Plasma cutting cut quaility

[vmipacman]

Does a water table on a cnc plasma cutter have any affect on cut quaility for 1/2 or thicker material?

 

[Kustomizer]

I cant imagine how, the water just captures slag and some smoke

 

[Doug]

Does a water table on a cnc plasma cutter have any affect on cut quaility for 1/2 or thicker material?

I use a water table all the time.
I have found keeping the water up to within 1/2" under the plate captures most all the smoke & steam, lower is not better. Lower water does not quench the steam and fire as well.

It also keeps the plate cool to keep it from moving.

I have seen large industrial tables (400 amp plasma) run the water up over the top of the plate.

 

[Oldwrench]

I've had parts plasma cut, laser cut, and waterjet cut. If there's a common characteristic, it's that every such supplier whacks out the job at as high a speed as possible and will expect you to live with the results. Sent out ten RFQs for a waterjet part two weeks ago, and all but two quoted $300 extra for a sample, and all but two quoted a completely unacceptable edge taper tolerance. If it were me and I knew my shop could do it right, I'd try like hell to get my sample in the hands of the customer.

 

[Garwood]

I can't count on both hands the number of times I've refused laser cut parts. Apparently most people don't do that because I have quite the reputation at the laser cutters I use most often for cutting the stretch wrap off and inspecting the parts before accepting them.

I remember one part out of 1/2" HRPO had two .33" holes. I planned to drill the holes, but the production manager said no problem, they could laser a nice .33 hole through 1/2" so I let them do it. They redid those parts 3 times until I told them to just leave the holes out like I originally planned and I'll drill them. This was like 500 parts each batch. They wasted lots of 1/2" HRPO by making such a stupid claim.

 

[Oldwrench]

...This was like 500 parts each batch. They wasted lots of 1/2" HRPO by making such a stupid claim.

I just rejected 250 laser pieces for such a poor cut quality that it rendered the part unusable. The guy blamed it on the material (3/16 4130). Said just scrap it, which we did, but would not requote the job. Trying waterjet this time around.

 

[Garwood]

I just rejected 250 laser pieces for such a poor cut quality that it rendered the part unusable. The guy blamed it on the material (3/16 4130). Said just scrap it, which we did, but would not requote the job. Trying waterjet this time around.

Question- What material quality do you need the 4130 for?

I used to make parts from 11 gauge 4130N. Ran into issues with laser cutting it. I milled the parts for awhile then stopped making them as it was too much hassle. Now I am restarting those products, but using 3/16" A514 and Blanchard grinding to thickness.

A514 is very common. Laser shops know how to cut it. A514 properties are very comparable to 4130. A514 is almost the same material as 8620. You can gas nitride A514, you can form it, you can weld it. It's no wonder it's so much more common than 4130 today.

 

[Oldwrench]

Needed to through-harden the parts, so need .30 carbon at a minimum. They are hook-type spanner wrenches that people (Bubbas) will use a cheater pipe on. I specify either 4130 or 4140. But waterjet isn't going to care about the metal purity.

 

[Doug]

Где админ?
Это очень важно.
Спасибо.

wHAT IS THIS SPAMMERS PROBLEM ?

 

[Oldwrench]

wHAT IS THIS SPAMMERS PROBLEM ?

What, you never watched Svetlana on TV?

 

[Mud]

When I was O/A cutting car parts from 4130 sheet I'd run into inclusions that stopped the cut completely, and have to restart the cut 1/2" away, ths supplier said "yes you'll have this with 4130". I never had that with mild steel. Is the complete edge bad quality or just portions of it?

 

[Mud]

wHAT IS THIS SPAMMERS PROBLEM ?

She doesn't seem to like being ignored.

 

[Oldwrench]

When I was O/A cutting car parts from 4130 sheet I'd run into inclusions that stopped the cut completely, and have to restart the cut 1/2" away, ths supplier said "yes you'll have this with 4130". I never had that with mild steel. Is the complete edge bad quality or just portions of it?

This guy claimed it was the material's fault too, but US-sourced 4130 of either MIL-T-6736 or commercial grade never had inclusions or any other metal-purity issues. I think it's coming from you-know-where.

 

[Mud]

This guy claimed it was the material's fault too, but US-sourced 4130 of either MIL-T-6736 or commercial grade never had inclusions or any other metal-purity issues. I think it's coming from you-know-where.

This was 1980s material from Dillsburg. Inclusion is probably the wrong word, was described as a non-homogenous alloy location. More carbon or chrome or something right there.

 

[Oldwrench]

Wow. Charley Vogelsong. A name from the past...
One sure thing, that didn't come from China. Maybe Korean war surplus, made during Youngstown Sheet and Tube's labor dispute?

 

[Herding Cats]

wHAT IS THIS SPAMMERS PROBLEM ?

I've ban the f*cker about 10 times now. New name a few times a day

I've started banning the IP addresses and emails

 

[vmipacman]

I’m looking at replacing our older 40a cutter on the Lockformer table we use mostly for thin ductwork sheetmetal with a new 100 amp plasma cutter for thicker stuff up to 3/4 but mostly 1/2”. It has a down draft table.

Im surprised that the torches and consumables you see on air plasma cutters aren’t more sophisticated. Hi def cutters using other gasses have a lot of technology in the tips compared to shop air cutters. Seems like there would be gains that could be made there.
I wonder what the difference is with a hi-def power supply and a shop are power supply. It would be cool to hack a nice hypertherm hi-def torch (maybe even with gasses) setup to a cheaper power supply.

 

[Doug]

I’m looking at replacing our older 40a cutter on the Lockformer table we use mostly for thin ductwork sheetmetal with a new 100 amp plasma cutter for thicker stuff up to 3/4 but mostly 1/2”. It has a down draft table.

Im surprised that the torches and consumables you see on air plasma cutters aren’t more sophisticated. Hi def cutters using other gasses have a lot of technology in the tips compared to shop air cutters. Seems like there would be gains that could be made there.
I wonder what the difference is with a hi-def power supply and a shop are power supply. It would be cool to hack a nice hypertherm hi-def torch (maybe even with gasses) setup to a cheaper power supply.

I think your accuracy is limited by the lockformer table.

 

[Kustomizer]

We had a supplier for 8 years or more we had waterjet glass parts, we would throw away 2-5% for chips, scratches etc. One day we got a batch of 500 pcs and there were only a few acceptable parts in the bunch, we bounced them and the next 2 replacement batches, Finally Wonder Woman went to their shop and they would let her look at them as they made them, she stayed several hours then after she left they went back to making junk. We now have a small waterjet, we cut about a dozen at a time, clean and check them then run another dozen, sure saves a lot of headaches

 

[Oldwrench]

The drive to bring work in-house sells a lot of machines...