Hypertherm 65 Questions

[Metriccar]

I had a few questions regarding the Hypertherm 65

1) When and why would you use "FineCut" nozzle and shield over the 45 amp nozzle?
2) When would you want to do unshielded plasma cutting?
3) How accurate are the suggested settings for cut speed, etc. in the manual? I was watching a video and the narrator suggested he runs less voltage than recommended in the manual.

[jimcolt]

Fine cut consumables are for use on steel and stainless steel thinner than 10 gauge. In comparison to the 45 amp shielded process the Fine Cuts can cut slower and with about a .006" narrower cut kerf.....this often provides better cut quality on parts or artwork with a lot of detail. I personally only use FineCut parts on 12 gauge and thinner....as the slightly wider kerf of the 45 amp shielded parts does not affect most of the parts I cut....and the shielded parts last longer than the FineCut parts.

Unshielded consumables are older technology....they do not cut as well a the shielded consumables and do not last as long. They do have the advantage in some applications as the assembled torch front end is narrower and more visible. Generally they are used for hand held and robotc applications for cutting 3 dimensional parts where you need better torch clearance. On the newer Hypertherm torches (Powermax45, 65, 85 and 105) the shielded consumables use a patented "conical flow" design which uses the shield air flow to increase the energy density of the plasma jet......this improves edge squareness, minimizes dross and improves nozzle life as compared to unshielded processes.

The many pages of cut charts in the Hypertherm manuals were developed by cutting tons of steel over a 6 month period during torch and consumable development. Hypertherm does a more thourough job of this as compared to any other company in the plasma cutting industry. The cut specifications in the manual are usually exactly correct....however different metalurgy in plate can cause some variations. Generally the only changes that need to be made would be an occasional speed change (faster to minmize dross).

The arc voltage that is listed in the cut charts is used as feedback to the arc voltage based torch height controls found on better quality cnc machines. The important thing about torch height is the physical height listing in the cut charts...if you are using a height control with a voltage setting....increasing the voltage will raise the height of the torch, decreasing it will lower the height. The voltage suggestion in the Hypertherm manual is accurate under laboratory conditions....cutting at all of the listed specs (speed amperage) and with new consumables. Often...different height control manufacturers or different installations will not be calibrated exactly the same as the ones in the Hypertherm labs....so the voltage must be adjusted in order to maintain the physical cut height.

There are some more advanced height controls that will accurately sense the surface of the material (using ohmic sensing technology) and then as soon as the cut starts will smaple the actual arc voltage and lock on that voltage to control height for the rest of the cut. These systems auto calibrate the arc voltage/cut height ratio....so the operator does not have to occasonally adjust the arc voltage setting.

Hope I didn't confuse the matter!

Jim Colt Hypertherm

I had a few questions regarding the Hypertherm 65

1) When and why would you use "FineCut" nozzle and shield over the 45 amp nozzle?
2) When would you want to do unshielded plasma cutting?
3) How accurate are the suggested settings for cut speed, etc. in the manual? I was watching a video and the narrator suggested he runs less voltage than recommended in the manual.

[Metriccar]

No, that helps. Thanks.