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Posted: Sat Dec 16, 2006 3:21 pm
by CS
HayMaker, it appears you welded that with some 7018, possibly a little on the cold side? 120 or something. I’m stating of the stereotypical signs of running the rod cold, with the smooth surface finish, and the high cross section. Not that its a bad thing... I might have ran it with some small diameter fast burning rod at a high temperature to get the penetration you want, then came back with the cold 7018 pass to 'cover'. I’ve heard it called 'dressing', although I'm not sure if that’s the correct term. None the less, some nice stick welding.

BLB, can't you drag over the bull nose live center on the tail stock to keep that from happening? I know on the 2" female adapters I lathe, on the NPT side they always will do a low pitched ear ringing tone. I’ve tried different tooling, and feed rates. Still get the problem.

Posted: Sat Dec 16, 2006 6:55 pm
by The Haymaker
Well, it aint pretty, but more pics of the steel air cannon are at http://www.xr650r.us/cannon/closeups .

Tanks are 4"x4' 1/8" aluminized EMT. Crossovers are 2"x 3/16" rigid conduit. The nipple and ugly cap are temporary so I could find leaks. I was quite surprised, there were only three!

The valve will be (if all works well) made from another piece of the 4" and be of a piston type. Outlet will be from the top, and breech loading for my caulking tubes.

Heavy? Yeah, but when your running a wheel bearing for a gimble and it's mounted on a sunk 4'x4', does weight matter? It won't explode or crack, and if anyone wants to steal it, they've got their work cut out for them!

E

Posted: Sun Dec 17, 2006 5:58 pm
by The Haymaker
More pics are now in the same folder mentioned above. The valve body.

Damn my brain hurts! Electrical tubing and stick welders weren't meant for building pneumatics!

E

Posted: Sun Dec 17, 2006 6:08 pm
by The Haymaker
I'll take that into consideration the next time I go out. I'm using 80AC's, as they make a nice finish and the slag just falls off when the weld cools. It deals well with coatings and a little grime. Some of the shine may be from use of the wirewheel, but I do know I'm missing the fine "waves" I should be seeing.

I may be using to low a heat, I'm running 85 amps max with 1/8" rod. If I increase the heat, I get a major splatter and vaporization, which I figured was too much heat. I was also running a lower heat because my biggest hole saw was a bit small, meaning that when I welded in the 1/8" end caps they were set inside of the tube, instead of setting on the ends as they should have been. There was even a gap, meaning I had to build the surfaces together before completing the weld.

Thanks for the help! Being schooled at the Home Redneck VocTech, I can take all I can get!