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Author Topic: Axis Limits in Toolpath screen  (Read 4195 times)

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Axis Limits in Toolpath screen
« on: November 01, 2011, 02:10:34 PM »
I am using MeshCAM Art to create 3D toolpaths for wood carvings on my Router table. I have encountered a problem, that I have been unable to dechipher.
Upon loading the G Code file created by MeshCAM Art, and then navigating to the Toolpath screen in Mach and clicking Regenerate Toolpath button (something I have made it a habit of always doing, to check that the program limits in Mach 3 match what was created in MeshCAM).
  Mach reads through the entire file, and updates the program limits for each axis. However, (and this is the core of the problem) the Z axis positive limit DRO now reads a NEGATIVE number. NOT GOOD, since depending on the program file loaded, indicates that the tool will start out by being plunged as deep as .25" into the work piece when it is supposed to be in a retracted position of 0.100" above the stock!
  After multiple attempts of starting over from scratch (I.E. -recreating the G code file in MeshCAM Art, and loading into Mach3), the problem persists. The tool retract in MeshCAM Art is set to 0.100" above the stock, and in the past has always generated G code which reflects this in the Mach3 program limits on the Toolpath screen. SOMETHING has changed in Mach3 for this to be happening, and I just can't seem to find exactly WHAT is causing this!!!?????
It is important to note here, that when the file is initially loaded into Mach, the program limits for all axis read correctly EXCEPT the positive Z limit, which reads 0.000" subsequent Regenerate Toolpath clicks yield the Negative value in the positive Z limit DRO. Does Anyone have any suggestions on where to look?

Offline BR549

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Re: Axis Limits in Toolpath screen
« Reply #1 on: November 01, 2011, 05:05:35 PM »
WHere do you have the point of origin set to in meshcam. Top of table, top of object, top of material, or ????

Mach is only reading what it sees in the Gcode file(;-)

Can you post a copy of the file for us to test?

(;-) TP
Re: Axis Limits in Toolpath screen
« Reply #2 on: November 01, 2011, 09:13:01 PM »
I will try, but it is a rather large file. This one is the logo for the Airforce. I really don't understand what has changed, because I have always loaded the gcode generated by Meshcam into Mach3, and navigated to the Toolpath screen in Mach, clicked on Regenerate toolpath, to verify that the program limits match what was done in Meshcam, before taking the file to the shop for cutting output. Before clicking the Regenerate toolpath button in Mach, it displays the correct range of -Z, and +Z. AFTER clicking the Regenrate toolpath button, it alters the program limits on the Z, such that the +Z limit is now a negative number, instead of the usual +0.1" range!
 This has been a devil hunt for the past 2 days (and I don't have much hair left to work with!!!).  I have tried setting the Program Zero in Meshcam to Top of Stock, Manually entering a zero into the field, Clicking on Set to Geometry Zero, ALL possible scenarios in an effort to run down the problem. I even uninstalled both MeshCAM, and Mach3, and reinstalled (and reconfigured Mach to the original settings) ALL to no avail! Any help would be greatly appreciated!

Offline BR549

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Re: Axis Limits in Toolpath screen
« Reply #3 on: November 01, 2011, 10:16:30 PM »
I would say the problem lies in your cam software as the program never goes above the -.233 point so probably your material z origin is set wrong or posibly the material height is wrong.

BUT you can run the program as is. You just have to set the top of the material to -.233.



(;-) TP
Re: Axis Limits in Toolpath screen
« Reply #4 on: November 06, 2011, 07:59:09 AM »
FINALLY figured out the problem. (It was ME!). I used the Fit to Geometry option in Stock Definition of MeshCAM. And set the program zero to Top of Stock, SW corner. And just IGNORED the negative numbers this yielded on the screen. It was these negative numbers that was the issue that threw me before. It defies logic, because setting the Z axis Zero to top of part is my standard practice. So when the negative numbers appeared in the various fields of MeshCAM, I manually edited them to 0.000" (This turned out to be the problem). NOW, when loading the g code into Mach3 and Regenerating the toolpath, all is as it should be in the Program Limits fields of the Toolpath screen. I still don't know what changed between MeshCAM and Mach3, because manually setting the values in MeshCAM to zero always worked before. And dry runs in Mach3 to test, always returned the correct values in the Program Limits fields of the Toolpath screen before.
   However, during a program cut, the brushes on my Porter Cable Router bit the dust. Does anyone know of a local supplier for the 869659 Porter Cable motor brushes? As I understand it, that part number is a generic part number which replaced the original Porter Cable part no31652. Any suggestions?

Offline Tweakie.CNC

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Re: Axis Limits in Toolpath screen
« Reply #5 on: November 09, 2011, 02:20:25 AM »
Quote
However, during a program cut, the brushes on my Porter Cable Router bit the dust. Does anyone know of a local supplier for the 869659 Porter Cable motor brushes? As I understand it, that part number is a generic part number which replaced the original Porter Cable part no31652. Any suggestions?

Sorry to hear that your spindle expired, but this is bit of an international forum so where are you located.

Tweakie.


nb. (This reminds me of a very old Tommy Cooper joke....
Man phones swimming pool and asks if he has got through to the local swimming pool. Reply was "It depends where you are calling from")
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Axis Limits in Toolpath screen
« Reply #6 on: November 09, 2011, 08:43:13 AM »
I am in McDonough, Ga. USA - However, I haver since found a supplier for the brushes www.toolsandmore.us I ordered them last Friday, they should arrive sometime today. Thanks