new to the site and have been reading post and noticed that your the man with the problem solving skills so here we go

when i cut out a circle or an oval about the last 20-25% of the cut my machine starts to try to get ahead of itself. it dosent matter how fast i go or the size of the object. this just gives me a little bit of extra clean up and alot of fustration

anything would be helpful
baker

When you mean get ahead of itself, are you referring to the machine moving faster then the plasma cutter is able to cut through the material? What changes during this last 25% of the cut, is the height changing at all or is the speed changing? Does it happen during straight line cuts, or straight lines mixed with arc movements?

it only happens in circles and ovals and nothing changes height wise the arm just jerky a little bit and the arc dosen't cut through the material

What material are you cutting, what thickness is it, what speed are you cutting it at, and what is your amperage setting on the plasma cutter?

might be a loose ground connection.

the ground is ok i clamp it to every piece instead of having it bolted to the table so i cam rule that out
the material is 3/16 mild steel @ 18 or 15 ipm and 35 amps
could it be something in the way that i'm programing it in the CAD and maybe it doesnt have enough nodes?
i mean i can see the gantry moove out of time when it happens so i am baffeled

thanks
baker

What kind of software are you using to generate the toolpath? What kind of consumables do you use? The 35 amps sounds like an odd consumable.

Our hypertherm 1000 uses 25, 40 and 60 amp consumables. Our voltage control is set around 100-105 for the 25 amp, 155-165 for the 40 and 160-180 for the 60 set-up.

By the way, we have a 4 x 8 torchmate system. Thought I'd throw you a few ideas, but the guys over a torchmate definately know their stuff. i've never had a prob they haven't been able to solve for us. Give em a day or 2, I'm sure they can solve this one for you. No pressure Mike......:)

Very strange that it will cut straight lines and square corners, but not circles.

Regards,
Mike

well since i've stated the problem the machine will not create the same "hicup" again so who knows

the 35 amp tip is from my little cutter its a hobart airforce 625, 40 amp machine but the extended cut tip and electrode are rated for 35 amps
i have to use that for now cause my 3 phase service is slowly coming along and then i'll be able to use my hypertherm 1650 which is no compairsion to the 40 amp one

thanks
baker

Hi

You have not lost it, cose mine does the same thing.

Only sometime and only on smallish holes it wil learch forwards. It's still cutting but just gives a rough finish. It learches about 2 to 3mm. The g code is just a straight three line code with no fancy arcs.

I would also be interested in this one.

I'll post the code when I get to work. Maybe vidio it too if I can get it to do it. It's almast like a tight slider or rack sticking but I don't think so.

Tack1000

well it only did it on larger circles and ovals like 18x24. inches ive done 10inch circles with .5 holes and it does fine, just the bigger stuff that would be difficult

baker

Hi

You have not lost it, cose mine does the same thing.

Only sometime and only on smallish holes it wil learch forwards. It's still cutting but just gives a rough finish. It learches about 2 to 3mm. The g code is just a straight three line code with no fancy arcs.

I would also be interested in this one.

I'll post the code when I get to work. Maybe vidio it too if I can get it to do it. It's almast like a tight slider or rack sticking but I don't think so.

Tack1000

If you could take a video or post a g-code so I could look at the problem, it might help diagnose the problem.