Tracking down cause of bad cut

[Metriccar]

I have a new plasma table setup I'm having issues with. Every single cut that I can get that cuts all the way through the metal will leave globs of metal on the bottom. I have a thread on the cut quality forum. However, I noticed that one of the lines in the cut was perfectly clean. It's an L shaped bracket and the bottom of the L was perfectly clean when the rest of the cuts had globs of molten metal on bottom. This will not come off clean witout a lot of work and it's still not coming off clean as Id like with a grinder. I don't need this kind o extra work anyways.

[larrycameron44]

Hi, you should post photos of the cut.
Plasma type and settings you are using, air supply (air dryer, filters?)
Metal Thickness
Speed in ipm
Voltage
Pierce Height and Cut Height
Amperage
Then the great people will be able to diagnose your problem easily

Larry
NZ

[jimcolt]

Ready to help, need more machine, plasma and process spec information...Dross (resolidified metal on bottom of material) can be caused by:
-Incorrect cut speeds (too slow is most common)
-Damaged or worn consumables (brand new nozzles can get damaged with improper piercing or cutting techniques)
-Incorrect air pressure, both on inlet side of the plasma as well as torch side.
-Incorrect consumables and process power for the material.
-Torch height incorrect (too high causes dross, warpage and bad cut angularity)



Jim Colt

[oliverjg@charter.net]

hi,

I am having the same problem.

I am using a hypertherm powermax 30. just completed the installation of my new PlasmaCAM system. Using amperage and cut speed recommendation in the owner's manual. (IMO pretty useless info. in the pmx 30 manual).

not sure how i am supposed to know what all those settings are supposed to be for every type of material I might want to cut?

max thickness I have tried to cut so far is 14 gauge steel. also tried same thickness aluminum and some thinner aluminum.

seems like there should be a formula or some reference tables someplace. but I haven't found them yet.

seems like there should be a baseline set of tables for some "reference" system (hypertherm pmx 45 maybe?) and then a formula to adjust the baseline tables for other machines.

[abmagrum]

there should be cut charts in youre manual . maybe cut back 20% after checking the following
air pressure do you have a pressure gauge at the back of the plasma cutter http://plasmaspider.com/viewtopic.php?f ... 641#p63641 you want 120-130 psi to start and you don't want to drop below 90 .
you want at least a 5 hp 60 compressor . with air dryer
you want youre ground clamp attached to youre metal not table.
you also want amps volts torch height set correctly
if all these are correct you should cut fine

you might want to step back take a breathe . all this stuff is over whelming at first .
try to learn a little at a time. once everything comes together it gets to be fun.

been there

[abmagrum]

hi,

I am having the same problem.

I am using a hypertherm powermax 30. just completed the installation of my new PlasmaCAM system. Using amperage and cut speed recommendation in the owner's manual. (IMO pretty useless info. in the pmx 30 manual).

not sure how i am supposed to know what all those settings are supposed to be for every type of material I might want to cut?

max thickness I have tried to cut so far is 14 gauge steel. also tried same thickness aluminum and some thinner aluminum.

seems like there should be a formula or some reference tables someplace. but I haven't found them yet.

seems like there should be a baseline set of tables for some "reference" system (hypertherm pmx 45 maybe?) and then a formula to adjust the baseline tables for other machines.

you have to know every setting for every metal type and thickness its not useless
good thing about the charts you don't have to remember. and the hypertherm charts are probably the best.

[jimcolt]

There are no mechanized cut charts in the Hypertherm Powermax30 operators manual because it is designed for hand cutting, not mechanized cutting. Fortunately...the same consumable parts that are used in the Powermax30 are also used for 30 amp cutting in the Powermax45. Here is the 30 amp cut chart that will work for mechanized cutting with your Powermax30. These specs will give you the best cuts.

Correct pierce height, cut height and cut speed are important. Too high (cut height) and you will get a wider kerf, warpage and dross. Too slow (cut speed) you will get heavy dross and warpage and a wider cut kerf.

Jim Colt Hypertherm

[oliverjg@charter.net]

i haven't seen that chart before.

the pmx 30 chart i had is same as the one here...

http://www.hypertherm.com/en/Products/H ... ax30.jsp#2

i now have material samples for copper, brass, steel, aluminum, stainless... in thickness of 26 gauge thru 1/4 inch.

going to do a bunch of test cuts until i get good results and put all the plasmacam settings in a spreadsheet.

that's my ultimate plan anyway. first i am just going to focus on getting good results with 18 ga cold rolled steel.

thanks for the info!

jim

[abmagrum]

its the powermax 45 chart using 30 amps
Jim said it is what you need.
REMEMBER if you are having a little trouble after this just cut back speed a bit