Monday, November 17, 2008

Now for the Bottom Bracket to Seat tube

I fluxed all the joints that I was planning to braze at the same time, so same as before I still didn't flux far enough away from the joint to keep down the discoloration. I came up with a Jig that requires no machining and just clamps together and uses bolts for leveling. I will be able to use this jig for most of the sub assembly and rear triangle.


Below you will see I didn't do to bad with this joint almost all the way around got good silver penetration and I only overheated area that were very thin or not properly coated... not bad I would say I am getting better but I now what the next 5 joints already look like...











I definately realized why Richard Sachs puts so much flux on and coats every single part that will even get closed to heat... it aids in less clean up and keeps the metal in better condition.






Here I did some quick clean up after dinner and it looks pretty good... except the lobe of the lug between the chain stays... it got penetration but left a little gap at the tube and tip...










So I went back and reheated the tip of this lug and dumped way to much silver in it... but it still cleaned up pretty well.








Next is the head tube/ down tube...





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The lessons I am learning are amazing and really fun to work out...

The pictures below are the work I did last night, finished grinding the bottom bracket sockets.
Notched out the seat stays to fit the drop outs...
And the big big moment... doing my 1st miter on the seat tube (Tim calls this one the most forgiving miter and he is right)

I think that many of the lessons and techniques I have learned from wood working are carrying over into metal working very nicely.

bottom bracket, right side done (before finshing sanding)

bottom bracket, right side done (before finshing sanding)
the left socket is just starting to get ground, notice how thin the walls of the right socket have gotten. there is a lesson there and you will see in following pics!

grinding with a stone

grinding with a stone
it took a while with this stone but with the tight corners I had to use it because I only have one small sand paper bit left

ooh ahhh... a little sparks flyin

ooh ahhh... a little sparks flyin
That lesson I spoke of earlier is happening in this pic...

Ahhh... oh DOH!

Ahhh... oh DOH!
is that blueing? Yup that is the lesson that I learned on this socket. the grinding stone heats the metal very fast and as that wall gt thinner it started blueing. Bad, bad, bad! so I will have to sand and reshape that wall a little because I even got some chipping around the blue.

Chain stays with the drop outs notched in...

Chain stays with the drop outs notched in...
So this one was a little scary because I wasn't sure if I would get them straight and true... it ended up ok but I can do better.

Notching wasn't to hard but keeping everything even was hard

Notching wasn't to hard but keeping everything even was hard
I decided to try the bevel sides on the notch, I think I can do better so I may do the stays again?

The big moment... my first miter!

The big moment... my first miter!
I should have taken some before during and after shots but this went pretty fast actually. this is the ruff cut, I rounded it out better and got rid of that hump on the back wall

A little different angle... check out my home made tube holder... works like a charm!

A little different angle... check out my home made tube holder... works like a charm!
I am so proud of the wood block tube holder... now I just have to make the other sizes

A quick fit test...

A quick fit test...
Not bad forthe 1st miter and fit check... I only need to file the inside edges to match the bevel of the inside of the BB

Nother fit check after some finishing

Nother fit check after some finishing
still need to angle the inside of the edges then it is done and ready for finihsing before brazing. I also still need to finish the socket wall to clean up any uneven edges or tooling marks