Using Sheetcam corner cut rules for DTHC, but not slowdown

[motoguy]

I cut one of the "tattered flag" files on a spare piece of 18ga the other day. I did NOTHING to optimize the cut...imported the svg into sheetcam, chose "outside contour" for the whole thing, used my usual "slowdown on corners and angles" rule, went with book 18ga specs, and off we go. Let sheetcam choose pierce points, cut order, etc.

All in all, it came out pretty good. For a "production" item, I'd want to change pierce points, change cut order (was cutting the "bars" before all the details were cut, so the flag "bars" started sagging), etc. Oh...and the dross on the back...LOTS of dross in the "slowdown" areas, which are basically everywhere EXCEPT the long, straight cuts. No dross there. Much more flap wheel work on the backside than I feel should be necessary.

So, I'm thinking of modifying my Sheetcam rules for this thin material, to disable THC in corners/curves, but keep 100% cut speed. I know normally you'll get torch dive and taper in a corner, but 1) I'll use the rule to disable THC, and 2) how much taper can there really be in 18ga?

I'll do some cutting over the weekend to test (assuming I can get caught up on all the drawing I need to do), but I thought I'd ask here...what effect will I see? Using the rules to disable the THC should remove the torch dive concern. Shouldn't have any taper, due to the thin nature of the material. I suppose any table rigidity/acceleration issues will become more pronounced, as it'll be hitting sharp corners at full speed, as opposed to a 40/60/80% slowdown before the corner. Are you guys still using corner/curve slowdown, when cutting really thin stuff (16/18/thinner stuff)?

[acourtjester]

I don't use the path rules when cutting 18 Ga. mild steel. I run 300 ipm 40 amps 78 volts pierce height of 0.090" and cut start 0.060" and use a switch on the arc OK for no delay there.
With SheetCam I separate the flag into layers so I cut the inside section as one the lines as another and the outside as the last cut. I cut it 24.25" long and 10.5" tall. No lead ins except for the outside.
image of G-code for flag

flag tree.jpg (72.49 KiB) Viewed 1307 times

flag tree.jpg (72.49 KiB) Viewed 1307 times

[acourtjester]

here is the G-code

AmericanFlagTattered 24 long 10.5 tall.zip

(15.4 KiB) Downloaded 89 times

AmericanFlagTattered 24 long 10.5 tall.zip

(15.4 KiB) Downloaded 89 times

[motoguy]

Thanks! I'm trying to get caught up on my drawing this holiday weekend (in the US), but I'll give your suggestions a try!

[Nacs Fab]

That is exactly how I do mine as well! Being a "Cad Guy" I have always used layers to define my cutting operations.