Gear Bolt

[paul330]

I will soon be fitting my gear The plans call for a 7.9mm reamer to drill out the gear mount for the 5/16" bolt. I guess this is necessary or they wouldn't specify it but I calculate that a 5/16" drill is only 1.5 thou bigger.....

Thoughts?

 

[GAHco]

Interference fit

For most close tolerance fastener installations involving non moving structures ( like a spar) there should be a slight interference fit. Typically it is .0005 to .0015 Do not turn the reamer at high speeds.

This is for softer metals structure such as aluminum and bronze, and the fastener being installed is steel or equivalent.

I hope this helps!

 

[BobTurner]

The reamer is much more likely to give you a round hole than a standard twist drill bit.

 

[Wayne Gillispie]

I used the reamer from Avery, but would try locally.

 

[paul mosher]

Don't forget the Boelube

Use Boelube when reaming. Yes it is a close tolerance bolt. You don't want it sloppy in the hole.

 

[paul330]

Thanks for the input. We have a local supplier in UK who does Avery products so I'll get a reamer from them.