low speed dross

[landmark]

I'm having trouble finding the dross free zone, with a powermax 600 and pac 123 torch. Heres my specs
1/4" mild steel, .068" cut heigth, .14" peirce, 75psi, 25' torch, 40 amps. No THC

I did test lines at 33 imp, 35 ipm, 38 ipm, 40 ipm, and 45 ipm. It ssemed like the 45 was too fast as the arc was coming out the bottom at an angle laggin behind the cut. But they all seemed to have the same amount of dross on the bottom. Pretty much all cuts I've made so far have dross no matter what speed I ran at. Im new to this so I don't know if the dross I'm getting is unusual but up to now I've just taken it off with a pneumatic scaler easlily.

I have one low cost filter on my air
http://www.harborfreight.com/industr...nit-98904.html
plus the filter in the unit, so I thought that would be enough. I've run the air through paper towels and didn't see or feel any wetness.

Any suggestions?

[jimcolt]

There are a couple of components in steel that affect dross from plasma cutting....silicon and carbon content. On most grades of steel these components are allowed to vary in a rather wide range. If either or both of these are on the high side...the dross free zone gets very narrow or non existent.

That being said, the design of the torch you are using affects the speed range of the dross free zone as well. Torches with better designs will have a wider dross free zone on the same material that a different style torch produces a narrow or non-existent dross free zone. I know that Hypertherm process engineering teams now have strict specifications when developing new torch and consumable designes to ensure the DFZ on most materials is as wide as possible.

The PAC123 torch is of a design that is a couple of generations old. It is possible that you have some material that simply will not cut dross free with that torch....but may cut perfectly dross free with the replacement torch upgrade (the RT60 torch) that was designed for the Powermax600. The RT60 torch is the same torch that is used on the Powermax1000, it has a technology called "coaxial assist" that increases arc velocity as well as energy density. The very latest torch from Hypertherm is the one used on the Powermax45, it has another innovation called "conical flow" that takes the RT60 torch technology even further.

Some manufacturers stick with the same torch design for many years, as it saves R&D engineering costs. Hypertherm is committed to continuously improving the process, so it is typical for a new torch to be developed every time a new system is released. This upsets some owners, as overnight their systems can be considered old technology, but it is done in the name of progress.

Heres an old trick if you cannot get rid of dross: Spray the bottom of the plate you are having issues cutting with a mig welding anti spatter spray. Usually this will eliminate the dross if you have your speed and height dialed in fairly close.

Jim Colt

[landmark]

Thanks Jim

I was wondering if it had to do with the older torch design. That will let me stress less and it's always nice when you can blaime it on something other than the operator. Well it's always been the plan to upgrade to the powermax 45 when I can so It'll just be sooner than later now.

[jimcolt]

Or upgrade to the RT60 torch....big performance difference that breath's new life into a 600!

Jim

[landmark]

IF the rt60 machine torch worked on the powermax 45, I would upgrade the torch then get the new power supply later but I think I'll just put up with the dross till I can afford the 45

[jimcolt]

The RT60 torch is the upgrade for older plasma systems such as the Powermax600, Powermax800 and Powermax900. You would not want to put it on a Powermax45, which has newer technology and better performance as compared to the RT60.

Jim

[julio_gyn]

I cut a lot of 6mm (1/2"), I start the cutting and increase the feed until the plasma beam run in an angle behind the path, and then reduce enough to get rid of the angle, I see much more smoke at that point.. It works for me.

[tulsaturbo]

Originally Posted by landmark I have one low cost filter on my air http://www.harborfreight.com/industr...nit-98904.html plus the filter in the unit, so I thought that would be enough. I've run the air through paper towels and didn't see or feel any wetness.

Here is my air setup for the powermax45. Works really well for me.

http://www.harborfreight.com/inline-...ter-94733.html
http://www.harborfreight.com/desicca...yer-97686.html
http://www.harborfreight.com/industr...nit-98904.html

[landmark]

nice looking set up. I didn't know harbor freight had those yellow air dryers.

How often do you need to replace the Desiccant pellets?

[tulsaturbo]

Originally Posted by landmark How often do you need to replace the Desiccant pellets?

The dessicant pellets are not replaced.

The dessicant pellets change color when they become saturated with moisture. The small dryer has a window to see the state of the dessicant.

When the time comes, you remove the dessicant pellets from both the large yellow dryer and the small dryer and pop them into the oven at about 400 degrees, if memory serves me right, until they return to their original blue color.

The instructions that come with the dryer explains the process. Its been 6 months now and I use my plasma cutter quite a bit and the pellets are still blue with no moisture indication or issues.