Tip:
There was a place where I needed to drill a couple of #10 holes in my chassis tubes but there was not enough space to get a drill in between the structure. Drilling at an angle was a desperation choice since I don't have an angle drill; an angle drill plus the length of the drill bit probably would not have fit in between the chassis tubes anyway. What to do, what to do.
While looking through my tool drawer for a #10 drill I noticed a stash of threaded drills and I had one that was the correct size! These drills have a short drill bit and the opposite end is threaded 1/4-28 to fit into aircraft countersink stops, etc. Then I saw the little pneumatic right angle grinder that I bought from Harbor Freight on sale for about $14-- it has a 1/4" collet so I put the threaded end of the drill into the collet, seated it all the way in and tightened it. I tried it and the drill ran true-- no wobble. There was my el cheapo angle drill-- works like a charm. Now I can make better use of all those aircraft surplus threaded drills that I bought on eBay.
Regards, Neil Tucson, AZ