Posts: 8,854
Threads: 318
Joined: Feb 2012
Location: Arizona/Minnesota
(06-30-2014, 03:32 PM)PixMan Wrote: Go ahead and modify the nut, nothing to lose.
I can make you a new nut PDQ as I have the tap I used for the one you've got. I can leave cutting the slit up to you if you want, though the cutter I have would probably go about that deep. You can measure the one I sent to see the max depth I can get, as it's easy to see where I stopped milling and went further with a bandsaw.
Ken,
I can't modify the current nut because if I take enough off to clear the trough I cut into the slit and I end up with two halves instead of a whole nut. If you could make me a new nut that would be wonderful, although I hate to have to ask you to do that.
I'm going to mock up the redesigned nut in aluminum without the acme thread. I'll make it a slip-fit over the acme thread just to test for clearances with the trough. I don't want to screw this up again. If all goes well with the mock-up, then I'll create a new drawing with the updated dimensions.
Sorry to put you through this and I'm eternally grateful.
Ed
Posts: 2,685
Threads: 29
Joined: Feb 2012
Location: Nova Scotia, Canada
Ed, just how much material (if any) would be left beyond the thread depth if you removed enough material from the rounded end of the nut? I would think you would not need much and the less material the easier for the setscrew(?) to distort the nut in order to take up for thread wear?
I'm remembering you changed the leadscrew Dia. from .5" to .625" as per Ken's 5/8" acme tap so that ate some material right?
Lastly what would be the problem with Ken just making a solid nut? It would seem to me that the new materials would be superior to the orig. and we're not talking about a 2 or three shift operation of the lathe. I'd bet a solid nut and maybe a back up spare would last longer than you.
Just my take.
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.
Posts: 8,854
Threads: 318
Joined: Feb 2012
Location: Arizona/Minnesota
(07-01-2014, 11:59 AM)stevec Wrote: Ed, just how much material (if any) would be left beyond the thread depth if you removed enough material from the rounded end of the nut? I would think you would not need much and the less material the easier for the setscrew(?) to distort the nut in order to take up for thread wear?
Steve,
Per post #136 "
I can't modify the current nut because if I take enough off to clear the trough I cut into the slit and I end up with two halves instead of a whole nut"
(07-01-2014, 11:59 AM)stevec Wrote: I'm remembering you changed the leadscrew Dia. from .5" to .625" as per Ken's 5/8" acme tap so that ate some material right?
Correct.
(07-01-2014, 11:59 AM)stevec Wrote: Lastly what would be the problem with Ken just making a solid nut? It would seem to me that the new materials would be superior to the orig. and we're not talking about a 2 or three shift operation of the lathe. I'd bet a solid nut and maybe a back up spare would last longer than you.
Just my take.
Actually, I will have Ken make a solid nut if this is going to work out. He doesn't have a slitting saw large enough to make the slit so I'm going to put the slit in since I have a 4" slitting blade. But that's a good thought. Leave the slit out for now and see how it works out. I could always add a slit later on if it became necessary.
Thanks for the thoughts Steve.
Ed
Posts: 3,003
Threads: 51
Joined: Apr 2012
Location: Ontario
There looks to be plenty of material on either side of the slot. Could you drill and tap the two sides, mill it down to make two separate nuts and TRY it. The set screw should still spread them to remove backlash. They can't turn with the lead screw through them.
Free advice is worth exactly what you payed for it.
Greg
Posts: 8,854
Threads: 318
Joined: Feb 2012
Location: Arizona/Minnesota
(07-01-2014, 12:39 PM)f350ca Wrote: There looks to be plenty of material on either side of the slot. Could you drill and tap the two sides, mill it down to make two separate nuts and TRY it. The set screw should still spread them to remove backlash. They can't turn with the lead screw through them.
Hmmm, that might be worth a try.
I'll have to think about that.
Thanks,
Ed