Void Lock Kerf Crossing suggestion

the cerve with is most around 2mm or below at a speed of greater 3000mm/min on 2-4mm mild steel
it is less then 0,01second 10ms to cross over the kerve the THC shoudt not move at all on a FLAT sheet as the sencing time
shoudt be at aound 10 times the amount

but anyway a good thing as it can be done

Yes its actually about 0.4 seconds at my cut speed so I suspect it is enough to cause a crash as Linuxcnc has 400 servo cycles to make a height adjustment.

I my view its not really about crossing kerfs on 2mm steel but all the other uses which are often more pronounced with thicker material.

Having a slug of 16mm steel drop out of a hole can cause a significant dive. YOU need a fairly significant overcut to allow the bottom of the kerf to catch up. That makes it hard to manage with cutting rules in gcode. So with void sensing, it will no longer be necessary to disable THC on holes. So the combination of velocity anti dive and void sensing will basically eliminate any need to implement hole cutting rules.

Severing a sheet is something I want to do more of and this will let you cut right off the sheet without fear of a crash.

Plus looping corners will become a reality or saving material and time by using both sides of the cut and getting square corners on parts.

Plus the ability to cut mesh and things like that so there are a lot of use cases for this feature.

Actually its a bit premature for me to be dancing. The signal needs to be turning off after the trough gets back to normal. BAck to the drawing board

tommylight wrote:

Looks promising !
Nice work.

It just needs some tweaking about where it turns off. I think that would be pretty easy from here. I've had a look at the plasmac.comp code, it looks pretty easy to add an external pin to lock the THC if I add one extra pin that says use_external_kerf_lock.

This is the hardest bit of code I've written for many years.

phillc54 wrote:

Why not use the existing thc-disable?

I hope you get more testing and feedback than I did last time I did some work on kerf crossing.

Cool, that will be easier. You did tell me it wasn't really designed for kerf crossing so I looked a bit further.

The whole thing about void crossing is that for the most part you can work around it but I think having it will be quite handy. But its not easy to understand.

phillc54 wrote:

You did tell me it wasn't really designed for kerf crossing so I looked a bit further.

I think that was in relation to external kerf crossing.

Isn't that what this is?