Messages

1

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 03:58:12 PM »

I have done that in the past with the same result.  I don't mind trying again, but I'm not really able to do it now because all the material for this batch has already been through the milling operations that give you what you see in the pics.  I may have to wait until the weekend to troubleshoot this further because we have a deadline for those parts.  We'll just run them this way and sand them for now, but if anyone has another idea that I could try when I'm able, I'm all ears.

Can't thank you enough for your help.

John

2

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 02:56:27 PM »

Here are a couple of pics of the setup.

3

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 02:50:49 PM »

How do you get it to travel in the right direction after doing that?

The machine is a harbor freight retrofit using some 90v NEMA 34s and a camtronics control box.  The Z screw is a known-good four-start screw with a very tight polymer anti-backlash nut.  The X-screw is the factory screw held tight with the coupler to the motor.  I suspected the X screw right away, but anything it's doing that would cause this would also show up in a diagonal/taper cut, right?

4

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 02:38:36 PM »

Same result.  Maybe a little less pronounced.  Any other ideas?  I've gone as far as to move the job around within the travel area to see if it was a blem in one of the screws.  Nothing seems to change it.  One IPM or 40 IPM; same thing.


Here it is with the step and dir pulse set to 5 on both axis.

5

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 02:25:33 PM »

Going to do that right now.  I'll let you know what happens.  Thanks again for taking the time.  I greatly appreciate it.

6

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 01:49:00 PM »

trying this again.  not sure what happened.

7

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 01:40:54 PM »

going to get the xml file now.  thanks again...

8

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 01:40:16 PM »

a picture is worth a thousand words.....

9

General Mach Discussion / Re: Problem with cutting quality when turning

« on: April 13, 2009, 01:31:39 PM »

Hood, thanks for replying.  Here's the relevant code;

G18
G2X0.3378Z1.0790K-0.1328I0.4212
G3X0.4566Z1.2939K0.2208I-0.1455

Not sure what you mean by xml for the turn profile.  I created the profile in Rhino, created the tool path in VisualTurn, and posted to Mach III

10

General Mach Discussion / Problem with cutting quality when turning

« on: April 13, 2009, 11:37:29 AM »

Hello everyone.  This is my first post so thanks in advance for helping out the new guy.

I have a problem which I believe I have narrowed down to Mach III mis-interpreting the g-code I give it.  I get a grooved pattern on the preview screen that is exactly duplicated when the part is cut.  No change in feedrate or depth of cut has any affect.  The gouges are always in the exact same place. 

First instinct says that the g-code is based on bad geometry, but this whole curve is only three lines of code, two G02s and one G03.  Any ideas?  I get perfect cuts if I go diagonally or straight.  It only does this on curves and it does the exact same thing if I use all G01s.  Any help is greatly appeciated.

Here's how the curve looks in my CAM software's simulation screen.....



and here's what it looks like in Mach III.  I would normally just attribute this to imperfect graphics, but the parts are very similar to what's on the screen.