Small Diameter Boring Bar

T

Tony Zinzola

AzB Silver Member
Silver Member
I'm pretty new to this and just discovered this page so this would be my first post. I bought a Hightower Machine in January along with some other equipment since and figured this is a good place to ask instead of constantly bothering Christ with my stupid questions.

I understand that you should be boring holes for pins and such. I drilled holes for my first cue and I must have got lucky because the cue turned perfect after both joints in the butt were glued up. I haven't been so lucky on my second attempt.

If I need a 5/16 hole to tap for the pin that has to be long enough for 1/2 the pin plus the tenon, I would need something smaller than that to bore the hole with. Everywhere I've looked, I can only seem to find something about an inch long at the smaller diameters.

Do any of you guys have any suggestions as to where I could find something like that?

Thanks
 
Bore as deep as your bar can reach, then finish the hole with a drill bit. If you bore is good, it should keep the drill bit from wandering.
I got a boring bar from MSC that will bore 1/4" holes 2" deep. You can squeeze a tad more out if it at larger diameters.
 
Boring Pin Holes

Hi:

What I do is bore the tap size hole with a 3 flute solid carbide drill (McMaster-Carr) in three progressive diameters and then tap the hole. I then BORE the hole for the barrel using precision pins as a guide starting at .378 so I can sneak up on the "just the right size" diameter for the pin. While most 3/8 pin barrels are .380 many are not. I only use pins with locating barrels (Petree or Atlas). The boring bar I bought from Hightower works down to 5/16 which is the normal tap size for 3/8 pins. You can grind it so that it will fit smaller pin holes for the 5/16 pins. I forget the size drill bit I use for the final tap drill diameter as it corrresponds with the pilot on my 3/8 tap (Atlas). It is NOT 5/16 as I found a metric diameter works better. If you need to know that size PM me. I am home now and the drills are at the shop.

Good luck,

Bob Flynn
Denali Pool Cues
 
Tony Zinzola said:
I'm pretty new to this and just discovered this page so this would be my first post. I bought a Hightower Machine in January along with some other equipment since and figured this is a good place to ask instead of constantly bothering Christ with my stupid questions.

I understand that you should be boring holes for pins and such. I drilled holes for my first cue and I must have got lucky because the cue turned perfect after both joints in the butt were glued up. I haven't been so lucky on my second attempt.

If I need a 5/16 hole to tap for the pin that has to be long enough for 1/2 the pin plus the tenon, I would need something smaller than that to bore the hole with. Everywhere I've looked, I can only seem to find something about an inch long at the smaller diameters.

Do any of you guys have any suggestions as to where I could find something like that?

Thanks
Click to expand...


I'll tell you a little trick you can use. Take a drill bit the finished size you want and grind the tip flat so it resembles an end mill. Now grind a small relief all the way around the bit starting about 3/16 back from the tip for a short distance. You then just drill an undersized hole and clean it up with the bit you just made and you will have a perfect sized and bored hole every time.
 
www.ultradexusa.com

www.ultradexusa.com is the website that I found with a boring bar for this.
I have not yet ordered it, but when I emailed these people about a boring bar that would give me a finished hole .3125"dia x 2" depth, they said that the bar they have that would do it is: C04H SCLDR/L1.5
The price on their website for that bar was $129.00 when I checked today. I will be ordering one now that my tax refund is here. Hope this helps.
 
macguy said:
I'll tell you a little trick you can use. Take a drill bit the finished size you want and grind the tip flat so it resembles an end mill. Now grind a small relief all the way around the bit starting about 3/16 back from the tip for a short distance. You then just drill an undersized hole and clean it up with the bit you just made and you will have a perfect sized and bored hole every time.
Click to expand...

I am a little confused can you post a pic of this bit your talking about making.
thanks
 
gregoryg said:
www.ultradexusa.com is the website that I found with a boring bar for this.
I have not yet ordered it, but when I emailed these people about a boring bar that would give me a finished hole .3125"dia x 2" depth, they said that the bar they have that would do it is: C04H SCLDR/L1.5
The price on their website for that bar was $129.00 when I checked today. I will be ordering one now that my tax refund is here. Hope this helps.
Click to expand...
I found this website when I was looking around. The only thing with what you mentioned is that if you need to bore 5/16", then the 5/16" bar you mentioned would make it nearly impossible to bore a hole exactly 5/16" wouldn't it? Also, isn't 2" a bit too short. 1.5" would be 1/2 of the pin length for a connecting pin but since the tap doesn't bottom out, wouldn't you would need a hole a bit longer, plus the length of the tenon?
 
Tony Zinzola said:
I found this website when I was looking around. The only thing with what you mentioned is that if you need to bore 5/16", then the 5/16" bar you mentioned would make it nearly impossible to bore a hole exactly 5/16" wouldn't it? Also, isn't 2" a bit too short. 1.5" would be 1/2 of the pin length for a connecting pin but since the tap doesn't bottom out, wouldn't you would need a hole a bit longer, plus the length of the tenon?
Click to expand...

The one that I use I got from MSC. It is 4" long and the minimum bore is .250. It uses a tool steel shaft with a brazed carbide cutter and I have no problem going 2.750" deep with it. It costs 15.17 and the MSC part number is 02649721.

Dick
 
I need a longer boring bar also. I've been using what looks like a small carbide keyway cutter. It has worked for Me, and has four different cutting edges on It that I can switch to, If one of them gets dull, but so far they have stayed sharp.

I can get 2" to maybe 2-1/4" of shank lenth if I stretch It. I know It is long enough to bore most shoulders atleast, but for example has just enough to do the entire bore (including threaded part) on a uniloc pin also. I do both shoulder pins and full threaded. I have installed a few pins at finished size with no room to trim the cue true to the pin should I need It, but fortunatly they went in DN's.
Sometimes I like to center drill My pins anyway, just in case I end Up needing It to help set the pin, but I have used other methods that helped with that also. Sometimes I can simply bump them In, and they are easy as pie, other times I can get a stubborn pin, and I have to fool with them until the glue starts kicking.

You probably already know this, but shouldered pins are alot easier to install, altough even with those It's better to atleast bore the shoulder area IMO, altough I have done them without boring also using only the drills. Good Luck with It:)

Greg
 
old solution

Tony Zinzola said:
I'm pretty new to this and just discovered this page so this would be my first post. I bought a Hightower Machine in January along with some other equipment since and figured this is a good place to ask instead of constantly bothering Christ with my stupid questions.

I understand that you should be boring holes for pins and such. I drilled holes for my first cue and I must have got lucky because the cue turned perfect after both joints in the butt were glued up. I haven't been so lucky on my second attempt.

If I need a 5/16 hole to tap for the pin that has to be long enough for 1/2 the pin plus the tenon, I would need something smaller than that to bore the hole with. Everywhere I've looked, I can only seem to find something about an inch long at the smaller diameters.

Do any of you guys have any suggestions as to where I could find something like that?

Thanks
Click to expand...

I'm sure DaveK could explain this better, old machining Xpertthat he is.

If you Googleize "D bit", "D drill" or some variation, you can find
instructions on how to fashion a tool out of drill rod that will
give results as accurate as a boring bar without the concerns
of the bar walking in deep holes.

I had a link once upon a time

Dale Pierce
 
pdcue said:
I'm sure DaveK could explain this better, old machining Xpertthat he is.

If you Googleize "D bit", "D drill" or some variation, you can find
instructions on how to fashion a tool out of drill rod that will
give results as accurate as a boring bar without the concerns
of the bar walking in deep holes.

I had a link once upon a time

Dale Pierce
Click to expand...

Hey Dale, I'm just a curious hack amateur machinist with a big mouth :D

http://www.geocities.com/Paris/5701/smallpipes/tools.htm is a pretty good discussion of these bits. I make mine using a cut-off saw, cutting about 1/2 way through. The curvature of the cutoff blade generates a bit of a relief angle on the "flat" side of the D (and it's WAY faster than grinding them out on a bench grinder, but the length of the "D"d cutting section is small (1/8") so there is little room for chips in a blind bore). I've never used one on wood, but I'm sure the same rules would apply, don't try to remove too much material with one of these, just use it to make the finished size.

Dave, whose advice is free and we all know how much that's worth :o
 
Last edited:
Thanks for all the replies and suggestions.

Over the weekend, I had sent a request from this site http://www.expresscuttingtools.com/ to see if they could make one for me and they called me back this morning. He said he could make one for $45 that would be a 1/4 inch boring bar with 3/8 inch shank and be a total of 4 inches long with about a 3 inch bore.

I went ahead and ordered one and he said I should have it in a few days. He wouldn't even take my credit card over the phone, said that he would just send an invoice. Seemed like a pretty easy guy to deal with if anybody else is looking for something similar.
 
Tony Zinzola said:
Thanks for all the replies and suggestions.

Over the weekend, I had sent a request from this site http://www.expresscuttingtools.com/ to see if they could make one for me and they called me back this morning. He said he could make one for $45 that would be a 1/4 inch boring bar with 3/8 inch shank and be a total of 4 inches long with about a 3 inch bore.

I went ahead and ordered one and he said I should have it in a few days. He wouldn't even take my credit card over the phone, said that he would just send an invoice. Seemed like a pretty easy guy to deal with if anybody else is looking for something similar.
Click to expand...

Let us know the results when you get the piece?
Kelly
 
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