Tape a piece of thick cardboard , wraped around the stab , while youre t it with the drill .
Better to chew that up , rather than good timber .
Center punched , and a sharp bit , with some LUBE , should see it go thru clean .
Ive had to do the same , using a 6 in drill & hand drill . Then needle file .
If youre bushing it , a bit of angle drilling wont hurt , The knob at the center of the drill reemoves , to reduce the angle .
or undersize & use a final size drill to ream , with a hand holder - like a large blade knife handle for the bit .
( if your soldering in a bush , a damp rag around the area , and a wet tissue to quench a.s.a.p. . My 80 W iron will get in guick . a slow one'l heat it more ,
Pre Tin - so youre not faffing about . )Actually a long ' brass toob' , so its STRAIGHT , then trim ( razor saw ) and dress ends . Little paint brush & adequate acid helps .
Another dry towel to mop excess , so we dont acidifdy the wood ! .
Seen recently something where he had more flap than elevator travel . Unusual but ' in trim ' , whatever it was on .
Other option 'd be halve the flap chord .
1 : 1 is usual with an aftish C.G. .
What is the aeroplane there ? .
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Picture of DRILL before hoodlum has wrenched centre support knob free ! .