Powermax 45 - 20mm plate

[SeanP]

No bother!
My first shot at 20mm, cut great especially being rusty stuff.
Went for 180mm/min, 1.5mm kerf, edge start at the drilled hole, dimensions were damn good, edges not to bad as well.
That was easy enough starting from the hole, edge starting to cut holes holes will be more tricky I guess.
1'' next

[gamble]

Wow that looks good. I can't cut anything over 1/2" with my PM45. Even 1/2" is a struggle with anything less than new consumables

[jimcolt]

Gamble.....yes you can. Just follow the proper techniques for starting, cut speed and cut height. All Powermax45's have the same ability!

Jim Colt Hypertherm

[gamble]

I tried doing some 1/2" with a longer pierce and it will work but then the torch hits all the slag that built up on the top of the plate

[SeanP]

That can be a problem on some plate, I try to flick it away sometime just as it's pierced, a quick smear of tip dip on the pierce area works well too, last week I also put a thin coat of duck oil on that seemed to help as well.
Also raising the pierce height to 4mm doesn't seem to go amiss as well for 12mm plate.

[Brand X]

It's never a good idea to cut very much of it. Machine was never designed for it.. Sometimes it's really hard to see just how good a cut is without looking at the whole piece. Meaning where is goes into sharp corners, and all the curves from every side.. That said, lower amp cutting on thicker materiel is a good way to get a quality cut.. Be it with a Hypertherm 45 or Cutmaster 52 type of machine.. I would not push a smaller machine to the 1 inch range for more then a few inches.. Just too hard on it..

Gamble, the .060 inch cutting height can be a PITA sometimes..

[SeanP]

1'' is listed in the cut charts though using edge start, would it really be using more amps at 1'' than 1/2''?
I thought it was the same just different cut speed, won't be doing much at that thickness in reality though.

[Brand X]

Arc voltage will be much higher.. look at your THC, and find out.. Too me, it's like spray-arc welding with a hobby 200 mig welder. Yes it will do it, but the machine will run much hotter then a 300 amp machine welding the same thing. One is not breaking a sweat, and the other is really blowing some hot air out the cooling fins.. There is no free lunch..pay on one end or the other. (IMO)

[jimcolt]

Brand x is right.....when you are maxed out on amperage (Powermax45) at 45 amps....you cut 1/2" at 45 amps, 132 volts. To cut 1" it takes 146 volts at 45 amps. The voltage is totally controlled by the length of the arc, which obviously is longer when cutting 1" as compared to 1/2".

The power supply works harder to maintain 45 amps when a higher arc voltage is required....so it gets hotter when cutting thicker....even at the same amperage. Because it gets hotter....the duty cycle is shorter than advertised when cutting thicker than the advertised production thickness.

Jim Colt Hypertherm

[SeanP]

Useful info there thanks Jim and BrandX.
When you reach the limit of the duty cycle does the pmax 45 just cut out? Always wondered, I seem to run for hours on end with little rest up to 12mm.
Yesterday I cut 5 sheets of 10mm at an hour a piece, nearly none stop, am I pushing to it too hard?

[Brand X]

If it's not overheating,and snapping off, seems like you are good to go.. I would mostly just worry about pushing the thick stuff, and not your normal things you cut.. If you are having issues the machine will tell you.. I personally would not worry one second about pushing a Powermax pretty hard in your general cutting ranges. I could get by just fine with a 45,just like my cutmaster 52,(A-40 specs) It is nice having the 65 around for the much better duty-cycle. I generally only cut brackets for projects I am doing around here for myself, so the smaller machine gets most of the use..Today I think I will use the 65, because I can.. not that I need too..

[SeanP]

Thanks BrandX that's sounds ok then, I guess the internal fan must do a decent job, plus we don't get any heatwaves over here!

[SeanP]

That can be a problem on some plate, I try to flick it away sometime just as it's pierced, a quick smear of tip dip on the pierce area works well too, last week I also put a thin coat of duck oil on that seemed to help as well.
Also raising the pierce height to 4mm doesn't seem to go amiss as well for 12mm plate.

Even better result today, a quick dab with a brush using tipdip onto the shield just before it lowers down to the pierce works wonders, the hot shield and air blows tipdip onto the pierce area, it also keeps the shield super clean and really helps getting that slag pile to blast away, did a full sheet of 10mm today without checking shield/consumables once, without it you constantly have keep an eye the shield base for buildup.

This was as I finished just a quick wipe with a cloth, cutting holes in 12mm will be the real test, but it looks good to me.
I tried it on some 8mm dia holes in 8mm plate as well, again it really helped.

That little black mark is a ding.

I was really squeezing the parts in here so only had a 4mm tangent leadin and 2mm out, even at that you would have struggled to tell which corner had the leadin.

[steel 35]

Sean would you please show your path rule for cutting the corner, I need a GOOD reference

[SeanP]

I just have dthc turning off 10mm before & after the corner just in case, no slowdown though.
We should start a separate post to share different rules settings, I think it would be interesting to see different ideas.

[gamble]

what percentage of overcut or overburn do you need for that thick of plate?

[steel 35]

Thanks Sean!

[SeanP]

what percentage of overcut or overburn do you need for that thick of plate?

To be honest I haven't had much luck with the overburn, I find it still leaves that tag at the end, using a slowdown on that area seems to catch it well on anything over 10mm.