problems with circles

[chrispare]

hi ive got mach 3 running my cnc router,
the problem is with circles they are more oval than round, im quite new at this and dont know how to fix it.

i tried just a circle in rinocam inported it as a dxf ant let mach convert it.

i am hopeing there is a simple adjustment to make in mach
please help

[ger21]

If you cut a square, is it square?

[chrispare]

i dont know havent noticed i will have to try that

[MattTheNoob]

I'd check basic moves in each direction and see if they are the distance you think they should be. You probably have your steps per unit wrong on an axis, or you are losing steps due to bad cabling, noise, freq too high. If you have backlash in your machine, that could probably cause your problem as well.

Give us some details on your machine and we might be able to help you a little more.

[chrispare]

what does the frequency do and how do i change it

[MattTheNoob]

Ooo. You are new. Since there are LOTS of thing in it that you'll need to know, I'd suggest reading the Mach installation and operation manual (may be called something slightly different). It give lots of good info about setting and testing the pulse frequency with your particular computer.

Lower is almost always safer and less prone to errors.

On the ports and pins config, in the axis settings, each axis has a pulses per unit setting, which must match your encoder/stepper, and leadscrew combination.

It sounds like you have some reading to do before you get to tinkering with that stuff though. Read the book and come back with questions. I think individual tid-bits of help you get here will leave out important things that you'll need to know.

I hope I'm not coming off as being unhelpful. That is not at all my intent.