Planebuilder......all good questions!
In order to use the Powermax1250 on a machine.....with the hand torch you will have to defeat the trigger interlock safety circuit....many have done this...but warning you in advance, I cannot help you do it! If you use the machine torch...interfacing the plasma start is simple....pins 3 and 4 on the rear panel interface plug when jumpered together will fire the torch. The function of these pins is disabled when a hand torch is plugged into the unit for safety reasons.....we don't want a remotely controlled start signal firing a hand torch. Hypertherm has a nice easy to connect (no tools) torch system.......I keep the machine torch on my machine......and when I want to cut by hand I take 20 seconds to unplug the machine torch and plug in the hand torch. I know it is more costly to buy both.....but over the years you will save the money you spent in time not wasted. It is difficult to connect and disconnect the hand torch to a torch holder....and ensure it is perpendicular to the plate.
To answer question 1.......the best qut quality in terms of edge angularity and surface roughness is with using the lowest powered process listed in the charts. When you go to a higher powered process....expect dramatically higher speeds but more edge angularity and top edge rounding. I would cut 1/4" at the optimal speed setting in the Hypertherm manual.....48 inches per minute with the 40 Amp shielded consumables.....if I wanted the best quality in terms of holes, fine features and edge squareness.
Question 2.....I would suggest never using unshielded consumables. Hypertherm continues to produce them as they are used for applications such as 3D robotic cutting where the torch has to get into tight spots.....as these consumables are a bit longer and pointier as compared to shielded. Non shielded parts do not cut as well as shielded, and will provide shorter life as compared to shielded.
Question 3......kind of the same answer as above.....use the FineCut consumables for best quality and narrower kerf on thinner gauge material. Speeds will be slower....but cut quality is much nicer on 10 gauge (many use the FineCuts up to 1/4".....more dross is evident but edge quality is very nice).
A little advice on what to order for consumables:
1. Even if you are using the hand torch on a cnc machine.....use the machine torch shield......which is designed for the proper standoff when using a torch height control. The hand torch shield is designed for drag cutting.....so use that one only for hand cutting.
1.With FineCut parts....I suggest using the 220404 shield.....this shield extends a few thousandths past the nozzle and protects the nozzle in the event of contact with the plate...use it for both hand and machine cutting with FineCut parts.
So....what parts to buy? You will have to make that decision based on speed or quality. I use them all in my home shop....depending on the needs required for the job I am working on.
Best regards, Jim Colt