Jon's bent is bent.

Jon Senior said:

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 [email hidden],

Jon Senior' jon_AT_restlesslemon_DOTco_DOT_uk said:

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 [email hidden] opined the following...

Quoted message said:

On 5/7/04 9:42 pm, in article [email hidden],

Jon Senior' jon_AT_restlesslemon_DOTco_DOT_uk said:

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.

Quoted message said:

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 <[email hidden]>, David Martin

Quoted message said:

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 [email hidden] opined the following...

Quoted message said:

In article <[email hidden]>, David Martin

Quoted message said:

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 <[email hidden]>

Quoted message said:

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" <[email hidden]> wrote in
message news:[email hidden]...

Quoted message said:

On Mon, 05 Jul 2004 23:32:59 +0100, Sandy Morton <[email hidden]>

Quoted message said:

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

Roger Hughes said:

On Mon, 05 Jul 2004 23:32:59 +0100, Sandy Morton <[email hidden]>

Quoted message said:

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 :-( ]

Quoted message said:

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 <[email hidden]>, Jon Senior

jon_AT_restlesslemon_DOTco_DOT_uk ('') said:

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.

--
[email hidden] (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

Jon Senior said:

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:

Look on the bright side: all the functionality of a £2,000 "proper" 'bent
for a fraction of the price :-)

--
Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

Just zis Guy, you know? [email hidden] opined the=20
following...

Quoted message said:

Look on the bright side: all the functionality of a =A32,000 "proper" 'be=

nt

Quoted message said:

for a fraction of the price :-)

I thought about making this comment myself but wasn't sure if you'd take=20
offense. Obviously not.

Jon

Simon Brooke [email hidden] opined the following...

Quoted message said:

in message <[email hidden]>, Jon Senior

jon_AT_restlesslemon_DOTco_DOT_uk ('') said:

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.

Part? Almost all of!

Quoted message said:

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).

The square fork was not an aesthetic decision, it was a practical one.
With a reduced time in which to build it and limited access to any kind
of jig it was the simplest and easiest way to do it. I've started
planning version 2 which will not only have a full triangulated rear
fork, but suspension and a larger boom and will thus eliminate the
problem.

Quoted message said:

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.

Agreed. When I built it I was aware that it would be the weakest point
on the bike but the whole frame had been deliberately over-engineered.
What I didn't take into account was the damage that I could do when
trying to tidy / replace one of my worst welds. The new reinforced joint
should (hopefully) hold until I can get the prices for the new frame.
I've just discovered that an engineering firm round the corner will weld
it for me so they may get some work to save me making the same mistakes
twice.

Jon

Jon Senior <jon_AT_restlesslemon_DOTco_DOT_uk> wrote in
news:[email hidden]:

Quoted message said:

The square fork was not an aesthetic decision, it was a practical one.

Jon, if you want to go for round tubes you might be interested in some of
the information and software available from here
<http://www.ihpva.org/people/tstrike/building/tubemit.htm>

The software allows you to print a template for cutting mitres on tubes of
various sizes, thicknesses and mitre angles.

Graeme

Finally managed to finish rebuilding the bent after work today. It has
survived its first ride home without ominous creaking noises but has
somehow developed an unusual speedo quirk. It is recording two pulses
for each pass of the magnet (I think) and adjusts my speed accordingly.
It is consistent and claimed a very ego-flattering 25mph for Leith Walk
(Ascent!) despite it being about 5mph more than I normally manage on the
fixer in sprint mode.

Ah well. At least I'm back in the realm of daft equipment problems not
broken frames.

Jon

In article <[email hidden]>, Jon Senior
<jon_AT_restlesslemon_DOTco_DOT_uk> says...

Quoted message said:

Ah well. At least I'm back in the realm of daft equipment problems not
broken frames.

Or daft _user_ problems! The thing about having a computer with two
wheel sizes is remembering to switch between them when changing bikes!

Jon

in message <[email hidden]>, Jon Senior

('jon@restlesslemon_DOT_co_DOT_uk.remove') said:

In article <[email hidden]>, Jon Senior
<jon_AT_restlesslemon_DOTco_DOT_uk> says...

Quoted message said:

Ah well. At least I'm back in the realm of daft equipment problems
not broken frames.

Or daft _user_ problems! The thing about having a computer with two
wheel sizes is remembering to switch between them when changing bikes!

<marvin>
Lusers. Don't talk to _me_ about lusers.
</marvin>

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

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