Messages

11

General Mach Discussion / Re: machine running irregular on button script

« on: December 15, 2010, 11:55:11 AM »

Hi TP....Mr. Little here....

I don't know what the big boys do...Had to figure it out by myself...

That's why I  want to do the following.

First the setup.
I have a probe permanently mounted on my Z-axis.
The probe can be brought in place when needed by activating an accurate pneumatic actuator.
The offset probe > mill is a fixed value in X and Y.

Say, I want to engrave an acrylic sign.
Acrylic is no way flat. On a 10 mm thick sheet thickness can vary about plus or minus 0.4mm.
When engraving with a v-bit at 0.1 mm depth this means a very thick trace...or no trace at all...

The acrylic sheet already has the size needed for the sign.
Only the engraving has to be done.

 What I do is:
- Place the acrylic on the table
- Probe position in X and Y.
- Set G68 rotation and offset
- Z-Probe the surface of the acrylic sheet (Till now with my crappy button script..)
- Pull the Z-probe results and the original g-code for the engraving through my "z-control" program.
- Load the z-adjusted g-code into Mach
- Zero tool
- Start...

It might be an unusual approach...but I like it...can't help it...


I did a dry run with the probing g-code Graham posted, machine offline.
Just lowered the number of points a little, replaced the M1234 and M1235 macro with M40 and M41.

When I probe in G68, 1 degree rotation, offset x10 and y10 I get the following results.  

10.00000,10.00000,-5.00000
29.99687,10.34688,-5.00000
49.99375,10.69688,-5.00000
9.65000,29.99687,-5.00000
29.64688,30.34375,-5.00000
49.64375,30.69375,-5.00000
9.30000,49.99375,-5.00000
29.29688,50.34063,-5.00000
49.29375,50.69062,-5.00000
8.95313,69.99062,-5.00000
28.95000,70.34063,-5.00000
48.94687,70.68750,-5.00000

Probe offset can be ignored, this is a dry run (as if the probe is in the centre of the mil/spindle).
  
Probe (M40) X and Y are not the same as the (red) X Dro and Y Dro.  
X and Y Dro show "integers" as probing points, like:
0.000, 0.00
20.000, 0.000
40.000, 0.000
etc

The X and Y values M40 "writes" in G68 mode, in my opinion, really are machine coords.

Offset and rotation are known, so machine coordinates can be "calculated back" to work coordinates.
But for me that will be a lot of work/reading.
So I was looking for a way around...still impressed by the simplicity of M40..!


Rich

Or actually D I C K,  but this is ****ed away quite often, on English sites...
(Mr Little is extra funny in this case!)
 

12

General Mach Discussion / Re: machine running irregular on button script

« on: December 15, 2010, 05:55:18 AM »

I already thought about that. But not only the offset should be subtracted but also the G68 rotation should be corrected.
Math on highschool is already 25 years behind me...

I have had some practice while writing the program for depth correction.
G1 G2 and G3 moves are broken into smaller parts to adjust height along the way.

So I think I will be able to do what you suggest, but it will be a lot of work with my lack of experience...
No problem, but a waste of time when an out of the box solution exists.. (Like M40 for writing the probe-data....)   

Rich
 

13

General Mach Discussion / Re: machine running irregular on button script

« on: December 15, 2010, 03:58:38 AM »

I am very happy to be able to do some smooth probing now...

Only one minor problem left.

With the button script I wrote it was possible to do surface probing in G68 mode. ( that was the one and only good part of the script... )

Using the probing G-code Graham posted together with the M40 command like BR549 suggested it is also possible to do the probing in G68.
But X and Y position are saved in MACHINE coordinates.  
Is there a way to store them in WORK coordinates??

Because...I love G68.....
Throw something on your table, probe position, START.

I am going trough all this because I have written a small program to adjust g-code depth (Z) to a non flat surface.
This is for engraving acrylic or pcb's with a v-bit...and keep trace width constant...
It works, but I need a good probing grid of the surface for interpolation of the new depth.
Preferably while probing in G68 mode...

Rich

14

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 06:36:04 PM »

That's it!! M40/M41 works!!

Everything is easy when you know how to do it...

But this is even easy when you don't know...

No VB script required!!

Thanks Graham, BR549 and rrc1962 for helping me!

15

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 06:10:42 PM »

TP,

I think you mean M40 and M41..

I will give it a try...

16

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 05:42:22 PM »

Huh??

My Mach MDI Page / g-code explanation button says:

G40 = Cancel cutter radius compensation
G41 = Start cutter radius compensation left


I guess I am confusing things

17

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 05:29:33 PM »

Hi,

Working on the macro's... but no results...

As rrc1962 already suggests I am having trouble letting the array survive when the M1234 macro is left for the next probing step.

I have tried making another macro to start with, M1233

It only contains the following line:
    Public arrXYZ(999, 2) As Double

First, I found that

   Dim arrXYZ(GetVar(3) * GetVar(4), 2 ) As Double

is not allowed.  GetVar is giving an error here.

Also, in M1234

   arrXYZ(0,0)= GetVar(2000)

Will not work. The array is not recognized as such.

I am happy things are not easy, life would be boring 

But how are others writing their probing-values???

I hope I find the answer before someone gives it to me.
Nothing would be left of my selfrespect

   

18

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 12:00:05 PM »

Thanks again, Graham.

You've more than put me in the right direction.

Now it is time for me to stop asking and start working.

Rich

19

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 09:37:24 AM »

I have already loaded the code into Mach in offline mode to see what is happening.
M1234 and M1235 are still missing...

Regarding to the M1234 (probe values to array) macro I have some questions.

Will a variable like #3 be "carried over" to the macro?  (this to set the size of the array)
How to avoid the array is re-declared every time the macro is called?? Do I need to use the ReDim Preserve command?

And just to be sure..I guess I need GetVar(2000) etc to write the values to the array...??

Pfff...I am just a dutch truckdriver in daily life... so please be (stay!) kind to me... 

20

General Mach Discussion / Re: machine running irregular on button script

« on: December 14, 2010, 08:16:02 AM »

Graham, you are the MAN!!

Reading around a little I already found some info.
I was beginning to see the light.....far away...
But this brings it all together! THANKS!


It seems that you can do a lot more with g-code than it looks like on first hand.
My CAM software spits out g-code to easy to study it in depth.
I know what G0 G1 G2 etc is..that's it... 
But now it shows that it might be VERY usefull to make it your second language... 

I will try to do the "writing"-macro's myself.

Thanks Again!!

Rich