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Ed Sikora asked about what to use for the shim between the main gear

rear bearing plate (GM ??) - aluminum ar phenolic.



First let me say that having 1/4 inch clearance back there at first

glance sounds like too much. I don't believe it is, and here's the

reason. When you're diddling that sucker into place to drill the bolt

holes where you want them, the extra wiggle room the 1/4" affords is

welcome. Of course, juggling an extra piece could be tough, but my

experience says it's nice to have some room to help get things adjusted.



As to the material to use, I'd use 1/4 in. phenolic simply because it's

easier to fabricate and I think it's lighter (by how much, don't ask!).

The shim is only in compression - something phenolic is suited to -

and you can bond it in once everything is lined up and drilled. Also

since it's only in compression, I wouldn't even bother to put any BID

over it. It ain't goin' anywhere once you pull up on those bolts.



No matter how careful you are in getting the distance between the

pivot bearings set up, when all is said and done, if you are a normal

human being, you almost certainly end up with around a gap of 1/8 inch

or so, i.e., fore-and-aft slop. Not so bad, really, but it makes for an

un-nerving noise every now and then as the horizontal shaft moves -

well, for and aft. Just cut a washer from the required thickness of

plastic like some of the stuff available from Aircraft Spruce - cut

out a little bit of the ring and snap it over the pin on the horiz. shaft.

Works for me.



Merry Christmas,



Santa flies a Lancair!



Dan Schaefer

N235SP