Jon Paxhia
Plastic
- Joined
- Oct 4, 2020
I need some help with a skinner 6” lathe chuck, it reads 2-v-6 van Norman-51. I bought a Logan 816, it was a little ruff but the price was right it has 1.5-8 spindle threads. It did not come with the chuck mounted or even the back plate ready. The back plate was Chinese but fit up right and after facing was running .001 out, more then enough for my work. The skinner had roughly .625 mounting holes with a lager counter bore for socket cap screws. I used a .625 transfer punch to mark the holes and drilled and tapped 5/8-11 holes and mounted with 2.25 long bolts. The run out on a piece of work is .035-.040 total swing. I thought the bolts may have been causing a distortion on the chuck since the back plate shoulder is about .001-002 smaller then the chucks. So I drilled 3 new holes to 1/2-13 and tried again. Same results. I have taken the chuck apart and tried to realign the jaws by closing them all the way and making sure there are no gaps, and it seems to stay timed when assembled. Short of grinding the jaws, witch I have no way of doing, and if I did I’d also have to grind the flip side of the jaws since there two piece. Any ideas would be appreciated. Or do I just go buy a new chuck from shars? Can’t afford a bison and such.