Wednesday, August 10, 2005

May I brag for just a moment?

I got an e-mail tonight from Richard Sachs. All it said was "nice graphics" with a link to my page of decals. Well doesn't that just swell my head up! Not that my metal-work is up to compliments yet, but it certainly was a nice comment from someone who is respected by framebuilders around the world. Cool.

Well, enough of that - I've been busy tonight. As you will see below, there are finally some pictures of this frame. My wife lent me her camera which does a good job, but for which I'm still learning how to control the flash and exposure levels.

I have some top-eyes for my seatstays, but I really wanted to try mitering the stay-end and brazing on a piece of tube to make a scallop. The first question was how to do this. The logical approach would be to form the end on the stay, then fit the stay in place - shortening from the bottom as necessary. However, I wasn't sure how to hold the completed stay on the seat cluster for brazing. And, it seemed like a pinned joint would be nice, to add some mechanical bond to braze.

So, I opted to work backwards. After fitting the stay to the drop-out, the upper end was rough mitered with a hacksaw (I sprung for a Lenox at the beginning of my building - what an improvement over my old generic steel adjustable hack saw - recommended). My 10" round file made a nice little bed in the seat-cluster for the stay to sit in. Then a 12" half-round bastard hogged out material until switching over to an 8" bastard which seemed to make the perfect shape for the section of 1" tubing I was using for the cap.

The tubing was split in half with a hacksaw, then cut off of the donor tube creating two half-round pieces. Once the stay was filed to shape and the cap seemed to have a tight fit, I trimmed the cap down (with aviation snips) to something closer to the shape of the end of the stay.

After some prophylactic cleaning, the stay was pinned to the seat-cluster and brazed into place. A little more cleanup, and then the stay-end was liberally fluxed. A loop of silver was set into the stay, held by the flux. The cap was pinned to the stay and cluster and fluxed up. Then, I turned the frame in the jig so that the cap faced the floor - and heated it up creating a Schmidt-style internal fillet. A light touch of silver went around the outside and touched up the stay to cluster junction - then I let things cool.

At this point everything looked fine, except that the excess cap needed to be trimmed. Generally, I'd use a file for this as the rotary tool can be a little tricky to handle. However, there was quite a bit of metal still to cut back, so I tried the rotary tool and got great results. I actually worked in closer to the tubes than I planned - there has been no hand filing yet in the pictures.

One thing that I learned is that the final cap will be blunter than the miter below it. The thickness of the tubing used for the cap shows itself more on the outside or downward edge. So while the miter looked like a very tapered bit, the final product is a little blunter than I'd have liked. Still, I'm very pleased with my effort. Now to make the left side stay match the right.

My next steps are to recheck the rear-end alignment, and correct if necessary. Adjust the angle of the left seat stay as necessary and recheck the rear-end alignment. Finish off the left side seat stay like the right. Check alignment. Fit and mount the brake bridge. Check Alignment. Fit the chainstay bridge and check alignment. Then its time to fit the left side downtube cable stop, the pump peg, and sand/file everything until its ready to deliver to Troy for paint.

The BB shell doesn't have a built-in chainstay bridge. None the less, the chainstays are round-oval-round without indents. They seem plenty stiff as is. I tried to do a cold set adjustment and just couldn't get the leverage to change anything. But I want a fender mounting point so I'll put the bridge on anyway.

That's it for tonight. See ya next time.

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