Fixing an out of true chuck

Trying to drill a hole accurately with a wobbly bit is a pain in the backside. This pain I lived with for several months until I figured out what was wrong. When I bought this eggbeater, I never had such issues, but since I dismantled the chuck for cleaning several months back, I noticed the wobble started.

I will go through the steps I have taken to find a solution. You can also follow these steps when you’re next at flea markets before buying a hand drill. You don’t want lemons because these hand drills aren’t cheap anymore.

The first thing I checked was the bit. I laid it flat on my table and rolled it. There were no irregularities, for good measure I placed it in my drill press and it was fine. So, I crossed that off the list.

Open and close the jaws in the chuck and watch if the jaws open and close evenly together. If not, get a new chuck.

Next unscrew the chuck completely off the threaded shaft and inspect the shaft. Crank the drill and eyeball shaft carefully. Your eyes will pick up any irregularities if the shaft is bent. You’ don’t need any expensive gizmos for this.

Threaded shaft must run true and straight

Next pop out the jaws and inspect the flat milled back that holds the bit. This must be clean, undamaged, and milled perfectly flat. It is highly unlikely that it isn’t perfectly flat, so inspections by eye are close enough. There can’t be any dings.

By now I was frustrated and I mean really frustrated. I checked everything I could check, and they all passed with flying colours, but did I. There was one last thing I didn’t notice when I put the darn thing back together again. Since I don’t know the part name, the two pictures will give a better picture of what I’m referring too.

Incorrectly seated
Correctly seated

That’s right folks, that part that I’m pointing too was flipped the wrong way round. The bit rests in the cylindrical depression you see in the middle, which aids in keeping the bit centred (centered for the yanks) coupled with the jaws holding the bit in place. These two combined aid the drill bit from wobbling whilst drilling. Amazing, isn’t it? Something that’s so easy to miss can lead to months and months of frustration and hair loss.