Yet Another Radial Pin Question

junkbond

junkbond

The dog ate my stroke.
Silver Member
I have a few cues with radials pins, and recently decided to try the shaft from one with the butt from another. It didn't work. The fit was much too tight, so I did not attempt to force it in. I have read several threads about radial pins, and noted that opinions varied as to what, if any, were the differences.

The two pins here are in cues from respected American cue makers, with their own shafts supplied. The major diameter of the pins is the same, but the stainless pin measures approximately .0030 larger on the minor diameter than does the brass pin. (The minor measurements were taken diagonally within the threads, not at the pilot.)

Are these pins from different manufacturers? Are different sizes of drills and taps used on the shaft? Are the dimensions of the holes in the butt different? (notice how I didn't use the term "butt holes"?)

I have been thinking about buying OB-1 and Predator shafts, just for grins, but now I am not sure which butt the radial pin after-market shafts will fit.

Any info will be greatly appreciated.

Howard

P51100113.jpg
 
Last edited:
The import radial variety was used on Omega and Varner imports.
Domestically, Schmelke and Gullyassy used them.
Bob Maddison also made and sold his version but were not exact duplicate.
 
These are not import cues or pins. The Chinese pins have a different thread count (I have a couple of them). These pins have the same threads, with the only difference I can find being the minor diameter.
 
junkbond said:
These are not import cues or pins. The Chinese pins have a different thread count (I have a couple of them). These pins have the same threads, with the only difference I can find being the minor diameter.
Click to expand...

Like Joey said....I'd wager the stainless one is made by Madison Bob. They are fine pins & I've used a lot of them...but not made to exact Unilock specs. I've had no problem with any aftermarket fitting though. :)
 
junkbond said:
I have a few cues with radials pins, and recently decided to try the shaft from one with the butt from another. It didn't work. The fit was much too tight, so I did not attempt to force it in. I have read several threads about radial pins, and noted that opinions varied as to what, if any, were the differences.

The two pins here are in cues from respected American cue makers, with their own shafts supplied. The major diameter of the pins is the same, but the stainless pin measures approximately .0030 larger on the minor diameter than does the brass pin. (The minor measurements were taken diagonally within the threads, not at the pilot.)

Are these pins from different manufacturers? Are different sizes of drills and taps used on the shaft? Are the dimensions of the holes in the butt different? (notice how I didn't use the term "butt holes"?)

I have been thinking about buying OB-1 and Predator shafts, just for grins, but now I am not sure which butt the radial pin after-market shafts will fit.

Any info will be greatl appreciated.

Howard

View attachment 96026
Click to expand...
If you specify Uni-Loc Radial youll get a pin like the one in the top photo.
The pin in the bottom photo is a knock-off. No telling who made it.
 
the bottom one appears to be "single pointed" where as the top one looks like a uni loc which being as they are mass produced is going to be a extruded pin

or rolled. You can tell also in the pics at the minor dia you can see tool marks, i would say the cue maker said screw buying them when i can make them for

cheaper which is good except there isn't a whole lot of data for these types of threads in the machinist world (that i know of).

Also if the pin was "single pointed" or cut on a lathe then the pilot should be the correct minor dia (unless turned down after threading for clearance but it

doesn't appear so). Where as measuring at that angle would give you a false reading, also check the major diameters in the joint of the shaft. On another

note his lead might be wrong compared to uniloc's pin, where the pitch is the commonly refered to as tpi threads per inch, the lead is a offset used when

single point threading which consists of pivoting your tool up to i believe 29 degrees depending on what type of thread.

A normal thread rides on the pitch diameter which is exactly between the major or minor diameter of a thread "half way up the peak of the V" I honestly cant

say where this occurs on a radial pin after looking at my shafts and it looks as most shafts are cut with a normal 3/8x8 tap with a larger than normal tap drill

to take out the pitch diameter allowing for the radius not to hit. Wow sorry for the long post but as you can see there is alot that goes into threads and i

haven't even scratched the surface.

Ok to recap here is my opinion on getting alot of different radial pins to fit different shafts, Check the hole diameter on your shaft if this varies this will most

likely be the problem of course make sure you have the same pitch or threads per inch same thing, the wear marks on my shafts show the radial thread

"rides" some where near the major diameter on the male or pin, so you may need to have your shaft drilled out. This is a maybe don't just go drilling shafts.

I have a joss with a uniloc my ob2 fly's on smooth as glass, my dominiak dominator 2 does not that is because the hole in the shaft wasn't drilled deep

enough.

So 1. Major diameter of pin should match
2. Check the diameter of hole in shaft along with depth
still no go maybe wrong lead. (no fix)
 
Last edited:
The stainless pin is apparently a Madison. Thanks for your help, gentlemen.
Now if we can get Madison to make his pins the same size as Uni-Loc...
 
To answer a few questions or comments made here. Uniloc does not use rolled pins. They all are single pointed. On Mad Bobs pins, He bought one of Uni-locs original taps that made the tapped shafts a little to loose. He then started having his pins made from a fellow and had them made so that that tap would make a tight fit. Problem is, most folks have the newer tap that makes the shaft fit tighter but since Bobs pins are a little oversize, they are to tight. When the fellow who was making his pins got fired and could no longer make them for him, he asked me if I could get them made from the same place that made all of mine. The place used the same program that they used to make my pins but they increased the size a .001 or .002 to match Bobs tap and since Radial pins are such a good fit they are to tight once again for most peoples taps.

Dick
 
Thanks for the info i just assumed due to the fact it seems like everything is shipped overseas for manufacturing these days that they would be rolled. good to hear some things are still being made the old fashion way:thumbup: Like i said i don't much about them just trying to pass on some info that might help. What part of the thread was he making .001 to .002 larger the major diameter? Just wondering because unless your talking about a class 3a thread 001. or .002 in the major or minor diameters shouldn't effect the tightness of the thread.
 
Last edited:
Uni-Loc Radial Pins

rhncue said:
To answer a few questions or comments made here. Uniloc does not use rolled pins. They all are single pointed. On Mad Bobs pins, He bought one of Uni-locs original taps that made the tapped shafts a little to loose. He then started having his pins made from a fellow and had them made so that that tap would make a tight fit. Problem is, most folks have the newer tap that makes the shaft fit tighter but since Bobs pins are a little oversize, they are to tight. When the fellow who was making his pins got fired and could no longer make them for him, he asked me if I could get them made from the same place that made all of mine. The place used the same program that they used to make my pins but they increased the size a .001 or .002 to match Bobs tap and since Radial pins are such a good fit they are to tight once again for most peoples taps.

Dick
Click to expand...
Dick,

Thanks for the explanation, but this sounds like a problem if you wanted to buy a standard radial pin predator shaft for your cue with one of these pins. I wish there weren't so many different types of cue pins in the cue world, but I understand cue makers wanting to make things "custom to their cues".

It's my understanding that Bill Stroud (Josswest Cues) invented the radial pin joint. Can anyone provide more info on this or am I correct?

James
 
scottyr44 said:
Thanks for the info i just assumed due to the fact it seems like everything is shipped overseas for manufacturing these days that they would be rolled. good to hear some things are still being made the old fashion way:thumbup: Like i said i don't much about them just trying to pass on some info that might help. What part of the thread was he making .001 to .002 larger the major diameter? Just wondering because unless your talking about a class 3a thread 001. or .002 in the major or minor diameters shouldn't effect the tightness of the thread.
Click to expand...

To measure the minor diameter of the pin , you can use the 3 rollers method.

The ball screws, which is what they are called in other industries, are designed to run on the root diameter in a near full contact like a ball screw does.The outer diameter is almost not critical. Obviously it does not want to be too big but can be smaller with no functional defect.
So when the thread is formed with the tap, if the root diameter is made too big, quite a large portion of the thread engagement is missing which also is the radial alignment.
Conventional threadforms are not designed to be using the root part of the thread form.

A flat form buttress thread would be stronger as there is no radial stress emanating from the angled contact areas.The compromise is that wood does not have a very strong shear strength, hence the course pitch in wood screws.
It could be done, but who knows what if little advantage there would be.
A possible use could be for sneaky type cues that do not have joint collars to strengthen the shaft radially.
 
You must log in or register to reply here.
Back
Top