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(04-28-2015, 04:15 PM)EdK Wrote: I guess I misspoke. My lead screw is pinned but not with a shear pin. It's pinned with a 3/16" spring pin with a breaking strength of about 4100lbs.
Ed
This will get me into a lot of trouble.
Your lathe was designed by engineers made by machinists.
DaveH
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Is crashing as much an issue with the crossfeed as with the longitudinal feed? The drive gear on the leadscrew of my lathe is a slip fit with a tapered pin, so the drive is only transmitted by the pin. However if I introduce a clearance fit into the middle of the crossfeed screw, as it is only supported at either end, I think it would cause problems with sagging in the middle (like me).
I'm not sure I have the confidence to produce a tapered fit, I'm only going to get one chance at this (unlike the threading of the new nut, thankfully) and don't want to risk destroying the driven section of the shaft.
Lathe (n); a machine tool used in the production of milling machine components.
Milling Machine (n); a machine tool used in the production of lathe components.
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Yes. I make plastic gears for the Logan gearbox. When I was first testing them I engaged the power crossfeed. It was up against the stop and I heard a snap. I don't wanna think about what it woulda sounded like if they were all steel gears! I also have an older Logan so it doesn't have the slip fit clutch and don't know what would have happened if I did. In the end I had one gear crack in half and the next day when I had more time I replaced it (without removing the gearbox) and was back in business. Unfortunately the next test didn't break the same gear, it broke a different plastic gear that's a pain the butt to replace. Morrow of the story, don't crash the lathe. Mine were intentional tho to test the strength of the gears. No more intentional stuff here now!
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(04-28-2015, 04:15 PM)EdK Wrote: I guess I misspoke. My lead screw is pinned but not with a shear pin. It's pinned with a 3/16" spring pin with a breaking strength of about 4100lbs.
Ed
sounds like someone replaced the shear pin with a spring pin. Not too difficult to correct.