Drilling at an acute angle

[stevedrew]

I was wondering how to go about this? Control surface wires exiting from, say, the rear of the fuselage to operate the elevator exit at a very acute angle to the fuselage, requiring drilling at this angle to make it lie properly, instead of exiting at 90 degrees, then bending, and finally attaching to the control horns.

What methods do you use to drill at this angle? Do you drill before or after painting? (I was thinking that masking tape might allow you sufficient "purchase" on the fuselage surface to get the hole started, then VERY careful manipulation of the drill might enable you to end up with the correct angle, but the masking tape might ruin the painted surface). Also, if you paint it after drilling, the paint might clog up the hole, forcing you to re-drill, with possible problem of removing paint back to bare plastic. Touching up wouldn't work either.

Any ideas?

['14-'18aviationcollector]

Hi Steve,

In this situation I simply start drilling the hole (not too deep of course) and then move the drill bit to the required angle.

Cheers,

David.

[THE GREAT WALDO]

Hi

I use a stepped drill in a proxxon mini drill, most small drills should be used at high speed.

Cheers

Andrew

[Rowan Broadbent]

As David has said, start the hole at a ninety degree angle to the plastic surface and then gradually change the angle as the hole increases in depth. Always mark the position with a sharp compass point or similar before starting. If the hole is at a particularly oblique angle, I suggest that the starter hole is made at the far end of where you want the finished hole to be, rather than in the centre.

I'd also suggest that you do this by hand for better control - it takes longer than with a motor tool, but a skipping drill at high revs will play havoc with your paintwork - ask me how I know!!

I'd also suggest that it is better to do this after painting, being sure to clean off any swarf with a soft brush - the puffer brushes used for camera lens cleaning are ideal. Then touch up after with thinned paint, so as not to clog the hole you've just drilled!

[NorcalBob]

One thing not mentioned is; be prepared to break off many drill bits whilst drilling at an angle!!!! Especially if you are using small bits (#79-80) for rigging holes. Personally, I break off too many bits (at over a dollar each) that I don't even bother any more!!! YMMV!!!!

[FOKKERJ]

G'Day Steve Drew,

All great suggestions so far.

Having handled a gazillion drills (+/- a few million! (Who's counting? )), I remember what I used to make small holes with before I discovered the drill! A Red hot needle and a steady hand (preferably before paint!).

As Andrew has precisely pointed out:
"most small drills should be used at high speed."
Too slow a speed just breaks the damned things!
Dremel speeds seem just about right!

Good Luck, Jay

[FOKKERJ]

I would also tend to drill any and all holes before painting, just like in real life.
That way screw-ups are less of a project to fix. Just my opinion.

You could blast a hole most anywhere, at any angle and finish it up with a cover just like they used.

Off the top of my head, I would say that you are easily looking at 10,000 to 15,000 rpm on these size drills in plastic. That said, I use a hand powered twist drill chuck with the helical shaft that you push down and up to get the drill to spin and I haven't broke any small drills.... yet!

Cheers, Jay

[bobs_buckles]

I use a bead reamer to prick the plastic before drilling. This method has saved me tons of fine drill bits.

BB

[albatros1234]

i also drill before painting. usually an airbrush layer of paint is not thick enough to clog the hole, if it does get clogged i use a sewing needle to clear any paint from the hole(carefully) my experience i always messed up the paint job when i realised i forgot a hole and had to drill after. its harder to touch up paint and get it to blend if you do mess up, so its safer to drill first and use a needle.