According to the proverb: "A poor workman blames his tools" but I've been spending an inordinate amount of time cursing my purchase of a General Tools 840 Doweling Jig at Home Depot as I was working on a customer piece, a replacement base for a china cabinet I had to repair.
- The one most important setting, the offset of the dowel hole from the edge of the workpiece, is set by a small knurled screw bearing on a smooth steel shaft, without so much as an expansion washer to keep it in place. Naturally with all the vibration caused by the drilling, this comes loose about every other hole. This ought to be a something like a rack and pinion setting which can be dogged down securely.
- The scale graduations on the other steel shaft are off by 1/32", which I did not realize until after I'd drilled my first two holes (not in a practice piece of stock, as I should have done, but in the final workpiece). So to center the dowel holes in 1 by stock, I have to set it not at 3/8" but to 13/32".
- These scale graduations are black scratches on the black shaft, pretty hard to see.
- The turret is cast steel, not hardened, and erodes away on contact with a drill bit. I mistakenly hastened this erosion by using a 1/2" spade bit at first instead of a burr-point bit.
- If the turret is positioned less than 3/8" from the edge of the workpiece, it covers up the hairline used to line up the hole with the pencil marks on the wood. Instead, you have to sight down the dowel hole to see if the line is centered, which is not as accurate.