[lloydinz]

Attachment 185792

After finally getting my machine to the cutting stage it has thrown this issue at me. As you can see in the picture it will be cutting good, then it will move 2-3mm to the left and carry on cutting good again, until it moves another 2-3 mm left.

The step isn't always in the same place, i have tried different feed rates but the step is apparent sometimes during the cutting ( on other cuts as well, but not all the time ). I have recalibrated and all is well.

Is this the kind of issue you get with the cheap ebay controller cards as that's what I'm using . I have bypassed the opto isolators but had no affect.

is there a way to prove / disprove the card?

thanks in advance for the help and at what stage do you finally stop watching the machine cutting.

thanks.

[ger21]

You're losing position, which can be caused by many different things.
Make sure there's absolutely no binding anywhere, by disconnecting the motors and turning the screws by hand, preferably over the full travel. If it gets tight anywhere, that can cause problems.
What feedrate and acceleration are you using? You may need to lower your settings, if your motors and drives aren't capable of going as fast as you'd like.
It also could be a computer issue, if other software is interfering with the control software. I don't think this is the issue here, though.

[lloydinz]

.thanks for the reply ger21.

I will give my machine a good going over and see if i can find any sticky spots. the computer is a dedicated one for the cnc so nothing running in the background. the steppers i tuned using the mach3 features so will reduce the settings and see what that gives me.