Cutting 1" Mild Steel

[3DSteve]

Hi all,
I am looking at buying a 4 x 8 table for cutting mild steel up to one inch. Is anybody having much luck doing this with a plasma? (one table mfg mentiond that oxy kits put out too much heat and will cause issues with the gantry/z)

Thanks
Steve

[massajamesb]

Unless you can afford a High Definition plasma cutter (starting in the 25k range) then the best option would probably be oxyfuel. I can't see the heat from the torch affecting the gantry too much, but it depends on the manufacturer, height of gantry above plate, etc.

You can cut 1" with conventional plasma, but you will get a heck of a bevel to go with it.

[Scott V]

Originally Posted by massajamesb You can cut 1" with conventional plasma, but you will get a heck of a bevel to go with it.

Interesting??

My single phase 151 cutmaster can cut at pretty much no bevel if you get the parameters set right. I was comparing it to my friends O/A cut with his track burner. The right side is the plasma cut. I will cut a bit more and show you the lack of bevel. O/A is probably the way to go overall but A generic CNC machine and a standard plasma can do a great job.

[massajamesb]

Mighty nice cut, that is.
Surprising that a conventional plasma did that, very impressive. I still (personally) would rather use oxyfuel, as there is guaranteed to be no bevel, but it looks like you have very little. Thumbs up!

[Scott V]

I happen to think O/A is the way to go myself, but I do not discount the possibility of other things working, no matter what people/books say.

Here are a couple of more . The edge going up is the A/O cut that my friend did. It was just scrap laying on the floor, so not even close to some of his other cuts. The one plasma picture show a bit of bevel at the very bottom, but it was the worse spot and minor for the most part. I am happy a POS table (was but not now) can get nice cuts. I am still working on my Y axis so I am only practicing my track cutting. Single phase and a standard air plasma cutter make you wonder just how good the big boy plasma's can do.

[massajamesb]

I saw a Hypertherm Hy Def plasma cut through 1" plate once, looked a lot like that, with a slight touch of bevel.
So you are saying your friends track burner is a POS and still cut that smooth?

[Scott V]

Originally Posted by massajamesb I saw a Hypertherm Hy Def plasma cut through 1" plate once, looked a lot like that, with a slight touch of bevel. So you are saying your friends track burner is a POS and still cut that smooth?

No my plasma machine was the POS. The edge going up in the second and third pic was just a cut made by his A/O track burner. He has some real nice cuts on some of the scrap he gave me. His nice cut pieces was used on things he builds. I just did not want you to think that was plasma cut. I could get it to look way uglier with my plasma, if I don't have the parameters just right.

[Scratch]

I have a TD 151 also, and it cut this on the first try. I'm happy enough with it that I would do it again...
I'm not real happy with the back side of the holes though...

100 amps
10 ipm

[Scott V]

Originally Posted by Scratch I have a TD 151 also, and it cut this on the first try. I'm happy enough with it that I would do it again... I'm not real happy with the back side of the holes though... 100 amps 10 ipm

Looks really good to me!!! What was your pierce height/ pierce dwell time/ cut height on the holes?? Also the type of tip/nozzle combo??

[Scratch]

Originally Posted by Scott V Looks really good to me!!! What was your pierce height/ pierce dwell time/ cut height on the holes?? Also the type of tip/nozzle combo??

It was a while ago but I think these were the settings...

Pierce height and cut height was .130
pierce dwell was 1.5 seconds

and I was using a 100 Amp tip and the standard nozzle.

I stuck a square on it and it's not quite as square as yours it looks like though...
What was your settings?

[Scott V]

Originally Posted by Scratch It was a while ago but I think these were the settings... Pierce height and cut height was .130 pierce dwell was 1.5 seconds and I was using a 100 Amp tip and the standard nozzle. I stuck a square on it and it's not quite as square as yours it looks like though... What was your settings?

Standard exposed 90/100 amp tip ( slightly used) Mine was a edge cut so I did not have a much pierce delay. (1 sec) 100 amps .200 Pierce height/ .190 cut height. 15 ipm. 70 lbs. air pressure while flowing. Different nozzles cut at at different speeds. I had good luck at 12 ipm. on another cut using another nozzle. I need to try a brand new eletrode and nozzle to see if it can improve. It's fine by me at this point.

[xjdubber]

hypertherm 1650's will cut trough 1" of metal and do a pretty nice job not on holes though, oxyfuel is the way to go on anything 1" and thicker as its cheaper just as fast and will get you nicer holes