This is my first post, so hello to everyone. I'm less than a newbie when it comes to this, but my friend asked me if I could help around his table. He has a custom build 2mx1m table with plasma cutter, running mach3. Now he bought it used and we can't reach the guy he bought it from. We don't have any manuals or names of motors. The machine is moving in all axis, so there's that.

So my problem is here - when I set the steps per MM on X axis, the units change. For example, when I home the machine, and I set steps per MM to 13 - it takes 2000 units on X axis to get to the end of the table (which is good). However, the machine 'shakes' when I jog through X axis, it's not a smooth movement. I figured out that I probably have the wrong amount of steps set up, but when I set steps per MM to a higher value, it does work more smoothly - but (and that's my problem/question) it takes far less units on X axis to get from home position to the end of the table (let's say 1000 units). So when I try to cut a circle, it's actually an elipse (Y axis is correct and runs smoothly).

I have a couple of questions and would be more than grateful if anyone could help me out or point me in the right direction - I googled extensively, but I probably word the questions wrong so I can't find the right answers.

1) How do I tell mach software that I have 2000mm x 1000m table?
2) I used the "set steps per unit" thing in settings, and after couple of times it set the steps to 267 - and it runs smoothly, but there is a problem I described above. How do steps per MM correlate to these values ?https://gyazo.com/9eb04445199581b3b16b26c20ef95468

I can provide photos of the machine, but there is nothing to identify which motors were used in building this table. I can also provide screenshots of mach3 settings, but that would be tomorrow, when I get to the workshop.

When I run some G code for a circle with 'correct' steps per MM on X and Y axis ( meaning, steps per MM that were set up by mach3 settings) - say the circle is 50mm in cambam, it's actually far bigger in reality. But when I set up steps per MM on X to 13 and 26 on Y, it makes a "perfect" 50mm circle, meaning it really takes 2000mm and 1000mm to travel through the table - it just is shaky, not smooth. How to manage that?


I'm very sorry if anything here is not clear, english is not my primary language. Please ask any further questions about things I didn't think of if it helps.


Thank you all for taking the time to read it and (eventually) help.

(As I had no idea where to post it, I posted it twice, once here and once in general forums. I am sorry if it's not fitting in one of the categories, please remove the faulty one).