Gearbox & Alignment issues

[PeterWright]

1.5 mm is more than enough to make the engine jump all over the place..

Agreed. You should align to less than ten thou (0.010") which is 0.25mm with your new fangled clock guage. While I think R&D couplings are great, I'm not a fan of their special red bolt for alignment. It seems to me it will get the engine parallel with the shaft, but not necessarily colinear.

Peter.

 

[Talulah]

The one occasion I've seen an engine jump around like that is where one of the prop blades wouldn't fully open to match the other.

 

[kacecar]

I'm not a fan of their special red bolt for alignment. It seems to me it will get the engine parallel with the shaft, but not necessarily colinear.
Peter.

That's interesting - perhaps I've been missing something so here's a genuine (and possibly stupid) question. Assuming one can get the gaps at the flanges, or at the R&D red bolt, within the 0.25mm acceptable variation, how does one then ensure the engine and shaft are colinear?