Needing a little bit of help....

[Eggman]

I have a plasma cam table with Hypertherm 65 torch. current issues are cutting none square edges and out of round circles. We have checked most everything and haven't came up with any one thing that says "this is the reason". Material is 3/8" and 1/4" steel plate. When cutting both plates we are on the 65A setting running on the 3/8" all the way down to 20 ipm up to 80 ipm and just haven't been able to get a round hole. On the 1/4" sheet, 65A and 70 ipm to 170 ipm (I think this is the max setting in the book), same results as the 3/8" plate. We have even switched to completely new consumables.

Most of the time we cut 20 gauge to 14 gauge steel, aluminum and stainless. Just started to cut the thicker stuff, with less than stellar results. Take a look at the pics and let me know what you think. Pics are of the 3/8" piece.

Thanks in advance.

[SignTorch Vector Art]

The out-of-roundness looks like backlash or slippage. What kind of table is it, specifically what kind of drive (rack and pinion, belt, chain, screw, etc)?

[jimcolt]

You should be using the 45 amp shielded consumables on 1/4" for best results on holes, the 65 amp process will do a good job on 3/8". Use the settings exactly as the Hypertherm manual recommends. Of particular inportance are pierce height, pierce delay and cut height. Make sure you are using the ohmic plate sensing function (requires use of the ohmic retaining cap) to accurately set pierce and cut height. Make sure you have checked the box in the software to use the ohmic height, and to calibrate the height before next cut. The speeds listed in the Hyperthem manual are correct....ther is no nee to experiment with slower or faster!

To me it looks like the torch is too high off the plate...or that you are using a nozzle that has damage from piercing a few times too close, or with too little pierce delay. I am attaching some pics of holes cut on my PlasmaCam on 1/4".

Jim Colt

[Gamelord]

It looks like slippage to me too. Double and triple check all your gears/belts/chains etc... They may look tight and feel tight but the motor may be sliding ever so slightly in the gears causing out of roundness. Also check for any backlash in your gantry, any movement at all could cause this.

[Eggman]

Jim...them are some nice holes!! Hopefully I can get this Sampson table working that way. According to my hypertherm manual the shielded 45 amp tops out at 10 gauge. There are no more listings above it. I can not use the ohmic function cause I do not have that option. I usually use a feeler gauge get fairly close.

Sign torch and Game lord...I will be checking the belts, gears and motors shortly. Luckily, I ordered new belts when I replaced 5 of 6 bearings on the table. How much play should there be in the belts?

Will let you know what I find.
Thanks.

[Eggman]

I'm thinking this is too much play in the belt? Minimal pressure on the belt getting.me about a 1/4" of gappage. I will adjust this back to tight...are should it just get replaced?

[Eggman]

Finally getting round circles!!!! Thank you all for the help. Running 45A 30 ipm is getting it done on 1/4" with fine cut consumables.

[jimcolt]

Fine cut consumables will not produce the best combination of cut quality and consumable life on 1/4". As your operators manual suggests....these parts are designed for a maximum thickness of 10 gauge...or about 1/8". As I suggested previously....you should use the 45 amp shielded consumables (find them in the mechanized cut charts in your Powermax65 operators manual) and you will get the best results....less dross, squarer edges, long consumable life. Follow the cutting specs exactly as the Hypertherm cut charts suggests....and you will get very high quality holes with the PlasmaCam machine.

If you do not have the Ohmic function on your machine...I suggest you upgrade to that option. It is worth every penny and will provide both better cut quality and longer consumable life. I have owned PlasmaCam machines for over 12 years...the Ohmic plate sensing feature is the best thing for cut quality, consumable life as well as allowing the operator to walk away whle the machine cuts parts.

Jim Colt Hypertherm

Finally getting round circles!!!! Thank you all for the help. Running 45A 30 ipm is getting it done on 1/4" with fine cut consumables.

[Gamelord]

Finally getting round circles!!!! Thank you all for the help. Running 45A 30 ipm is getting it done on 1/4" with fine cut consumables.

What was the culprit?

[Eggman]

I found one of motors had a screw that wasn't as tight as I thought it should be, but the major influencing factor was both belts were loose. Tightened both of them up and thus came the round circles. I have since ordered some of the 45 amp nozzles for the torch and will be getting them by wednesday. I will also be looking at the ohmic tip for the plasmacam table today.