Machine Accuracy Issues PRO4824 Mach3
I thought I would turn to the forum for some further expert advise!
I have a PRO4824/Nema23/mach3 Setup.
I have an issue with the router not being very accurate.
I believe it is a mach3 issue but I'll take any advise as to what to check.
When I cut circular pockets say 3-1/2" or 2-1/4" in MDF or Acrylic the end result are holes with an OD that is undersized by .020 - .023 inches.
Grooves or Slots also produce a width along the slot that is undersized by an almost similar amount.
I consider this an un-acceptable amount.
The perplexing issue is I have calibrated both X/Y axis to a distance of 4" & 5" with precision gage blocks, dial test indicator, dial indicator, calipers. Pointing out I'm doing this calibration with precision equipment. After the calibration is complete I return to the 0,0 point (Work Zero) of where the calibration started from and get a reading of being dead on at 0,0. One I jog move the axis is immediately inaccurate by .002-.005 thousands and grows somewhat larger as I move closer to the original calibration distance of the 4" or 5". The error occurs in single step and continuous mode. I figure things aren't quite right, proceed to re-calibrate mach3 for the correct steps repeating the process over again. This subsequent second time I have mach3 do a calibration move 5" in X or Y it moves perfectly that distance in calibration mode with no changes needing to be made to the motor steps.
Cory at CNC Router parts mentioned earlier today to run in CV mode rather than exact mode, upon checking I'm already running in CV mode so thought I would switch to exact mode to see if it made a difference. It made no difference. Further I'm believing the CV Mode setting relates to circular or arc movements only and as noted above it is happening with both circular cuts and straight line movement.
I've ruled this out as being a mechanical issue unless someone here thinks otherwise. I've gone over everything mechanical and find nothing out of order.
Hoping someone here can offer some guidance on what the problem could be.
Re: Machine Accuracy Issues PRO4824 Mach3
my biggest accuracy problem was solved when i realized one or both of my x axis motors seemed to be "hiccupping".
I pulled the drive components off, and I discovered that the tiny setscrews for the drive gears had spun out! two of them hit the floor and i lost one.
I went to my machine shop and got some more, and i put them in with some blue loctite and made sure they were as tight as possible.
After that, my accuracy increased tremendously!! I still have to do the Y axis, and anywhere else there are setscrews.
Just thought I'd mention to check these setscrews.