Controlling THC/Coolant? Path rule?

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Ernesto
Posts: 18
Joined: Wed Dec 06, 2017 7:25 pm

Controlling THC/Coolant? Path rule?

Post by Ernesto » Sat Jun 30, 2018 3:10 am

With stand alone THC systems, it's nice to be able to choose when the torch height controller is on or off. This is handy on small holes, near the end of cuts, and when decelerating for sharp corners. I posted another thread about modifying the grbl post processor to use M08/09 to trigger a relay to deal with this but am wondering if there's already a Sheetcam feature that will help me control this.

Is there a way to use the path rules section in operation edit to control M08/09 and add a return to safe z after every M09?

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Les Newell
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Joined: Thu May 11, 2006 8:12 pm

Re: Controlling THC/Coolant? Path rule?

Post by Les Newell » Tue Jul 03, 2018 8:14 am

This is pretty much waht path rules were designed for.
First create a code snippet (Tools->code). Call it THC on and for the code use M08. Repeat for THC off.
Now go to Tools->cutting rules. In the 'Rule set' dropdown select 'add new rule set' and give your new rule set a name.
Now Click on 'Add rule'. For the rule select 'On small shapes'. set 'smaller then' to something like 1.5". For the start and end codes select your THC on and THC off snippets. You'll probably want to create a few more rules for corners etc.
In 'Always apply rule set' select the rule set you created.
Now when you run the post THC will be turned off whenever any of your rules are triggered.
Is there a way to use the path rules section in operation edit to control M08/09 and add a return to safe z after every M09?
You can do that. Your code snippet would look something like this:

Code: Select all

M09
G0Z2
You can but you must be careful to only use this snippet on rules that apply to complete shapes. For instance you would not want to use it on an 'on all corners' rule. You can have as many snippets as you want so you can have one that just turns off THC and one that turns off THC and returns to safe .

Ernesto
Posts: 18
Joined: Wed Dec 06, 2017 7:25 pm

Re: Controlling THC/Coolant? Path rule?

Post by Ernesto » Tue Jul 03, 2018 4:07 pm

Thank you so much! I will try this as soon as I can get back to the machine. :)

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