I have SB Heavy 10 w/the 2-1/4 - 8 threaded spindle nose. I'm trying to use my collet chucks as opposed to my 3-jaw, for no particular reason.
I'm trying to turn 7/8" cold drawn 12L14 having OD at 0.874" to 0.875" as measured with a good micrometer that's been calibrated.
For 7/8", I have 2 sets of 5C collets. An older SB 5C collet that may have some slight wear and a new Chinese 5C collet that's never been used. Both collets have different lengths of external thread, but both bottom out when not in the lathe. The steel rod slides into the collets; no problem. And both 5C collets seat fully into the collet sleeve when not in the machine.
The problem happens when I assemble everything into the spindle. I have the handwheel type, and after getting it tight, the collet sleeve sticks out a bit from the thread protector. As soon as I take a cut, it becomes evident that the assembly isn't fully seated. I can usually move it with a decent whack from an open palm. This happens with both collets. Something seems to be too long.
I was under the impression that drawbar length came in 2 different sizes. One for the handwheel and the other for the collet closer. But, a recent review of a SB spec sheet lists different part numbers for the different models (10", 13", 14.5", and 16"+).
I'm guessing that there's a difference in length, and I need the shortest one. As there doesn't seem to be a part number on the drawbar, is there a length I should be looking for to ensure I can find the correct length drawbar to be able to use my collets??
Thanks in advance,
JustaTOOL
I'm trying to turn 7/8" cold drawn 12L14 having OD at 0.874" to 0.875" as measured with a good micrometer that's been calibrated.
For 7/8", I have 2 sets of 5C collets. An older SB 5C collet that may have some slight wear and a new Chinese 5C collet that's never been used. Both collets have different lengths of external thread, but both bottom out when not in the lathe. The steel rod slides into the collets; no problem. And both 5C collets seat fully into the collet sleeve when not in the machine.
The problem happens when I assemble everything into the spindle. I have the handwheel type, and after getting it tight, the collet sleeve sticks out a bit from the thread protector. As soon as I take a cut, it becomes evident that the assembly isn't fully seated. I can usually move it with a decent whack from an open palm. This happens with both collets. Something seems to be too long.
I was under the impression that drawbar length came in 2 different sizes. One for the handwheel and the other for the collet closer. But, a recent review of a SB spec sheet lists different part numbers for the different models (10", 13", 14.5", and 16"+).
I'm guessing that there's a difference in length, and I need the shortest one. As there doesn't seem to be a part number on the drawbar, is there a length I should be looking for to ensure I can find the correct length drawbar to be able to use my collets??
Thanks in advance,
JustaTOOL