Cutting wood threads with a tap.

Lexicologist71

Lexicologist71

Rabid Schuler fanatic
Silver Member
I've had success cutting 5/8" 18TPI threads in 3 consecutive cues made of curly maple. I received some curly maple from a career furniture maker that was kiln dried and then stored for an undefined length of time. I tried to cut the same threads in this wood using the same sized hole as the first 3 cues (per the tap mfg directions) but the threads keep stripping. I cut the forearm shorter twice and rebored the hole twice, but the same thing keeps happening. Could the wood be too dry? If so, should I wipe with a damp sponge before waxing and tapping? I still have enough of this curly maple to make at least a dozen cues. I'd hate to use it for coring as it does have a nice figure to it. It isn't insanely curly, but it is consistently curled every inch or so. If anybody has guidance, it'd sure be appreciated.

This post was originally concerning the A joint, but thanks to everyone who posted. Any good info is useful info.
 
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Sometimes I bore my hole, pour thin CA in and let soak. Pour out the CA, let dry, rebore and tap. Should work.
 
Trying to help Paul with his pin

Lexicologist71 said:
I've had success cutting 5/8" 18TPI threads in 3 consecutive cues made of curly maple. I received some curly maple from a career furniture maker that was kiln dried and then stored for an undefined length of time. I tried to cut the same threads in this wood using the same sized hole as the first 3 cues (per the tap mfg directions) but the threads keep stripping. I cut the forearm shorter twice and rebored the hole twice, but the same thing keeps happening. Could the wood be too dry? If so, should I wipe with a damp sponge before waxing and tapping? I still have enough of this curly maple to make at least a dozen cues. I'd hate to use it for coring as it does have a nice figure to it. It isn't insanely curly, but it is consistently curled every inch or so. If anybody has guidance, it'd sure be appreciated.
Click to expand...

Paul,

I don't believe your problem is the tapping, I believe it lies within Dick's question and observation. Here is my take on it and believe me I was in your shoes asking the same questions a few years ago developing my guidelines and procedures for repeatability. If you are confused in any way about my description in this post, give me a call at 847 641-0276 for clarification.

I cut my threads with a "Drill Tap" and a "Bottom Tap" and get my pins to indicate between 0 and 1/4 thou every time. I understand about the differential between the wood's hardness within the radial wall of the minor hole and that is very important.

When I install my pins with the epoxy they always initially indicate between 1 and 2 thousands off and sometimes more than that. I attribute this to the hardness factor as described above. When I drill and tap into aluminum for example and install my pin, it runs pretty much the same as my chuck and validates my previous observation.

I know 5 cue makers in my area and we are all very open and supportive with each other. We all acknowledge to each other that before the epoxy sets we all lever our pins or bump them into our tolerances after indication and locating the high side.

I have a .372 centering barrel on my pin and I have learned that boring my hole to receive the barrel at a close tolerance to that barrel was actually counter productive to my final pin set. My opening up that bore from .373 to .376 gave me enough room to lever my pin to the correct location. When I had this tolerance too tight and had to lever the pin I could not get the pin to adjust and it resisted and moved back to the high spot. Once I opened that bore tolerance, I was able to actually move the high spot to the opposite jaw number on my chuck. It was only then that I was able to extrapolate the lever pressure and dial in right in. I use Loctite Hy-Sol for my pins and it cures in 36 hours and is the hardest stuff I have seen. Great for pins.

I know how to live thread and have that capability on my lathe but I choose not to do it because after live threading you still have to lever your pin for the same reasons.

To those who suggest that someone has a problem if they don't live thread, please answer this question if you will. After you live thread the hole do you epoxy your pin in and wipe off the juice and walk away without indicating. Or do you put out your high precision indicator like me and massage your pin to zero or real close. If you have to massage the pin then live threading is no better than tapping. I have asked this question many times to some that have suggested that I have a problem if I use a tap and got nothing but silence for an answer. If you can testify that you live thread, epoxy the pin in and walk away knowing it is perfect in wood, I will be the first to say live threading into wood is better.

People who are asking a questions on this form are usually at a point where they are confused because as Paul said, "it worked real good on the last few times and now theres a problem". I have a pretty good idea if paul would have bored just a little more that he would have been able to move the pin a little without side wall resistance on one side.

I hope Paul gets through this little speed bump he is experiencing and I think with a little bit of support he will be nailing every pin with confidence. I got to my place without anyone's help as I was trying to bore to a body fit because I had a mind set that the centering barrel was where it was at. It was only after making a mistake and boring a little past my dimension that I found my salvation. That mistake was the first cue I made with zero run out after the epoxy cure. Go figure.

Live threading is a very good way to go but is not a panacea. In this case there are two ways to skin a cat. Both work very well if you are flying the airplane, not visa versa.

Rick Geschrey

Here is my pin a 3/8" 14 tpi with centering barrel and 3/8" 16 tpi inserting threads into the butt. Focusing on the centering barrel feature blinded me to the bigger picture.

P1050975.jpg
 
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To those who suggest that someone has a problem if they don't live thread, please answer this question if you will. After you live thread the hole do you epoxy your pin in and wipe off the juice and walk away without indicating. Or do you put out your high precision indicator like me and massage your pin to zero or real close. If you have to massage the pin then live threading is no better than tapping. I have asked this question many times to some that have suggested that I have a problem if I use a tap and got nothing but silence for an answer. If you can testify that you live thread, epoxy the pin in and walk away knowing it is perfect in wood, I will be the first to say live threading into wood is better.
I indicate the pin's pilot no matter how it's installed.
I don't know why it matters as long as the pin's minor or alignment barrel is a dead on, the pin should be dead on unless the threads are way off.
The threads are not the register.
I've seen mangled tapped threads on veneered blanks.
But, Lex is asking about 5/8 18 tpi threads on maple.
5/8 18 taps you see were not meant for WOOD.
They were meant for steel. The minor and major spec'd out were meant for steel . Not wood.
18 TPI might be a coarse thread for steel but not for wood.
I suggest going to 13 tpi with three taps . Start smaller then get bigger.
If you goop up that hole with CA then wax, it would require a lot of cleaning and decontamination for the epoxy to really do it's job.
It's easy to clean up male threads but not tapped blind holes .
Joey~Likes custom-ground threaders~
 
One of the problems with a tap and wood is they basically don't cut anything. They tear through it. I'm sure you've noticed the difference in the different types of wood you've tapped. Coco for instance is going to accept a tap a lot differently than maple. Why? is the question you have to answer to yourself. I have tried almost every technique one could think of to stabilize a hole prior to tapping to get repeating results. The SG..the wax (for the life of me I can't understand why anyone would use wax on a hole or a tenon they are going to apply glue to and expect optimal results on the bond. Try gluing a piece of maple to a block of wax and report back your findings.)

Until you have a live tooling setup and understand the proper way to do things you are going to have hit and miss results. The only thing a tap is good for is cleaning up a live tooled hole after the piece has been removed from the lathe. Insanity has been described many times as doing the same thing over and over and expecting different results. Continue to use a tap on your holes and you will undoubtedly receive different results every time you do so. So I guess you wouldn't be considered insane. I only use a tap for one operation in cue building and I had it special made and ground for a specific op that works as well as living tools but speeds up the job for that specific operation and I use it as a hand tap not in the lathe.
Why should anyone expect precision results yet use one of the worst tools and setups for trying to achieve it?
IF you are just learning and must use a tap I wouldn't use anything but a 10 or 11 tpi to cut into wood. You'll at least get a higher percentage of acceptable work.

All of this is just the opinion of someone who has already beat their head against the wall numerous ways to get optimal results before they found the best. Take it for what it's worth.
 
OP... you asked if wood could be too dry? A moisture meter will answer that question but any one online would just be guessing. You should also have a clue by the feel/sound of the chips when you drill. If the wood is too dry to tap it is also too dry to make a good shaft with. Assuming you tapered the shaft before cutting the joint you should also have chips from that process that would tell you if the wood was over dry or not. Also very important to back the tap up every couple of threads and break the chip and blow it out. As Joey suggests, a 5/16x18 is not exactly the best for tapping into wood and extra care must be taken.

Bob Danielson
www.bdcuesandcomix.com
 
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BarenbruggeCues said:
One of the problems with a tap and wood is they basically don't cut anything. They tear through it. I'm sure you've noticed the difference in the different types of wood you've tapped. Coco for instance is going to accept a tap a lot differently than maple. Why? is the question you have to answer to yourself. I have tried almost every technique one could think of to stabilize a hole prior to tapping to get repeating results. The SG..the wax (for the life of me I can't understand why anyone would use wax on a hole or a tenon they are going to apply glue to and expect optimal results on the bond. Try gluing a piece of maple to a block of wax and report back your findings.)

Until you have a live tooling setup and understand the proper way to do things you are going to have hit and miss results. The only thing a tap is good for is cleaning up a live tooled hole after the piece has been removed from the lathe. Insanity has been described many times as doing the same thing over and over and expecting different results. Continue to use a tap on your holes and you will undoubtedly receive different results every time you do so. So I guess you wouldn't be considered insane. I only use a tap for one operation in cue building and I had it special made and ground for a specific op that works as well as living tools but speeds up the job for that specific operation and I use it as a hand tap not in the lathe.
Why should anyone expect precision results yet use one of the worst tools and setups for trying to achieve it?
IF you are just learning and must use a tap I wouldn't use anything but a 10 or 11 tpi to cut into wood. You'll at least get a higher percentage of acceptable work.

All of this is just the opinion of someone who has already beat their head against the wall numerous ways to get optimal results before they found the best. Take it for what it's worth.
Click to expand...

You mean you don't taper shafts with single point tool ?:D
 
What Joey said. The threads are not the register, so whether they result in zero runout without any need for checking isn't the end all and be all to live threading, and isn't really the point. Nobody is going to live thread and not check the results, so your challenge regarding this is the criteria to determine whether live threading is better than tapping is poor.

Due to a wandering tap, live threading, IMO, on average, has more potential to be truer and result in less runout. A wandering tap can be overcome by a good bored hole and a piloted tap, and good technique.

The obvious advantage is the thread form is simply better when live threading, particularly in maple. If the thread form is better, the fit (whether it is being mated to a metal pin or another live threaded piece of wood, etc) is likely to be better with tighter tolerances. This should result in more surface area for contact and adhesion, ie, less solid chunks of glue. If this isn't a concern to you, and you are able to get very accurate results via tapping, then I would agree maybe live threading offers no advantages to you.

Kelly
 
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good video...

for you cuemakers that are hand tapping...
here is a video from MIT that seems to cover threading with a tap pretty well. Any comments on if this is a good method for cues?? the tapping is the first section of the video and starts at approximately 1 minute into the vid.
I would assume that a piloted tap improves the end results?
Jeremy

http://techtv.mit.edu/videos/134-machine-shop-9
 
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EddySJ said:
For you cuemakers that are hand tapping...
here is a video from MIT that seems to cover threading with a tap pretty well. Any comments on if this is a good method for cues?? the tapping is the first section of the video and starts at approximately 1 minute into the vid.
I would assume that a piloted tap improves the end results?
Jeremy

http://techtv.mit.edu/videos/134-machine-shop-9
Click to expand...

Hi,

Do you guys that live thread have to lever or bump your pin during the install process?? I have asked this question 5 times in the open forum when ever this point comes up and I never seem to get an answer. I only ask this question because I would really like to know. I am not trying to bust balls and I admit live threading is better but is it really needed in a hole that is going to be epoxied. We are talking cue sticks here not helicopter rotor seal retaining nuts.

If you do have to bump the pin a little, it is six to one half and dozen to the other. If the pin is right on imbedded in the wood without bumping, then I will shut up.

Paul wanted some help in this area and declared himself by stating he wanted to use a tap and could not afford the live thread.

Live threading the shaft into wood is another story.

If the pin is indicating true as the epoxy sets then what's the difference how it looks like inside there when cured.

I will stand by and wait for an answer.

Respectfully,

Rick
 
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scdiveteam said:
Hi,

. . . .If the pin is indicating true as the epoxy sets then what's the difference how it looks like inside there when cured.

I will stand by and wait for an answer.

Respectfully,

Rick
Click to expand...

Rick,

I am not always the most intuitive guy . . . can you explain a little more what you do when you "lever the pin"? I see in my mind one way, but I don't see how you lever it and then check the runout as the epoxy dries. And if that is a technique you'd rather not share, I understand.

This thread has been very informative!

Thanks All!

Gary
 
An accurately installed pin, by definition, MUST run true.

scdiveteam said:
I have a .372 centering barrel on my pin and I have learned that boring my hole to receive the barrel at a close tolerance to that barrel was actually counter productive to my final pin set. My opening up that bore from .373 to .376 gave me enough room to lever my pin to the correct location.
Click to expand...

My thoughts on this common problem:

If your .373 bore is concentric & the tapped hole that retains the pin is accurately tapped & the pin itself is straight - the installed pin MUST run true. If the pin runs out, then one of the 3 conditions isn't being met.

Let's assume the pin is straight & let's assume that your .373 hole (you DID bore it, didn't you?) is concentric. That leaves the tapped hole as being slightly off & distorting the desired location of the pin.

On the pins I use, the retaining threads are slightly undersize & only 1/2" long. The locating barrel (.382 on mine) is 1.125" long. The combination of a long locating barrel & short threads that can "float" works together to promote an accurately installed pin, even when using a tap.

There's another subtlety to this pin configuration: almost ALL taps are .005/.006" oversize. It's not a coincidence that the locating barrel is the same size. The bored hole now acts as a guide for the tap.

Now please understand that I'm not knocking your pin design but I can see room for improvement: shorten the retaining threads & lengthen the locating barrel. Making those threads undersize will also help. Trust me, you will never have one loosen or break free. Look at all the cuemakers who don't even tap their hole but simply press the joint pin in a hole a few thou undersize. They seem to be having good luck...for now :-)

I bored & tapped for many years with good results but since I live-tool everything, life is just so much easier. Do I wipe off the excess glue & walk away without checking the pin location? No. That would be foolish. It takes only a few seconds to verify that it does, indeed, run true. And if, by chance, there is a problem, I'd rather catch it before the epoxy sets up. That said, I have not had to force a pin into location in a long time.

And, a final thought... If you are forcing the tip of a pin INTO location then you are, at the same time, forcing the base of the pin OUT of location. That's why opening up the bore to .376 helps.
 
dzcues said:
My thoughts on this common problem:

If your .373 bore is concentric & the tapped hole that retains the pin is accurately tapped & the pin itself is straight - the installed pin MUST run true. If the pin runs out, then one of the 3 conditions isn't being met.

Let's assume the pin is straight & let's assume that your .373 hole (you DID bore it, didn't you?) is concentric. That leaves the tapped hole as being slightly off & distorting the desired location of the pin.

On the pins I use, the retaining threads are slightly undersize & only 1/2" long. The locating barrel (.382 on mine) is 1.125" long. The combination of a long locating barrel & short threads that can "float" works together to promote an accurately installed pin, even when using a tap.

There's another subtlety to this pin configuration: almost ALL taps are .005/.006" oversize. It's not a coincidence that the locating barrel is the same size. The bored hole now acts as a guide for the tap.

Now please understand that I'm not knocking your pin design but I can see room for improvement: shorten the retaining threads & lengthen the locating barrel. Making those threads undersize will also help. Trust me, you will never have one loosen or break free. Look at all the cuemakers who don't even tap their hole but simply press the joint pin in a hole a few thou undersize. They seem to be having good luck...for now :-)

I bored & tapped for many years with good results but since I live-tool everything, life is just so much easier. Do I wipe off the excess glue & walk away without checking the pin location? No. That would be foolish. It takes only a few seconds to verify that it does, indeed, run true. And if, by chance, there is a problem, I'd rather catch it before the epoxy sets up. That said, I have not had to force a pin into location in a long time.

And, a final thought... If you are forcing the tip of a pin INTO location then you are, at the same time, forcing the base of the pin OUT of location. That's why opening up the bore to .376 helps.
Click to expand...

Tap Tap Tap :)
 
dzcues said:
My thoughts on this common problem:

If your .373 bore is concentric & the tapped hole that retains the pin is accurately tapped & the pin itself is straight - the installed pin MUST run true. If the pin runs out, then one of the 3 conditions isn't being met.

Let's assume the pin is straight & let's assume that your .373 hole (you DID bore it, didn't you?) is concentric. That leaves the tapped hole as being slightly off & distorting the desired location of the pin.

On the pins I use, the retaining threads are slightly undersize & only 1/2" long. The locating barrel (.382 on mine) is 1.125" long. The combination of a long locating barrel & short threads that can "float" works together to promote an accurately installed pin, even when using a tap.

There's another subtlety to this pin configuration: almost ALL taps are .005/.006" oversize. It's not a coincidence that the locating barrel is the same size. The bored hole now acts as a guide for the tap.

Now please understand that I'm not knocking your pin design but I can see room for improvement: shorten the retaining threads & lengthen the locating barrel. Making those threads undersize will also help. Trust me, you will never have one loosen or break free. Look at all the cuemakers who don't even tap their hole but simply press the joint pin in a hole a few thou undersize. They seem to be having good luck...for now :-)

I bored & tapped for many years with good results but since I live-tool everything, life is just so much easier. Do I wipe off the excess glue & walk away without checking the pin location? No. That would be foolish. It takes only a few seconds to verify that it does, indeed, run true. And if, by chance, there is a problem, I'd rather catch it before the epoxy sets up. That said, I have not had to force a pin into location in a long time.

And, a final thought... If you are forcing the tip of a pin INTO location then you are, at the same time, forcing the base of the pin OUT of location. That's why opening up the bore to .376 helps.
Click to expand...

Thanks Bob,

Today I have some accurate tapered ID colletts matching my butt geometry that dialed in my concentricty.

I am going to have some new pins made out of Monel at some time in the next year and will be sure to include your undersized design feature to the engineering spec.

Thank you for sharing that with me, the idea is very logical. I appreciate it very much.

Rick
 
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On the pins I use, the retaining threads are slightly undersize & only 1/2" long. The locating barrel (.382 on mine) is 1.125" long. The combination of a long locating barrel & short threads that can "float" works together to promote an accurately installed pin, even when using a tap.
And undersized bottom threads where the major is a hair smaller than .375 ". :smile:
I believe Stroud with his radial pin came out with it first .
 
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