canadian oddy wrote:
liduno wrote:
You can’t the bottom flush and do some massaging to get it round?
I've been looking at this convergent cone a bit closer.
It is round but not perfectly. Where the two ends touch and are tack welded it's round-ish but the lips are tough to get perfectly round.
I could massage this cone.
I'm having some second thoughts now and may not toss it in the garbage. Not sure yet.
I am wondering how perfect these have to be ? Maybe try it anyways ? Many pipes on machines you see are dented anyways and the machine runs fine. We are not running for the world championship here.
I'm going to move on and try to lay out and make the second cone (Divergent) .
This pipe is being made with 20 gauge sheet metal.
It's a work in progress.
CO
I wonder if its not round because they wanted more clearance for heat. Meaning after they had the main section welded up they stepped on it to make it oval then welded the rest up? 20ga should be plenty if not over kill I would have went with 22ga, it does make it harder to weld, I have seen a few drag Banshees that felt like 24ga. but they are always trying to save weight and getting dented is not usually a problem. I have seen some of the AAEN sled pipes that were 18ga not sure why, they are protected on sleds, the welds on AAEN pipes are always nasty looking so they might just use the 18ga because its easier to weld.
Unsure how not being round would effect the sound pressure waves I am not a pipe guy or that into the design aspects.
Pro tip for you as a sheet metal worker, the short side will roll tighter first, stop going end for end with the cone, adjust the roller tighter on the long end than the short end then keep feeding in the same way. Follow me? As the cone gets tighter you can clamp a needle nose vice grips on the small end too pivot off of and the large end will rotate around the pivot point. So you might make a few passes with the grip on then a few with it off keeping the gap where you will be welding more parallel. Hard to explain. I have rolled hundreds of tapers in my career, its something you will get an eye/feel for in time then can anticipate what technique is required at each stage of the forming process. It takes practice but once you see how the metal responds, it becomes instinct.
Another pro tip when welding keep moving the hose clamp closer to where you see a gap, also when welding have a filler rod in hand and on the ready you see a hole forming push the filler rod in like your tig welding. For large gaps you can put copper behind the weld to take the heat and the weld will not stick to the copper. Find some 3/4" or larger copper tube beat it flat with a hammer, back off the rollers and finish rolling it flat as you can you want it as tight to the metal as you can get it, use long C grips to reach inside to clamp if you have some. For filling that blow hole if you have no filler rod use a metal coat hanger sand the paint off before use. You could even use the strip of metal from your double cuts just flatten it out, you wont need much filer.
We made a bunch of 16" 10ga 316L stainless steel pipe and fittings once, straight pipe 4' long 45 and 90 degree elbows then welded it all together in as long of sections as possible then made the final welds in the field, We spent 3 weeks in the shop fabricating then another week in the field installing. What a pain in the ass that 10ga stainless was without a power roll, imagine how hard it was getting the crown out of the weld ends lol. We would tack weld on the inside grind the welds smooth put it back in the slip roller and roll it round as we could then beat it the rest of the way with 2lb hammers. We were tig welding the stainless.
Looking good can wait to see the finished product. Careful of the pinch points on the roller
Login 
Register
FAQ
PilotOdyssey.com Chat
PilotOdyssey.com Google Search
FL400 Parts
FL350 Parts
FL250 Parts
Admin Email
