Dross removal. Best way?

[mike 1948]

That looks great! I wondered what was up with that. It seems to cut better in one direction than the other. I"ll look into reversing it and see what happens.
I may have just got a hook up. My friend works at a place and gets a discount, but i have to cut them myself.
It will bring my cost down from $23 a sheet of hot rolled to about $8 a sheet of cold rolled.

I think it has to do with the direction that the plasma arc swirls when it comes out of the nozzle. It tends to push the molten stream to one side. I think!
$8 as sheet is a excellent price. Much cheaper than I can find.

Mike

[gamble]

What do you sell your buckey badgers for? And you just clear coat the raw material and spray paint the W?

[mike 1948]

What do you sell your buckey badgers for? And you just clear coat the raw material and spray paint the W?

I get $125 +/- depending on size. I grind with a swirly pattern, spray clear coat then spray paint the red W. There are some that I put a black backer board( made of underlayment) on behind. The black through the cut outs really makes the metal stand out. Problem is, I have to give 10% the UW for licensing fees.

Mike

[gamble]

Wow that's a lot. I made the blackhawks head and it's about 14" wide made a bit smaller or larger. Enough to get 2 on a 2x2 sheet almost touching. And nobody will even pay $40 for it.
So you use just a flap disc and do a circular motion? I have my torch on a pretty crazy angle just to get the dross off.

[Zippo]

Best not to get any to start with, I get few spots here and there. But I have set my system to my line cuts and really don't get any. What I do get is from directional cutting (with the swirl) Which come right off with a Braided wire wheel.
Here an 9 inch Tree of Life , I just cut out of 16g cold roll, Nothing nice about it it was an old rusty piece of scrap that was covering an old exhaust vent hole. Even so had approx 6 areas less than 1/8 spots of dross.
Was cut without my THC, 100 volt, 80 imp, 20 amp tip set at tad over 30 amp on an Cutmaster 52 (with machine head), 75 psi.
Took me a little under 5 minutes to use the wire wheel, Shine up with 80 grit flapper wheel, Then powder coat it , was in the oven in less than 10 minutes total. Took longer to hit cure temp than to prep.

It make all the difference in the world if you take the time to fine tune your machine, you won't be taking the time to clean up issues that could have been solved before you started the cut.

And has nothing to do with having an high dollar system, Mine is Homemade an DIY type, 5' x 6", 1 to 1 gear ratio, 320 oz motors, 120 on Z, 301D THC, Mach3, Sheetcam, Have an 4" water table sitting on the slates. Running an Cutmaster 52 plasma. here will post a pic

[davek0974]

I can't seem to cut without dross?

I have a hypertherm 30XP on a 2x2 home built table, mach3, sheetcam, candcnc thc and recently cut a tree design far less intricate than your picture and had dross 100% that took 30mins to clean up on each panel.

If I cut faster it will not cut through, this is with fine cut consumables at 30A on 2.5mm bright steel.

The cuts are very fine and detailed but the dross

[gamble]

Did the tree warp at all? Anything I cut with a lot of detail seems to warp very quickly. I thought about cutting at higher amperage and higher speed but it doesn't help.
Or do you have the water level pretty high? I checked and mine is pretty low maybe about 2" below the material.
I don't think I have a way to measure the arc voltage so I just set it for around .07 to .100 for height. No really good way tot do it for me. I just use a scrap piece of what I was cutting. WIth stainless I try to get it as close as possible, with aluminum I like to be around the .100 mark and mild steel I use .070 but I know it doesn't help me that much.

[Zippo]

Did the tree warp at all? Anything I cut with a lot of detail seems to warp very quickly. I thought about cutting at higher amperage and higher speed but it doesn't help.
Or do you have the water level pretty high? I checked and mine is pretty low maybe about 2" below the material.
I don't think I have a way to measure the arc voltage so I just set it for around .07 to .100 for height. No really good way tot do it for me. I just use a scrap piece of what I was cutting. WIth stainless I try to get it as close as possible, with aluminum I like to be around the .100 mark and mild steel I use .070 but I know it doesn't help me that much.

did not warp, water approx 1/2 inch under the steel,

Some system programs themselves will cause dross,and/or loss of detail. they are factory set to slow down on curves and such(Which makes you run hotter & slower) . May have to tweak some settings , or what percent of reduction while radius cutting , Also some plasma cutter will reduce the amps up to 40% of value if the tip touches, or arc values change while cutting.

On my system I added an THC 301D and with that I am able to control voltage even when not using the THC to control my touch height
Here an example Mach3 will not use THC if it is running less than the full ipm setting, so you see when Mach3 reads an curve coming up an slows down the cut to the percentage of reduction that is set, it also disables the THC. An factory built in setting .....so it causes larger kerfs (burn more metal away) so you can help yourself by changing your line types in your drawings (dxf), in my case i use spline instead of arcs and circles, that reduced a lot of detail loss and dross

[Metriccar]

I can make that tree out of 14 gauge using manual settings and only have dross in the highly detailed areas where the machine slows down. I use a braided wire wheel that knocks off 99% of dross, then I use a flap disc for the remainder. I do not like making that tree though. I spend no more than a few minutes knockign the dross off it. I found the braided wire wheel to actually take the dross off while the flap disc grinds it, which slows the process down.

Setup is extremely important. I find no need to deviate from manual settings. The times I did, trying to slow the machine down for stability and lowering the amperage to compensate, resulted in warping metal and dross. I then go by manual settings and reduce the acceleration and it's no longer an issue. I have found that plain and simple, with these lower end machines, you have to reduce the acceleration. I pretty much set mine at .05 now because I do a lot of detail work.

I do not use a water tray.

Here's another thing. I made some test runs trying to get everything dialed in. I intentionally ran at the wrong cut height for a while. The metal started warping. I'm assuming you have a namebrand cutter? Like a TD, Miller or Hypertherm? If so what's stopping you from going off manual settings? If you are going off manual settings and still having problems I suspect THC is the issue.

Just for comparison I have a Hypertherm Powermax65 and using 45a Fine Cut consumables I cut at 220 IPM at 45a, .06" cut height.... the voltage is calculated by my machine, I do not adjust it but it's supposed to hold .06" cut height. With these settings I get little to no warping. I cut at 100 ipm for a while and reduced amps to 35 or so, which below that it wouldn't cut all the way through. It cut but I got warping and dross.

[tnbndr]

only have dross in the highly detailed areas

That design is nothing but highly detailed areas!!

[kbenz]

If the height controls wasn't over $3000 I would have one. It's hard to justify that option when it costs more than I have into the entire setup. lol

Maybe I'll try more amperage for a faster cut speed to reduce warpage?

I ran into that also with my TM. I ended up going to CandCNC and got everything new including THC for less than the just the THC from TM.

Far superior set up too

Hypertherm is also worth every penny. I have 2

[smutboy420]

I recently found a very useful dross removal tool in in my bin of scrapes. Thats the best way I have found for quickly getting off any random bits of dross of . and all it is is a cut out from a pc I made that is 1/4th inch thick shaped like a small battle ax but about the size of a small hatchet thats not sharpened and just the 90 degree edge were it was cut from the pcs of sheet. I just slide it side ways and whack any dross off. and its got a handle on it like a hatchet so its easy to give a good whack if there is a pcs of dross thats stuck really bad. Even on pcs I have to then go and hit quick with a flap disk after it way cuts down on the amount of time needed to flap disk the pcs. also saves on wear on the disk.

Now a good tip on the costs of stuff If you have a small table and only can use small plate see if you can buy drops scrap from your steel suppler. instead of full sheets that way its a hell of a lot cheaper and also for a small table most drops are small size pcs and you will also not have to cut down a full sheet to pcs to fit your table means less time spent on top of less money spent. Then if you need to drop you price on the finished pc your not really taking as big of a hit out of pocket esp if you can make more pcs in the saved time. If you can make 2 of them in the time its taking you to make 1 and you sell them for say $50 each thats more money in your pocket per hour then what you get from 1 and if people in your area are "cheap" you might be able to be more in there range of what they are willing or able to spend on an non essential item. Tho keep in mind that no matter how good your price is every one always wants to get some thing for less and will say thats to much no matter how cheep it is. So the key is finding a good balance were its not to much and not to low either. dont undersell you self even if you give a deal to someone.

[smutboy420]

I also forgot to mention if money is tight which I can way understand. some day if you want to get a hypertherm when things start selling more or you are able to squeezed more profit thats yours to keep after selling an item. There is always the option of buying used. and even a used one at a great price is a way better option then not being able to afford one at all and thus not being able to have one.