Turning Archive 2007
>A while back I posted about some fancy bearings that I got, on an engineers recomendation (supposed to be better quality than the Koyo bearings others have recomended), for my angle drills. I just went through the first set. I got somewhere between 350 and 400 bowls, most of which were in the 8 to 14 inch diameter range, out of them before they (3 out of the 6 in the drill) failed. This was the only time that I heard them go out, with a small tick sound, then 5 minutes later, the drill stopped. Usually they start sounding bad slowly, and get worse over the course of a week or three. I am getting them done again, and will keep better records of how many bowls I get done with them, then get a brand new drill with stock bearings and see if there is much difference.
I asked the repair guy if he knew why they failed. He said that it was the dust. I said that the bearings were supposed to be sealed. He said that eventually dust still gets in, and that using the drill for a sander was exceeding the intended use and abuse of the tool. I do use 3 inch discs exclusively. I figured that maybe since I was now running the discs at a slower speed, that the drill bearings might last a bit longer, but it doesn't appear so, at least not on this set.
Testing still in progress.