on 900rpm which is realistic figure for stepper using R&P provided run on enough volts. (60-70v)

20.95mm x 900rpm = 18855mm/min or 18.85mtr/min which is just about spot on for decent sized plasma machine.! . . . . Well Done . .Lol

Edit: Opp's I forgot the ratio.!!
So it's 20.95 x (900/3) = 6285mm/min or 6.3mtr/min which is still ok for cutting but on the slow side for rapids on large machine.
In practise provided all is setup well and correct voltages etc I'd estimate 8mtr/min or more will be quite do-able.