Cut Quality Chinese machine

[RickyL]

Hello,

I'm fairly new here but have lurked for a while.

I'm in the UK and have a chinese machine. I'm unsure if to upgrade to a hypertherm, but not sure how it'll work with my THC and table software.

The machine I have is 160 amps, (apparently) However I have lots of cut quality issues.
At lower amperages and currents it cuts great with no issues. However I have a big job coming up and need to cut some 8mm 3/8ths mild steel plate. I ran a few test pieces and get very bad taper and not a great cut. Dross is ok, and some parts of the cut are fine, however when it changes direction the angle varies massively. I have tried the obvious. I.e. Torch angle etc.

I'm using 100 amp's and a cut speed of around 1500mm a min to get best results.
Air pressure is around 80psi. (air supply is super clean/dry) we have a refrigeration unit and never see any water in the traps.

These aren't the best, but are about the average.

I am using Sheetcam to program.

Here's a good side on 1 part.


Corner is horrible, not sure if this can be avoided.


Same part but the other side with really bad taper


Thanks for any help.

[acourtjester]

image are not posted yet my hypertherm manual states for 3/8" a speed about 1200 mm per, 65 amps, and a cut height of 1.5MM you may be going to fast.

[RickyL]

Thanks for the reply. I think the images should be working now?

Is that because 65 amps is the max on your machine though?

I've tried lower amp's but the time taken to pierce makes me think the nozzle will become damaged. That's why I have the power set to 100 amp's. I will try a lower amperage and slower speed though to see if the results are better.

Thanks.