Trials failed

[Kermit]

I'm trying to figure out what kind of bit you guys use to bore long endgrain holes--you know, ramrods, shotgun stock bolts, shaft holes on boats. I watched an old shipwright bore a hole about 2" diameter and 6 feet long once, and he came out 1/4" off his planned exit point. I've done trials on some scraps (walnut, maple, cherry), and I have had holes come out an inch and more off where I want them--in 12-15 inches.

Shipwrights used "barefoot augers" (no lead screw) for long endgrain holes. What do you use? Where can I get such a beast?

[coutios]

   I just use a standard gun drill made from O-1.. Just make sure its cut on center and sharpened properly..  Layout and starting into the hole are probably 99% of the job....

Dave

[WadePatton]

I'll have to check for the exact angle, but the twist drill bit we used for my rr hole had a "new" grind on it.  nearly square iirc-just like a spade bit. worked wonderfully and methinks was a new to Mr. Anderson (who has been doing it for a while).

experiment with that

a bit. 

whoops, i pun.

cheers

[Dphariss]

I'm trying to figure out what kind of bit you guys use to bore long endgrain holes--you know, ramrods, shotgun stock bolts, shaft holes on boats. I watched an old shipwright bore a hole about 2" diameter and 6 feet long once, and he came out 1/4" off his planned exit point. I've done trials on some scraps (walnut, maple, cherry), and I have had holes come out an inch and more off where I want them--in 12-15 inches.

Shipwrights used "barefoot augers" (no lead screw) for long endgrain holes. What do you use? Where can I get such a beast?

First make SURE the drill is properly directed. Aimed right.
Second use a gun drill rod hole drill as sold by Track of the Wolf.
If drilling a fullstock make sure the ramrod goorce is parallel to the bore and the same size as the drill.
Make a couple of blocks with the same size groove.
The blocks should fit ove the groove making a colse fit on the drill and shank. The shank should be the same diameter as the drill. Using a chisel or gouge make sure the drill has a surface to start properly, Clamp the blocks on the stock, one close to each end of the  channel. You will need 2-3" to give chip clearance when the drill is pulled from the hole to clear the chips.
Drill no more than 1" at a time preferably less if the drill stops cutting pull it to get the chips out of the drill.
If its every 1/2" so be it.
Trying to drill to far before clearing the chips is a big mistake and can cause problems.
With do care a gun drill type drill will not run out significantly and will usually cut with just a few thousands at the end of the hole.
The various twist drills will only do this now and then in my experience. Having a drill with a reduced diameter shank just makes this worse.

If the gun drill does not run to the point desired then it was "aimed" wrong.
Once in  past  the depth of the flute its almost impossible for it to run off, The shank simply won't allow it.

If you have a milling machine or a friend with one these are easy to make from 4 foot long mild steel rod bought at Home Depot etc. Mill in 1/2 the rod diameter to make a groove, grind too sharpen to one cutting egde.
I case harden the cutting end for about 1/2".
On 1/2 stock guns using the rod pipes for a guide a tapered barrel should be shimmed at the breech end to keep the drill from running low at the far end.
Dan

[Steve-In]

I used to weld drills to rods but it got to be a pain.  Now I take a new twist drill face the shank off square and tap it 10-32.  I do the same to whatever straight rod I choose and then take a grade 8 10-32 bolt with long threads and cut all but the threads off.  I go slow and I have not had a problem with straight holes yet.  I may regret this someday but I don't plan to use it that often.

[Chris Treichel]

I find it very important to go slow.  So I use a brace instead of a power drill.  That also allows me to say, do 10 revolutions and dump sawdust. Small hand vaccum with a small attachment works well. Seems if too much saw dust fills up the cutting grove it can start to push your bit... 

[doug]

     I use a twist drill with an extension silver soldered on.  I think the most important part, other than aiming it right, is that the tip or point should be close to square across.  I think that a long sharp pointed drill will tend to follow the grain

cheers Doug

[Robby]

Crude but effective. Just bar stock sharpened as seen, and case hardened. It works more like a scraper, and is slow, But it is sure. Never had one run off target. After about fifteen holes I thought I would try one of those gun bore drills from TOW. It picked up and ran with the grain !  Went back to my home made system, and to date have not had a failure.

Robby

[rich pierce]

Robbie, is that a half-round?

I ground a twist drill so the edges lead and so far this has been a great drill.  I need to take better photos.  I read about it in Muzzle Blasts or somewhere.

[bgf]

Robbie,
That is the sort of thing I was thinking about -- but I didn't know if it was a crazy idea or not (usually my ideas are about 50/50 .  I went searching for pictures last night and couldn't find anything, so thanks for posting that picture -- it isn't a bad idea, I guess!

[t.caster]

I've always had good luck with brad point bits welded (by others) to a long rod  of the proper diameter. You have to go slow using a brace and bit (hand cranked), not an electric drill! Go an inch or so at a time and back it out to clear the chips. I actually count the turns, 15-18 then back it out. Proper alignment of the outside forend groove is a MUST, before even starting!
Hope this helps.

[Robby]

Rich, I scribed a line across the end using a center square, ground two flats about equidistant from the line, sharpened it to the line, case hardened it, and use a fine stone to keep it sharp. The brad point bit that t. caster uses, and what you did, were my original plan, but didn't have a lathe. Glad to know those ideas work well, I may now have access to a lathe.
bgf, crazy is my stock and trade!
Robby

[Dphariss]

Twist drills are prone to wander because they are too flexible and may not run through hard spots etc.
They also have sharp edges all the way back.
These features allow them the run off will a little encouragement from the point.
The drill pictured does not flex and is difficult to force of course. I suspect that any stiff drill, the scraper type pictured, tends to rub straight as well.
In basic form the cutting edge is the same as that used for drilling gun barrels and other deep holes in steel. Its not as efficient in wood due to the flute plugging but it still runs very straight. Gun drills use high pressure oil to clear the chips and drill holes , slowly, but without stopping.
I have used various points on twist drills for ramrod holes in the past but I was never happy with the result and now consider them a poor second choice.
This one has only drilled one hole and came out dead center to its intended point. The stock used was cut to final dimension before it was drllled and I needed no more wood than that.
I don't have to aim the drill up toward the breech of the barrel as a safety measure. I set it up to drill to the point I want and drill it. I always sweat them regardless but I have yet to have one run off and I have used them in more critical projects than ramrod holes.
Dan