Step Support Block

What am I missing here? Step 1 calls for drilling the holes in the blocks with a #10 bit, but the holes in the ribs for the bolts (AN3) are #12. Why the (slightly) larger holes in the blocks, especially if you're using them for guides to match drill the #12s in the ribs?

Thanks.

Jeff

material difference

Hi Jeff,

It's been a long time ago for me, but I believe when you drill the blocks, the holes shrink a little once you remove the bit. Probably due to the material type (UHMW or Delrin???). I think you'll find the #12 bit you use to match drill into the aluminum will have a snug fit when you pass it through the #10 holes in the blocks. Maybe confirm this theory if you have a piece of scrap. There are other areas I believe the same #10 technique is used. Check flap arm mounting blocks, rudder pedal blocks, etc.

Yep!

Sean,

You're quite correct. Just got off the phone with Gus at Vans. (I usually forget that service is even available b/c their hours and mine usually don't coincide.) But that's exactly what he said.

Thanks!

Jeff