Bike 0001

[Luke]

Thanks Curt !

I've stopped touching the lugs until I get my tubes. I'll clean up the edges before and after the braze, as you suggest.
I want them crispy.
As far as my clamps on the jig...they are for alignment purposes only...I understand your concern.
I will make the openings 'less-than-snug' when I get the tubes...no pinching, only holding.
I hope my design works for me as I expect it too.
I will be the first to admit that I have little experience in this field...I can only adapt what I've learned in the past.
;)

[Luke]

This is the last Yamaha that I built...3 years ago,I believe.
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[Luke]

Tuesday night Crits...popped 17 mintues in...damn...and off the back, and off to bed.
No progress in the shop, but had a blast racing.
;)

[Luke]

I have some crisp new brass add-ons...
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A left and right side BB attachment fixture.

[Luke]

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Both screw directly into the BB shell, and give me a fixed 'zero' point against the plate steel.
(This is just stacked on my workbench here)
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[Luke]

Here is the fixture installed.
Now I'm ready for my tubes...and ready to start the alignment process.
After sizing and pinning, I plan to tack everything and then pull it off the jig to braze completely.
I can attach this BB fixture to my welding cart or in a vise for 360 degree access.
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<Whispers... M A C R O>

[e-RICHIE]

Hey disregard what the others say - this shit is cool atmo. It's all very intuitive (so far).

[devlin]

Yep! Macro rocks!

[Luke]

Hey disregard what the others say - this shit is cool atmo. It's all very intuitive (so far).

I appreciate that...very much RS!

[prolix21]

that BB fixture is slick

[pruckelshaus]

Is there any concern that the brass bb shell sexay could also act as a heat sink, and make it a bit more difficult to braze in the BB shell area? I'd also hate to see what happens if a little stray silver finds its way into the threads, you would have a job removing the fixture.

[Luke]

that BB fixture is slick

Thanks Pro...I've debated whether or not the outside piece is really needed.
I could easily bolt it up using only the inside piece.
It also works as a gaurd, protecting the shell and the threads...so I'll leave it attached.
It is square as hell. I'm happy.

[Luke]

Eighty-six...
That's my zero number.
Now everything will come off of that centering point.
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The headtube cone stantion...
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and a seat tube lollipop...
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That should leave me with about 11.5mm on the near side of the dropout when I lay out the CS...
figuring off of a 7mm thick dropout. Just enough room to squeeze it in.

Enjoy.

[Luke]

Is there any concern that the brass bb shell sexay could also act as a heat sink, and make it a bit more difficult to braze in the BB shell area? I'd also hate to see what happens if a little stray silver finds its way into the threads, you would have a job removing the fixture.

I thought of that as well...
It's 360 brass, and should be a bit harder than any rod.
They insert only .5 into the BB shell, originally I was thinking .75, but shortened them for that reason.
They lay short of being directly below the tubes...but that silver could chase threads. Yikes.

I will tack them and get the hell out of there. LOL
;)

[e-RICHIE]

I will tack them and get the hell out of there. LOL
;)

Don't even tack it atmo. Pin it. The structure created by the main triangle will hold the shell square. When
you remove it, the pins will keep the frame as square as the inserts would. Then check the linearity on a
surface, correct if needed, and braze once. I have never tacked (or certainly brazed) a shell in my fixture.

[Luke]

Don't even tack it atmo. Pin it. The structure created by the main triangle will hold the shell square. When
you remove it, the pins will keep the frame as square as the inserts would. Then check the linearity on a
surface, correct if needed, and braze once. I have never tacked (or certainly brazed) a shell in my fixture.

Okay...I didn't know if the pins would hold it rigid enough. Now I know.
That's how I shall proceed...
Thanks for the insight!

[datas_brother]

Tis is really cool! Keep going!

BTW I think it's funny that you ruler has instructions for converting cm to mm printed on it.

[Luke]

Practice, practice...in the form of an old Trek rigid MTB.
I cut a few tubes out before junking the rest.
I figure I will spend a few nights building a few sets of faux-lugs, then braze them when I have a pile put together.
Everything is practice to me at this point. LOL
I get to have fun with metal...and files...
and get to relax after an ackward evening at a Bday party filled with old school mates drinking away the evening.

I came home and grabbed a hacksaw.
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[Jonathan]

Pretty cool and nice work. Now make some wood tube blocks to hold those tubes and the future frame in the vise.

[Luke]

I made a few more practice lug mouths...

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