[MaciWorks]

Hello, everyone.
At first, sorry for my bad english.

I'm working with a Hypertherm 260XD based plasma cutter. It's a new machine but I am a little bit disappointed. I've used a lot of plasma or laser systems, but this one has a disappointing cutting quality.
We tried almost everything, changed / replaced upper / lower head, cables, gas console etc. but the quality of the holes are really bad - or the machines I used before were all better, I don't know.
This machine is capable to cut with true hole technology. With this technology we have to see significantly better holes, but we don't.
The upper side of the hole is ok - good. But the underside is terrible. It looks like when it is cutting, that the arc is moving. It's not constant, is moving forward and back, little bit to the sides too, and the result is very-very far away from a round hole.
We tried many times the service, the seller, but they said it's a plasma, it is ok.
Do you think, it is ok, or not?
See pictures.
Lv10 mm S235 plate, hole diameter is 14 mm (True Hole). 130A, new, original and not dirty consumables. Oxygen / air.
Thank you.

[jimcolt]

What CNC machine, cnc control, software? Water table or downdraft? The plasma does not do the hole cutting by itself, rather it requires well coordinated motion involving the x-y drives, z axis height, gas control system, the cut file and the plasma process. The pictures clearly show you have some machine motion issues....and I would strongly suggest working with the builder or integrator of the machine. More details and I can suggest the next move! The best first step is to replace the torch with a pen and do some tracings of the part file you have issues with...at the same speed, etc. Jim Colt Hypertherm

Hello, everyone.
At first, sorry for my bad english.

I'm working with a Hypertherm 260XD based plasma cutter. It's a new machine but I am a little bit disappointed. I've used a lot of plasma or laser systems, but this one has a disappointing cutting quality.
We tried almost everything, changed / replaced upper / lower head, cables, gas console etc. but the quality of the holes are really bad - or the machines I used before were all better, I don't know.
This machine is capable to cut with true hole technology. With this technology we have to see significantly better holes, but we don't.
The upper side of the hole is ok - good. But the underside is terrible. It looks like when it is cutting, that the arc is moving. It's not constant, is moving forward and back, little bit to the sides too, and the result is very-very far away from a round hole.
We tried many times the service, the seller, but they said it's a plasma, it is ok.
Do you think, it is ok, or not?
See pictures.
Lv10 mm S235 plate, hole diameter is 14 mm (True Hole). 130A, new, original and not dirty consumables. Oxygen / air.
Thank you.

[MaciWorks]

Dear Jim, thank you wery much for your answer.
It is a MicroStep Maxtercut-X with iMSNC software, and AsperWin as nesting soft. The machine has a bevel head, we use bevel consumables.
It has a normal downdraft and not water table. We worked together with the builder and the seller / and service team / of the machine. They made pen tests too and everything was fine with the portal or head movements.
With the pen we made perfect circles. Once again, we have problem only with the underside ot the cutted plates / holes. The upper side is ok. Not perfect, but ok.


upper side

underside

Oh, and other weird things: the arc is almost before and not behind the head. Is seems, the head "pushes" the arc. I know it so, that the arc should be a little bit drop behind.
We are not satisfied with le life of consumables too. At 50-80-130A we have 700-800 startings. That is so-so ok. But with 260A we could not make above 200-250. With 260A the consumables are very discolored, much darker than normal.
How much starts has to live a Hypertherm consumable set at 260A?
The service team always said, everything is normal, but we don't think so.
Thank you,
Peter Szanto

[bytor]

The issue here I believe is your nesting software and or your control. While the plasma is capable of true hole cutting, the nesting software and or the control may not be. I am unsure, and Jim Colt may be able to answer this, if the control has been licensed to Hypertherm for True Hole cutting. Next, is the nesting software capable of programming True Hole type holes?
True Hole technology involves an integration of the control and the nesting package to perform a co-ordinated motion to slow the cutting speed, lower the torch cutting height, ramp up/down cutting current, etc ...
The variables here are further refined based on the size of the hole being cut and the material it is being cut from. While the seller is somewhat correct, it is plasma, a better answer would have been to say it is how the machine moves the plasma arc
Remember, plasma is not a Laser - the arc cutting through the material is not perpendicular. Rather you are pulling the arc through the material. An analogy would be to drag a string behind you and then turn. the top of the string comes with you right away, but the bottom lags behind you. So it is with plasma. the tops of your holes are round, but the bottom is not because the arc is being dragged away before it has cut the bottom of the material. It is pulled away because the machine is moving too fast.
Additionally, the torch height must be locked. you cannot use Arc Voltage for height control when cutting small holes.
I would suggest you contact Viresh Sitapara @ Microstep. He would be able to assist you in this matter.

[MaciWorks]

Thank you very much the help. (Your analogy for plasma arc was really good.)
The nesting software we are using (Asper) is capable of true hole cutting only from hole diameter = plate thickness x1 to D=plate thickness x2. In the software I can only enable / disable it but cannot change any parameter within. (It's ok, as you too wrote it, true hole is a "complete technology package", where the the system coordinates a lot of things, like speed, cutting height, etc.) In the cnc code I can just see an M102 Dxx(*TRUE HOLE *) parameter. Oh, and torch height is always locked with true hole.
The control software (imsnc) too can handle true hole. Not with all head settings and plate thicknesses, but it can cut true hole.
What is interesting for me, when I turn true hole off, the holes are much more cone-shaped, but they are smoother.
So I can accept your analogy for plasma arc, but it is not clear, why are the normal holes smoother? (They are much more conical, but they are closer to circle than true hole holes.

[bytor]

I'm glad you have an understanding of what needs to be accomplished. I can offer no further advice except to suggest the following:
Ensure you have the latest software/firmware upgrades for the 260XD.
Contact Viresh Sitapara @ Microstep for engineering support. He is well versed in cutting good holes. I know this first hand.