S202 OM605 build .
S202 OM605 build .
So I got some things done in the past couple of weekends .
The bobweights are nearly done . Got the accelerometers glued on the the balancer .
While I was on this topic I made 6 weights, just in case I get a v6 to balance .
Today I managed to drill out the prechambers . center hole is now 3mm and those to the side
are 2.5 2.65 2.5 2.65 ....
It gets tricky pretty quick . The material is pretty hard at the tips, and really easy to deform on the side where the clamping bolt contacts it .
I used carbide drill bits for PCBs, and they're pretty brittle .
You really need to align them well before drilling as the different chip load on the side cracks them .
For that I turned a 2.25 diameter which fits snugly in the prechamber holes and use that as an alignment tool in my simple jig .
Nothing fancy, just a thick plate with a reamed 16mm hole and a bolt (with a flat face or better yet a copper bolt) to fix it in .