Pictures -- made a mini forge today

On Sat, 27 Dec 2008 21:04:51 -0600, the infamous "Martin H. Eastburn" scrawled the following:

No, I'm almost positive that they're plasma. I could see the arc blem at the start of each cut in the closeups.

Martin, are you doing custom work for folks in the group here? If so, please let the rest of us know. We might have occasional work for you.

(Oh, are you the guy doing the plinking targets in armor plate?)

-- We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality. -- Albert Einstein

I had access to a PlasmaCAM (Fairly inexpensive PC-driven table arrangement) with my 1/4" plasma cutter. The thicker the metal, the more heat-effects bugger the work. There are ways to deal with that, but add to setup and constraints in the image. My buddy was always after "thicker, faster", and got a big plasma cutter, then found he couldn't get as fine a detail, and had repeatability issues with thin stuff for switchplates, etc. And with his 1" cutter, he still decided that the heaviest he ever intends to cut is 1/2 inch plate. Thicker than that, he runs into the stuff I hit at 1/8" - you lose live on the cutter tips, slag and blow-back from intersecting lines and pointy features can plug the tip, and just generally foul the thing before finishing cutting out the current setup or piece.

Sometimes the money isn't worth the wear, tear, and effort. Especially if you try something and find it isn't fun at all.

I figured at one point that it made sense to charge by the drawing. About 5 cents per inch of cut, plus 10 cents per piercing or start. At the time, about $1 per square foot of 16 ga steel, and $25/hour for my shop time. I mostly did craft stuff, and left the slag on, for 'character'. On good days when the humidity worked, when the temp was in a good range, when the power on the power lines held reasonably constant, and the steel scrubbed up nicely before I started cutting, it went well. But that cutter could get miserable, too.

Now the cutting I do is by hand (same cutter), and less decorative than making something to fit, or cutting the nut off a bolt. Or cutting 24" steel pipe length ways for cattle feeders. And it is generally a lot less frustrating. 1/4"x1 1/2" strap for a straight edge rules!

Here's trick I've seen the professional use: The art is submerged in water! The table has to be a pool ofcourse.. The heat distorsions are practically nil. Jukka

BradK wrote: (...)

(...)

Interesting!

Do you still use the PlasmaCAM?

--Winston

I have a plasmaCam table and yes it takes a learning curve. I do as I want and cut all sorts of metal. Some takes more work after cutting - some not needing it and some it doesn't matter.

I have a Hypertherm 600 and cut 1/2" armor plate that is pre-hardened. It is rated for normal hot rolled. But I know the machine and ability.

Wish I had a 1000 but didn't have 3phase at the time.

I suspect the plasma cutter you had was a limiting machine. Good for body work and such but not brackets or thick stuff.

Mart> BradK wrote:

I have a Powermax 1000 and I don't have three phase. The CE country version of the 1000 is three phase only, the US version is single or three phase and wide input range. It takes a 50A 240V 1ph feed quite happily.

I have a Max 100 and that one cuts one inch plate... Takes three phase only...

The 1000 is rated 1" cut, 1.25" sever, and will do so with either 1 or 3 ph power.

Thanks Pete - I think I knew that.

I have 3 phase 380v in the shop as well as single phase 240. Handy sometimes.

Mart> "Mart>> I have a Hypertherm 600 and cut 1/2" armor plate that is pre-hardened.