10 March 2012

Pushbike engine connection rod rebuild

I had a pushbike engine explosion that did some damage when the connection rod broke as a result of my oil dipper being attached with less than "specification" tension.

I consulted "the boys", who weren't mechanics, nor guys at my experience level in gizmology for their opinions on fixing the problem. I don't know why I did, because I ignored all of them. LOL high fives!! :-)

So, despite one end of the piston housing being damaged, and not having access to cheap parts, I decided to make a new connection rod myself and ignore the damaged housing.

I made a simple plan in sketch-up for the part which included all my dimensions, and selected a piece of aluminium to suit.



I actually made the part at work because all the machines there are somewhat more solid than my hobby tools at home.


The beginning of a piece of engineering takes shape.



Some additional clearance was required which I didn't foresee in my plan. This was odd because I'd actually built a 2D scale model out of paper before I started!! My paper-tolerances weren't quite up to par it seems. A millimeter of orbital movement can make a large change in lateral displacement!!



Looks pretty good.


I don't have any photos or video, but this has all been re-assembled and works fine. I'm pretty pleased. :-)