I hate dross

[RayRay]

I use the Thermal Dynamics A80 Cutmaster. I have only been doing plasma cutting for only a couple of months and have only cut 14 gauge A1011 HR steel plate thus far, but the gross cleanup is horrible. I have to chip or grind the dross off the back after each piece is cut. I have a water table and I use the setting exactly as shown in the Thermal Dynamics manual.

I'm using a 40amp tip, kerf width set at .04, volt at 105, amp on the unit at 40, 70 psi, everything the manual says for 14 gauge with a 40amp tip. Travel speed is around 100.

I want to start experimenting on thinner AND thicker material but I am so tired of scrapping everything I cut. Nothing I make is useful, at least in my perfectionist mind.

Any help from any and all would be greatly appreciated. If anyone is near Ft. Worth wants to drop by let me know.

Thank you in advance.

RayRay

[jimcolt]

14 ga cuts 100% dross free with the Hypertherm Powermax units.....and should do the same with your A80. I am very familiar with the setup of the Hypertherm systems....and from that....it appears to me that you are cutting way too slow.....which causes low speed dross.

Here is what I would suggest:

Use 40 Amp consumables......set your power to about 35 to 40 amps. Don't worry about setting the arc voltage exactly as the T-D manual says....rather, do a test cut at the final speeds and power levels....and ajust the arc voltage control until the standoff between the torch and plate is correct. I'm guessing that the T-D torch should be running at between 1/16" and 1/8" off the plate (Hypertherm runs at 1/16" for this thickness).....speed....100 ipm is way too slow. Try 200 to 230 ipm on 14 ga. Actually.....start at about 150 doing test cuts (maybe a 3" long strip) and keep increasing speed until the dross barely disappears....this point will be the beginning of the DFZ (dross free zone).....keep going the test faster and faster....eventually dross will come back.....this is the high speed end of the DFZ. If you set your cut speed in the middle of this range....you will have the least amount of dross.

Dross is formed by :

1. Going too slow
2. Too much power
3. Damaged nozzle (tip)
4. Going too fast
5. Corner slowdown (machine has sluggish accel/decell)
6. Intricate part design. (lots of close together small features that allow heat to build in the material)
7. Torch height too high

Try some of these things out, let us know how they work......and remember, it was Hypertherm that is helping you out (if you ever buy another plasma!)

Best regards, Jim Colt

[Loyd]

That's funny...."I hate dross"..... Me too
Loyd

[RayRay]

Thank you Jim,

I appreciate the inputs and will give your suggestions a try and report back in a few days.

RayRay

[griffin]

I have a A80 as well, I am pretty well a newbie to this as well though. I can look and see what my setup is saved at for 14 ga hot roll tommorrow. I can tell you, I have been cutting quite a bit of it and have little to no dross at all. In fact, if there is any on it, all I do is drop it on the concrete from about 4 ft up and it just flies off. Sorry I don't know this stuff off the top of my head like alot of the pros on here. So far I am very pleased with my A80. I have a Hypertherm machine as well, but I use the TD A80 on my cnc machine.

[Loyd]

Griffin,
I just looked at your website. You guys do some extensive and nice work! Way to go! Ever heard of GRT racing? They are not too far from me. They do my powder coating for my reels.
Loyd

[AnotherDano]

I fought the dross far too long before I decided to work with the machine. It took a lot of trial cuts but I finally got it tuned in.

My materiel of choice is 14ga cold rolled. I was using flap disks and it left too many round-over edges. Plus, they wear down too fast and cost lottsa $. From there, the 4" knotted wire bruch did the trick but was almost as hard on the edges.

After giving up on making the machine do what I wanted it to do, I decided to work with it. Now I use a 3" straight wire brush in an angle grinder and what dross is there flies off easily. I still have buildup on sharp coners, like an elk antler tip, so I have a bit more tweaking to play with.

Jim Colt is right. 14ga should be virtually dross-free. And I'm 98% there.

Plasmacam/2 with PowderMax-30.

Dano

[Loyd]

Jim is right....it is just like machining....speeds and feeds. If I pay attention I can cut dross free most of the time.
Loyd

[Wine Country]

Jim Colt is the Guru for this website. I too had to experiment with the speed and cutting height with my machine. I use
a PowerMax 1000 with fine cut consumables. I now cut 16ga to 10ga practically dross free, and if there is dross ,all it takes is tapping the part on my steel table. I do sometimes have to be more aggressive in complex areas due to the machine slowing down. Just experiment with scrap material and soon you will find yourself cutting very clean. I was in the same boat as you were in the beginning and this website is the best for beginners to veterans.

[griffin]

Griffin,
I just looked at your website. You guys do some extensive and nice work! Way to go! Ever heard of GRT racing? They are not too far from me. They do my powder coating for my reels.
Loyd

I'm sorry, I forgot about this thread. I have never heard of GRT. What kind of cars do they build? That is my next investment, Powdercoating.
Thanks for the compliment. You are one on here that I really pay attention to. You do some really nice work. I am getting better with my machine. I cut alot of the same materials, so I got them figured out pretty good. It's when I try something new that I realize how much I need to learn yet. Thanks for all the advice and insperation you give on here. This is a really good forum for us newbies.