Pierce divots

[Largemouthlou]

Have tried many different pierce and lead ins/lead out, even tried with no lead out.

The divots are on the back of the aluminum and the gauges very from .090 to .125

Mostly on small lettering.. Thinking it may be the length of the lead in and out.

variable settings and tips
40 FC, 1250 HT set at 35 amp .090
40 FC set at 40 , .125

Have to admit everything else about the cuts have been good

Cut some .25 6061 mill finish DP the other day and had problems with the folts going out of gange on a few of the sides and the THC couldn't keep it on track.. I stayed with the THC button and kept catching up to the volts then would bring them back down to the 160 volts I was using for the .060 height

[jimcolt]

Make the longest possible lead in, the shortest possible pierce delay time, and make sure you do not have a delay at the end of cut that keeps the plasma on after the motion stops. Als...use the lowest power rating consumables for the material thickness.

-lead ins...longer, if you have room for it...is always best
-pierce delay time is the time programmed to allow for a complete pierce. The specs in the Hypertherm manual are pretty close to correct...however some machines add additional delays that add to the programmed setting. Experiment with shorter times....as long as the pierce barely makes it through to the bottom..then the pierce delay is adequate.

Also....machine acceleration rates (if sluggish) will cause more pronounced divots as well as any mechanical backlash that your machine may have.

Jim Colt

Have tried many different pierce and lead ins/lead out, even tried with no lead out.

The divots are on the back of the aluminum and the gauges very from .090 to .125

Mostly on small lettering.. Thinking it may be the length of the lead in and out.

variable settings and tips
40 FC, 1250 HT set at 35 amp .090
40 FC set at 40 , .125

Have to admit everything else about the cuts have been good

Cut some .25 6061 mill finish DP the other day and had problems with the folts going out of gange on a few of the sides and the THC couldn't keep it on track.. I stayed with the THC button and kept catching up to the volts then would bring them back down to the 160 volts I was using for the .060 height

[Largemouthlou]

Thanks Jim, I will work on them some more.. I have pierce delay in sheetcam to zero do to Mach having a built in delay.. most of my lettering is small so some of my lead ins and outs are .125 or less. Have been using the 40 FC and on the 090 have the HT set at 35 for now, may try a little less.

Been thinking of picking up the acceleration a little on the machine lately but it is cutting pretty good so it is hard to change anything, but I do know it can be better..

It seems that sheet cam may leve the tourch on a second after it is done running.. Do you know how to disenable that??

Going to send ya an email later with some cut quality pics.. As always thanks for the help..

[jimcolt]

I am not familiar with SheetCam....so cannot help you with the end of cut delay setting. On my PlasmaCam it is part of the normal cutting setup....normally I leave it set at zero....and I have no issues with end of cut divots.


Jim

Thanks Jim, I will work on them some more.. I have pierce delay in sheetcam to zero do to Mach having a built in delay.. most of my lettering is small so some of my lead ins and outs are .125 or less. Have been using the 40 FC and on the 090 have the HT set at 35 for now, may try a little less.

Been thinking of picking up the acceleration a little on the machine lately but it is cutting pretty good so it is hard to change anything, but I do know it can be better..

It seems that sheet cam may leve the tourch on a second after it is done running.. Do you know how to disenable that??

Going to send ya an email later with some cut quality pics.. As always thanks for the help..

[Largemouthlou]

Found it, in SC as well.. I've had is set to zero also..

I will have to watch closer but starting to figure out it is the shorter lead ins. but some of the stuff I cut is small.. I'll send ya some pics through the email..

[Carlton]

I have found editing the start points helps a lot to eliminate divots. My CAD software does not always pick the best start point to eliminate divots, so I do it manually.

[Largemouthlou]

Thanks Carlton.. I do sometimes edit the start points to thicker areas so the lead in can be a little longer.. But to be honest some times where sheet cam places them the peirces come out better then where I place them.. Still learning everyday!!