SonexBuilders.net

Hello all,

I am ready to up drill the bolt holes through the Forward Center Wing Spar stack-up per plan pages ONX-W16 and ONX-W13.

Is there an optimal drill size to use for the holes these bolts fit into?

The bolts are:
AN3-10A
AN3-11A
AN3-15A
AN3-20A
AN525-8R20

Bolt diameter (measured) = .186 inches = 4.73 mm

Thanks,
Don

After a search of 'drill bits' I will use a leveled drill press to drill these bolt holes.
I believe 3/16" is the right diameter drill bit to use.

I'd appreciate any good feedback.

Don

Hi Don

3/16" worked well for me


Robbie Culver
Sonex 1517
Chicagoland
Tails and Wings complete - finishing fuselage.
N1517S reserved

Are you going to use 3/16 Reamer or drill bit ?

Thanks Robbie.

Concorde,
Drill. Is there an advantage to the reamer?

Much appreciated gents.
Don

Off to the hardware store it is.

The reamer vs drill bit debate has been had over and over again.
Yes you can get better quality (tighter fit) holes drilling slightly undersize and then using a reamer, however, it does take more time and effort and it's easy to stuff up a hole as well.
Anyway Jeremy Monett (Sonex CEO) stepped in on the discussion on the old forum at one stage. He said that if proper care is taken, you should be able to complete your whole Sonex aircraft without using a reamer at all.
A 3/16 drill bit will be fine for your AN3 bolts.

Reamers may not be required, but over the years I have found that a low cost set of 0.001" under - over reamers one of the more useful tools to have on hand.

David A.

Thanks guys for the useful information. I will experiment, with both, on scrap stock.