If you ever wondered what a typical day in the shop is like, I can say with confidence that you rarely know what you’ll get. As much as I’d like to say that it’s all cutting and carving wood and making lovely instruments, it often is far from that.
This morning I wanted to drill a few holes in a fixture I was building, but the drill bit was vibrating a bit as I set about to drop the quill. A quick inspection with my favorite Brown & Sharpe indicator showed about .005″ run-out at the chuck. This would translate to a more severe wobble at the end of the bit, so it had to be fixed. Sometimes a chuck will have debris inside, or the bit may have a burr; either of which can create a bit of run-out. I examined the bit, and it seemed fine—a roll test on the surface plate showed it was true. I was confident that a quick blast of compressed air would clean the chuck interior and I would be on my way. Or perhaps it was the arbor coming loose. My conscience demanded that I set things truly straight by disassembling the whole thing to put my mind at ease. I’d been wanting to reduce the return spring tension as well, so no better time than the present. The best way to determine a problem is to systematically go through each step until you find the source of the problem.
Out came the wrenches, wedge set and the arbor drift. Before I knew it, two hours had passed. Measured, solvent cleaned, then lubricated properly—the whole thing went back together beautifully. The culprit? A little bit here, a little bit there all added up to too much play in the end.
When I put the indicator on the arbor it was only showing about .001″— which is pretty much dead nuts for this type of machine. With the chuck cleaned out and fitted snugly, it was ready to rock. By then it was lunchtime. At least I knew that the rest of the day could move ahead without incident.