Bladerunner AIO Accuracy?

[binfordw]

Hi,

I'm having some issues with my Plasma table, I have a bladerunner AIO kit- which I had trouble with in the past. The 2 X steppers would go out of square, so the longer I cut the more out of square the gantry would become. It went unnoticed on small parts, but larger items were impossible. After support helped me troubleshoot the issue as a messed up board, it was replaced and I thought the problem was solved. However, I recently ran a large job, lots of small parts nested on 4x4' sheets. I found the gantry would go out of square after the long runtime per sheet, and some of the last rows of parts would sometimes run into the other parts/off of sheet. If I didnt shut off the bladerunner and re-square my gantry after each sheet it got pretty far out of whack.

Does anyone else use a bladerunner kit- and can you cut a large sheet of small parts without noticing errors? Hopefully my bladerunner is just still messed up and can be straightened out.

[rock4xfab]

I have the blad runner kit but am still building... but CNC and machine building are not new to me.. I think I may have seen your post on yahoo groups site.. anyway. Couple things I would look at trying to diagnois.. the 2 motors in question that are loosing step. swap them( meaning the cables first) Then the physical motors... and see if you loose the step to the opposite side. if so I would then look at that indavidual motor or signal. Also look for any drag on your table a stepper motor can loose it self if you have some binding going on... just some thought.

[Torchhead]

It turns out he does not lose position on a dry run (torch off) no matter the number of moves. i had him setup indicators and return the axis to 0 after each run and even run the long job that had the problems. It was dead on. It appears to be a noise related issue possibly getting back into the PC and/or parallel port. Racking would occur if the slaved motors were not getting the same pulses and the same time. If one got more than the other or the DIR signal as noisy on one it could get ugly. only other cause would be one motor is losing steps (stalling) from the tuning being a llittle to high. The DIR delay problem earlier was immediately evident if you ran a large program with lots of direction changes and was consistent (happened no matter what).

TOM caudle
www.CandCNC.com