Author Topic: Cambam seems ok but LinuxCnc makes it bigger  (Read 705 times)

Offline takeitslow

  • Ewok
  • *
  • Posts: 6
    • View Profile
Cambam seems ok but LinuxCnc makes it bigger
« on: April 30, 2021, 16:01:41 pm »
Hello,

It's been awhile but I started out again to try and use the cnc. I imported a dxf file (a guitar), clean it nicely so as to be able to make a NC file. As I still don't know how I should index my pieces of wood so that the CNC knows where my center line is when I work with a two pieces body, I wanted to try some scrap before going with a one piece body... For this, I draw a rectangular box about 42x34cm (16.53" x 13.38") in which I put my guitar shape...
Anyway, my actual problem is:
When I worked with cambam, it seems that it understands well the size of it. When I created the NC file, when I tried to open it, it seems that LinuxCNC make it a lot bigger... Something like 13559.8 x 8451.3 (mm???  13m? 531"? In fact I don't know the units...)
It showed me a message that said something like "the size is much bigger than the size the machine can handle. do you want to continue" and I thought it was just about my center line so I said OK . And then the "Z" went all the way up and wanted to keep on going up that I "emergency" stopped it ... I made some changes in cambam but it's always the same...

Any idea how the solve the issue? how to succeed to make it work?

Thanks in advance and sorry for my bad english, I'm still french ;D...

Take care

Offline dh42

  • Administrator
  • CNC Jedi
  • *****
  • Posts: 6557
    • View Profile
    • Cambam V1.0 French Doc
Re: Cambam seems ok but LinuxCnc makes it bigger
« Reply #1 on: April 30, 2021, 22:26:30 pm »
Hello

The CB file looks Ok on the first picture (I see that because the axis lines are 200mm of length and I see also that units are set to mm)

No idea why the Gcode is wrong ; can you share the resulting Gcode (and the Cambam file too) ? what post processor are you using ?

Quote
Thanks in advance and sorry for my bad english, I'm still french

me too ;)

++
David

Offline takeitslow

  • Ewok
  • *
  • Posts: 6
    • View Profile
Re: Cambam seems ok but LinuxCnc makes it bigger
« Reply #2 on: May 01, 2021, 16:31:30 pm »
Hello David,

Merci pour l'aide! ;)
Thanks for the help!!!

Here's the files... I hope they uploaded fine... For the computer, I tried some other stuff (mother of pearl inlay, truss rod cover...) and everything is fine but I just cannot tell what what's inside or how much ram memory I have...

Offline dh42

  • Administrator
  • CNC Jedi
  • *****
  • Posts: 6557
    • View Profile
    • Cambam V1.0 French Doc
Re: Cambam seems ok but LinuxCnc makes it bigger
« Reply #3 on: May 01, 2021, 23:07:35 pm »
Hello

No problem in your GCode itself, if I open the GCode you provide in Mach3, it show the right size, same if I open it in CamBam (CamBam can display a GCode file).

So the gremlin is somewhere in the LinuxCNc setting, but I can't help with LinuxCNc ...

On the Linux screen, I see 13548 x 8269 ; its look like the original sizes has been multiplied by 25.4 (533 x 325), so it is certainly related to the Inch/mm ... Linux seems to convert Inch to mm rather to use the given value of the GCode as is ..

++
David

Edit: Have a look on NCnetic, it also show the GCode size
https://cambamcnc.com/forum/index.php?topic=9085.0

« Last Edit: May 02, 2021, 01:19:28 am by dh42 »

Offline takeitslow

  • Ewok
  • *
  • Posts: 6
    • View Profile
Re: Cambam seems ok but LinuxCnc makes it bigger
« Reply #4 on: May 03, 2021, 07:19:46 am »
Thanks David!!!

I don't know what NCnetic is or used forcause even if I bought my CNC 6 or 7 years ago, I never got the ability tu use it really.... I'll try to take a look...

Cheers

Offline ubiquity

  • Ewok
  • *
  • Posts: 49
    • View Profile
Re: Cambam seems ok but LinuxCnc makes it bigger
« Reply #5 on: May 22, 2021, 09:41:04 am »
We use CamBam and LinuxCNC although our machine has a smaller milling area of about 450 mm x 450 mm but will gladly check the NC file on our version of LinuxCNC and report results.
I won't have access to our machine until Monday morning Australian time so will not be able to report results of any investigation until Monday morning French time.
Cheers
Paul

Offline ubiquity

  • Ewok
  • *
  • Posts: 49
    • View Profile
Re: Cambam seems ok but LinuxCnc makes it bigger
« Reply #6 on: May 22, 2021, 10:44:50 am »
As David says your cb and nc files, as uploaded, look fine but if you check the GCode in line 4 of the NC file you have displayed as linuxcnc.jpg (the third one in your original post) when I make it bigger to read it is fuzzy but I think it starts with G20 not G21 as in the uploaded file. This would be telling LinuxCNC to use inches not millimetres, although the display is clearly millimetres.  (I may be wrong).

If I am correct you can edit that .nc file with a text editor to make it G21 then save it and reload it in LinuxCNC without needing to go back to CamBam.

Which version of LinuxCNC are you using (looks like version 2.7 which is the most stable version but generally runs on Debian Wheezy which is out of support now)?
Which version of Linux are you using?

If information from this forum is insufficient try the French LinuxCNC forum too https://forum.linuxcnc.org/46-francais
« Last Edit: May 22, 2021, 11:02:21 am by ubiquity »