Double Threads

[Hukshawn]

I want to convert my tailstock to a quick-release. I think a double thread might do that. My question is will a regular nut work on a double thread or do I have to cut a double thread nut to go with the double thread rod?
My plan was to turn it between centers and rig up some kind of barrel nut to go over the threaded spindle and used kind of like a homemade dog in order to just spin the dog halfway and get the second thread. Could I get super fancy and use my 3 jaw Chuck with the dog and do a triple threat and still have that work on a regular nut? Pending that nut has a thread I can divide by 3...

 

[Tony Wells]

No, that won't work.

 

[Wreck™Wreck]

Do you mean a 2 start thread?

 

[Hukshawn]

Yes, sorry, a 2 start thread.

 

[Hukshawn]

So I have to cut a nut to match?

 

[chips&more]

Yes, must make a nut to match.

 

[Hukshawn]

Alright. I actually sat down and thought about it. I see now why th4 nut needs a two start thread too.

What are some other people's ideas to make the tailstock a quick release?

 

[Wreck™Wreck]

One may purchase 4 start acme screws and nuts that travel 1" per revolution for little money, it is not even close to cost effective to make such a product once.

An example
https://www.mcmaster.com/#precision-acme-lead-screws/=15ij1ec

 

[RJSakowski]

If the pitch on a screw thread is increased, its locking ability is decreased. A multiple start thread really doesn't gain you much in this application.

You might consider a camming washer. The distance from free to lock can be maintained while not increasing the incline angle as greatly due to the larger radius. An example would be a common window lock.

 

[12bolts]

There are quite a few lathe mods that come up with a google search. An eccentric seems to be the most common/popular method. But it does require some permanent modification to your TS. So depending on whether you consider the user benefit outweighs the possible devaluation of your machine.

Cheers Phil