Topics

21

General Mach Discussion / G31 again: Logged data is ... wrong!

« on: September 17, 2013, 04:48:37 AM »

Hi all

Yep, g31 again. I am trying to use a Z axis touch probe to level up some machining jigs.
Dedicated WXP, R3.043.022, ESS
The touch probe has a resolution of about 10 microns. It gets sensed quite happily by the ESS diagnostics and the Mach diagnostics. In fact, I can run the following program quite happily and create a data file as expected.

m1   (Go when ready)
f10
m40                    % open log file
g0 z0
m98 p10 L5         % probe 5 times
m41                    % close log file
g0 z20
m30
%------------
o10
g4 p0.2               % redundant delay
g31 z-2                % probe downwards
g4 p0.2
g0 z0
m99

The program runs, the touch probe creeps down and touches/stops at about -1.2 mm, the Z axis retreats to 0, and the whole thing repeats. A log file is created. So far, so good.

The PROBLEM: the data recorded is the position at Z=0 in machine coordinates! All 5 entries too.
Well, most of the time. A few times the file has contained actual program coordinates for the trigger point.
I have checked #2000-2 and they usually do contain the machine coords as listed in the data file.

Has anyone met this one???

This is all with Probe on 2/15, Active Low, which fits with the diagnostic screens. Interestingly, if I flip the active state to Hi, the subroutine does not even execute. It would seem that m40 or opendigfile() may do a sanity check on the state of the probe input, and abort if it is asserted.

Cheers
Roger

22

General Mach Discussion / Amusing subroutine label bug

« on: January 26, 2012, 10:22:06 PM »

I seem to be good at this ... :-)

I write my own programs in a parametric style, so there are lots of subroutines.
Sometimes I need two very similar subroutines, so I will do a copy and paste.
Sometimes ... I forget to edit the subroutine label, so(for example) I end up with two o100 subroutines.
Guess what Mach3 does for me when it encounters this?

Flag an error? Nope.
Execute just the last (or first) one? Nope.
Execute both of them sequentially from ONE call? Yep. The results can be a little unexpected. :-)

Any one else seen this?

Cheers

23

General Mach Discussion / Sometimes Mach just 'goes away'?

« on: January 15, 2012, 04:12:50 AM »

Hi all

I'm wondering whether anyone else has seen this problem. (I tried searching for it, but ...)

Sometimes, shortly after starting Mach and loading a program, I will be trying to move or zoom the tool path and Mach will just disappear. No Q about 'do i really want to quit' or anything, just blip and it is gone.

But! It is still there in the Task Monitor process list, and trying to restart Mach always fails without explanation. Trying to kill the existing Mach process also fails (which is really wierd!).

When this happens Mach also loses contact with the SmoothStepper, and fixing that is a pain. With the Ethernet SS I actually have to cycle the power on the CNC to reboot the ESS. But a similar problem was happening with the USB SS.

Or is it just me?

Cheers

24

General Mach Discussion / Losing Constant Velocity setting

« on: January 11, 2012, 04:30:44 PM »

Hi all

I have been experimenting with a touch probe and wanted to flip the active state for the Digitiser input. No problem: go into Ports&Pins and change it over.
Well, that worked, but every time I did that the system flipped from Constant Velocity to Exact Stop. No, I had not changed that myself (and that's a different screen anyhow).
Has anyone else noticed this?

Cheers

25

General Mach Discussion / Edits to M6End not being seen?

« on: January 02, 2012, 01:03:51 AM »

Hi all

I will cheerfully admit to all sorts of incompetence, but ...

I have been trying to edit the basic M6End macro (in Mill) to get it to lift the Z axis up clear of the job before making any XY moves. Saves on broken cutters that way.

But despite stopping and reloading Mach many times, it still does not see the modified macro. I've got a M100 message macro inside it as a check; it does not appear and there is no Z-axis movement anyhow. No XY axis movement either, for that matter. Old position is not being restored.

I looked in the Operator pull-down list for the 'view what macros you have loadd' option, but it wasn't there either.

Um ... Help?
And is it OK to use Notepad to edit the m1s files?

Cheers

26

General Mach Discussion / DRO anomoly with g68

« on: December 03, 2011, 05:02:48 PM »

Continuing my efforts to find ways to misuse Mach and subroutines (yeah, I know).

I was milling three slots at 120 degrees, with multiple Z passes. It seemed much the easiest to work out how to mill one slot the way I wanted, then to make that into a subroutine and call it three times with a g68 a0 b0 r(angle) command for each subroutine. So far so good, and the slots were all milled properly.

But I nearly had a fit when I looked at the DROs!

What I was expecting to see were the X & Y DROs showing the coordinates for the slot: X varying over the slot length and Y fixed at plus and minus values giving the slot width. Well, for the slot at 0 degrees that is exactly what I got. For the slot at 120 degrees I got the same numbers but in red, signifying a rotation. Again, so far so good. But then, before the machine finished milling that slot, the numbers went black and gave very different values. A bit of thought showed that the DROs were quite correct: the values being displayed in black were the unrotated XY values. This was repeated for the 240 degree slot of sourse.

Now I do understand (thank you TP) that Mach calculates ahead and uses a data buffer to queue stuff out. But why does it lose track of the rotation? It is almost as though the data in the queue is missing the relevant rotation value so that Mach uses the value from the current look-ahead calculations - which at some stage is going to be wrong for the display. Most disconcerting when watching the DROs!

Cheers

27

General Mach Discussion / VarCheck Monitor unreliable?

« on: November 21, 2011, 02:38:54 AM »

I was debugging a parametric program today (genuine spiral surfacing), and as usual things were not-quite-right. You know?
So I brought up the VarCheck diagnostic monitor so i could watch the critical parameters as the control point swept around the expanding spiral.
After much anguish, I finally realised that the displayed values bore absolutely no relationship to the path being traced.
Oh yes - the path as shown on the screen is correct, but the displayed values for the #n parameters used in calculating the path were simply ridiculous.

Is this just me again  , or has anyone else noticed that the display is sometimes wrong?

cheeers

28

General Mach Discussion / Setting cutter radius with G10?

« on: November 10, 2011, 10:09:22 PM »

I want to use cutter radius compensation.
M3M says that G10 L1 P1 R5 Z6 should set the tool table entry for tool diameter to 10 (and tool length compensation to 6) - although it is rather brief and hesitant about the radius bit.
However, I don't seem to be able to get the radius setting to do anything. The Z parameter works fine.

Would I be right in thinking that this radius/diameter feature has not yet been implemented in Mach3?
Or have I just not done the right thing yet?

Cheers

29

General Mach Discussion / When a servo motor smokes ...

« on: October 24, 2011, 05:27:51 AM »

Came back from lunch to a really bad smell of an electrical fault, on a 'stationary' machine.
Noticed Y axis vibrating, or humming.
Tapped jog to try to stop vibrations - whee, off to one end and thump! (and eStop automatically).
Motor stinking hot and leaking very hot ???grease???

Testing:
Disconnect motor from servo amp and from ball-screw.
Motor turned by hand OK, smoothly.
Motor still spins when low voltage applied.
Optical encoder has power but signal lines are static (not changing) when motor turns. (Vampire tap inserted in line.)
Signals very obvious on other encoders.

Diagnosis:
Faulty optical encoder on the motor giving conflicting signals to servo amp, which was oscillating trying to hold position.

What amazes me:
That the servo amp survived the experience.
That the thermal and electrical current limits did not trip.
That the motor survived (maybe I caught it in time). (ElectroCraft Servo S240 series)
That the guys who assembled this apparently put the trim panels on around the axis with small button screws and an airgun! (Biggest hassle was getting these screws out to get access! Tiny hex keys ...)

Hopefully, a new optical encoder (HEDS-5540A13) wil restore sunshine and joy.

Cheers

30

General Mach Discussion / Variables and 1024.set boxes/DROs

« on: October 19, 2011, 03:54:06 AM »

I am sure there is a listing somewhere ... but i can't find it.
On the standard M3M screen there are 4 axis boxes, for X, Y, Z & A
My mill does not have an A axis, so that box/DRO is not used.

I would like to use the A box/DRO to display a loop counter to tell me how far the program has got.
It sticks in my memory that assigning a value to some high variable will result in that appearing on the screen in that box - yes?
Or will the contents of the A box/DRO get overwritten by the sysrtem immediately?

Is there a listing for the standard 1024.set screen of what variables are used?

Cheers