Broken drill bit in main spar

[Sonex1517]

Opinions welcome - I emailed tech support already



A question about a broken drill bit in the main spar.

I was drilling the upper aft wing skin onto the main spar where the leading edge overlaps the aft skin. This is the really thick part of the spar.

My pilot #40 drill bit broke inside the hole - it is not showing outside and cannot be removed. I didn't try too hard for concern of doing damage.

Suggestions?

All I can come up with is a hole in-between this hole and the next one to make up for it.

It is not aligned with a rib.




Robbie
Sonex 1517

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[Mike53]

If it broke only part way in drill to proper hole size from the other side (if thats possible)till you reach the broken bit then use a punch to drive the bit out the way it went in or sometimes just getting it pushed out far enough you can grab it with vice grips and slowly twist it out.Best to use a punch if you have the proper size but another dull drill bit will probably do the trick.
Been there done that.
Mike

[Sonex1517]

Unfortunately, not only is no part of the drill bit sticking out, but behind it is a stiffener already riveted in place.

I've had to try that trick (successfully) but in this case it is almost impossible without removing a stiffener on the spar.

Thanks for the reply!

Robbie
Sonex 1517

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[Sonex1517]

Mike

Thanks! You got me thinking and I went to take a long look at the situation.

The drill bit is actually visible and has come part way out of the spar on the inside. It may indeed be possible to punch this out, but only after I disassemble the wing later for deburring....


Robbie
Sonex 1517

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