- Joined
- Feb 1, 2015
- Messages
- 9,645
When you release the pin, M6-256 on my lathe, you should be able to rotate the bull gear, M62-241X separate from the pulley, 2140-10. The pin has two detents for engaged and free. There is a ball and spring followed by a set screw which rides in the detents. If the set screw is turned too far in, you won't be able to move the pin to the free position. With the pin in the engaged position and the back gears engaged it will lock the spindle.
It is possible that the previous owner permanently pinned the bull gear to the pulley. The pin will work against the Zamak pulley and wear tyhe pulley to the point that you can no longer lock the pulley to the gear. Also using the pin and the back gear to lock the spindle to change the chick can shear the Zamak if too much force is applied. A solution, albeit a poor one, would be to pin the two together. This would permit direct drive but prevent not driving with the back gears.
If you can rotate the spindle and the gears in the gear train are properly engaged, you will be able to turn the lead screw. If the carriage is not moving with the lead screw turning and the half nuts engaged, the problem is the half nuts. Looking at your photos, the lead screw looks OK but the half nuts need cleaning. You can remove the half nut assembly by unscrewing the two screws on either side of the half nut lever. Clean the half nuts with a fine wire brush or a toothbrush and some WD-40. You can clean the lead screw in the same way.
It is possible that the previous owner permanently pinned the bull gear to the pulley. The pin will work against the Zamak pulley and wear tyhe pulley to the point that you can no longer lock the pulley to the gear. Also using the pin and the back gear to lock the spindle to change the chick can shear the Zamak if too much force is applied. A solution, albeit a poor one, would be to pin the two together. This would permit direct drive but prevent not driving with the back gears.
If you can rotate the spindle and the gears in the gear train are properly engaged, you will be able to turn the lead screw. If the carriage is not moving with the lead screw turning and the half nuts engaged, the problem is the half nuts. Looking at your photos, the lead screw looks OK but the half nuts need cleaning. You can remove the half nut assembly by unscrewing the two screws on either side of the half nut lever. Clean the half nuts with a fine wire brush or a toothbrush and some WD-40. You can clean the lead screw in the same way.