The wobbles

opiesbro

opiesbro

Big Al Customs
Silver Member
So I am in the middle of a build for a customer. I am just all but done and fit he shafts to the butt. I rolled the first shaft and its good...I rolled the second shaft and it wobbles. This wobble is not only rolling it on the table but also when the cap is on the bed and joint on the rail. During the build I indicated all prices in on the lathe, bored starter holes, and even replugged the shafts because the tailstock was out. One interesting thing is I thought it might be the joint faces so I unscrewed the shaft a little and same result. Then I repeated over and over again to see if it got worse. What I found was it rolled perfect at certain spots when screwed on at different distances. I'm at a loss because I have put everything back in the lathe and indicated the joint then put it on the pin. The pin is only about .002" or less out at the very end. The joint I screwed a pin in and did the same and it was less than .001". Not sure where to go now.

uploadfromtaptalk1406948072703.jpg
 
Is the wobble in the middle of the shaft when rolled separately or does the tip come off the table? If in the middle, it's not the facing, just the way the shaft wood has moved, IMO. You re-plugged the shafts due to a tailstock issue, did you redo the joint pin also? That was done with the same tailstock issue I would assume. That would affect how the tip rolls. Also, has the humidity levels gone up and down recently? That can play havoc on shaft wood really quickly. If you spin the shaft between centers on a lathe, how does it look?
Dave
 
Hi,

If the shaft rolls true on the table and the good shaft does not bounce at the joint when rolled on the rail then I would guess that your thread in the bad shaft could be canted a hair.

You can Plug it, indicate the shaft, then re tap.

Before doing that I would indicate the cue in the lathe and then check the pin again. The fact that the cue behaves differently when it is rotated off the face may be an indication that the pin be out a hair and the threads in the shaft being out a hair also. In one position the cue behaves ok then rotate it and all hell breaks loose. Two errors can work to a good end result then go 180 degrees and then can work against the concentricity. This may also explain why one shaft rolls good.

Every cue maker has faced this situation so don't feel bad. Just test you butt and two shafts again, take a deep breath and do what need to be done. If your pin is running out it is a pain in the arse but you know what has to be done.
Good luck.

JMO,

Rick
 
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Dave38 said:
Is the wobble in the middle of the shaft when rolled separately or does the tip come off the table? If in the middle, it's not the facing, just the way the shaft wood has moved, IMO. You re-plugged the shafts due to a tailstock issue, did you redo the joint pin also? That was done with the same tailstock issue I would assume. That would affect how the tip rolls. Also, has the humidity levels gone up and down recently? That can play havoc on shaft wood really quickly. If you spin the shaft between centers on a lathe, how does it look?
Dave
Click to expand...
The shaft rolls pretty straight off the butt and when its screwed onto the pin in a couple depths. When the pin was installed I used a self centering radial. I bored the hole for the barrel and made it snug so i don't think it's the pin. I also have a Jacoby shaft that I use and it rolls normal on the butt. The first shaft I plugged and redrilled rolls good. I just don't understand how it rolls good at certain depths on the pin and how the facings aren't pulling it straight.
 
opiesbro said:
The shaft rolls pretty straight off the butt and when its screwed onto the pin in a couple depths. When the pin was installed I used a self centering radial. I bored the hole for the barrel and made it snug so i don't think it's the pin. I also have a Jacoby shaft that I use and it rolls normal on the butt. The first shaft I plugged and redrilled rolls good. I just don't understand how it rolls good at certain depths on the pin and how the facings aren't pulling it straight.
Click to expand...

Don't let too many things lead you astray.

By the look of your pictures alone, it appears that the tapped hole is not concentric with the outside of the cue shaft.

Bore and plug the existing hole.
Mount the cue shaft in your lathe so that the entire shaft has little or no runout. If you're using a back chuck, it's very easy to "bow" the middle of the shaft that is inside the lathe spindle. To ensure this doesn't happen, lightly tighten both chucks, then back them off and re-tighten one at a time making sure that the shaft is under no stress from the other chuck. When you are done, both ends should run true, and there will be no "bow" in the middle.
Re-drill, bore and tap the hole making sure that none of these operations show any wobble or movement.
Clean up the face and countersink and you should be good to go.

Another choice is to use a steady rest and only chuck down on the tip end of the shaft. It's much more difficult to mess it up that way.


Royce Bunnell
www.obcues.com
 
JoeyInCali said:
How do you tap?
With a tap handle or drill chuck?
What kind of lathe?
Click to expand...
Its a deluxe with a 4 jaw on the front. I put the tap in the tailstock and leave the bolts loose to the bed so it will float. The tap for the shaft is the undersized with the pilot.

I purchased a 4 jaw independent adjust that I have to modify to fit. Then my next purchase is a 14X40.
 
opiesbro said:
Its a deluxe with a 4 jaw on the front. I put the tap in the tailstock and leave the bolts loose to the bed so it will float. The tap for the shaft is the undersized with the pilot.

I purchased a 4 jaw independent adjust that I have to modify to fit. Then my next purchase is a 14X40.
Click to expand...



When your shaft is chucked up in both chucks, is there any runout at the tip of the shaft? If I understand it right, the tip is hanging out of the left side of the headstock. It must run dead true. If not, the hole you bore and tap will install the shaft to exactly the same runout as you would see when the shaft is in the lathe.


Royce Bunnell
www.obcues.com
 
RBC said:
When your shaft is chucked up in both chucks, is there any runout at the tip of the shaft? If I understand it right, the tip is hanging out of the left side of the headstock. It must run dead true. If not, the hole you bore and tap will install the shaft to exactly the same runout as you would see when the shaft is in the lathe.


Royce Bunnell
www.obcues.com
Click to expand...
It appeared to be running true at lower speeds that I would use to bore. Only when I sped it up to where I would sand or buff did it start to wobble at the tip. I will plug and start over again. I won't send trash out the door.
 
Are you positive that the shaft isn't warped near the joint end, which would still roll good across the table? If you have already rebored & retapped and still have the same problem, then doing it a third time likely isn't going to change anything. While it's possible that you screwed up twice on the same shaft and got the others right on one try, it doesn't seem logical. Something's wrong with the shaft. Have you considered cutting the rings off and gluing them on a fresh shaft?
 
qbilder said:
Are you positive that the shaft isn't warped near the joint end, which would still roll good across the table? If you have already rebored & retapped and still have the same problem, then doing it a third time likely isn't going to change anything. While it's possible that you screwed up twice on the same shaft and got the others right on one try, it doesn't seem logical. Something's wrong with the shaft. Have you considered cutting the rings off and gluing them on a fresh shaft?
Click to expand...
I will check it again for warp. If doing the joint again doesn't fix it I will make another.
 
I haven't piped in because you've been getting great advice, but when you posted earlier "The shaft rolls pretty straight off the butt " - I raised my eyebrows - pretty straight? It is or it isn't.
Anyway, it will be educational to learn what the problem is when you solve it, and that's one of the great things about this forum is learning.
Gary
 
Is that boring bar razor sharp?
You might be pushing wood instead of peeling .
The tap compresses the hole to size, hence crooked threads on some part.
Best radial threads I could achieve was after I started milling the holes in the shafts.
 
There have been lots of good suggestions.
I think back to basics is a good place to start.
Check to see if the lathe is still correctly set up, so all 3 headstock, steady rest and tailstock all align , at the headstock end and at the far end of the lathe.Any slight warp of the bed or twist can easily throw your machine out. Even a change in temp from when it was set up to being used now can effect it. I have seen that with my set up. Just a small amount more torque on the front or back screw of the headstock clamp is enough to move the headstock on the Taig type lathes at the far end of the bed a very measurable amount.In some cases the error will be in the vertical plane not the horizontal, in which case, the way the bed is clamped will need to be adjusted to get it to zero.
Any miss alignment, and the shaft or handle will easily bend a very small amount without showing any signs of being not straight.
It looks like a radial pin was used. I bore the hole for the tap so it is a neat fit on the tap but can still slide, so not loose.
You should be able to get the pin to run better than 0.002 inches.
When you tap the shafts, and take the tailstock away from the tap in the shaft, so the tap is still in the cue shaft, when rotating, the tap shaft should still be running true.
An error here can be as simple as your drill chuck does not hold a pin true to the run of the machine. I have seen plenty of bad drill chucks that do not work as intended.
Some where along the line, there is small errors and with one set up, they look to have almost cancelled each other out, the other set up has exaggerated or you have booked error. We call it booked error, as when the parts are matched, the error is exactly doubled. On joint faces, the error is magnified 34 times approx at the tip. Smaller joint diameters, and this number goes higher.

Neil
 
I've been thinking about this all day yesterday trying to remember everything I did. One thing I don't think happened is when I took the shaft out I don't remember having to loosen the back chuck. I'm thinking that it may have came loose while in use or I didn't sinch it down to begin with. I bet the hole is nice and straight to the orientation the shaft was at that time. That's why when I put a pin in it I saw it run true. Regardless it won't be a big deal to plug it again.
 
Did you reface the shaft? I don't know what kind of lathe you have but have seen face problems do the same thing. When you screw the shaft on the butt is it flush with no over hang? If they line up then it is a face problem or the shaft is not straight. Sometimes have to face a couple of times to get right as the tool post has some play or the tool is dull.

If it overhangs on one side and the butt overhangs on the other then it is a bore, plug, drill and tap the shaft to fix.
 
opiesbro said:
I've been thinking about this all day yesterday trying to remember everything I did. One thing I don't think happened is when I took the shaft out I don't remember having to loosen the back chuck. I'm thinking that it may have came loose while in use or I didn't sinch it down to begin with. I bet the hole is nice and straight to the orientation the shaft was at that time. That's why when I put a pin in it I saw it run true. Regardless it won't be a big deal to plug it again.
Click to expand...

I think you're looking in the wrong area. It's nothing wrong with the machine, and the rear chuck would have to be so loose that the shaft would rattle around in it at high speed. Spin the shaft as if you are going to face it, but without the tailstock or steady rest. Have the shaft chucked up but unsupported at the tip end. Indicate the joint so it turns true, all the while having no visible runout at the tip. When you achieve this, you can then slip on a steady to support the shaft for making your face cut, and you can be 100% sure it's right.

I don't mean to sound like a broken record, but I'm betting the shaft has movement that will prevent you from ever being able to get it chucked up true. You don't even have to make a new shaft to compare it to. Follow the same exact steps with a straight shaft blank & see how easy it is to get chucked up true compared to the shaft you have already made. This is why one shaft was perfect but nothing you do seems to work for this one. You should never support the tip end of the shaft for facing until you can first observe it spinning true while the joint is also turning true. It's that simple. And if you cannot get both ends turning true no matter what you do, then the shaft is junk and is wasting your time.
 
Brickcues said:
Did you reface the shaft? I don't know what kind of lathe you have but have seen face problems do the same thing. When you screw the shaft on the butt is it flush with no over hang? If they line up then it is a face problem or the shaft is not straight. Sometimes have to face a couple of times to get right as the tool post has some play or the tool is dull.

If it overhangs on one side and the butt overhangs on the other then it is a bore, plug, drill and tap the shaft to fix.
Click to expand...
I have not refaced it again. I have a deluxe. The shaft does not have finish on it and is about .010" small from the butt. The mismatch feels even all the way around. The tool I used was a PCD diamond shape from kennametal for the facing.uploadfromtaptalk1407081584811.jpg
 
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