Hypertherm Fine Cut

[slvr98svt]

Hey guys I have a Hypertherm Powermax1250 G3 and seem to be having some trouble getting what I would consider acceptable cut quality on 14ga. I am using 220329 40A Fine Cut nozzle with a machine torch. I am using just a normal retaining cap, not the Ohmic one (not sure what that is needed for?) and using the 220404 shield for the "ohmic" retaining cap. I switched to the 120979 deflector as well as 220325 deflector CE that are recommended with the normal retaining cap and seem to get even worse dross and burn through.

Basically what I am asking is what is your setup for 14ga and machine settings as far as amperage and speed. I have cut a bunch using the Hypertherm specs and tweaked from there but still think it should produce better quality.

Thanks,
-Matt

[jimcolt]

You do not say what cutting machine.....or what type of torch height control system you are using. If you have a torch height control that has "Ohmic contact" plate sensing....then the ohmic cap.....which has an electrical connection for acurately sensing the surface of the plate before each cut...must be used. Without this function on your THC....there is no need for that special cap.....but you will have to pay very close attention to ensure adequate pierce height.

Here are the specs for cutting 14 gauge steel with the Fine Cut consumables. Asuming you are not damaging your nozzle by piercing too close....these will provide very nice quality.

Consumables: Shield-220404, Retaining Cap- 120928 (without ohmic) 220061(with ohmic), Nozzle-220329, Electrode-120926, Swirl Ring-120925

Amperage Setting-40 Amps, Arc Voltage-79, Pierce Height .120", Pierce delay-.6 seconds, Cut height-.080" (thickness of a nickel), cut speed 135 inches per minute.

These specs are right out of the Hypertherm Powermax1250 manual.....and I guarantee they will work. The key is to ensure your machine has good acceleration (at least 40 miligees), and has a good height control that can set proper pierce height, pierce delay (the amount of time the torch stays at pierce height, with no x or y movement, after the arc is initiated), and cut height.

-if pierce height is too close....nozzle will be damaged on first pierce.....and will cut with dross and varying bevel after this occurs.
-if cut height is too high.....poor bevel angle and dross will form.
-if speed is too low.....dross.
-if dross is present at recommended speed....increase the speed 5 ipm at atime until dross is gone.

Ensure that inlet air is at recomended pressure (70 psi is good)...adjust by turning amp control fully counter clockwise (this activates air flow)...and adjust regulator for 70 psi flowing. Ensure that there is no moisture in the air system.....most air systems require filters and air dryers durring humid weather. Moisture will cause poor cut quality, misfiring, and poor consumable parts life.

Le me know if this helps....also, let us know what you are using for a cutting machine, and the type of toirch height control system.

Jim Colt

[slvr98svt]

It is the 1st production TrackerCNC Pro 5x10 machine they released in 2009. Using their torch height control. I have been using the hypertherm book as a guide but for some reason I think the results should yield better quality! I don't know maybe I am asking to much of the machine. I will have to cut a couple things and take some pictures for you to look at.

Thanks,
-Matt

[JoeyD]

Hello, I have a Samson 5x10 with Plasmacam and with a Hypertherm 1250. I just finished cutting a bunch of parts out of 14 ga steel and I tweeked on it for awhile until I got an acceptable finish. I started with the reccomended specs from Hypertherm. This produced a good cut, but I wanted a better one. Stepped up the speed, like Jim said, until I got the desirable finish. I ended up with 140 speed and reduced the speed on 1" or smaller radius. 75 lbs of air pressure seems to have worked the best.
Hope this helps!