powermax65 low speed chart , standard nozzles

[btburn]

I thought I saw a low speed cut chart for the pm65 for the standard nozzles but I can't find it.
I try to keep my table under 150-200ipm to keep shaking down.
Can anyone help me out?
Thanks

[beefy]

This is actually the handicap of the Duramax torch when you have tables like yours and mine, that wonderful torch cuts too fast LOL. The following may not be something you want to do but I'll chuck it in just in case.

I personally didn't get the speed down enough using the low speed cut charts. I had the original hand torch of my PM1250 for general manual cutting use while the Duramax machine torch was always on the cnc table. All that time it had never occurred to me to go back and have a look at the cut speed of the hand torch. Turned out it was much lower, so I made an overhead swinging arm that I could quickly hang the hand torch cable on and swap out torches.

I got my speed down to a bit more than half of the Duramax torch (below table shake speed) and ended up with nice cuts using my old hand torch. IF that's an option for you, check if the 1250 hand torch would fit on the 65.

Of course the real solution is to build our tables correctly in the first place, or rebuild them when we don't do it right. Talk about live and learn.

Keith.

[jimcolt]

Cutting at higher power levels on thin materials at lower than optimal speeds causes a dramatic increase in heat input to the material being cut. This causes 1. A wider kerf, 2. More hard to remove bottom dross. 3. Additional heat input causes warpage of the material.

I fully understand that some machines simply are not stable at plasma speeds. We had this same issue about 35 years ago with large industrial plasma's that were being retrofitted in the field to photo cell and early cnc tables that were designed to work with oxy-fuel cutting....which was under 50 ipm most of the time. The fix was for the table manufacturers to build better cutting machines that were stable at higher speeds.

Not only cutting speed important, acceleration is important too. Think of cutting a small, 1/4" diameter hole in 16 gauge steel at 250 ipm. A hole is a series of straight lines and left turns. The cnc machine has to coordinate both x and y motion and keep changing direction while trying to achieve that 250 ipm speed. If the mass of the gantry and torch carriage is more than the drive motors and the mechanics (think gears meshing, metal flexing) can handle...the machine gets unstable and holes are out of round, heavy dross is formed (too slow) etc. etc.

If you want better cuts at slower speeds....it is best to use a smaller nozzle, lower power.....always. Hypertherm's Finecut consumables are designed to cut at lower speeds on 10 gauge and below. I use them daily and they work great...and there are cut speed charts (low speed) that can keep you below 150 ipm. Want to go slower? Turn the amperage down.....your Powermax65 will go to 25 amps...do some test cutting and experiment with lower speeds. The charts in the operators manual are suggestions that we know will work. If you want to experiment cut slower and at lower power levels. My best advice is to try to maintain the suggested pierce heights (this makes the consumables survive piercing), maintain the suggested cut height (this keeps the most "energy dense" portion of the plasma arc where it needs to be), and experiment with power and speed....you will likely find a sweet spot where the cut is acceptable.

We are working in our process design labs at a variety of consumable designs that may allow for lower speed cutting at lower power levels. Don't ask me when, because I cannot answer that, however we do hear some requests for lower speeds........which in our industry (high production is almost always the important factor with our industrial plasma's) is contrary to normal procedure.

Those that are looking at buying cnc machines.....sometimes it is important to pay a little more for better technology....one less battle to fight! Acceleration and speed (and height control) are the keys to good cut quality.

Jim Colt Hypertherm

I thought I saw a low speed cut chart for the pm65 for the standard nozzles but I can't find it.
I try to keep my table under 150-200ipm to keep shaking down.
Can anyone help me out?
Thanks

[btburn]

Thanks, I like using the finecut low speed chart and it cuts really well at most of those speeds but the finecut consumables seem way more finicky with the ohmic sensing and my water table. I love my Powermax 65 but it is more sensitive to water on the consumables causing faults than my Miller 875.