Messages

1971

General Mach Discussion / Re: edge finding/2.5D probing

« on: November 07, 2007, 11:17:15 AM »

Hi Guys. Thanks for the positive comments. I just need to do a little more testing and tidy things up a bit and then I'll post it for you and anyone else that wants to test it out.

TP - The workaround was to find a way of taking the G31 "code" command/statement out of the VB search routine. In it's current implementation when G31 fails to touch something several times, it corrupts the VB stack.

Cheers

Ian

1972

General Mach Discussion / Re: edge finding/2.5D probing

« on: November 06, 2007, 11:59:06 AM »

OK - a bit of an update. After having found a way to kludge round the problems with G31/VB I now have a working 2.5D probing routine. My homemade probe's a bit crappy  so the resolution is no way as fine as I would like, but anyway - some progress! 

Haven't got into posting on youtube yet so in the meantime here's a couple of vids on my site of it probing (a french curve) and then running the auto-generated toolpath.

http://www.razordance.co.uk/probe25D.htm

1973

General Mach Discussion / where did CV go?

« on: November 01, 2007, 01:31:15 PM »

V2.56.1

So I'm using the machine all morning and all is well.

I resume this afternoon and CV is gone - disappeared - ceased to be - awol. Jerky toolpaths enough to shake the thing to bits. Not only that but I'm getting limits going off all over the place. 

I look everywhere for what's changed. Can't find anything - so then I give up and just do a re-install. Same profile though and hey presto everything's immediately cool again 

Is it me or is Mach getting a little Kellogs these days?

1974

General Mach Discussion / Re: Limit switch / Spindle start problem

« on: October 31, 2007, 04:29:47 AM »

you haven't said what your config is for your e-stop and relay signals but if I was to take a stab at it it I'd say it was dodgy sig gnds.
Something I learned recently is that not all parallel port and cable manufacturers properly tie all sig gnd pins to proper sig gnd. Some only bother with those they know will be used by a printer. Check pins 18-25 are all bussed together and if not do so. Otherwise some of the sig gnd pins you've used may actually be floating. Worked for me 

credit where credit's due http://www.cnczone.com/forums/showpost.php?p=356625&postcount=9

1975

General Mach Discussion / Re: Problem with 2.56

« on: October 31, 2007, 03:59:02 AM »

check IJ mode is set as you require it on config/general config. I usually have it set to absolute but noticed 2.56.1 had reset it to incremental.

1976

General Mach Discussion / Re: edge finding/2.5D probing

« on: October 26, 2007, 09:09:16 AM »

BUT in your example it still points to a switch problem in the probe.

Sorry TP but I don't understand your conclusion - A G1 command neither knows nor cares about the existance of a probe - or shouldn't do anyway.

Also now that I've littered my code with debugging traps and printouts I'm getting indications of all sorts of wierdness. Seems to me there are serious sync problems between the mach and vb threads and possibly even some corruption of the vb workspace by mach. Art has indicated he's aware of timing issues in the interaction between mach's implementation of G31 and vb. I'm beginning to think this is only the half of it.

Seems to me that the reason the bed o' nails approach is possibly more successful is more to do with the fact that g-code is static i.e. pre-created and is then run in Mach as per normal. With 2.5D probing the g-code has to be dynamic, i.e. created on the fly as it works round the profile. Clearly in this case the interaction between Mach and VB is more critical. Certainly more critical than Mach/vb seems to be capable of at the moment. Shame.

Whether V2.57 will solve the issue I don't know - any update yet?

1977

General Mach Discussion / Re: edge finding/2.5D probing

« on: October 25, 2007, 04:47:51 AM »

Tp - tried your suggestion. Just the same. Not sure where to go from here - think I'm stumped... but...

I have seen sometimes that when running VB inside of mach it tends to get ahead of itself and forgets things.

could you expand a little - this may be a clue.

1978

General Mach Discussion / Re: Constant velocity

« on: October 24, 2007, 04:58:35 AM »

tried to break it - but it just wouldn't - nice job. Thanks to all involved.

TP, mine also reports 2.56 but I noticed during install that it said it was upgrading to 2.56.1

Ian

1979

General Mach Discussion / Re: edge finding/2.5D probing

« on: October 23, 2007, 12:09:33 PM »

Hi TP - yes it has.

I have a little routine to check the consistancy of my probe. It goes something like this:

G91
while I have nothing better to do
  G31 X10
  while ismoving()
  wend
  store touch point
  G01 X-5
  while ismoving()
  wend
wend

There's an object at about X5 so it just merrily bounces back and forth recording the touch point each time. Most of the time it's fine BUT - once in a blue moon it fails to execute the G01 and therefore doesn't back off. Actually - the first blue moon is round about 10 to 20 iterations in.

Ian

1980

General Mach Discussion / Re: Help Configuring Limit and Homing Switches

« on: October 23, 2007, 11:57:22 AM »

When jogging the Y Axis in the "-" direction, I hit the "-" direction limit switch with my hand (This will also be my Home SW.
As soon as I hit it the travle stops, and all three Leds (- + and home) are lit in the "Diagnostic screen". I noted the "Y" direction as an example, all Axis act like this.

This is exactly as it should be. Remember you're sharing input pins.

I must have touched some thing some where in Mach3 because I can now jog off the held SW and then I can press and clear the Reset light.

probably auto limit override was what you touched.

In the video I saw only the opened limit SWLED  light up.  This is what I would like to happen.

Then you'll need either external logic or individual switches for limits and home i.e. 9 in all for a three axis machine where each switch is allocated it's own input. You'll therefore need to add a second parallel port.

Also they talk about it automatically driving off the "Hit" SW automatically.  Would also like to have this happen if Mach3 will do it.

Sorry can't help you here - are you sure you arn't confusing limits with home. I still think it's a bad idea to have anything happen automatically after a limit but that's just my opinion.

I did a quote, to get to add this additional information, but I don't see where to add an attachment.  Is it possible to add attachments in this situation?

see additional options to the bottom left of a standard reply.

Cheers

Ian