Hypertherm powermax 65 cutting problem

[Danny78]

Hi guys completely new to the forum and was hoping for some advice on getting my new cnc plasma system cutting right. I am running a powermax 65 and I can't get it to cut right, I have tried all hypertherms cutting parameters but having no luck. The THC seems to be operating correctly but for the life of me i can not get rid of massive tapers on the cuts some being very uneven from one edge to another, I have checked for my torch being square and it is pretty spot on. The best cut I was able to achieve on 3mm or 1/8" mild steel was 45amps at 2000mm or 78" a minute. I have plenty of air supply compressor is 52cfm with 1200lper minute free air delivery. Some input would be greatly appreciated. Thanks . Danny

[djreiswig]

Check your nozzle. A bad pierce will wreck it in a hurry. Also, is your work lead on the material and not just the table slats? And verify that your THC is keeping your cut height accurate. Maybe post what equipment you have. Might be helpful to know what you are working with.

[Danny78]

Thanks for your reply, I have changed consumables and still get the same results. I am running A Chinese plasma table and controller and using fastcam.

[sphurley]

Do a straight line cut and look at the taper. Is it both sides? Then your cutting height is off. There will always be a good side and a bad side to some extent as the swirl goes one way. You should be able to determine inside or outside cut and start direction for that reason.

[Old Iron]

Change the o-ring on the torch under the retaining cap plus use dielectric grease to lube the o-ring.

[Danny78]

I have just been doing some tests on 4mm mild steel and had some success, I have cut rectangles 300mm long and 40mm wide,these have come out reasonably even with little taper. It seems when I cut at book specs it doesn't play nice, also when cutting circular shapes the taper is far worse in these areas . As it stands at the moment I am getting the best results cutting at 45amps and 2000mm or 78" a minute, does this seem to be very slow for the hypertherm 65 ? Thanks for your input guys. Danny

[acourtjester]

Have you verified the actual speed of the axis movement, just do a straight movement for 78" at 78 IPM and time it to see if it did it in a minute.
Be sure to include the F value in the G-code I don't know about FastCam but Mach keeps the last speed command used (if the last G-code had a different speed Mach would use that).
Using a hypertherm plasma it should cut book spects very closely unless there is another unseen influence at play.
Are you using true Hypertherm consumables ?

[sphurley]

Do you have 45amp consumables on it or 65amp?

[Danny78]

Acourtjester i just verified the speed and that is correct , I can set the speed at the control without having to put a f command in the gcode , spHurley I have got the standard 65amp hypertherm consumables, thanks, Danny

[djreiswig]

If you are cutting at 45 amps, you should be using the 45 amp consumables.

[Danny78]

djreiswig I have 45amp consumables arriving later today, hopefully have some better results with these. The reason I was cutting at 45amps is because at book specs with 65 amps I couldn't get a reasonable cut, cutting at the 45amps gave me a lot less taper on the cut. Thanks to all who are helping me troubleshoot, I would be stuffed without your input

[Danny78]

Ok so I have tried the hypertherm fine consumables first thing I did was set it up to the recommended specs and tried cutting. The THC started bouncing up and down like a sewing machine, I found that once the arc voltage was around 90volts it settled the THC quite a bit but not totally, book specs called for 76volts, I also found that it was depending on what shape was being cut to how it behaved, then after about 10minutes of trying different cuts the torch would fire and cut about 100mm then stop and get a 0-30 alarm this continued till I went home.

[sphurley]

I would not have started my learning curve with finecuts. Did you buy any 45amp standard nozzles?
You need to learn your system with the THC off cutting test lines and writing down your voltages based on manual height settings and speed and see what gives you the best cut.
That will be the voltage you set for the THC once you are ready.

[Danny78]

Sphurley im such a newbie at this I wasn't aware the I could get 45amp standard nozzles to fit my torch,how do I go about switching off my THC I haven't seen anything that would disable it, I have set to initial pierce height and manually done some straight line cuts and they had come out nearly perfect looking, but when I run a program that's when things go to shit. Do you think possibly the THC could be the issue? I have had the same problem with the standard consumables also, the THC bouncing up and down while cutting, it seems to run fine while cutting simple shapes but when there is something a little more intricate it starts bouncing around.

[sphurley]

You mention Chinese Plasma table and THC but no make/model number so we can look it up to help.
"most" THC's have some place to turn it off. Also there should be some adjustment you can make to stabilize it by reducing the window of voltage it is trying to adjust to. Make the window too small and it will hunt up and down trying to find the sweet spot. Maybe give it a bigger window and slow down its actions and you will have better luck.
Now corners/curves is a different story. If your controller cannot keep up with the curves (you're not driving a Corvette) it will slow down and then the voltage will change causing the THC to dive the torch.
The better system have ways around this and who knows maybe yours does.

This forum is here to help, we have all been where you are at right now, trust us

[jimcolt]

Can you post a few pics of the torch nozzle (that was used for one of the bad cuts) and shield, good closeups of the exit orifice on each. Your Powermax65 will cut best if you follow the operator manual cut charts exactly, especially the choice of consumables, pierce height, pierce delay time, cut speed, amperage and cut height and arc voltage. Be sure you adjust the arc voltage from the book setting....go higher or lower on voltage in order to maintaine the correct torch to material distance. Jim Colt Hypertherm

[Danny78]

Hi guys can somebody please tell me how I can attach photos and manuals for my machine. Thanks. Danny

[djreiswig]

Click full editor button at the bottom. Then click the attachments tab.

[Danny78]

This is my setup for cutting 4mm mild steel

[Danny78]

This is the results, as you can see the cut is good in the way of dross but bevelling is happening, I put all new consumables in just before I took these pictures, checked the torch for squareness and it was good, just after these cuts I lowered the amps to 45 and voltage up to 133v cutting speed was 2200mm and the result was better on the bevel but more dross. Just to be clear I have 65 standard consumables in the torch at the moment. I also have air pressure gauge fitted to the back of the plasma unit and have good pressure.

[sphurley]

machinecut4.jpg (97.11 KiB) Viewed 2156 times

machinecut4.jpg (97.11 KiB) Viewed 2156 times

Did you get the 45amp consumables yet? You can fine tune the 65amps little but not 20amps.
Look at the attachment and note the cone shape of the plasma arc, this is if you are running them at their designed amperage.

[sphurley]

XPTHC-4b.pdf

(1.31 MiB) Downloaded 79 times

XPTHC-4b.pdf

(1.31 MiB) Downloaded 79 times

Do you have this manual?

[Danny78]

Sphurley, can you tell me what parts I need to change for the 45amp setup is it just the nozzle or other parts aswell. And yes I do have the manual for the THC, thanks

[sphurley]

Just change the nozzle.

PM65consumables.pdf

(172.94 KiB) Downloaded 63 times

PM65consumables.pdf

(172.94 KiB) Downloaded 63 times

[googe]

Torch height or voltage has always been the reason for angling on our machine. We use 80A consumables and 130v on 3~6mm plate. . Whenever there is some angling we tap the volts up 2~3v and always fixes it.