Centroid Community CNC Support Forum

I am trying to center punch (mark) holes for drilling. I see the "Marking Time" setting in the THC menu and it is set to 125ms. I'm running the following test.

Marking Test.nc
(1001)
G90
G53
G20
M65
(Mark Holes)
G0 X0Y0
M64

The torch moves to the WCS zero position and performs a touch off but never lights up to mark the spot. I don't have THC so it is disabled in the profile. Do I need THC to use marking?

Have you tried increasing the timer? Try increasing the timer by 100milliseconds until the delay is long enough to fire the torch. Once the torch fires then tune the size of the mark by changing the delay but 5-10MS. Hypertherm box's have worked well with the default M64 delay. Some users may prefer a very light mark so that the size is just big enough for there drill bit to start from. The Lighter the mark the less metal has heated and cooled causing the metal to harden which may be annoying when post fab drilling.

Thanks Joey, that did the trick. My Everlast 50s takes forever to light the torch so a timer setting of 775ms was needed to slightly nice the surface.

Maybe I spoke too soon. My plasma cuter is inconsistent in how long it takes to fire the torch. So when I have several holes to mark I get some nicely nicked which are easy to drill and some with potholes that are hardened. I have had better luck raising the torch height between 0.260" and 0.360" and pressing the "Test Fire" button until the torch just lights.

I'm thinking about creating a custom material profile with a higher pierce height and see if that will work better. But I'm not sure how the marking cycle works with the material parameters.

The marking macro will only use the Pierce height from the profile currently being used.

When the M64 marking macro was first created we were using a timer that would start when the voltage first reached the target voltage. But obviously that would require a THC to use the marking macro. The Ark OK signal wasn't a very reliable starting point for the marking delay timer either as the ARK OK signal had quite the delay and by the time the arc OK signal was given it was already past the point at which the torch should shut off. I was really hoping the marking macro would work for you but that does require the box to have a consistent torch fire time like the Hypertherm does.

Thanks again Joey. I have been looking for a Hypertherm at auction and online for a long time now. It seems like everyone else is too because even 2 or 3 generation old units go for over $1,000, way too much for an old retired guy playing in the garage.

Maybe I will just CAM up a separate marking job that positions to each hole and pauses so I can hit the test fire button

No problem. I'll talk to the guys tomorrow and see if we can think of anything that can be done as a work around.

I broke the job into 2 operations. The first just set the marking Z height, moved to each hole with a M0 in between. I hit the Test Fire just long enough for the torch to light. Then cycle start to the next hole. I loaded the second job and finished the plasma cutting. On to the drill press to drill and tap the holes. Not ideal but it did get the job done.

Just for reference I was cutting 7/32" A36 steel. The holes I needed to mark were to be drilled and taped 1/4-20. I'm still holding out hope that I will find a Hypertherm that I can afford someday.

PS. The contours cut great.

Good thinking. That saves a little bit of time. What size hypertherm are you looking for? Thought id keep an eye out in case I see anything local to me. I see a lot of xp30's,45's and old 1000's but rarely see and xp65's or 85's. Also doesn't help that a lot of users don't really care for the Newer Sync models.

We dug up a previous marking macro that starts the timer from the Arc O.K. signal. Thought you might want to give it a try. I would set the timer delay to 0 for the first try. Chances are the Torch will fire for much to long as its waiting for the Arc OK signal. Theres a slim chance that the ARC OK signal is fast enough but its the last option we came up with. I've attached the new file - marking_cycle_macro.cnc. Just paste this file in the "System" folder of the "CNCM" folder. There should be an existing file named "marking_cycle_macro.cnc" that this attached file will be replacing.

Drilling out a hole after it’s been plasma cut is a pain in the rear. It usually requires a cobalt drill. I have never tried to tap one, have you?I’m curious if a standard HSS tap will even cut through the hardened metal once it’s plasma cut.