BoostedAudi

I've tried everything I have... "Evolution" stainless blade in my Hitachi sliding compound miter saw (slowed down to about 1500rpms) -chop saw with abrasive wheel and finally settled on my 4x6 Northern tol (tiawanese like all the others) metal bandsaw. I'm trying to cut the collector parts at 10 degrees as this is for a long collector needed for my V-band Tial Turbine housing inlet.
I layout and mark the ieces absolutely precisely, I ease into the cut VERY slowly/carefully to avoid wandering... The parts just aren't fitting.

How close to the pieces need to fitin order to make acceptable welds? I have some parts that fit together perfectly, and others that are an 1.8" "off"

Next is what sandpaper works on 304 stainless? I have a 6x80, 4x36, 4x24, 3x21 and 8" disc sanders. I've learned that schedule 10 304 just takes the sand off the sanding belts, so I next tried Zirconia belts/discs. These don't last much longer than aluminum oxide belts!

If I can find sanding belts/discs that will cut the 304, I can tweak my collector parts into perfect fitment... anyone know what to use and where to get it?


Thanks

Toysrme

Fit, it's okay if there is a gap, you use the gap to get full penitration. The max I would recommend would be 3/32" just to make it easy. The max you would ever want on this ---- would be 1/8". 1/16-1/8" would be a well accepted standard gap. Ive never migged schedule-10 stainless pipe, but if I were going to Id probably run 1/16" gap. Ive welded similar thin materials, I seem to recall liking any combo of 1/16-3/32" gap size with a 1/16-3/32" landing.

Obviously the longer the collector the better. 12* is nipplreriffic. To facilitate making them easy tho most of us do them at 15* unless we have a reason not to do so.

Somebody else can help you with the sand paper issue, I just grind them. Nothing special, just palm my hitatchi 4 1/2" angle grinder in one hand and the workpiece in the other.

Eville140

Get some 1.5" pvc pipe and cut some for practice.

turbob16hatch

also if you have some gaps in the collector, tack them together in 2 peices. that way you can put them in a vise and tighten it down to elinate the small gap.


also pvc is your friend. i have cut 30-40 feet of pvc in the last 2 weeks, getting collector jigs made.

BoostedAudi

I actually made a complete PVC mockup header. the pvc went together amazingly well... then I cut equal length pieces of stainless, carefully mark the parts, clamp in the jig/vice and cut. that's where it becomes hit or miss... I'm not getting consistent results for some reason
If you're saying 1/16" gap is OK, I'm within that tolerance.
I cut this collector at 10 degrees because it is goint into a V-band turbine inlet. The collector parts come together into a slight clover shape, and the V-band flange is round of course. I'm not quite sure how to address this, but I'm leaning towards getting it as close as possible, grinding the inside as close to reound as I can get it, and make up the difference (for the ID material removed) with a reinforcement ring which will gusset the original weld I better get some pics up here , as this is looking kinda tricky, and of course VERY hard to explain without photos...

turbob16hatch

if it is just 1/16th smash that bitch in the vice and tack it. problem solved. no need for gussets or reinforcing of it.

BoostedAudi

Here are some pics of my mess. please let me know what you think. should I proceed with this, or do I need to spend another week fitting (and practicing my hideous welds)





mockup:




mockup on the engine:


I'm setting these ******* PRECISELY at 90 degrees off the first cut for the "ghost cut" stacked tolerances throw this WAY off. as you can see, the mockup collector fit pretty well, the pic showing two collector sections held together reveals that I'm not cutting at 90 even though I'm clamping it at 90... I have a kickass blade/cutting grease, and I start the cuts VERY slowly while holding a screwdriver handle on the back of the blade to minimize wandering. also, even though I'm cutting off a clamp jig and indexing every part the same, I'm getting variations...
So I'm wondering if I should start over, grind 4 of the 6 pieces I've cut into compliance, or is this close enough that I can squeeze them in a vice as you're suggesting?

thanks for the help

turbob16hatch

ok for one that is almost no gap, it is not perfect but just tweak it a little bit and your golden.

also when i cut my collectors i place them to cut so it removes almost to much material. that way when the saw come's down on the peice and it puts pressure on it. it wants to pull it down so it will kinda roll over a bit.

it then comes out right in the end.

also i check to see if my cuts are right buy placing 2 peices on my bench, and if they fit up flush to the table and each other then they will fit up good.

88dx

holy ---- u had to spend a lot of time with that PVC pipe.

Toysrme

fit is good, i still think u may wind up gaping it more than it fits together. you can cheat it with a tig and just burn out the bottom without depositing relatively jack ----. not going to happen like that on wire.