Monday 26 July 2010

Not much left to do

Two holes to be drilled and tapped M1.6 in the bottom of each conrod and then the shells have to be made. Like the small ends, the big end shells are made from Phosphor Bronze. Two flat pieces are soft soldered together, held in a four jaw chuck and drilled (under size at this stage) on the joint. Then the outside diameter is turned to size and parted off. Warm gently to melt the solder and split the shells. Fit them in the big ends and tighten with the M1.6 screws, then set up on the mill and bore the big ends to size. Job done. Then its a matter of fitting it all together and seeing if the engine runs.

To give you an idea of the size, the distance between centres is 29.0mm.


Conrods with small end bearings fitted

Sunday 18 July 2010

Nearing completion, but its a lot of tedius work

The crank shaft is almost finished, its been hard work as only small cuts at a time can be taken so as not to strain the setting. Its only held between centres in the lathe and if a tool were to pick up it would be disaster. As it is I'm very pleased with it. I need to reduce the weight a little and I've been studying some pictures of the Saito twin cylinder crank shafts and the balance weights have been shaped as a semi diamond on both sides ie where the counter balance weight would be. So I'm going to do the same.




You can see what I mean by the diamond shape...

I need to cut the same on the other side.

Monday 12 July 2010

A Jet event at Westonzoyland

This was by invitation only and some pilots from the South East area Arrived on site for the weekend to "have a go" at flying from tarmac for a change. Everyone enjoyed themselves and there were no accidents or incidents. Normal Club flying activities continued as usual and the whole event went very well.



Friday 9 July 2010

Some engineering at last

I've shelved the earlier crank shaft and decided to manufacture it a different way. This is how its done... a picture paints a thousand words, so here's a video.