Re: [CR]was: current steel frames . . . . now: monsieur ryffranck


Example: Framebuilders:Cecil Behringer
Date: Fri, 31 Aug 2001 19:10:12 -0700
To: rocklube@adnc.com, Chris Root <root@student.uchc.edu>
From: "Joseph Bender-Zanoni" <jfbender@umich.edu>
Subject: Re: [CR]was: current steel frames . . . . now: monsieur ryffranck
Cc: classicrendezvous@bikelist.org
In-Reply-To: <3B8FE57A.4799@adnc.com>
References: <NDBBKAHDALCIDGMNCLNEEEDNCDAA.root@student.uchc.edu>


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