straight connection

[kiinstructor]

Hey guys, What do you consider the most important factors in keeping the cue straight when screwed together at the joint. I know keeping the faces flat is very important but what needs to be true to keep the shaft and butt straight even as you screw the cue together. I think if there is tension at the joint, that has to affect the hit. Maybe Im wrong but I think fit is everything. I need some opinions. Ive seen cues that didnt seen true until they were tightly screwed together. When you loosened them slightly they were crooked. Gotta be a machining problem. If Pin is true with butt then it has to be threads in shaft and visa versa. Thanks a bunch


Mark

 

[rhncue]

Hey guys, What do you consider the most important factors in keeping the cue straight when screwed together at the joint. I know keeping the faces flat is very important but what needs to be true to keep the shaft and butt straight even as you screw the cue together. I think if there is tension at the joint, that has to affect the hit. Maybe Im wrong but I think fit is everything. I need some opinions. Ive seen cues that didnt seen true until they were tightly screwed together. When you loosened them slightly they were crooked. Gotta be a machining problem. If Pin is true with butt then it has to be threads in shaft and visa versa. Thanks a bunch


Mark

If cue is straight when screwed together, this, of coarse means that the joint and shaft faces are perfectly squared to each other. If when screwed together lightly and not being straight and later by tightening the connection tighter the union becomes straight means that either the joint pin or the insert in the shaft are not installed perfectly in alignment with the axis of the cue. They are coming together at the angle that the pin provides and then the joint faces pull the connect into linear alignment. In cues where the pin to insert fit is loose this is usually not much of a problem as there is clearance in the threads to allow this alignment. In cues where the pin and insert are a snug fit, it takes much more effort to gain alignment as you are either stressing the pin or the insert.

I recently worked on a cue with a radial pin that was not installed correctly. It's hard to not install a radial pin correctly if the directions are followed. In this case, the pin at it's tip spun perfectly when the cue was in the lathe. The problem was that the base of the pin where it comes out of the joint, had a large yaw to it. This scenario was caused from the drill bit drilling a hole that was not centered and in alignment with the axis of the butt. The alignment channel for the barrel was then enlarged some so that when the pin was glued into place the tail stock center was brought down to center the nose of the pin. After the glue had dried the nose of the pin was now perfectly centered but the pin itself was canted.

Dick

Dick

 

[cueman]

Dick,
I agree with your conclusions. It also makes me want to bring up another point. Some people seem to think the center hole in the end of the joint screw is to be used as their turning center. I tried that on some cues in my early years and some were perfect and some were not. Unless the pin is installed dead perfect and the cue does not warp any at all during the tapering process, I think this is a bad idea. It is much more important that the pin be dead center where it goes into the cue than making sure the very end of it is the part that is dead center.
Needless to say I abandoned that turning method many years ago. I do still put the center hole in the end of most of my pins, but it is more of a tradition than funtional part now. Although I do use it sometimes when polishing, but not for tapering.

 

[KJ Cues]

Another condition that falls into this category is when both the pin & the insert are not installed on the center-line of the cue. This is most evident when connecting the cue (or breaking it down). You will see the perimeter of either collar oscillate depending on which one you're turning.

This is not such an earth-shattering condition and is compensated for by the builder by block sanding the joint once the cue is assembled. I see this most often in low-end cues. The cue will still go together straight and roll straight and there should be no internal stress at the joint.
It does complicate things when I'm trying to mate & match a custom shaft to the cue though. My work starts out on the money but now I've got to dummy it up to fit this particular cue. Turns out to be more work than it needs to be and any sense of correctness is lost.

To add to what Chris described, I too (many years ago) had been taper-turning off of the center hole in the pin. It didn't take me long to realize that this is a very bad thing to do. If the pin is canted even the slightest, it throws the whole cue off. The longer the exposed pin, the more severe the center-line of the cue will be affected.

 

[rhncue]

Another condition that falls into this category is when both the pin & the insert are not installed on the center-line of the cue. This is most evident when connecting the cue (or breaking it down). You will see the perimeter of either collar oscillate depending on which one you're turning.

This is not such an earth-shattering condition and is compensated for by the builder by block sanding the joint once the cue is assembled. I see this most often in low-end cues. The cue will still go together straight and roll straight and there should be no internal stress at the joint.
It does complicate things when I'm trying to mate & match a custom shaft to the cue though. My work starts out on the money but now I've got to dummy it up to fit this particular cue. Turns out to be more work than it needs to be and any sense of correctness is lost.

To add to what Chris described, I too (many years ago) had been taper-turning off of the center hole in the pin. It didn't take me long to realize that this is a very bad thing to do. If the pin is canted even the slightest, it throws the whole cue off. The longer the exposed pin, the more severe the center-line of the cue will be affected.

An off center pin doesn't bother me when building an extra shaft as I have a method of easily compensating for it and getting both the shaft and the butt to roll good either together or apart. The real problem arises if farther down the road either the shaft or the butt need to be re-faced. When refaced, the shaft now contacts the joint at a different place so the deco-ring will protrude on one side and be low on the other of the joint.

Dick