Joe,
So you mean I wasn't just blowing smoke out of my posterior? Imagine that; some of us old timers actually have learned a thing or two over the years!
Thanks for the support you guys, you really made my day. Ah, such simple pleasures!
Brian Baylis
La Mesa, Land of the fruits and nuts.
>
> I'll second this. I have designed industrial brazed joints. A gap is
> specified and maintained by the tooling. The perfect fit no more allows
> brazing material to flow than water. The ammunition container drive shaft
> for the F15E fighter features a lugged and brazed chromoly drive shaft.
> Wherever did I get that idea? The lugs incorporate the drive splines.
>
> As originally designed the F22 ammunition container incorporated a Viking
> titanium bicycle chain. No other power transmisson device could provide
> more power for less weight in the narrow space envelope. I figured when
> they got off the weight kick they could go back to a Sedis. They did one
> better and eliminated the chain entirely in the final design as it had a
> redundant function.
>
> Joe
>
> At 12:28 PM 8/31/01 -0700, Brian Baylis wrote:
> >Chris,
> >
> >Interesting story. I can think of many ways to make a "perfect" miter
> >that would be considerably easier and less time consuming than the chalk
> >and water sequence, which I've never heard of before. Also one must
> >produce the correct resulting angle as specified or the "perfect" miter
> >will become moot. God knows there are two few true hand craftsmen left
> >in this business so I'm not dissing Monsieur Ryffranck, but if a miter
> >is too perfect, as the tube expands while pre-heating the lug for
> >brazing there will not be a suffecient gap for the braze to flow through
> >and form the very important fillet on the inside of the tube joints.
> >This is especially true if one is brass brazing the frame, but is still
> >a consideration while silver brazing. I would say that the water test is
> >way too tight unless he leaves the tube short (in the case of the top
> >tube) about .005" to .008" depending on what circumstances are present.
> >The down tube and seat tube are not "captive" that way and usually can
> >expand without restriction. Sometimes getting too precise can be your
> >undoing as a framebuilder. I'm not saying that a frame is likely to fail
> >under conditions of too tight as long as there is good penitration of
> >the braze; but one couldn't classify it as a perfect junction without
> >the fillet inside the joint.
> >
> >Something to consider. Just because an operation looks time consuming
> >and fastidious doesn't neccessarily make it perfect. Just my $.02 on the
> >subject.
> >
> >Brian Baylis
> >La Mesa, CA
> >>
> >> speaking of monsieur ryffranck,
> >>
> >> i went up to canada for a long weekend this summer and was able to hang
> >> out in his shop to watch for a day and a half. he is really really fussy
> >> about his work, very concerned with delivering the highest quality miters
> >> and brazing. if anyone read the bicycle guide article some time ago, he
> >> talks about fitting up a miter, then pouring water in the joint and waiting
> >> 15 min. for it to finally leak out; he's wasn't joking, it was neat to
> watch
> >> him in action:
> >> he would miter the tube in question, say a top tube, and clamp the head
> >> tube steady in the jig, then coat the edge of the mitered top tube with
> >> chalk. he would then tap the mitered top tube against the head tube and
> see
> >> where it left chalk on the head tube. these were the high spots of the
> >> miter, so he would go back and file these areas of the top tube, re-chalk,
> >> re-tap, and so on back and forth until when the top tube was pressed
> against
> >> the heaad tube, it left one complete ring of chalk, which meant no high
> >> spots, and a perfect miter . . . .
> >>
> >> chris root
> >>
> >> apt. 207
> >> 44 brittany farms road
> >> new britain, ct 06053
> >>
> >> root@student.uchc.edu