Messages

121

General Mach Discussion / Re: Gcode questions pt2

« on: October 19, 2009, 04:10:23 PM »

Thanks fellows for the feedback. Makes sense.
al

122

General Mach Discussion / Re: Gcode questions pt2

« on: October 19, 2009, 02:11:49 AM »

put the revised # value in square brackets -

#100 =[#100+0.010]

this should work now

Thank you! I wonder how many others besides me puzzled over this one? I vaguely remember years ago dabbling in GW-BASIC and the # declared a double-precision variable, a $ was a string etc.  But arithmetic operations used parentheses not square brackets.
So just out of curiosity, where does the square bracket come from?
al

123

General Mach Discussion / Re: Different Cuts

« on: September 15, 2009, 12:30:48 AM »

On the ‘Program Run” screen press the ‘M-Codes’ button at the bottom of the page and you will see that M30 is ‘Program end and rewind’. Thus your last line is beyond the end of your file and won’t ever be executed. Move it up a line so it is run before the end of the file (M30) and you should be OK.
HTH
al

124

General Mach Discussion / Re: Notes in GCode files

« on: September 01, 2009, 11:46:36 PM »

Thanks Ray,
But would you believe I stumbled on a way to imbed the parentheses.

  ;SetOEMDRO(827, NewValC) 'C-axis

FWIW
Al

125

General Mach Discussion / Re: Notes in GCode files

« on: September 01, 2009, 02:08:23 AM »

Ray, is there any way to include a memory jogger in a comment that also contains a parentheses?
Example, (SetOEMDRO(827, NewValC) 'C-axis) gives a nested comment error.
TIA
Al Lenz

126

General Mach Discussion / Re: USING DIFFERENT STEPS PER UNIT

« on: August 31, 2009, 06:30:56 PM »

You can have anything you want on any axis, think about a 4th axis its not the same as X,Y or Z

Graham

True, but this only reinforces Rich’s concern, since there are feed rate issues associated with certain linier/rotary interpolation moves.
Al

127

General Mach Discussion / Re: Mach-3 quit loading g-code

« on: August 23, 2009, 09:49:10 PM »

I had that happen. If the file was corrupted on the last closing, mach may not be able to read it. Then it does just what you describe. A window flashes momentarily, the path and file name appear in the ‘File’ window but nothing else.

 You might try opening the file in notepad and see if there is anything obvious. If not, copy the entire file and paste in another open notepad. In my case the new copy saved OK and the file then opened in mach.

al

128

General Mach Discussion / Re: 4th axis

« on: August 07, 2009, 06:59:35 PM »

That pop-up box has a 'Rapid Height' setting which appears to be zero by default. Set it to a value greater than your current height and it will go that position instead.
Al Lenz

129

General Mach Discussion / Re: 4th axis

« on: August 07, 2009, 05:30:33 PM »

Yes, I would do exactly what you suggest. (I was only trying to work with the code as presented).
Sure, set Z-zero on the surface of the cylinder and the cut depth to minus .005. Enter the actual radius (to split hairs it would be the radius less .005) of the cylinder in the DRO and it should work fine. The error that I referred to earlier will now be when Z is positive and cutting air, so no problem. In fact, this is how I should have suggested in the first place. Your cylinder is constant diameter so no need for mach to recalculate new angular feeds based on dia change. If the cylinder is not constant diameter for the full length, then mach does have the ability to compensate, that is, it keeps track of the Z value and the angular feed in deg/min is decreased as the diameter increases. It only needs one small tweak to be useable and that is to recognize that a change in Z is NOT a change in diameter but a change in radius.

I’m not familiar with RhinoCam but the code does (IMHO) have a few rough edges. I took the liberty of modifying a few lines to illustrate what I’m referring to. It should run faster. That doesn’t make it right or wrong, just a personal preference. The code is not optimized, that is, it jumps back and forth from place to place.

In regard to the mirror image comment, I had to rotate the view in the tool path window so that it could be read from inside the cylinder looking out <grin

Al

PS Try the modified snippet and see what happens.

130

General Mach Discussion / Re: 4th axis

« on: August 07, 2009, 12:18:20 AM »

Yeah thanks, that confused me even more LOL. I'll reread what you said. I was doing 5IPM because I was engraving with a fine bit.

So I have my parts center as the center so it should be going to like 1.2" up and cutting but it doesn't do much. I'll mess with the settings.

Greg has you on the right track.  Here in a nutshell is what’s required.

In Config> General Config be sure ‘Rot 360 Rollover’ is NOT checked. (Your code uses both pos and neg A values).

In Config> ToolPath select the ‘X-axes’ button; check ‘A-Rotations Enabled’ and check ‘Use Diameter for Feedrate’.

On the Settings page you have a choice with the ‘Rotation Diameter’ DRO. Unfortunately due to a problem within Mach, neither is accurate, but in your case one is better than the other.

 If you enter 0.0001 in the DRO then Mach will read all Z values as a diameter and calculate the feed rate accordingly. Obviously, this is incorrect as the Z is actually a radius. The angular component of your X-A move will be off by a factor of 2. Probably not acceptable.

If you enter the Z value that is in the first block containing a Z then in this case (and in this case only) Mach will correctly use this value as a radius. However changes in Z will be incorrectly interpreted as a change in diameter thus creating another error. But this error is less and in fact wouldn’t even be noticeable if your Z clearance height were reduced. (Less change in Z; less error). Is there a reason that you need over an inch of Z clearance? (I normally use something more in the order of 0.050).

Another thing, your code uses only   G01 (no G00), although it does increase the feed from F5 to F20 for the rapids. You may find it more convenient to use G00 for the rapids and thus only have to set the Feed rate once at the beginning. Easier to make changes.

 Is it just me, or are you engraving a mirror image?

Hope this helps,
Al