Extending 3/8x10 threads in shaft

muskyed

muskyed

AzB Silver Member
Silver Member
Some may remember a year or so back I was looking for suggestions as to adding a little weight to some McDermott shafts of mine so I could take a corrosponding amount off the butt weight bolt.
Suggestions were adding a brass 3/8-10 insert of which I thought was a good idea, or drill a deep hole for a 1/4" screw, simple also but not much weight. Took awhile to get a different lathe with a large bore, then honestly just never got around to it.
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I've since got a bit of stuff like taps and pins and noticed I had some brass 3/8-10 joint protector pins so I thought why not machine down the fat end and dremmel a screwdriver slot in it and drill and tap the hole deeper.
I modified the pin, and it weighs .3 oz, so what I'm hoping to find out is can I just drill a deeper hole, the minor of the hole in the shaft, and just run the tap in further to accomodate the length of the pin?
 
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muskyed said:
I've since got a bit of stuff like taps and pins and noticed I had some brass 3/8-10 joint protector pins so I thought why not machine down the fat end and dremmel a screwdriver slot in it and drill and tap the hole deeper.
I modified the pin, and it weighs .3 oz, so what I'm hoping to find out is can I just drill a deeper hole, the minor of the hole in the shaft, and just run the tap in further to accomodate the length of the pin?
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If the tap is long enough, why not. I've done that kind of thing on a butt to get a 3/8 16 weight bolt in back of the pin to give the butt an ounce of forward weight. Had to plug it to retap for the pin after though. The 3/8 16 tap is a deep tap and whole lot longer than the standard 3/8 10 I have.
 
Thanks, that is what I figured. I guess, worst case situation is if I had problems, I could just plug it and do it in one clean drill & tap. I have 3 of these McDermotts that I don't use except that one of them I use as a breaker with a Pechauer black Ice shaft.
One is a beautiful no wrap, but just a little too butt heavy for me so I'm sort of interested to see if I can change that balance slightly. Will it replace my Schon's, not likely, just something I wanted to try. I really don't think .3 oz will move it much.
 
So I added that pin, was quite simple actually. The pin was .3 oz, but I only took .1 oz off the weight bolt as I had wanted the weight a little heavier anyway. Because of that the balance didn't change much, moved a 1/4". Not sure how much it would of changed if I had taken off the .3 oz that I added to the shaft. All in all, I was able to get the weight where I wanted with a slightly better for me, balance point also.
Was a good test case as I just purchased a Jacoby cue with the radial joint, and while I really like the cue, it also is rear balanced, but I have the weight where I like it. Just looked at those taps and are expensive for a one time deal. Jacoby is close to me so I think I'll just take it to them and hopefully have them drill and tap the shaft for me.
 
dendweller said:
If the tap is long enough, why not. I've done that kind of thing on a butt to get a 3/8 16 weight bolt in back of the pin to give the butt an ounce of forward weight. Had to plug it to retap for the pin after though. The 3/8 16 tap is a deep tap and whole lot longer than the standard 3/8 10 I have.
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I bought a 3/8 10 tap from cue fits and welded it to another cheap tool shank to make it 8 inches long.
 
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Well I sent a couple emails to Jacoby but no reply yet, so I was bored today and decided to do it myself in a slightly different but similar way. I had some 5/16x3" pins and a 5/16 tap for them so I sample bored a few holes in the end grain of some maple, and then drilled a deeper hole in the radial threaded shaft and threaded it. then I took a 3" 5/16 pin and cut it somewhat in half but slightly different and put a screwdriver slot in both pieces. So what I ended up with was one piece at .3 oz, and the other at .365 oz. I used the .365 oz one.
This was simpler than the other way I did it as I had a touch more clearance for the drill bit, and it tapped easier. By the time I took a corresponding amount off the weight bolt the balance point moved from about 18" to 18 9/16". I really like it there, may actually like it better than my Schons at about 19". Splitting hairs now I guess, either is fine where they are and I don't notice so much difference when switching cues now.
 
muskyed said:
Well I sent a couple emails to Jacoby but no reply yet, so I was bored today and decided to do it myself in a slightly different but similar way. I had some 5/16x3" pins and a 5/16 tap for them so I sample bored a few holes in the end grain of some maple, and then drilled a deeper hole in the radial threaded shaft and threaded it. then I took a 3" 5/16 pin and cut it somewhat in half but slightly different and put a screwdriver slot in both pieces. So what I ended up with was one piece at .3 oz, and the other at .365 oz. I used the .365 oz one.
This was simpler than the other way I did it as I had a touch more clearance for the drill bit, and it tapped easier. By the time I took a corresponding amount off the weight bolt the balance point moved from about 18" to 18 9/16". I really like it there, may actually like it better than my Schons at about 19". Splitting hairs now I guess, either is fine where they are and I don't notice so much difference when switching cues now.
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Did you epoxy the weight in or leave it just threaded in so you could remove it later if you chose to?
 
No didn't glue it in, it's pretty tight when I tighten it down and hasn't come loose yet. Do you think there is a chance of wrecking the threads if I don't glue it in, if so I'll just glue it in. At .3 oz I didn't think there would be much of a stress problem on the threads. Also, I'm making a trip down to Jacoby to pick up a quick release extension and bumper for it and their quick release bumper is slightly heavier than their standard bumper that comes with the cue so until I know where I want to be at, I don't plan on locking the weight in the shaft unless you think I should. No big deal glueing it in, as I can do my final weight adjustment with the weight bolts. I got a kit from them with multiple sizes, and I could cut some back or grind some off to get right where I want. If I take too much off, they are just 3/8 allen bolts that I can get anywhere.
Thinking about it, might be better if I glue it in as while it tightens up fine now, there probably is some stress on the shaft as the tightening up effect is probably from the fact that the tap doesn't fully tap to the bottom of the threads. Or maybe I'm just overthinking it now because you asked? Ha ha.
 
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muskyed said:
No didn't glue it in, it's pretty tight when I tighten it down and hasn't come loose yet. Do you think there is a chance of wrecking the threads if I don't glue it in, if so I'll just glue it in. At .3 oz I didn't think there would be much of a stress problem on the threads. Also, I'm making a trip down to Jacoby to pick up a quick release extension and bumper for it and their quick release bumper is slightly heavier than their standard bumper that comes with the cue so until I know where I want to be at, I don't plan on locking the weight in the shaft unless you think I should. No big deal glueing it in, as I can do my final weight adjustment with the weight bolts. I got a kit from them with multiple sizes, and I could cut some back or grind some off to get right where I want. If I take too much off, they are just 3/8 allen bolts that I can get anywhere.
Thinking about it, might be better if I glue it in as while it tightens up fine now, there probably is some stress on the shaft as the tightening up effect is probably from the fact that the tap doesn't fully tap to the bottom of the threads. Or maybe I'm just overthinking it now because you asked? Ha ha.
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Just remember it's there and it could loosen, you don't want to screw it on the butt and have it bind. One turn to much against a loose screw could cause a chisel effect.
 
The weight bolt for shaft should be fit tight to prevent it loose day by day. To me, the hole diameter should be less than the minor diameter of thread rod 0.002".
 
For me the minor was one with the best fit I had available at the time without being too tight. I tried three sizes of bits, all apx .010 apart on some maple I had laying around and went with the smallest drill of the three. I had another bit apx .012 smaller but while I felt I could tap it, I was afraid of the tap seizing up somewhat at that hole diameter. It actually was a little tough backing the tap out with the bit that I did use. My chart showed me a bit that was .004 smaller, but I didn't have that and honestly the hole I drilled wasn't loose at all. Silicone would work also for these threads on this shaft weight pin.
As to the butt weight bolts, Jacoby has drilled a very deep hole, probably about 6" or so and the screws screw in very tight, so tight that they squeak going in and you have to really grip the butt when putting in and taking them out.
All in all, it's been a fun experiment as I have done to two different shafts and did it two different ways. Personally, I prefer doing it this second way, by just drilling a hole and tapping for a 5/16 pin. Much easier and less stressful as the drill bit required easily cleared the existing 3/8x10 and radial threads in the shafts. I didn't put a lot of weight in the shafts, .035 oz, but after adjusting the butt weight bolt, it moved the balance over 1/2" and that was what I was hoping to achieve.
If it was my only cue, I probably wouldn't have bothered and just shot and got used to it, but I have other cues I play with, and this allowed me to get them to somewhat better match up.
 
I've decided I'm going to glue in that weight pin in the shaft so I don't have to think about it loosening every time I use it. No big deal really as it accomplished what I wanted to do, and any further weight adjustment can be done with the butt weight bolt.
 
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