gun drill collet set up?

BMCC

BMCC

AzB Silver Member
Silver Member
I had seen a post a while back talking about using a collet with a gun drill and now I can’t find the post. I was wondering how much using the collet helped or any other ideas on helping keep a gun drill centered. My holes are usually vary close to center but some times the bit runs a little. Just trying to keep my tolerances as tight as I can realistically.

Thanks
Kyle Josefy
Black Mesa Custom Cues
 
Well, depending on what type of tool post you have, you can get a 5C collet holder for your tool post. That would hold it steady, and as an added bonus, you could use it for other things with different size collets, as opposed to using a boring bar holder, which you could only use for just the gun drill, or a really big boring bar.

Thanks,

Jon
 
Your question makes no sense to me... where do you expect to put a collet?
 
I will try to explain it better you know how the cutting edge of most gun drills are larger than the rest of the shank or ad least most, I have dealt with are. The post I saw had someone inserting a collet to help support the rest of the bit after the initial cutting surface has entered the piece of wood it looked like it had a lip on it to keep it from being forced in the hole but its main purpose seamed to be to help support the weight of the bit at the beginning of the hole thus helping keep it in line. But my real question was dose anyone know where I can find that post I can’t find it? There was a picture of the collet set up and everything or if anyone else had any ideas on helping keep the gun drill on center. Seamed kind of weird that it would help much from what I could tell because of the v shape of the rest of the shank. I was wondering if who ever posted the original post that can not find could elaborate on it and tell me how much it improved their accuracy. Check out this link http://www.gundrill.com/DrillGuide.htm it shows one that has a v in it but the one I saw in the post did not have the v it was just a homemade round collet.

Thanks
Kyle
 
A drill guide can be used to locate the gun drill at the center of the workpiece so that you do not have to center drill it before hand. Just mount the guid in a fixed steady rest. Drill guides can be purchased in either steel or carbide, and are very accurate as to their size. You should be very careful to line up the drill guide exactly center, or very close to it for the best results. Make sure that when you mount your work in the lathe that it comes right up to the drill guide and does not have much of a gap between the work and the guide. That way chips will not get caught there at the guide and clog up your drill.


Royce
Owen Bunnell Inc.
www.obcues.com
 
RBC said:
A drill guide can be used to locate the gun drill at the center of the workpiece so that you do not have to center drill it before hand. Just mount the guid in a fixed steady rest. Drill guides can be purchased in either steel or carbide, and are very accurate as to their size. You should be very careful to line up the drill guide exactly center, or very close to it for the best results. Make sure that when you mount your work in the lathe that it comes right up to the drill guide and does not have much of a gap between the work and the guide. That way chips will not get caught there at the guide and clog up your drill.
Royce
Owen Bunnell Inc.
www.obcues.com
Click to expand...

In saying this, are you talking about using a single flute gun drill?
 
I was recently looking at some gun drills, and It does seem that you can get the bushings to use in a support rest with the drills. You can also get chip deflectors to go on them I believe.

Greg
 
Gun Drill

BMCC said:
I will try to explain it better you know how the cutting edge of most gun drills are larger than the rest of the shank or ad least most, I have dealt with are. The post I saw had someone inserting a collet to help support the rest of the bit after the initial cutting surface has entered the piece of wood it looked like it had a lip on it to keep it from being forced in the hole but its main purpose seamed to be to help support the weight of the bit at the beginning of the hole thus helping keep it in line. But my real question was dose anyone know where I can find that post I can’t find it? There was a picture of the collet set up and everything or if anyone else had any ideas on helping keep the gun drill on center. Seamed kind of weird that it would help much from what I could tell because of the v shape of the rest of the shank. I was wondering if who ever posted the original post that can not find could elaborate on it and tell me how much it improved their accuracy. Check out this link http://www.gundrill.com/DrillGuide.htm it shows one that has a v in it but the one I saw in the post did not have the v it was just a homemade round collet.

Thanks
Kyle
Click to expand...


Hello

The gun drill shown in the CAD drawing is for metal and mounting on a gun drill machine. The round drive connect is on the left. Next is rotating guide bushing in support plate. Next is rotating guide bushing in chip box. On opposite of chip box is wear bushing against which the object to be drilled is butted against or inserted. Big bucks!
Why not try drilling at a slow speed with progressively longer jobber drills in a collet or drill chuck after center drilling. This technique uses the existing hole as a guide. If you are drilling a 1 inch core hole twist drills are available from stock up 18" from most industrial suppliers with straight or taper shank. For wood brad point drills are also available in extended length and give a flat bottom hole allowing a square ended dowel.
Tricks for extra accuracy :

- Clear chips regularly or they will for drill off center and make hole oversize
- Bore the front of the hole with a boring bar to slightly undersize or to size to guide drill exactly on center.
- Start hole with center cutting end mill. ( Has to be exactly on center or will cut over size because flutes cut. )
- Mount drill guide bushing in steady rest ( Available from Carr-Lane ) between drill chuck and work. Must be exactly on center or hole will oversize, off center, and angle off the center line of the work piece.
- Poor mans drill bushing. Mount steel plate in steady rest and drill through it. Make new one ever time set up taken down and throw away old one.

Good luck

Trueheart
 
Cue Crazy said:
I was recently looking at some gun drills, and It does seem that you can get the bushings to use in a support rest with the drills. You can also get chip deflectors to go on them I believe.

Greg
Click to expand...
No need for chip deflectors.
Just an air hose gun at the back.
Blows them chips easily.
Wear eyeshield or face mask.:D
 
JoeyInCali said:
No need for chip deflectors.
Just an air hose gun at the back.
Blows them chips easily.
Wear eyeshield or face mask.:D
Click to expand...

Man, I don't understand what all these jigs and cures for problems, that as far as I know, don't even exist. If you are having a problem boring straight holes with a gun drill there is something bad wrong with your set-up. A gun bit is the truest way to bore a small hole of any length, mainly because there are no chips to divert the bit. It bores truer than a boring bar after about 8 to 10 inches. You need a pilot hole started the same size as your boring bar about 1" deep and then just make sure your bar is straight. I very seldom can tell which end of a round blank that I started from. Both ends are about dead nuts.

I have my bar mounted in a quick change with a male air quick disconnect sticking out the back. When I mount the bar on my tool post I leave the tool post loose so that it can pivot, I move the bar out to where I can insert the nose of the gun drill into the pilot hole in the blank and then move the cross slide to align the air quick disconnect up with my tail stock dead center and then lock the tool post in this position. This guarantes the gun drill to be aligned with your lathe bed. Depending on the woods hardness, I usually run the lathe at about 600 to 700 rpm and feed at around 4" a minute.

Dick
 
rhncue said:
Man, I don't understand what all these jigs and cures for problems, that as far as I know, don't even exist. If you are having a problem boring straight holes with a gun drill there is something bad wrong with your set-up. A gun bit is the truest way to bore a small hole of any length, mainly because there are no chips to divert the bit. It bores truer than a boring bar after about 8 to 10 inches. You need a pilot hole started the same size as your boring bar about 1" deep and then just make sure your bar is straight. I very seldom can tell which end of a round blank that I started from. Both ends are about dead nuts.

I have my bar mounted in a quick change with a male air quick disconnect sticking out the back. When I mount the bar on my tool post I leave the tool post loose so that it can pivot, I move the bar out to where I can insert the nose of the gun drill into the pilot hole in the blank and then move the cross slide to align the air quick disconnect up with my tail stock dead center and then lock the tool post in this position. This guarantes the gun drill to be aligned with your lathe bed. Depending on the woods hardness, I usually run the lathe at about 600 to 700 rpm and feed at around 4" a minute.
Click to expand...

Dead on..... once again, I couldn't have said it better.... I figured out that trick to lining up the bit, and it made things a lot faster to get set up. Gun drills give you a really nice hole if you use them right... no drill bit is going to even come close, IMO.
 
Good info, thanks Guys, As some of you know I have been wanting get one for a while, so I guess I,m still ignorant how well they work. I was'nt even sure If I should step drill with a smaller one first or not, but I guess that's because I'm use to the boring bars or the standard longer drill bits that like to walk off with you. Good to know these drill that straight.
Well anyway, I'm about finally ready to get one here very shortly, because some woods I just won't put in a forearm without coring, and that limits me on design, so I've started looking at some to purchase recently.

I am trying to decide on what size bit to start with? I don't want to thin My sidewalls out too much, but at the same time I suppose too small of a diameter may have adverse effects also. Can anyone tell me what size I should be in the market for. Keep in mind also that playability is always a main concern for me, as I'm sure It is for others.

Thanks Greg
 
Gun Drills

Hi all:

I use an 18" gundrill .758 in diam I bought from Drill Masters of Vermont (802-442-3525)($136.63). That may not be unusual: however, I use it with a Deluxe Quesmith and can drill forearms no problem in about 5 minutes. If I bought another one I would not purchase an 18" one as a 12" one will do just fine.
Just drill half way and turn the forearm around and drill thru. I mount mine in the tail stock chuck and when finished I pass a piece of 3/4 round drill rod through it to insure it is dead straight and a "slip" fit. The drill rod usually slides thru as slick as snot. You must drill (bore) 3/4" starting holes in the ends about 3/4 to 1" deep. The tailstock has to be dead on with the chucks. There are several ways to do this and using a 12" length of 1/2" drill rod through both chucks and the tailstock chuck is perhaps the easiest but not neccessarily the most accurate. Get a plastic coffee can lid and mount it on the drill to keep the chips from blowing back in your face (you have to use compressed air to clear the chips). There is absolutely no need for a center support. About 800 RPM seems do work quite well.

Bob Flynn
Denali Cues/Guitars
 
Drilling Straight

Cue Crazy said:
Good info, thanks Guys, As some of you know I have been wanting get one for a while, so I guess I,m still ignorant how well they work. I was'nt even sure If I should step drill with a smaller one first or not, but I guess that's because I'm use to the boring bars or the standard longer drill bits that like to walk off with you. Good to know these drill that straight.
Well anyway, I'm about finally ready to get one here very shortly, because some woods I just won't put in a forearm without coring, and that limits me on design, so I've started looking at some to purchase recently.

I am trying to decide on what size bit to start with? I don't want to thin My sidewalls out too much, but at the same time I suppose too small of a diameter may have adverse effects also. Can anyone tell me what size I should be in the market for. Keep in mind also that playability is always a main concern for me, as I'm sure It is for others.

Thanks Greg
Click to expand...

One of the most important things in drilling straight is a properly sharpened quality drill. Improperly sharpened drills wander and cut oversize. For accurate deep hole drilling professional machine sharpening is a must.

Charlie
 
Trueheart said:
One of the most important things in drilling straight is a properly sharpened quality drill. Improperly sharpened drills wander and cut oversize. For accurate deep hole drilling professional machine sharpening is a must.

Charlie
Click to expand...


Thanks Charlie,

Yes I am aware of this, I use solid carbide Myself, and they usually work very well for me. I still center and step drill up to size though, because from My experience even some sharp drills will still wonder ocasionally when they are longer, and i run them right up in there. That's Why I prefer using stub lenth drills when installing a pin or something that needs zero tolorence, and I'm not using a boring bar for My final dia. I prefer to use a boring bar when able to though. I have minature ones I use for things like inserts, and they work very well for me. I use both drills and boring bars at any given time though, as long as they get the job done to My satisfication.

Actually My statement was in relation to the fact that I have yet to core any of My forearms, and the gun drills are very long, so I just have no idea as to how they perform. It's obvious to me that they can still walk by the fact that there are supports used with metal, and as mentioned here, into wood It can be done without the support, If a 1inch deep pilot is drilled first.

With that said, yes, nothing worse then a dull bit, been there, done that:D .
 
1 inch size chosen at random, most popular coring size is 3/4 plus glue line thickness.

Support has to be aligned but its main purpose is to keep the drill bit from flexing, bending, and breaking under pressure.
 
When using a gun drill with a drill guide, the purpose of the guide is to locate and support the drill so that the hole is perfectly centered. A starter hole is not necessary because the drill guide locates the drill. This can be a time saver if you are drilling volume. My experience with gun drills is that the shank of the drill is smaller than the carbide ground front of the drill. Therefore the drill guide does not support anything once the carbide front of the drill is completely in the wood being drilled. I also recommend keeping the wood being drilled very close to the drill guide. That way the wood chips will not get caught on the end of the drill guide and get clogged up.

Royce
Owen Bunnell Inc.
www.obcues.com
 
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