Hi-Def inspired Hole Cutting

This interesting. There's no reason why we can't do this. Right, now I have too many other irons in the fire but I'm gonna let this sit here open. Down the line, upvotes will tell me if it's worth the time to really dive into this. I will say that my Air Plasma machine makes spectacular holes running Hypertherm 45XP. I mostly cut mechanical parts, very little art work, and I often cut 1/4 holes in 1/4 plate with great results. Usually you can get pretty good results with some cutting rules for hole slow downs. I definitely want to see where this thread goes though! Maybe we can get some of the LinuxCNC folks over here eventually.

Hello Joel,
You can actually do this now in JetCad with Rules.
We make CNC Plasma Tables here in Australia, and i have made a bunch of rules myself and they mimic Hi-Def Hole Technology.
You can turn off THC and set slow downs ect, with rules you are unlimited with the functions you can setup.
Turning the THC off and the Slowdowns are the big ones, with the lead in and out being important but you can get really good holes with standard leads.
There is a screen shot of one rule i made.
Rules for Lead-ins and Lead outs with Overburn we are looking into for the future.

Thanks, Scott. Did you watch the video? I already do slowdown on holes. I'm referring specifically to the other features -- i.e. fancy lead-ins on holes, ability to slow down even more close to the end of cut, and over-cut.

I don't see a way in the rules to specify that something fires a specified distance before end of cut. This would be very handy for some use cases, and perhaps I should submit a separate feature request for this.

Hey Joel & Scott,

I don't know if you noticed but a couple releases ago I added logic to the leads manager. When it's decreasing the lead in length (or radius for arc leads.) It does a final "Pierce Bleed" check on all leads and if there's not at least kerf*3 distance from the tool-path to the pierce start point it over-rides automatically to a line lead which then starts on the hole center. So it's essentially a hard rule (still obeys over-ride's and cutting rules) so if you have lead-outs disabled the lead in on small holes (determined but cut chart kerf) will automatically pierce on hole centers like you want without no cutting global or per item rules set for that. This only regards to holes though, since there's no way to do this on random contours where the lead manager does "best effort" to minimize pierce bleed but in that case it allows some bleed to still get a lead in otherwise the worst case (what sheetcam does) is just drop the lead all together. SO worse case, pierce bleed is still minimized on art work vs SheetCAM's philosophy. I tested quite a bit of Joels geometry (while working on SheetCAM job file imports) and my lead manager was able to place leads in many instances where SheetCAM just drops leads entirely, mostly on art. I think that will result to cleaner art work when posting Gcode out of JetCad3 vs SheetCAM

There's no real reason why I can't build these fancy lead ins but there's higher priority's right now. I will be keeping an eye on how many up-votes this gets though. I think this is mostly an "advanced" feature where maybe 5% of JetCad3 users would actually understand what this does, most guys cutting on their plasma tables just want arc leads to be placed automatically without any tool-path collisions, which the leads manager already does now. The leads manager currently allows leads to intersect but will not allow leads to intersect (accounting for arc bleed) with toolpaths.