Gun Drill/Coring Sizing

cuetrip

cuetrip

Rob Hardman Cues
Silver Member
Hey guys,
I'm about to pull the trigger and order a gun drill so I can finally start coring. This is something I've had anxiety about trying to get set up.
For a .750 core dowel, how much oversize should I get the gun drill? .758? .760? I think I'm planning on using Gorilla poly glue.
Also, are you guys buying .750 dowels or, expecting them to not be straight, buying larger dowels and turning them down to .750?
I'll be on the hunt for laminated maple dowels if they're not too expensive. I read somewhere that locust was a good coring wood and is pretty cheap. Like $4-$5 for 3 feet at .750.
Once again, thank you all for your help on these boards. If you think of any questions that I should be asking, please feel free to answer them.
Rob
 
cuetrip said:
Hey guys,
I'm about to pull the trigger and order a gun drill so I can finally start coring. This is something I've had anxiety about trying to get set up.
For a .750 core dowel, how much oversize should I get the gun drill? .758? .760? I think I'm planning on using Gorilla poly glue.
Also, are you guys buying .750 dowels or, expecting them to not be straight, buying larger dowels and turning them down to .750?
I'll be on the hunt for laminated maple dowels if they're not too expensive. I read somewhere that locust was a good coring wood and is pretty cheap. Like $4-$5 for 3 feet at .750.
Once again, thank you all for your help on these boards. If you think of any questions that I should be asking, please feel free to answer them.
Rob
Click to expand...
I think you will be better to do a final turn just before you install your cores. you may need cores that are different weights for different blanks.
 
I turn/make all my own cores, otherwise you will be trying to shove a hard banana into a straight hole....
There are a few things to decide before ordering the Drill, 1) how will you mount it and drive it thru the blank? Boring bar holder in the toolpost? or MT2 end or straight 1/2" end for a chuck and hold it in the tailstock? Depending where/how you hold it will dictate where the nipple will be for air connection. 2) length of drill, the OAL is NOT the drill depth....so make sure you order one that gives the amount of depth plus what goes into whatever method of holding device. Also make sure your bed length will allow for all this. As far as size, first, are you coring forearms or handles, or both? I core the forearms with a .680 all the way, then from the handle side go in with a .750 about 9 - 10 inches and core the handles at .750. Some day I will be going to a larger size for the handles as I screwed up at the begining and ordered exact size of the core, I have a work around, but need to upgrade some day.
Hope this helps.
Dave
 
Think about ways you can build your cues so you are always cutting down a little bit to virgin wood for the next part that's going together on each step. This allows you to correct any slight imperfections all the time. It's really not as simple as what size to core, the gun drill is just one component of your whole cue building equation. Everything has to fit concentrically each step of the way. You can never add wood, only subtract so think oversize everywhere.

Think of ways to not use expanding glue.

Joey gives you gun drill sizes but that is meaningless without seeing the entire process of how he's putting them together.
 
I make my my coring drills .025 larger than ring I'D size. That way I can make my cores about .015 oversized to ring ID and turn the ends of the coring dowel that sticks out each end down to a snug fit for the rings.
 
cueman said:
I make my my coring drills .025 larger than ring I'D size. That way I can make my cores about .015 oversized to ring ID and turn the ends of the coring dowel that sticks out each end down to a snug fit for the rings.
Click to expand...
When I first read your book you explained this concept and it took me building some cues to understand why you do it like this. Very smart wish I would have thought of it by myself. :)
 
JC said:
When I first read your book you explained this concept and it took me building some cues to understand why you do it like this. Very smart wish I would have thought of it by myself. :)
Click to expand...
I figured that one early on. And because I thread all my collars and caps, it presented a problem with stock 5/8 and 3/4 ID rings ( brass and nickle ) . Their holes had to be expanded by some .050" for phenolic tubes with 5/8 and 3/4 ID if I wanted to thread those tubes . Thankfully DZ shared his ring boring jig. That allowed for boring those thin brass and nickel rings . Coring sizes is not one size fits all, of course . Hence, the need for 6" to 7" boring bar. If you are using a real soft wood for forearm, the thinner you have it at the bottom ( at a certain point ), the better . Meaning you can have your core dowel larger at the bottom . For example, .750 the first 6 inches then .850" or the bottom 6 inches . That way your core dowel influences the hit much more that a straight .750" . Add .100" to that for handles .
 
I core everything............. with a .7500 gun drill I bought on Ebay for 15$........... it is easy to modify them for air and to hold them in the tailstock.............. I buy 1 inch cheaper shaft dowels and turn them close to size and then sand for a nice fit................. don't over think it.....

Kim
 
It is really so much about the goals and motivations that guide you in your cue-building. There are different ways to get the task made ... depending on the equipment and the tools in your possession.
For example when it comes to my major concern when building a cue ... that certain hit I'm looking for ... and the coring wood so as the other options already mentioned contribute too. I've got the results I was really happy with certain combinations of woods, construction used and other details. Unfortunately great materials are not cheap but I love certain exotics for my cores.
When it comes to me if I build a cue on a full length core I prefer a tight fit and I only use epoxy.
When I had my experience with a full spliced cue the other glue worked well for me but in that project the other factors meant a lot to get a great bond.
Learning... getting the experience with each cue built ... drawing conclusions to improve where it's possible in future projects...
Nothing replaces your own experience so good luck in your journey.
 
Some good replies already. I have a .650" .760" and .885" and a few long boring bars, so i have plenty of options to get the right weight and balance. As for the core itself, it's the most important piece of wood. Buy oversized, turn down slowly and let it sit for as long as you can before turning to final size. Laminated cores are fine, more work or more money though. I like tight tolerances, hence I prefer West epoxy over PU glue. I thread all my stuff too. As Joey said, tapered or steped cores is a great way to further fine tune the hit and balance.
 
Dave38 said:
I turn/make all my own cores, otherwise you will be trying to shove a hard banana into a straight hole....
There are a few things to decide before ordering the Drill, 1) how will you mount it and drive it thru the blank? Boring bar holder in the toolpost? or MT2 end or straight 1/2" end for a chuck and hold it in the tailstock? Depending where/how you hold it will dictate where the nipple will be for air connection. 2) length of drill, the OAL is NOT the drill depth....so make sure you order one that gives the amount of depth plus what goes into whatever method of holding device. Also make sure your bed length will allow for all this. As far as size, first, are you coring forearms or handles, or both? I core the forearms with a .680 all the way, then from the handle side go in with a .750 about 9 - 10 inches and core the handles at .750. Some day I will be going to a larger size for the handles as I screwed up at the begining and ordered exact size of the core, I have a work around, but need to upgrade some day.
Hope this helps.
Dave
Click to expand...
And then add some extra length for dust collection between the chuck and the wood. The business end of these drills is where the cost is, making them longer is inexpensive when ordering.
 
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