Monday, January 12, 2009

Wow this is getting fun...

Well I got a lot done this weekend, I finished the rear triangle and a new fork as well as getting started on the brake bridge (more on that tomorrow)

Above is my jig to keep the rear triangle in place while I tack it and cut and prep the seat stays.

This basic jig made it easy to lay the frame on the drawing and pull the alignment measurements up off the drawing.

getting ready to cut the seat stays






almost done with the filing.




finish filed






Here is the seat stay fitted and almost ready to braze.





Both Seat stays ready for brazing, but next is the seat stay ends at the top tube




Both Seat stays cut to length

Fitting the cap to the seat stay.


So while I was brazing the cap to the seat stay I tacked the chain stays in place... not the greatest tack but it worked.






After brazing the cap and a little triming on the grinder.



Just about to file it down.



Fitted up after filing and sanding... they aren't perfectly square but I am happy with it.







You can see in this picture the left cap is just a little bit bigger than the right... that is haunting me now.


Now I am brazing up the rear triangle after a few checks to the drawing for accuracy and to make sure I have the right BB drop.





Well after all the overly simple jigs and what not the rear triangle came out pretty straight and square, I had one slight mistake. It seems that the rear wheel is just slightly out of square so the by about a mm at the rim. So the brake bridge is going to be slightly off center but I will see what i can do.
I will have more pictures of the new fork and brake bridge tomorrow.


2 comments:

Unknown said...

Nice to see it coming along Mark. It looks warm there!
Craig

Mark said...

Thanks, I am so close to finishing I am getting a little nervous.
yeah it is pretty warm here in socal, it has been blowin 30 to 50 mph Santa Ana winds for the last 3 days which makes it about 80 degrees day and night... the only bad thing is the wind blowin into my garage and moving the flame on the torch :)

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