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Discussion Starter #21 (Edited)
I realize that a bunch of lobster-looking pie cuts looks very "racer-ly," but to me it seems like a whole lot of work for something that's not very aesthetically appealing.

View attachment 50785
Yeah. That is overkill.

I was thinking this.
RjcwQzQ4NUE5MDQ3MEFFRjQzQzE6ODQ0Y2E2MmFhNWJmMTIzZWM3MWNiZTQ3MGU0NDZhMDY6Ojo6OjA=.jpg

The other thing is that I can fab just about any CLR to match the stock pipes while with mandrel bends I'm stuck with one or two.
 

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Discussion Starter #24
First one took a while. By the 5th one, I could probably lay it out , cut and debur in about 5 minutes.

Obviously I'm off, but a little massaging with the grinder should get me close or I could use these for welding practice, too.

20170204_162319_Burst01.jpg
 

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With TIG, what size tungsten and what sort of current are you using? 1/16" and 60 - 85 or something completely different? I am just learning to TIG weld and just starting to be able to run a bead and it's not pretty, but I do have pipes to weld soon.
 

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Thanks, I read that 1 amp per rule and for .035" steel that's not a lot of amps and even with a small diameter tungsten, I was blowing holes and leaving pigeon poop. More practice is what I need. I used 85 amps or so for teh chrome moly frame tubes and that was much easier to control, but welding round a complex joint was interesting. I need more flexible wrists too.
 

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Thanks for the tips. I did find that I need to keep those small tungstens clean and sharp. It made quite a difference. I may have to think about that swivel head too. I used oxy this evening and ran out of gas, so back to airgas on Monday for a refill. I was just there last week for a 40 pound argon bottle. I bought a 60 pound bottle prefilled from the place in your link but Airgas in Waukegan was closer. Of course they only had 40# and 80#, and 40# is enough for me.

.058 4130 was a whole lot easier to weld than the .028" tank that I started out trying to weld. I ordered a smaller O-A tip to do that and I should probably think about a copped heat sink too. I did look at welding classes, but the only one I could find was close to downtown. I expected to find evening classes at local colleges but no luck there so far.
 

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Discussion Starter #31 (Edited)
I started out oxy acetylene welding, too. Still keep it around to heat and cut sometimes.
Once u get the hang of it, hand and foot coordination, I think tig is easier. The haz(heat affected zone) is so much smaller.
Besides acetylene is f'ing expensive these days.
A copper heatsink will help alot if you try TIG again.

Good luck. I'm gonna clean up the above a little.
 

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Discussion Starter #32
Reset the saw and banged out 5 more. Better. Much easier when there is less grinding to do.

20170204_231037_Burst01.jpg

Hopefully I'll have a nice bend welded up next time. Then more cutting, but at least the saw is set. Things should move a little more quickly.
 

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Discussion Starter #33 (Edited)
a couple hours mostly spent cutting up an old MAC headers to reuse the flange right at the head. About 2 inches was recycled. :)

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Not perfect... but I'm getting a feel for how this all fits. pie cuts look all clean because they are just tacked. I might just ceramic coat the whole thing after I'm done...

That's it for the day. Time for the super bowl party.
 

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Discussion Starter #34
20170205_231634_Burst01.jpg

Left to right was my progression welding on this stuff.

Got the heat right (only 35amps) by about the 3rd segment.

Not great but I'm just getting back into the swing after a winter out of the garage.
 

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Discussion Starter #35 (Edited)
Some of the details on how to cut the tubing.

Alternating the cuts this way \ then that way / was one of the parts I had to figure out.

Here's what I did. Certainly not the only way or the best.


First draw a straight line along the tube. Fortunately, the weld line of the tubing made the perfect reference line.

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I marked the opposite side of the reference line using a cutting template I made in solidworks. Wrapped it around the pipe and there was a printed mark on the exact opposite side.

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Then I placed the tube in the cutting saw and painted white marks on the clamping surface both front and back at the same height 1/2 the diameter of the tube.

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Then I would cut the pipe using the cut line I drew with the template(alternatively I could of fabricated some sort of stop on the cast iron cutting surface). Rotate the tube 180deg redraw the line and line up the reference line with the white mark on the opposite side. Cut again. Then repeat.
 

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View attachment 51153

Left to right was my progression welding on this stuff.

Got the heat right (only 35amps) by about the 3rd segment.

Not great but I'm just getting back into the swing after a winter out of the garage.
If my tig looked like that I would attempt to make a buggy.........I need practice.

This threads great. I've always wanted a 4 into 2 for my CB.........and not the MAC style currently avaiable.

I'll be watching. I'd love to see a stainless version.
 

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Discussion Starter #37
A bit on how to assemble the pie cuts...

So when you cut straight tubing on an angle, the cut sections oval just a bit (no longer a perfect circle). Therefore, you always want to match a cut angle end with another cut angle end.
When you start the bend coming off a straight piece of tubing, you have to EITHER cut the straight tube on an angle OR add a small segment (wedge) that is cut square on one end and angle cut on the other.

You cannot (or shouldn't) butt the wedges straight onto the end of a tube cut square. They won't match perfectly.

Accordingly, the smallest angle you can make is 2 times the angle cut of your tubing. For example, in my tubing I'm making each cut 4.5 deg. the smallest angle I can make is if I butt two tubes with 4.5deg cuts on the end which equal a 9deg bend. Each wedge I put between the two straight sections add another 9deg. So my choices are 9 (no wedges), 18 (1 wedge), 27 (2 wedges), 36 (3 wedges), 45 (and so on...), 54, 63, 72, 81, 90deg.

When I set the chop saw to cut at 4.5deg, I will always get pieces that if put together result in those angles.

To change the centerline radius or the width of the bend, all I have to do is vary the length of tubing cut as calculated by the excel program I linked earlier. The angle of the cut doesn't change.


View attachment 53449
 

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Discussion Starter #40
I tried the tube bending with the rear frame hoop using sand and oxy acetylene torch. That guy is crazy skilled.

Your pie cuts link looks like Titanium. You can get some sweet colors with Ti. Even with stainless sometimes. But mild steel just turns dull.
 
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