Live Threading 3/8 -10 vgroove and flat

[JerseyBill]

Can anyone explain the differences and how to create the differences in the shaft to match the different 3/8-10 threading inbetween threads the deeper v groove versus the flat bottom groove and who thinks the one is better and why?
thanks, Bill

 

[cueman]

To make a shafts that match the two different kinds of 3/8-10 there is not much difference. You might bore the hole a different size before thread milling.
Making the pin itself takes a different threading tool, but it is the same for the internal threads on the shaft.
It is a matter of personal taste on which you choose. The flat minor diameter pin gives a little more consistant alignment, and since it is different some like it better for looks. You would probably be hard pressed to tell the difference in the hit, if you had two identical cues and did not know which pin was in it.

 

[JerseyBill]

3/8-10 threads , flat vs. v groove

To make a shafts that match the two different kinds of 3/8-10 there is not much difference. You might bore the hole a different size before thread milling.
Making the pin itself takes a different threading tool, but it is the same for the internal threads on the shaft.
It is a matter of personal taste on which you choose. The flat minor diameter pin gives a little more consistant alignment, and since it is different some like it better for looks. You would probably be hard pressed to tell the difference in the hit, if you had two identical cues and did not know which pin was in it.

Thanks Chris,
So really they are almost the same inside the shaft, the greater difference is in the making of the pin.
Bill

 

[JoeyInCali]

I thought the minor on 3/8 acme is .308 and regular 3/8 10 is .3125.

 

[AtLarge]

I thought the minor on 3/8 acme is .308 and regular 3/8 10 is .3125.

The minor on the new-style, flat-bottom pin is often about .308". The old-style pin, like McDermott uses, has a smaller minor diameter, about .020"-.030" smaller.

The result is that a shaft made for the new-style pin will fit on the old-style pin, but a shaft made precisely for the old-style pin won't fit on the new-style pin. However, a cue maker can easily enlarge the hole on the old-style shaft a bit so it will work on both pins.

 

[cutter]

Live threading.

I thought the minor on 3/8 acme is .308 and regular 3/8 10 is .3125.

The minor is what ever the pin maker decides. Acme has both flat tops and bottoms. The new 3/8-10s with the flats in the minor diameter aren't really acme thread. You need a specially ground thread mill to live cut flat bottom
pins. You can use a regular "v" point thread mill to cut the internal threads.

 

[RBC]

Bob Dzuricky has done some pretty extensive research on this and shares his findings on his website.

http://www.dzcues.com/videos.htm

It's at the bottom of the page, and there is a link to another page with even more information.

I love his website!

 

[cueman]

Thanks Chris,
So really they are almost the same inside the shaft, the greater difference is in the making of the pin.
Bill

That is correct with the popular flat bottom minor diameter pins. With Acme threads there is a flat major and flat minor diameter and that would take special tooling. But for the popular flat minor diameter joints you just bore the hole in the cue a different size than for the normal v threads and use the same thread mill to cut the thread.