-------------- Original message from Ernest Christley <echristley@nc.rr.com>: --------------


> I thought this would be easy. It's not. I'm trying to come up with a
> better idea now.
>
> Problem: The gearbox I have bolts up to a 1/2" plate. There are 6"
> standoffs between the plate and the rear face of the engine. Two of the
> standoffs are drilled to encompass a single bolt, and the other two are
> wide enough to contain 2 bolts each. We planned to use bolts through
> all the pieces into the back of the engine. The bolts would need to be
> 180mm long M10 with a 1.00mm thread pitch. Because it will be holding
> the prop, I consider it prudent to specify 10.9 grade bolts (equivalent
> to Class8). Wilders, the local bolt specialty shop, gives me a quote of
> $36 each. I'd need 6 of them. I could get a box of 10 at $30.67
> each. Ouch!!
>
> I could do that, crying the whole time, and may possibly have to yet;
> but, I think it might be smarter to explore other options first (and ask
> people smarter than I). I'm thinking the best way to go would be to
> find a way to use standard length bolts. For instance, for the two
> standoffs that have two holes, we could cut a recess into each side to
> uncover the drilled hole. That would allow one bolt to attach the
> standoff to the engine and another to attach the plate. But that would
> severely compromise the clamp-up forces that hold the whole thing
> together and allow it to get "wobbly". Threaded rod or studs are
> possibilities, but I've not been able to find either.
>
> Where can I find extra long, high grade metric bolts that aren't
> specialty order items?
> What other options do I have for securely bolting a plate to the back of
> the engine with 6" spacer?
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html