Hi all, just starting with the Hafco AL336-D lathe, and to my disappointment yesterday found that I am unable to engage one of the leadscrew gears. Specifically - gear selection is made via 4 dials on the front of the quick-change gearbox, with most of the position selections being ok - engaging the leads crew to move the carriage for turning and threading etc.

Please see the below images for the 4 gear selector dials - with particular note to the “S / M” dial that does not engage in the “M” position.




When selecting the “M” position on the upper right dial, the leadscrew simply disengages, so that I can with everything switched off rotate it by hand even though it should be engaged. Once the lathe is switched on and run, and I engage the half nut, the carriage does not move as the gear that should be selected at this position is not engaging. Hence as the carriage does not move, I am unable to for example thread at 20 tpi. The “M” position on this dial selector seems to correspond with coarse thread pitches and moves the carriage (or should do) quicker than the “S” position - hence I can only do very fine threading.

This is obviously very frustrating. Though I am a noob In terms of lathe use, I am pretty sure I am not omitting something here in the gear selection process, but am happy to be corrected. Alternatively I would appreciate hearing from anyone who may have had this some trouble before - and fixed it, or from anyone who could either recommend pulling the gearbox down or otherwise in an attempt to rectify this issue.

This is a lathe that I purchased from a guy who bought it but never used it as he didn’t know how to, and it had all the packing grease still on it - obviously done no work, so I would not have expected this issue on an as new lathe.

Any help or suggestions would be greatfully received.

Thanks, Mark.
Attached Images




Read the full thread at metalworkforums.com...