How much amperage can you swing with consumables?

[Wagnaar Fab]

Using a powermax 65 with 45a fine cut consumables cutting 1/8" mild steel my cut speed seems to be all over the place. Using the line speed test in auto mode (not sure if i'm suppose to) none of the cuts will even go through the plate, it just scratches the surface and maybe cuts 75% of a couple runs. I also notice that once it pierces and cuts for about 1/2" the torch raises up to a cut height of what looks like 1/2-5/8". In Manual mode with the settings from the manual it does better. But still on 100ipm it will not cut 10-20% of the job all the way through. The other 80% looks ok.
How far can you run on a rated consumable? 10-20 amps either way? Or should I leave the amps alone only adjust cut speed? Seems like I'd have to run 85-90ipm.
Thanks

 

[LECS-Chad]

Line speed test shouldn't be run on AUTO only MANUAL.
Your AMPERAGE should match the NOZZLE rating.

The LINE SPEED test has 10 lines 170-80 with the outside perimeter at 100.

Make sure you put the settings from the cut chart into the AVHC. Mind the pierce delay.

Don't go over the amp rating but you can go under.

You should expect about 600 pierces out of an electrode and you'll replace the nozzle twice in that time. This of course is dependent on settings and water level.

 

[Wagnaar Fab]

When do you use AUTO mode? I've ran a couple jobs where it get about 80-90% of the way through and the torch hits the material because its not 100% flat. I'm running in manual mode with a .06 cut height. I tried to run the job in auto and torch picked up about an inch again... voltage set at 78 cutting 16g. Also I dont see the sample voltage in my VMD? Are there multiple VMD versions/packages? Or is it the "current" voltage meter now?
Thanks

 

[LECS-Chad]

The latest version of the VMD has SAMPLE VOLTAGE. What sample voltage does is the system monitors and enters the voltage for you. So an AUTO AUTO.
You would want to use AUTO throughout the majority of the materials up to about .5" as usually that material stays pretty flat.
Auto is a comparison game. THe voltage read in vs. the voltage that is SET. Usually the best way to get the proper voltage is after you run a line speed test and determine the proper speed for that thickness and amperage is to geneerate a small file that has some inside feature. Like a 4" square with a couple of holes. Run that at the speed you get the best cut on the line speed test and watch the CURRENT VOLTAGE. Then take that average voltage and add 2. Enter that into your SET VOLTAGE. Now for that speed, thickness of material that will be the voltage every time. Kick into AUTO and the head will profile the material based on the comparison between the current and set voltage.

 

[jimcolt]

For the Hypertherm systems the amperage rating is listed for each nozzle. Finecuts can run from 10 amps to 45 amps, the 45 amp shielded consumables work best from 30 to 45 amps, 65 amp nozzles work best at 65 amps. There are many pages of mechanized cut charts in the Hypertherm operators manuals....I suggest using those specs! Exceeding the current rating for any plasma cutting nozzle will cause the nozzle to wear rapidly, consequently, operating at lower amperage reduce the energy density of the plasma arc and will cause dross , angularity, and generally ugly cuts.

One tip for Finecut consumables....which are designed for cutting below 10 gauge (thin materials) is on 14, 12 and 10 gauge run slightly higher than the book spec of .060" for cut height. .075" to .080" works better on the thicker materials......keep everything else at book specs (cut speed, pierce height, amperage).

On 10 gauge and thinner running Finecut consumables and with the height control working properly....I generally get 1000 to 1500 starts from a nozzle and twice that from an electrode. Rapid nozzle wear is caused by 1. piercing too close, 2. incorrect pierce delay time.

Jim Colt Hypertherm