Hypertherm Powermax 85 Q&A

[dpac]

Hello,

I received my powermax during the week and sent Jim a few private messeges. He kindly responded and thought it might be helpful for others with similar questions to post it up on the forum.

So if it helps, here they are.


Should I leave the air pressure on the automatic setting?

I would leave the air pressure on automatic. You can experiment with raising or lowering the pressure if you feel the need, but generally that will only cause worse cut conditions or shorter consumable life.


-What is the point of different lead in types? I have been using arc for circles

I always suggest different types of lead ins based on the mechanical and acceleration capability of different cutting machines. A machine with small stepper motors will have lower acceleration as compared to a machine with inertia matched servos. A circular or radial lead in will work better with the more sluggish machine....and will show less of a ding or divot at the arc leadin/leadout point of holes. Same issue with machines with mechanical backlash. I use straight lead ins on my PlasmaCam (high acceleration), on most other entry level machines I use radial lead ins.


-What should the lead in length be? Is there a general rule

The lead in length serves a few purposes. 1. It should be long enough so that the torch height control has adequate time to index down from pierce height to cut height before reaching the cut contour. 2. It should be long enough so the plasma arc gets time to stabilize (different with different plasma's, different nozzle amperages, etc.) 3. It should start the torch a sufficient distance from the cut contour so that any slag pile (from piercing) will not cause a collision at the end of the cut with the torch (especially important on thicker materials)

-My machines fan is almost constantly running on 85amps and is very loud, is this normal?

The Powermax85 has a good sized fan, and it is loud. The fan activates long before the unit is close to its duty cycle. It will come on far sooner when cutting thicker materials, even at the same amperage as thin materials because the arc voltage is higher....heat build up with kilowatt output, which is amperage x voltage.


-Should the machine be in a well-ventilated area? It is currently sucking in some plasma dust.

While the Powermax 85 has a clean side / dirty side (fan only blows by components that cannot be shorted by metallic dust) and vertically mounted circuit boards (dust falls with gravity...less likely to settle on vertical boards), it is a good idea to keep it out of the direct path of cutting and grinding dust. I have a Hobart Mig welder that is right next to my grinding bench...the sparks from grinding often go right at the welder. I pulled its cover off and found almost a half inch of pure steel powder inside on many components...while it was still operating normally...it was probably just a matter of time before something shorted! I moved the welder and placed a sheet metal shield between it and my bench.


-I have been running off the recommended setting/speeds could I achieve better cuts with high speeds? ie less dross

The recommended speed settings are the point where low speed dross starts to develop....this speed gives the best combination of edge angularity and minimal dross. Faster speeds will minimize dross (on most materials, not all!), but will increase angularity and slower speeds will provide a squarer edge with more dross and more chance of warpage from heat.

- Is it okay to run a 45amp tip at say 50-55 amps or will this shorten the life dramatically?

Increasing the amperage to a nozzle over its rated amperage will increase the energy density of the arc...which is what high definition plasma cutting is all about. With our industrial high definition systems we use a complex 2 piece vented nozzle with two orifices and a vent between them...that allows us to increase energy density without decreasing the life of the nozzle orifice...the orifice is also liquid cooled.

The Powermax nozzle needs to be low cost, cannot be liquid cooled (again a cost and complexity issue) so we engineer it with the best balance of energy density and life. Turning up the amperage will increase the heat load on the orifice and cause faster erosion...although you likely will experience great cut quality for a while....how long, I don't know!


So thanks for your help Jim.

Much appreciated.
Dave