Trans-side case half sitting on top of the yet to be trimmed stator-side case half.
Here is the same piece viewed from the rigtht, you can see how rough the cut aluminum is.
Stator-side case half roughed in, ready to be finished off.
One of the challenges I had trimming the cases down was positioning them securely in a way that let me brace my hands, so that the hss burr wouldnt grab the aluminum and walk. I tried clamping them in a vise and using c-clamps, but the easiest way I found to hold them was to drill some holes in the plywood I was working on top of and bolt them down.
With the case halves bolted down, it was easy to get the crank case halves trimmed and file the remaining aluminum flush to the rest of the case.
I easily spent 20 hours to get the case halves looking good enough, Luckily I only made one mistake while trimming them down ( bottom pic ) with the drill press, I'll just tig that and file it back down:)
Early on in the project I was thinking of how I should go about variating the tomos engine. Should I go dual or single variated, should I use a motobecane front variator-clutch assy, or should I go with peugeot parts? I looked into maybe using a aftermarket variator, something like the doppler er3 with an aftermarket clutch pulley from doppler, or if you can afford it a mykitech clutch pulley and at the end of the day one could probably make any one of these ideas work with enough modification. After looking at all the different possibilities an idea popped into my head, why not use gy6 parts! I worked at a scooter repair shop for a couple years and the cvt side of a gy6 engine is burned into my memory from fixing drive belts on chinese crap all day long. I thought to myself a gy6 crankshaft is close in size to the trans side of the tomos crank maybe it would fit and In comparison to mopeds, scooter parts are for the most part much cheaper!
I yanked the koso variator off of my friend arons af16 swapped spree and threw it on the tomos crank, it fits!!!!! sweet!!!!
The tomos crank and the af16 both have a 14mm crank.
The 14mm dia section of the tomos crank is longer than the af16, so there is more than enough room to fit the ramp plate and boss before you hit the splined section of the crank. The only problem is that a tomos crank has a different number of splines compared to fixed sheave of the gy6 variator. one option to fix this would be to enlarge the splined center of the steel fixed sheave to 14mm, then make a 14mm id spacer to push the ramp plate, boss and fixed shaeve to the end of the 14mm dia section of the crank and weld the 1st gear clutch hub to the fixed sheave basically making the tomos clutch hub the new splines of the fixed sheave. confused? Ill post up some more pics later on and explain it better later on.