View Full Version : Help with lathe lead screw

02-07-2005, 10:31 PM
I know I seen it on someones 7x10 mini lathe website but I can't find it anymore, but can someone please tell me the best method to attach a shaft to another shaft end to end, because I want to put a handle on my lead screw to traverse the carriage, seen it done alot on the mini lathe but don't know how to couple the leadscrew to another shaft,welding is out of the question, I have attached handlles to lead screws quite often with bolts, but my lathe needs and extension of shaft before I have clearance to put on a handle.
I thought about drilling and tapping into the end of leadscrew but we know that aint going to work for obvious reasons, if I have to go with keyway then I'll have to make a new bearing block because the key would be right tin the bearing block. Also thought about pinning it but again the pint would be in the bearing block is there an easier way...
any ideas please....

[This message has been edited by dvk (edited 02-07-2005).]

G.A. Ewen
02-08-2005, 12:20 AM
<font face="Verdana, Arial" size="2">Originally posted by dvk:

I thought about drilling and tapping into the end of leadscrew but we know that aint going to work for obvious reasons,

[This message has been edited by dvk (edited 02-07-2005).]</font>

http://bbs.homeshopmachinist.net//confused.gif Why not? is the lead screw less than 1/2" diameter?

02-08-2005, 10:07 AM
Threading might unscrew when turned the opposite direction.

The easiest method is to drill the shaft on center, turn down a stub shaft to fit and knurl and press fit, loc tite, soft solder or silver solder in place. Method used will depend on forces involved and materials at hand, with silver solder being the strongest.

02-08-2005, 10:22 AM
Drill and tap, use Loctite or a jam nut against the end of the lead screw.

02-08-2005, 01:04 PM
I bet the "obvious reason" is that the screw would not be capable of driving the carrige while it's in the chuck!

02-08-2005, 04:41 PM
Thanks everybody...
both ideas are good, but I want to avoid having to make a new bearing block if I can, the end of the lead screw is turned down and rides in the bearing block. But as I'm looking at this I see 2 ways this can be done without disturbing the bearing block, I'll have to try both methods and see wich one works better.
Thanks again guys as always I appreciate the helpful hints..

Lynn Standish
02-08-2005, 04:51 PM
Look for Varmint Al's mini lathe website.

G.A. Ewen
02-08-2005, 06:06 PM
DVK, another idea is to have someone make you a new lead screw. This way there is no danger of ruining the one that you have and you wouldn't have to modify the bearing block.

02-08-2005, 07:40 PM
I found this and believe it is what you are looking for. Varmint Al's site doesn't have anything like this.