16gauge Cuts

[mav68erick]

Powermax 65

Clean Air ( no water past my filters ) then have extra filter on the back of the unit just in case, and any debreis in my pipes.

Was using 45amps with shielded nozzle then decided to try my fine cuts.

Heres the issue if I use the settings for torch to height distance in the manual I get a positive bevel on all 4 sides of anything I cut, initially I thought this was from my Z not being set up right but If ran with out the torch on and when it dispalys .060 torch to work distance I stop it, and check it with a gauge block its within a couple thousandths so my distance is good. Now I turn my DtHC from my candcnc kit off because bu the time it adjust the cuts are done ( im cutting 3d puzzle butterflys I dled from here from one of the members ) it just acts screwy.

So today I did a .5 wide x 4" long rectangle with a line in the center for a line test. I went from the suggested settings

.060 cut
.150 pierce
Cant remember the delay
at 250IPM

if I lowered the height to .030 or even .020 no bevel, adjusted my speeds and got almost no dross awesome! Then changed back y cut and pierce back and still no dross, figured I was set, I also changed the acceleration rates on my table from 30 all the way to 70 to get of dross coming off of the corners, dam was this thing moving,

Redid my butterfly program with the new settings absoltley no change dross on every side everywhere, I expect some but its to much and way to big of a bevel on 16ga its atleast 10+ degrees and Ive checked rechecked my torch to table and its as square as I can get it prolly not even off a few 1/10ths of a degree if that.

Its obvious thicker stuff cuts better, and I thought it was the water splashing up, so I drained some out of the table, I dont have pics of the parts themselves but Ill get them uploaded here tonite.

Ive also read from Jims postings if theres dross speed up the IPM til you hit the dross free zone, well If I have a dross free part thats rectangular and then I switch to a program thats all curves and arcs and has dross on the entire thing do I need to speed it up more? Seems backwards to the fact I read you cut cirlces holes and radiussed corners at 80% cut speed.

I even notice my cu direction was wrong as I accidently clicked the reverse button in my sheetcam and didnt notice thought that was the ticket Same issue.

And when I get my line test pics up, when its excatly what the manual specs are and I get bevel on both sides my kerf width is correct at the top, and prolly only .010 on the bottom as you can barely slide a sheet a paper in the crack with the fine cut.

Anyways enough rambling heres a vid of what I was cutting although it doesnt show much,

http://www.youtube.com/watch?v=3630-icb ... ture=share

And after I spent about 45mins a piece deburring them as I didnt wanna waste it. so took half the day to get 2 together and tacked together.

[mav68erick]

I was thinking it was the fact the cuts are so close to each other and the sheet was geting warm, if I feedhold I can lay my hand on the sheet and its no warmer then room temp. Maybe Ill go cut some 1/8 and see what I can get for cut quality, I have read there is some bad steel but. But then again straight cuts are fine but when the part is 99% arcs and curves its poo poo. and atm Im unsure if theres speeding up or slowing down options anywhere and Ive looked.

[I Lean]

I've noticed the butterfly file doesn't cut nearly as well as some other files do. I think it's because some (many) of the parts are made from tons of little segments, rather than arcs. The machine has to treat each tiny straight line by itself, and if there's a ton of them it has a hard time going through them fast enough to keep a nice even speed.

[mav68erick]

thx I lean, I was thinking possibly the same thing but I think I found my problem.

1. Looks like I have a hand fine cut deflector, when I ordered It the website said hand or mech use on the site and it was the only one. I tried lowering the height to .015 - .020 doesnt seem to help. I think the fact its so small is an issue to. I double the scale and cut a big one still had dross but it came off easy, its just so many pieces its time consuming.

Even though I have fine cut deflector issue thats prolly whats causing my bevel as it prolly made to drag. But I still had issues with the 45amps, Oh well guess im to picky as Ive ran a laser for a couple years before = P. Its just sad when you see someone cut 1" on here and I barely see a 1-2* bevel on the side and it looks like it came off the laser.

The funny thing is all I can think of doing is these puzzles, I dont need a bracket out of thick stuff yet, at work I always thought up stuff to cut, now that this things in the garage I have cutters block. Iam going to cut some cool looking cable carrier holders to replace my rushed brackets to get the table going though maybe Ill do that tomorrow out of some 12 gauge or some ss I got from work.

[jimcolt]

A couple of thoughts, suggestions.

-The dross buildup on your butterfly cuts are due to two things, 1. Heat buildup on the materials from all of the close internal cuts. This promotes rewelding of the flowing molten metal. This is a case where you may get a better part if you raise the water to the same level...or slightly above the level of the metal. 2. The other reason for dross is that the complex shape is likely not allowing your machine to get up to the programmed speed. Think of every curve as a short straight line....and you machine is trying to stay on path....making direction changes as well as acceleration and de-acceleration changes to stay on path.

- 220948 deflector shiled is what you should be using with you FineCut parts. It is the best shield to use for mechanized cutting as it protects the nozzle from contacing the plate....which causes short nozzle life.

-For detail cutting....your machine accelerations should be at the maximum settings that will still provide a smooth cut.

- You can operate the Fine cut consumables at amperage down to 25 or 30 amps....then develop lower speed cutting (find the dross free zone) which may improve your cut quality.

Remember....you realy cannot compare your air plasma / low cost cnc machine to either a high end, High Definition cnc plasma or a laser. The high definition plasma cnc will cost over $100k, the laser will likely be over $300k. These machines use some pretty igh end technology to cut with great precision and minimal dross!


Jim Colt Hypertherm

[mav68erick]

Thx Jim, I can adjust the accerlation rates in mach3,

I assume you meant 25 and 30 amps.