Downdraft design questions

-not is used to invert a pin, say you had a limit switch you wanted to be normally open and its wired normally closed, you would put -not at the end of the text in the HAL for that switch to invert it.

thefabricator03 wrote: -not is used to invert a pin, say you had a limit switch you wanted to be normally open and its wired normally closed, you would put -not at the end of the text in the HAL for that switch to invert it.

That's simple enough, thanks!

Be sure to use Halshow a lot to see the signals and the pin names as you build this out.

Can I use a sensor for an axis home AND positive limit? I did not have limits on my old table, only home switches... so I am not familiar with exactly how limits work.

Yes. linuxcnc.org/docs/2.8/html/config/ini-homing.html

rodw wrote: Very cool. Thanks for sharing. We await the next one with smokey burning rags.... or even better a torch arc!

This video shows a 90 second duration, 600 CU FT, smoke emitter. I am unsure how well this simulates the actual smoke from cutting steel plate, but... I do know this... if you forget to connect the compressed air line to the solenoid manifold before this test, your shop will fill up with this smoke. :whistle:

Looks very good towards the beginning of the table, but a bit less towards the end.
Either way, it seems to have more than enough flow to suck the ..... smoke nicely !