Re: [CAD_CAM_EDM_DRO] X- Axis won't do as it's told

Hi Richard,

I'm wondering where you're getting the +5V for the Gecko's from, and
whether you're running common ground or +5V. Gecko's like direction
changes at the start of the step pulse (check the white papers for the
EXACT description). The setup time may be off. +5V power should come
from the PC, or a wall wart. However these things usually affect all
three axis, not just one. The parallel port could be suspect, try
another one if possible.

You've tried other stepper motors? You're only having problems in the X
axis? I'd unplug the Gecko on that axis, and swap it with one for
another axis. If the problem "follows" the Gecko, then you have to
suspect it.

Start off on the controller programs with the accelerations quite low,
and the feeds slow, watching for proper operation.

Let us know if this helps.

Alan KM6VV


baccus61 wrote:

>
> Hi Gang,
> I am slowly going bald here as my router has been playing up on the
> X- axis ever since I first built it and I am pulling my hair out at
> an alarming rate.
> I am using Gecko drives, 24 volt supply (36v), 20,000uF Cap and all
> the usual stuff crammed into an old computer case. I have tried
> Master5 and CNCPro and Kelly Cam with the same results on all
> programs. This is mark2 of the control box as I thought I may have
> been getting extraneous RF pulses through the circuit causing it to
> malfunction. I had sheilded the control cables with Al foil and
> earthed them at one end without any effect.
> My problem is that the X-Axis is very unstable and has a mind of
> it's own when it comes to the direction I want it to go. Sometimes
> it goes right then all of a sudden it goes left and may go that way a
> few times then back in the right direction. I had it running
> smoothly 2 days ago and thought I had tweeked it the right way but
> the next day upon startup it behaved erratically and roughly again
> with no intervention on my part. I have tried to slow the pulses down
> and also set the acceleration to heaps of different values.
> I am now on my 3rd motor as I have tried 3 size 23 1.8deg different
> value steppers 4 wire and 6 wire and I am now using a size 32 2deg
> stepper. ( my last as I burnt the last 2 out trying different values
> for the resisters)
> My router has linear bearings on round bar and 3 start 3/8 acme
> teflon coated screws with plastic nuts and runs very smoothly when
> turned by hand with no power on and very little friction so I am
> positive it isn't mechanical.
> The Y and Z axis run very smoothly and I have tried swapping wires
> around using the drive of another axis but still have the same
> problem. Even went to gearing the drive down with toothed belts
> about 3 to 1 for more power. I am nearly convinced that I am doing
> something wrong with the speed and acceleration settings in the
> software but nothing I try seemes to work. Should I uninstall
> everything and reload the Progs from scratch?
> Before I fitted the 32 stepper I had a vexter 1.8deg 4V 1.4A 4 wire
> motor fitted which ran very smoothly but I always lost a heap of
> steps when doing a project. Sometimes 0.020 in an inch but mostly
> just enough to cut out the side of letters when cutting a sign. It
> was always smooth going right but lost steps when travelling left.(I
> even tried turning my nut around to face the other way). That is why
> I went to the larger motor for a bit more grunt just incase things
> were too heavy for it but the problems seems to have worsened. (very
> stuttery and unsmooth)
> I hope I have given you enough info as I am getting a churning
> feeling in my guts and the 14lb "linear rectifier" is sitting next to
> the router for some serious tweeking should I not be able to work
> things out. This has been going on for 4 months and I can't seem to
> find anything in this list that has helped yet and I have scoured it
> nearly every night in that time. This list has been a godsend for
> building my machine and it is so frustrating to be so close yet so
> far so I hope an angel is out there watching over me that can help.
> Warm regards
> Richard.