Sorry - meant 40x10 tube ...
Also: Do you think it is worth building a tilting mechanism instead of a
stiff trike rear end?
I am considering of building a python trike by myself (a special one ;-)
and I am collecting ideas.
Cheers,
Jürgen.
On 21.08.2017 09:11, Jürgen Mages wrote:
Hello Patrick,
thanks for the update and interesting failure analysis. Could you
provide a photo from the crack in the 40x20 tube together with the pivot?
Regards,
Jürgen.
On 19.08.2017 21:43, Patrick van Gompel wrote:
Today, I had to say goodbye to my Pythonjetrike. After almost six years,
thousands of kilometers and tons of trailer loads, it's life has come to
an end.
During it's years I repaired and upgraded it a few times, but lately
(due to the stiffer dyneema cord) the 8mm bolts for the rear swing arms
snapped twice. So I wanted to make a dual 8mm rod end setup to fix this
problem for the future. BUT, when turning the trike upside down, I
discoverd a big crack in the frame near the pivot point (steering). This
section has just violently been ripped apart. Never seen that before,
but a 40x10mm rectangle tube of 2mm wall thickness is ripped open around
a weld and the corners of this tube are splitting in two halves (so it's
not only a weakened weld zone).
Of course, I could fix this with rewelding the cracks and reinforce this
section, but I realised it is the overall design of the trike for it's
intended use that is lacking. And a fix will only displace problems.
As far as I can see the main problem with this design are the huge
forces that are translated through the swing arms of the tilting trike.
It might be ok if it were only a trike, but together with a big trailer,
it's simply too much. By seeing the damage it has done to my cords,
swing arms and now the frame, I estimate forces of 500-1000kg.
The front part always held well and I am considering to sell it if
there's interest. See http://cycle.free-creativity.com/ for my 2-wheeled
Python.
I have made a new design a few years ago, but never came to build it.
But it's desperately needed now. If I only had the time...
For now, I say goodbye :'-(
Patrick
============================================================
This is the Python Mailinglist
//www.freelists.org/list/python
Listmaster: Jurgen Mages jmages@xxxxxx
To unsubscribe send an empty mail to
python-request@xxxxxxxxxxxxx
with 'unsubscribe' in the subject field.
============================================================
