Problems with persistent Aircuts

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sonolink
Posts: 1
Joined: Wed Nov 07, 2018 9:39 am

Problems with persistent Aircuts

Post by sonolink » Wed Nov 07, 2018 9:50 am

Hi

I'm using Autoleveller last version and I'm experiencing problems. My machine is a Win7, Parallel port JK02 chinese board and Mach3. The machine runs fine.

I first create a toolpath in Aspire. I then export the toolpath as GCode and open it in Autoleveller. I set a 1 mm inset and click on Autolevel. Then I home my machine and set Z=0 with its probe. I open the Autolevelled GCode and follow the instructions. Mach3 probes the board and then asks me to take off the clip. But when it begins milling the PCB it will barely touch the board.

Any ideas?
Thanks

daedelus
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Posts: 371
Joined: Tue Oct 01, 2013 1:41 pm
Location: London, UK
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Re: Problems with persistent Aircuts

Post by daedelus » Sat Nov 10, 2018 11:10 am

Hi,

I would first ask what Z is set to in you original GCode?For example:

Code: Select all

G00 X-0.3555 Y0.4146 
G01 Z-0.1778 F254.00 
G01 X-0.4146 Y0.3555 F508.00 
G01 X-0.4870 Y0.3137 
G01 X-0.5678 Y0.2921 
G01 X-90.4322 Y0.2921 
G01 X-90.5130 Y0.3137 
G01 X-90.5853 Y0.3555 
G01 X-90.6445 Y0.4146 
G01 X-90.6863 Y0.4870 
G01 X-90.7079 Y0.5678 
Here Z depth is set to about -0.17 (milimeters) because of the second line, but if yours is 0 or 0.0001 or some small number, then during milling, the tool will barely touch the board. So the original GCode is the first thing I would check.

The second thing is, click 'Generate PFG' rather than 'Autolevel', this will produce GCode to just probe and not etch. It will also produce a log file which records all probe points, and you can use this file to check for any probing errors.
http://www.autoleveller.co.uk/. Software to probe and adjust a GCode file for PCB's or any probe-able surface.

http://www.autoleveller.co.uk/cnc-probe-guide/. A short guide to setting up the probe.

-James

WoodWorkerB
Posts: 10
Joined: Thu Nov 28, 2013 2:51 am

Re: Problems with persistent Aircuts

Post by WoodWorkerB » Thu Nov 22, 2018 4:56 am

I have a couple of thoughts:
  • What is your Z cutting depth set at? Autoleveller won't fix this if you're just cutting too shallow.
  • Slop in your coupling or excess backlash. Check your Z-axis coupling. Milling the PC board is just a few thousandths of an inch, so any 'slop' or even a tiny bit of backlash can cause problems.
  • Make sure there is zero up-and-down play in your spindle.
FWIW.
BrianV
https://hobbycnc.com

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