Putting together a front end
I've been shotting the construction of Mark's bike and thought I would cross post some of the construction shots from my blog.
Here is Mark's front end- tacked from the jig:
http://farm7.static.flickr.com/6195/...750a383226.jpg
I tack the tubes to hold the basic shape. Note the tight miters- close coping allows for a precise fit up, and tacking the frame "locks" these positions.
http://farm7.static.flickr.com/6069/...f653306a70.jpg
From the jig the front end goes to the alignment table to check the position. I use the info I find here to plan the brazing sequence and use the heat and brass to straighten the frame.
Here is that same joint with a layer of brass stitching the tubes together.
http://farm7.static.flickr.com/6083/...f88fe331e1.jpg
The even fillet width and shape with the smooth feathered edges will make for relatively little post brazing "clean up". Here is a shot of the same joint coming around the bottom of the down tube- you can see how smooth the edges of the brass are where they flow onto the down tube and BB shell.
http://farm7.static.flickr.com/6080/...3291bc9107.jpg
A similarly smooth head tube/ down tube joint-
http://farm7.static.flickr.com/6197/...e31f2a84bd.jpg
Once the full front end was brazed I soaked it in a heated and agitated water bath to remove the brazing flux- this is that down tube joint bare from the torch.
http://farm7.static.flickr.com/6187/...df1bc750c8.jpg
To help keep the organic "flow" of the frame each joint is brazed with a fillet that not only compliments the size of the tube, but the size of the other fillets on the frame-
http://farm7.static.flickr.com/6085/...e99b9b8c40.jpg
I've started in on the rough finish work- I like to get these fairly well finished as a sub assembly- it's easier to manipulate the front end on it's own, and it allows better access to the seat/ top tube joint before seat stays are added. I'll post pictures from that process soon.
Thanks- more soon!