3/8 10 frustrations

dafunkdawg said:
Wow thanks for all of the input. I have not bored the hole because I do not have a small enough reamer. I do center drill then drill with a .25 bit then a 5/16. I have also tried following the .25 with a .295. I was using new but relatively inexpensive black oxide bits. I do have some select sizes of brand new cobalt bits from an industrial supply out in my shop. I will have to try to see if I have a decent size. I have ordered a .307 reamer for use with the Atlas tap that is coming. I have tried wax on the threads . I have not measured tro on my lathe but I have aligned tailstock and double checked it by putting pointed centers in each and they are pretty much on the money. It is a mid america lathe that I am using so I have no way to use live tooling.
I do have an Enco 14-40 that I have secured a purchase on from a friend but have quite a bit to do in the shop before I get it here. I have a 110' x 26' quanza hut style building that i snot sealed very well. I get a lot of condensation in it so I am going to frame up a 16x 24 room with a window unit in the back end for my "cue shop". That seems to be the most economical way to overcome the tropical rainforest climate here in Louisiana
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I'll suggest you forget about your reamer and drill bits for precision and finish the hole with a boring bar.

That aside, can you measure how big of a hole your .295 bit is actually making???

I know virtually nothing about that lathe, but if your chuck runs out .005 and you tail stock is .005 out of alignment, then you'd have big problems.

I'd also suggest you contact Todd(?) and speak with him.
 
Thanks to all of you guys for the overwhelming response to help. Just like anything, it looks as if you have thought of every possibility and tried everything but the longer you study it the more layers you uncover. I have a good solid page of notes from all of you and I am going to whittle away at it until I find my sweet spot. Maybe I will will post some results when I get it ready for primetime.
 
My normal routine for doing a modified 3/8 x 10 flat minor of .308 is to chuck up the shaft, or butt, run a dial indicator on it and shim as needed to get it to read as low as possible. Then I center drill it, then using a solid carbide 1/4" endmill, go in the depth I need, then follow with a .307" carbide drill. Then I use a tap handle as pictured, with a .308 piloted tap, then follow with similar tap that I cut the end off of to make a bottoming tap. Everything so far comes out right on, and with clean Very useable threads.
Not to knock anyone's method, but IMO, Using a phenolic insert or any other insert for that matter, is only for longevity of the threads, not for how clean you can make them. Live threading is awesome, but some here forget.....not everyone has the $$$ or equipment to do that. Very Usable threads can be done with proper procedures and Sharp taps.
Dave
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If I read this right you are trying to use a standard 3/8-10 tap and a modified flat bottomed pin. Is that right? If so you are mixing apples and oranges. If not,then I am all wrong.
Also, why are you tapping under power? To save time? There's no reason to hurry on such a critical operation.
My apologies if I misread your post.
HTH
Gary
 
Dave38 said:
My normal routine for doing a modified 3/8 x 10 flat minor of .308 is to chuck up the shaft, or butt, run a dial indicator on it and shim as needed to get it to read as low as possible. Then I center drill it, then using a solid carbide 1/4" endmill, go in the depth I need, then follow with a .307" carbide drill. Then I use a tap handle as pictured, with a .308 piloted tap, then follow with similar tap that I cut the end off of to make a bottoming tap. Everything so far comes out right on, and with clean Very useable threads.
Not to knock anyone's method, but IMO, Using a phenolic insert or any other insert for that matter, is only for longevity of the threads, not for how clean you can make them. Live threading is awesome, but some here forget.....not everyone has the $$$ or equipment to do that. Very Usable threads can be done with proper procedures and Sharp taps.
Dave
View attachment 423048
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I only tap radial threads these days because live threading gets me better results.
And I don't use the T handle tap holder anymore.
I just chuck up on the tap and spin the head chuck manually.
I trust my lathe bed and tailstock quill more than the T-handle tap holder.
I use linseed oil for lube and wood conditioning before tapping.
It smells nasty, but it sure works.
 
GBCues said:
Also, why are you tapping under power? To save time? There's no reason to hurry on such a critical operation.
My apologies if I misread your post.
HTH
Gary
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Why not tap 'under power' ? It has advantages and yes it's quick, no muss-no fuss.
Consider that with hand-tapping, you have start - stop, angle and lateral-load can change.
Tap mounted in the tailstock is perfect alignment start to finish.
My taps are marked for depth so under pwr, when I'm nearing a mark, I hit rev. on the fly
and back the tap out of the hole. This is not a critical operation; it's quick and easy.
My talent, confidence and machinery are not limiting factors. I do this for a living.
 
KJ Cues said:
Why not tap 'under power' ? It has advantages and yes it's quick, no muss-no fuss.
Consider that with hand-tapping, you have start - stop, angle and lateral-load can change.
Tap mounted in the tailstock is perfect alignment start to finish.
My taps are marked for depth so under pwr, when I'm nearing a mark, I hit rev. on the fly
and back the tap out of the hole. This is not a critical operation; it's quick and easy.
My talent, confidence and machinery are not limiting factors. I do this for a living.
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At first I was nervous tapping under power and did it like Joey...wasn't much fun. Even if I take a wrench to the drill chuck, the tap spins when it's done. NOW...that T handle job that Barringer uses in his video can do alot of damage if you aren't careful.

Also. I experimented with reamers and carbide drills. I don't have to bore anything when I do a pin. It wasn't real cheap, but I take solace in knowing it's going to be perfect.
 
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pescadoman said:
At first I was nervous tapping under power and did it like Joey...wasn't much fun. Even if I take a wrench to the drill chuck, the tap spins when it's done. NOW...that T handle job that Barringer uses in his video can do alot of damage if you aren't careful.

Also. I experimented with reamers and carbide drills. I don't have to bore anything when I do a pin. It wasn't real cheap, but I take solace in knowing it's going to be perfect.
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What did you buy? :)
 
KJ Cues said:
Why not tap 'under power' ? It has advantages and yes it's quick, no muss-no fuss.
Consider that with hand-tapping, you have start - stop, angle and lateral-load can change.
Tap mounted in the tailstock is perfect alignment start to finish.
My taps are marked for depth so under pwr, when I'm nearing a mark, I hit rev. on the fly
and back the tap out of the hole. This is not a critical operation; it's quick and easy.
My talent, confidence and machinery are not limiting factors. I do this for a living.
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it must be a SHELDON thing
i tap under power too
3rd pulley, whatever rpm that is
my rpm chart is missing
 
Lol. Could be another reason that Sheldons are ideally suited to be cue-lathes.
Damn good machine.
 
KJ Cues said:
Lol. Could be another reason that Sheldons are ideally suited to be cue-lathes.
Damn good machine.
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Metal lathe snubs!
Err, instant reverse?
3 phase ?

On some old belt drive American steel, you can tap under "friction" .
Release the spindle and power up.
The belt will still spin the chuck with some power .
It actually works well for linen wrap work.
 
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BHQ said:
JoeyInCali said:
Metal lathe snubs!
Err, instant reverse? NOPE
3 phase ? NOPE
just know when to back off :thumbup:
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Brent, you have been pretty lucky so far. Your motor, utilizing single phase and going from forward to reverse without stopping first is an oddity. Once a single phase motor gets a little speed on it it makes no difference where the power comes from. It will continue to accelerate in the same direction.

I know it's not good for my tailstock ram but I loosen the chuck slightly from the ram, loosen the tailstock from the bed so that it slides easily. I then start the lathe and then turn it off and then while holding the chuck I push the tailstock forward engaging the tap. When the tap bottoms in the shaft you no longer will be able to stop the chuck from spinning and the threads will not be damaged. I then lock the chuck in the tailstock, put into reverse and pull the tailstock out under power.

Dick :grin-square:
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rhncue said:
BHQ said:
Brent, you have been pretty lucky so far. Your motor, utilizing single phase and going from forward to reverse without stopping first is an oddity. Once a single phase motor gets a little speed on it it makes no difference where the power comes from. It will continue to accelerate in the same direction.

I know it's not good for my tailstock ram but I loosen the chuck slightly from the ram, loosen the tailstock from the bed so that it slides easily. I then start the lathe and then turn it off and then while holding the chuck I push the tailstock forward engaging the tap. When the tap bottoms in the shaft you no longer will be able to stop the chuck from spinning and the threads will not be damaged. I then lock the chuck in the tailstock, put into reverse and pull the tailstock out under power.

Dick :grin-square:
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not reversing dickie,
stopping it complete, then reverse
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Near instant reverse is a great benefit of the 3 phase and VFD.
Some woods pieces definitely tap nicer than others even though it is maple.
Neil
 
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