Otto;
The practice in aircraft is to make a joint with one piece of tubing
slipped into a slightly larger piece of tubing. The larger tube is cut
on a diagonal or "fish mouth" so that the weld will not be a simple
circumferential weld. Rosette welds are usually added on each side of
the joint for added strength.
Butt welds are not the first choice but sometimes one doesn't have a
choice. To maximize fatigue strength, make the joint at an angle, again
to avoid a straight circumferential weld joint. Fatigue is the primary
consideration.
Regards, Neil Tucson, AZ
-----Original Message-----
From: owner-land-speed@autox.team.net
[mailto:owner-land-speed@autox.team.net] On Behalf Of Glen Barrett
Sent: Wednesday, March 29, 2006 8:44 AM
To: Askotto@aol.com; drmayf@mayfco.com; joe timney; John Bjorkman
Cc: land-speed@autox.team.net
Subject: Re: Internal sleeves in butt joints
Otto
I would not run a chassis with butt welded joints, over the years I have
seen many broken and cracked welds. There is so much twisting and
flexing on
a chassis at any track surface you are asking for problems. Talk it Joe
Timney at Delaware chassis and get his in put. From the topic on your
car it
sounds very flexie. Your safety and that of others come first.
The rule book states it's up to the builder to show proof of the
design/strength and safety of the chassis.
2006 rule book page 16 pp 2.C
Glen
----- Original Message -----
From: <Askotto@aol.com>
To: <drmayf@mayfco.com>
Cc: <land-speed@autox.team.net>
Sent: Wednesday, March 29, 2006 12:55 AM
Subject: Re: Internal sleeves in butt joints
>I heard of a racer that had to install internal sleeves in two lower
frame
> tubes after the car was built. The butt joints were straight and were
> actually
> behind the rear axle and only supported the rear section of the body.
He
> looked at my car and indicated I needed to sleeve the butt joints.
>
> There is no rule in the SCTA or ECTA books regarding internal sleeves
in
> butt joints. I checked with Keith Turk and the ECTA does NOT require
> internal
> sleeves. The SCTA rules don't require internal sleeves. The
engineering
> handbook
> doesn't require internal sleeves. I guess that means internal sleeves
are
> not required under the SCTA rules, written or otherwise. Is this
correct?
>
> Otto
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