Problem today drilling holes through a rafter / joist combination for coach
bolts - needed to drill 36 holes and couldn't get the ordinary drill into
the joist space at the right angle - ok go buy a cheap angle drill - look at
Screwfix - only expensive battery ones that probably aren't powerful enough
anyway. Got one of those nasty 90 deg gear boxes but they spin all over the
place and run horribly hot.

Improvised Solution: Standard Bosh angle grinder has a 14mm male stud - ex
old drill chuck has a 3/8" UNF male stud. Made an adaptor out of 35mm of
3/4" hex steel bar with a 14mm female thread at one and and a 3/8 UNF female
thread at the other - screw it all together and we have a (rather fast)
angle drill at zero cost. Drills 10 mm holes nice and square to the joists -
problem solved! OK it runs far too fast really but got the job done, and to
think I've struggled all these years under floors drilling slightly angled
holes for cable runs that you can never pull through in long lengths due the
the angles and I had a disguised angle drill in the tool box all the time!

Andrew Mawson