Coring wood question

[PracticeChampion]

Are you guys coring the entire butt or ?

 

[DeeDeeCues]

Are you guys coring the entire butt or ?

That is generally what they are talking about.

 

[Michael Webb]

Are you guys coring the entire butt or ?

Most core by sections. Works well building an inventory. Some core full length using a 1 piece core.
Most important part is seasoning the woods.
If your going to do it, DO IT!
If your going to assume that you turned the pieces green and it will work because you put them together, DON'T DO IT.
Don't assume. Give yourself and the wood a fair shot.

Added.
This post is not aimed at you as an individual. It's aimed at EVERYONE.
Respectfully of course. Lol

 

[PracticeChampion]

Most core by sections. Works well building an inventory. Some core full length using a 1 piece core.
Most important part is seasoning the woods.
If your going to do it, DO IT!
If your going to assume that you turned the pieces green and it will work because you put them together, DON'T DO IT.
Don't assume. Give yourself and the wood a fair shot.

Added.
This post is not aimed at you as an individual. It's aimed at EVERYONE.
Respectfully of course. Lol

I understand

With that said does it matter the diameter of the core? Example: could it be cored 3/8" vrs 5/8" and reach the same conclusion or is more always better?

 

[Michael Webb]

I understand

With that said does it matter the diameter of the core? Example: could it be cored 3/8" vrs 5/8" and reach the same conclusion or is more always better?

Size matters!

 

[PracticeChampion]

Size matters!

That's what she said

 

[cueman]

My theory on coring is.
I turn and season the woods first. That includes the coring dowells. If the woods are not seasoned, they could still move.
My tolerances are pretty tight at .003 to .004 max.
I put a lazy thread on the dowells when they're.020 from size and I also cut glue relief channels in when the dowells are over size on my table saw. When I turn them to size, they're good to go. I only use slow drying epoxy with an additive. The additive helps with over absorbing into dry spots.
I cap one end of the tube, and add the epoxy. Using a delrin rod the epoxy gets swirled, coating the inside of the tube. I coat the dowell well also then install it into the tube..turning it as I go. I use a press to install the dowell. After the gurgling stops, I remove the cap and push thru.
If any choose West system. Take the time to learn about it's products. It's not cheap but it's very good.
These are some pieces from a full 29 inch core I did. No voids and you can see the relief channels. They don't have to be cut deep but just eneogh so there's no hydraulic blow out.

This one of the best posts I have seen on how to do epoxy coring. Do you use a dye to cut the threads?

 

[JA062669]

Is it best to drill straight through from one end to the other or drill halfway from each end.

 

[Michael Webb]

Is it best to drill straight through from one end to the other or drill halfway from each end.

Try both and report back please.

 

[Coos Cues]

Is it best to drill straight through from one end to the other or drill halfway from each end.

My experience is it's very hard to drill from both ends and get the middle to meet cleanly. It's also hard for me to come out the far end of a 15 inch piece of wood dead center. Some wood is better for this than other. Some drift off for reasons I can't explain. Maybe my technique? Core your wood at the largest possible OD to minimize problems down the road and absorb heat. Don't taper wood before coring it. Take a light cut on the round just prior to drilling to make sure it's dead straight. If your wood is already thinish cross your fingers and say a word before starting. Make sure your pilot hole is straight and as deep as the business end of the gun drill. I bore that starter hole and it seems to work best with about a thou or two of clearance to the gun drill to get it started straight. If you see any wobble of your gun drill when starting the first inch or two out stop and turn the piece around and try again. If you have enough length you can also cut it off and start again. Wobble at the start equals coming out the far end close to China. There is a sweet spot of air flow and feed rate, use a regulator on your air supply and find it. Some species just core better than others. BEM is the worst those eyes are hard as a whore's heart. Oily woods are the best.

These are just random thoughts from my experience.

 

[Renegade_56]

My experience is it's very hard to drill from both ends and get the middle to meet cleanly. It's also hard for me to come out the far end of a 15 inch piece of wood dead center. Some wood is better for this than other. Some drift off for reasons I can't explain. Maybe my technique? Core your wood at the largest possible OD to minimize problems down the road and absorb heat. Don't taper wood before coring it. Take a light cut on the round just prior to drilling to make sure it's dead straight. If your wood is already thinish cross your fingers and say a word before starting. Make sure your pilot hole is straight and as deep as the business end of the gun drill. I bore that starter hole and it seems to work best with about a thou or two of clearance to the gun drill to get it started straight. If you see any wobble of your gun drill when starting the first inch or two out stop and turn the piece around and try again. If you have enough length you can also cut it off and start again. Wobble at the start equals coming out the far end close to China. There is a sweet spot of air flow and feed rate, use a regulator on your air supply and find it. Some species just core better than others. BEM is the worst those eyes are hard as a whore's heart. Oily woods are the best.

These are just random thoughts from my experience.

A pilot hole is much more likely to run off center than a gun drill is. True gun drills do not require a pilot hole and actually will run truer to center without a pilot hole.

 

[JoeyInCali]

A pilot hole is much more likely to run off center than a gun drill is. True gun drills do not require a pilot hole and actually will run truer to center without a pilot hole.

I'd like to see how a drill guide is accurately mounted.
I don't know how a bored pilot hole makes the drill less accurate.

 

[robbycar]

The bored hole is cut with a boring bar so is perfectly centered with the spindle.

If done properly, this will get the gun drill started properly.

 

[Renegade_56]

A gun drill does not need a guide once it gets deep enough that the body of the drill is sufficiently deep enough to have all of the periphery of the drill in the material, ie, once you get more than a quarter inch or so of depth no pilot hole is needed. Take a gun drill and measure the diameter of the body of it at the cutting end. Notice it is the same as the gun drill cutting size. It is a concentric body that is designed to run on center and is pulled on center by the angle of the cutting edge, exactly the same way a center drill works basically, but moreso because the concentric body will not allow runout. If you manage to cut over the measured size of a gundrill more than a few ten thousandths of an inch you have serious problems with your technique.

Industrial gun drilling machines only have guides for the first few hundred thousandths of drilling, yet gun drills are quite capable of drill many inches, even a few feet in depth in some applications, and it is all due to the geometric design of the cutting end of the gundrill that forces itself on center and its base diameter that cannot run out due to the fact it has no radial relief.

A pilot hole actually does nothing to help start a gundrill. A Bushing type guide for the outside diameter of the gundrill tip, if it is truly on center, is much more effective than a pilot hole.

 

[Renegade_56]

I'd like to see how a drill guide is accurately mounted.

Below in the picture you can clearly see.

I don't know how a bored pilot hole makes the drill less accurate.

Because it is too hard to bore a pilot hole ecactly on the same centerline the gun drill will naturally find on it's own, and not being exact can create unnecessary side loads on a gundrill, that the gundrill itself would not do.


This is the gundrilling concept in industrial practice,,,,, notice there is absolutely no pilot hole, only a short guide bushing to get it started till it can self center.

 

[JoeyInCali]

Below in the picture you can clearly see.

Because it is too hard to bore a pilot hole ecactly on the same centerline the gun drill will naturally find on it's own, and not being exact can create unnecessary side loads on a gundrill, that the gundrill itself would not do.


This is the gundrilling concept in industrial practice,,,,, notice there is absolutely no pilot hole, only a short guide bushing to get it started till it can self center.
View attachment 657810

You have a picture of your setup?

 

[Coos Cues]

Below in the picture you can clearly see.

Because it is too hard to bore a pilot hole ecactly on the same centerline the gun drill will naturally find on it's own, and not being exact can create unnecessary side loads on a gundrill, that the gundrill itself would not do.


This is the gundrilling concept in industrial practice,,,,, notice there is absolutely no pilot hole, only a short guide bushing to get it started till it can self center.
View attachment 657810

This all makes perfect sense based on the results I have achieved being off at the exit hole by as much as .020" even when I thought my pilot was perfect. Other times it pops out almost perfectly. How do we achieve the starter bushing setup using our common metal lathe? I would also love to see your setup. It seems like we would have to use some sort of bronze bushing for the tolerances you describe. Appreciate your expertise as many of us were not machinists prior to building cues and our cue building gun drills are the only ones we've ever seen or used.

 

[Renegade_56]

This all makes perfect sense based on the results I have achieved being off at the exit hole by as much as .020" even when I thought my pilot was perfect. Other times it pops out almost perfectly. How do we achieve the starter bushing setup using our common metal lathe? I would also love to see your setup. It seems like we would have to use some sort of bronze bushing for the tolerances you describe. Appreciate your expertise as many of us were not machinists prior to building cues and our cue building gun drills are the only ones we've ever seen or used.

A bored hole the finish diameter of your gun drill and about half the length of your gun drill tip in the end of the butt is all you need. There is no need for expensive or exotic special tooling. Bore the hole, guide gun drill in it and begin with low rpm and light pressure so as not to instigate wobble or runout. Once the gun drill tip is fully engaged and doing what it's designed to do you can increase rpms. No need to make it any harder than that.

 

[JoeyInCali]

This all makes perfect sense based on the results I have achieved being off at the exit hole by as much as .020" even when I thought my pilot was perfect. Other times it pops out almost perfectly. How do we achieve the starter bushing setup using our common metal lathe? I would also love to see your setup. It seems like we would have to use some sort of bronze bushing for the tolerances you describe. Appreciate your expertise as many of us were not machinists prior to building cues and our cue building gun drills are the only ones we've ever seen or used.

Sounds like a problem with the inside bore of your lathe.

I still want to see how that bushing is mounted accurately.
Using the steady rest would be a pain.
I use that for dust collection.

 

[JoeyInCali]

A bored hole the finish diameter of your gun drill and about half the length of your gun drill tip in the end of the butt is all you need. There is no need for expensive or exotic special tooling. Bore the hole, guide gun drill in it and begin with low rpm and light pressure so as not to instigate wobble or runout. Once the gun drill tip is fully engaged and doing what it's designed to do you can increase rpms. No need to make it any harder than that.

Got pics how you mount that bushing?