Messages

781

General Mach Discussion / Re: Stupid Probing Question....

« on: January 03, 2010, 01:11:11 PM »

Hi Ray

When are you going to release the code.

Phil

Phil,

Shortly, once I've tested them thoroughly.  I've also added a number of new functions for doing measurement, without clearing the DROs.

Regards,
Ray L.

782

General Mach Discussion / Re: Stupid Probing Question....

« on: January 02, 2010, 11:47:50 PM »

Most probing routines take 2 or 3 hits per reading, first is a fast traverse to find the object, it then backs off say 1mm (.040") and then slow feeds to find position. For very fine detail it backs off again .25mm (.010") and then creeps to find the position. At this point the final reading is taken. The accuracy is then down to the trigger action of the probe.

Graham

Graham,

That is basically what I'm doing - I do a first fast probe (50 IPM), then back off 0.020" and repeat at 1 IPM.  This gives me excellent repeatability to 0.0001".  But I still expect to find considerable variation in the over-travel at different rotations of the probe.  I plan to test this tomorrow.

I *really* want to get a good contact probe going, that does not *have* over-travel....

Regards,
Ray L.

783

General Mach Discussion / Re: Stupid Probing Question....

« on: January 02, 2010, 11:45:02 PM »

I also have one of those probes

Believe me i am not knocking it because it is great VFM but it is easy to confuse its accuracy or lack of, unless effort is put into the probe routine.

The test i did after getting weird results was to get a piece of stock with a nice hole in it use a say G55 centre the usual way with a DTI

Zero the offset Then probe the hole using the probe using G54

You can then compare the error between the two methods

If all is well both will read zero, but you may be surprised as to the results

So although i am questioning the accuracy "Out of the box" the repeatability is good

If anyone wants to know how i did it just ask

Phil,

I'm trying a similar approach - I took three 1-2-3 blocks, and clamped them in a vise, with the outer two standing on-edge, and the third on it's side, so i have exactly 2" between the two outer ones.  I will then probe that to come up with proper calibration, and see how much variation I get based on the rotation of the probe.  This should tell me what the over-travel is between first contact and switch opening.

Regards,
Ray L.

784

General Mach Discussion / Re: CNC4PC C11G Analog Output Spindle Control

« on: January 02, 2010, 06:16:48 PM »

I'm using CNC4PC C11 rev. 9.3 and I just can't get it deliver more than 9.3V from the 0-10V analog output. I get the 9.3V at S20500 while the max is S24000. If I go over 20500 rpm the voltage will drop again to somewhere around 8.5V. My VFD does not deliver 12V so I'm using an external DC/DC converter which delivers 11.88V from the 5V supply, a 0.1% error I guess shouldn't make that much difference, or? Any ideas what to try next. (Unless - being sarcastic - the card rev # 9.3 means that you need to stick with 9.3)    

/Risto

What voltage are you providing to it?  The spindle control will NOT be able to provide the full input voltage.  So, if you want 10V out, you'll have to provide it with 11-12V in.

Regards,
Ray L.

785

General Mach Discussion / Re: Need an easy to understand "macropump" example

« on: January 02, 2010, 01:11:50 PM »

Tried it and the macro does work in code but does not work when clicking spindle start. There must be an easy way to do this. I thought macropump would be the way to go but back to my original question I just dont know how to script it.

See my last post - this is easily fixed....

786

General Mach Discussion / Re: Need an easy to understand "macropump" example

« on: January 02, 2010, 12:19:38 PM »

I guess I thought the only time those macros came into play was with running a program. Are you saying that when I mouse click the spindle icon it is reading the "M3" macro? How does the software know to "M5" when clicked again?

There are buttons in the default screenset that control the spindle without invoking the macros (a VERY bad idea, that will be fixed in v4), but that is easily fixed by simply editing the screenset to make those buttons call the macros.

Regards,
Ray L.

787

General Mach Discussion / Stupid Probing Question....

« on: January 01, 2010, 11:46:11 PM »

I now have one of those spiffy probes with the little, tiny ball end, and the switch consisting of the three little arms at 120 degrees apart, resting on ball bearings.  In terms of precision and repeatability, it's excellent - I get very consistently +/-0.0001".  But, I have two problems:

1) It's near impossible to get it calibrated to where the ball end is *precisely* aligned to the spindle center.  Getting much under +/-0.0005" is a real chore, and I'm not at all convinced it'll stay there for any length of time.

2) Even worse, the distance the probe tip moves between the time it first makes contact with the workpiece and the time the switch opens is completely unknown, and, I suspect, due to the gemotry of the switch, probably varies based on the angular position of the contact point.

So, how in the heck are these two problems resolved?  Certainly, it would work just fine as-is for probing an object to get a point cloud, but I want to use it for machine setup, so I have to know *exactly* where the spindle centerline is relative to the contact point, as I did when I used to use a rigid probe (which Mach3 liked to break off from time-to-time....).

On a related note, I'm working on a "semi-rigid" probe design that will have a 0.200" diameter tip just like the rigid probes I've used, but will ber able to "give" on over-run by having the probe mounted in a spherical ball bearing, with a spring-loaded centering mechanism.  I think this will be far easier to adjust perfectly concentric to the spindle, and should return precisely to that position after being bumped off-center.

Regards,
Ray L.

788

General Mach Discussion / Re: Need an easy to understand "macropump" example

« on: January 01, 2010, 06:49:06 PM »

If Spindle operation is dependant on some other operation being done, or vice-versa, it would make a whole lot more sense to put those checks into the M3, M4 andM5 macros than into the macropump.

Regards,
Ray L.

789

General Mach Discussion / Re: touchscreen monitor

« on: January 01, 2010, 03:17:59 PM »

where can I get a resistive overlay

Did you not bother *reading* the responses to your own thread?

790

General Mach Discussion / Re: One Macro calling another Macro.

« on: January 01, 2010, 03:05:25 PM »

Please tell how or point me in the direction for some document that explains how one Macro can call another Macro.

Thanks

There is no document that I'm aware of.  However, all you can do is call M macros, using the Code function.  You cannot call them by name.  And, just to make it more interesting, each M-macro is launched in its own thread, so *you* must provide a mean of synchronization if you require the called macro to complete before the calling macro resumes execution.  This can be done as follows:

Calling Macro:

...
MySemaphore = 1100     ' define Var to be used as semaphore
SetVar(MySemaphore, 1) ' Set the semaphore
Code "M666"                  ' Call my sub-macro
While GetVar(MySemaphore) = 1
    Sleep 100
Wend
...

Called Macro (M666.m1s)

...
' Do whatever we need to do here
MySemaphore = 1100     ' define Var to be used as semaphore
SetVar(MySemaphore, 0) ' Clear the semaphore, telling caller we're done


If you need to "nest" deeper than a single macro, have each calling macro (except the first) increment the Semaphore, and each called macro decrement it when it completes.  The caller must then save the value of the Semaphore *before* incrementing it, and wait for it to return to the saved value, thus ensuring ALL sub-macros have completed.

Regards,
Ray L.