Monday, March 6, 2017

Three carbon booms
These were a long time getting done.  I used a bend piece of alumium as the pattern and while the moulds worked out well some how when assembled the width ended up being .42 on a mm too wide to fit the bottom bracket shell.   As I used some clear gel in the mould I could carefully sand a bit off to make it the right size.  

The procedure I used was to first brush clear coat into the mould.  Once this was hard four or five layers of carbon were laid in the mould being carefull to make sure they fit in the corners well.  This part was infused.  Once I had both sides done they were removed from the mould, trimmed to size and put back in the mould to be bonded together using a blander to push the joining material to the inside the boom.  Once out of the mould and bit of fill in the join line and then a layer of carbon it make it all neat.  

Also in the picture is the headlight assembly with a carbon and glass mounting bracket.  The bracket has a fair bit of adjustability so the light position can be fine tuned to the shell.  There is a captured nut bonded inside the front of the boom so it is possible to adjust the mounting position without having to reach in with a wrench.  


  1. Hello, there's a post in a long-dormant blog! Since it has been quite a while, how about a post to bring your readers up to date. What velomobile are you working on, with these struts?

  2. I'm curious as the Borealis still being produced?