Jon's bent is bent.

Oops. For those that didn't catch it in the other thread and who are
interested in the saga of my recumbent, a new page has been added at:

www.hoovesofdestiny.co.uk

Enjoy.

Jon

Jon Senior wrote:
Oops. For those that didn't catch it in the other thread and who are
interested in the saga of my recumbent, a new page has been added at:

www.hoovesofdestiny.co.uk

Enjoy.

Jon

Makes interesting reading - don't get me started with bike building, I just
read Sheldons site about buildng a fixed. The plans I have for when I get my
employment sorted out.

You really ought to paint 'Hooves of Destiny' on the boom Jon.

On 5/7/04 9:42 pm, in article ,
"Jon Senior" jon_AT_restlesslemon_DOTco_DOT_uk wrote:

Oops. For those that didn't catch it in the other thread and who are
interested in the saga of my recumbent, a new page has been added at:

Out of interest, what is the steel you used, and could it be a heat
treatment problem (heat affected zone) from the welding potentially making
the weld material/non HAZ metal transition vulnerable to tearing.

Would pre/post welding heat treatment help? Any metallurgists here or should
I chat to my Dad (FWeldI, FIM, FIP FICorr and a few others) before I start
to play with making a similar monster.. (except my welding is really bad).

...d

David Martin opined the following...
On 5/7/04 9:42 pm, in article ,
"Jon Senior" jon_AT_restlesslemon_DOTco_DOT_uk wrote:

Oops. For those that didn't catch it in the other thread and who are
interested in the saga of my recumbent, a new page has been added at:

Out of interest, what is the steel you used, and could it be a heat
treatment problem (heat affected zone) from the welding potentially making
the weld material/non HAZ metal transition vulnerable to tearing.

The steel is standard mild steel. Quite probably. I carried out no post-
weld heat treatment, and do not have the technology to do so.

Would pre/post welding heat treatment help? Any metallurgists here or should
I chat to my Dad (FWeldI, FIM, FIP FICorr and a few others) before I start
to play with making a similar monster.. (except my welding is really bad).

I would be very interested to hear any opinions on the matter. I'm
planning a new version of the frame which will involve a move to a
lighter gauge material and would quite like to be confident in my
welding skills first. With regard to welding skills. I learnt to weld as
a part of the project and my welder is permanently stuck on its highest
power setting. You can't really be starting from a worse point!

Jon

In article , David Martin
wrote:
Would pre/post welding heat treatment help? Any metallurgists here
or should I chat to my Dad (FWeldI, FIM, FIP FICorr and a few
others) before I start to play with making a similar monster..
(except my welding is really bad).

I thought that bike frames were brazed? Uses a much lower
temperature than welding.

--
A T (Sandy) Morton
on the Bicycle Island
In the Global Village
http://www.millport.net

Sandy Morton opined the following...
In article , David Martin
wrote:
Would pre/post welding heat treatment help? Any metallurgists here
or should I chat to my Dad (FWeldI, FIM, FIP FICorr and a few
others) before I start to play with making a similar monster..
(except my welding is really bad).

I thought that bike frames were brazed? Uses a much lower
temperature than welding.

Depends. Steel can be (reasonably) easily welded using standard arc or
MIG welding. Brazing gives a greater degree of control and allows for
corrections to be made (The braze can be melted out and a tube removed
or repositioned. Depending on the alloys of steel however post-braze
heat treatment may still be necessary. I believe that they principle
feature of Reybolds 853 is that heat-treatment is unnecessary. Brazing
also requires close fitting lugs for optimum performance and certainly a
close fitting join is a minimum requirement.

Aluminium is generally TIG welded for reasons of strength. It can be
stick / MIG welded but these welds tend to be less reliable and require
greater skill. I'm not sure about brazing.

My frame is made of 2mm mild steel and can be welded quite happily
without too great a fear of problems. This is good given my obvious lack
of skill with a welder!

Jon

On Mon, 05 Jul 2004 23:32:59 +0100, Sandy Morton
wrote:

I thought that bike frames were brazed? Uses a much lower
temperature than welding.

Either, but you can only braze a frame if you can get lugs to suit the
joints you want to make, which I imagine to be less likely with an
idiosyncratic recumbent design.

Welded frames go back a fair way - a lot of 1940s/early 50s framnes
were welded because the factories that made the lugs had converted to
munitions production for the duration.

Roger

"Roger Hughes" wrote in
message ...
On Mon, 05 Jul 2004 23:32:59 +0100, Sandy Morton
wrote:

I thought that bike frames were brazed? Uses a much lower
temperature than welding.

Either, but you can only braze a frame if you can get lugs to suit the
joints you want to make, which I imagine to be less likely with an
idiosyncratic recumbent design.

Fillet brazing?

cheers,
clive

ps greenspeed certainly used to MIG weld their stuff

On Mon, 05 Jul 2004 23:55:47 +0100, Roger Hughes
wrote:

On Mon, 05 Jul 2004 23:32:59 +0100, Sandy Morton
wrote:

I thought that bike frames were brazed? Uses a much lower
temperature than welding.

Either, but you can only braze a frame if you can get lugs to suit the
joints you want to make,

Hey hang on...fillet brazing is used extensively and with a high rate
of success by recumbent builders, and particularly in the high stress
areas, like attaching a boom to an existing headset. What's critical
is the 'snugness' of the butt joint before brazing.

Here are some thoughts by Mark Stonich - a well respected American
homebuilder.

http://mnhpva.org/tech/brazing.html

and 01120015.JPG shows a simple example from another, completely
unrelated site

http://snorlax.lampi.org/images/020112/INDEX.HTM


Garryb
[has donor bikes cut, but Mapp gas standing idle...
...for months now :-( ]

which I imagine to be less likely with an
idiosyncratic recumbent design.

Welded frames go back a fair way - a lot of 1940s/early 50s framnes
were welded because the factories that made the lugs had converted to
munitions production for the duration.

Roger

in message , Jon Senior
jon_AT_restlesslemon_DOTco_DOT_uk ('') wrote:

Oops. For those that didn't catch it in the other thread and who are
interested in the saga of my recumbent, a new page has been added at:

www.hoovesofdestiny.co.uk

I expect part of your problem here is the shape of the frame. Seriously.
The right angles in the fork are points of high stress. You'd be much
stronger if instead of having parallel fork legs you had them mitred
into the main tube and diverging from it in a very narrow 'Y' shape (I
know this isn't the aesthetic you want, but think about the stresses).
You would also be better off with stock which was not square in cross
section - if it was twice as deep as it is wide you'd get better
strength here. Alternatively you could weld on a triangular web under
the groin of the fork.

Consider that the frame is essentially a beam supported at the wheel
axles and with the load on it mainly on your seat which is practically
over the point of divergence of the fork. That's where you need maximum
strength and it's where your design has maximum weakness.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; For in much wisdom is much grief; and he that increaseth
;; knowledge increaseth sorrow.." - Ecclesiastes 1:18