Boring End Grain in a Dowel

dusty · Post by **dusty** » Tue Feb 12, 2013 6:52 am

You who turn will probably scoff at this because you drill blanks regularly but I am about at wits end.

I am attempting to drill a 1/4 through hole in a 5" long 1" dowel. Drilling the hole is not the problem; I can do that. Drilling the hole so that it exits at the center is the trick.

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I devised a clamp to hold the dowel on the drill press and it holds the dowel just fine but apparently not straight. I clamp the block to the fence. This squeezes the kerf closed and thus secures the dowel. I am satisfied that the 1" hole in the block is adequately square to the face of the block. I am also certain that the drill bit is square to the table top.

I have had a couple holes break through close but I have scrapped three dowels.

All tips will be greatly appreciated.

algale · Post by **algale** » Tue Feb 12, 2013 7:29 am

Recently, when I was drilling through end grain for the lower mount for my extension table support leg, I used a tip another member posted for drilling pen blanks: I chucked the dowel in my Nova G3 and mounted the Shopsmith drill chuck in the tail stock using the tail stock arbor and bored it horizontally. Now, that piece was by design bored from both ends at different diameters so I can't vouch it worked perfectly but the two different diameter holes seemed concentric and centered in the dowel. I'd give it a go.

Al

dusty · Post by **dusty** » Tue Feb 12, 2013 7:58 am

algale wrote:Recently, when I was drilling through end grain for the lower mount for my extension table support leg, I used a tip another member posted for drilling pen blanks: I chucked the dowel in my Nova G3 and mounted the Shopsmith drill chuck in the tail stock using the tail stock arbor and bored it horizontally. Now, that piece was by design bored from both ends at different diameters so I can't vouch it worked perfectly but the two different diameter holes seemed concentric and centered in the dowel. I'd give it a go.

Al

I started to do this when I discovered I have no way to mount the drill chuck in the tail stock. I assume the tail stock arbor has an appropriately sized morse taper (which I do not have but most get).

http://www.shopsmith.com/ownersite/catalog/dr_tailstock_chuckarbor.htm

This sounds like the "right way" to tackle this task and I appreciate your input. I, however, now have a personal challenge. I can drill holes with both ends properly located. I know I can. I think I can Well, maybe I can.

I thought about drilling a through hole in a block of wood and then chucking that up in the lathe and turning a 1" dowel around the hole but that would now be cheating.

pennview · Post by **pennview** » Tue Feb 12, 2013 8:05 am

Another possible method is to use horizontal boring. First clamp a piece of scrap 2x4 on edge to the table and then drill a 1" hole through it. Next, insert the 1" dowel in the hole and drill with the 1/4" bit. If you can keep flexing to a minimum or the bit from drifting because of the grain in the dowel, you should get a concentric hole.

Another possibility is to set up as above, but only drill half way through the dowel and then reverse it and finish up the hole from the opposite end.

bffulgham · Post by **bffulgham** » Tue Feb 12, 2013 8:41 am

pennview wrote:Another possible method is to use horizontal boring. First clamp a piece of scrap 2x4 on edge to the table and then drill a 1" hole through it. Next, insert the 1" dowel in the hole and drill with the 1/4" bit. If you can keep flexing to a minimum or the bit from drifting because of the grain in the dowel, you should get a concentric hole......

My guess is the bit is following the grain. I experienced this a few days ago drilling pen blanks in some 40 year old black walnut. A long 1/4" bit can/will flex quite a bit. One way to verify this would be to orient the grain in one direction for one attempt. Attempt #2 would be to rotate the next trial 90 degrees and do it again and check the differences.

robinson46176 · Post by **robinson46176** » Tue Feb 12, 2013 8:41 am

Dusty, have you tried drilling in your block mount as you have but about every 1/4" of drilling rotating the entire block mount about a quarter turn?

.

fredsheldon · Post by **fredsheldon** » Tue Feb 12, 2013 8:59 am

I think Bud F has hit the nail on the head. I have had the same issue when drilling very old black walnut. I found that it's important to have a very sharp drill bit, and the shorter the better, less flex. And flipping end to end half the way thru didn't work because the holes didn't meet up centered. What might help is to drill a pilot hole with the smallest drill bit you have to give the larger bit a pathway to follow.

oldc6 · Post by **oldc6** » Tue Feb 12, 2013 10:55 am

Dusty: somewhere i seen an article that says use a spade bit when
drilling end grain. all others will wander off..........
Cant find where i read that but, might be worth a try..........

fjimp · Post by **fjimp** » Tue Feb 12, 2013 11:12 am

One hint; Drill very slowly and back bit out frequently so as to limit heating. Jim

terrydowning · Post by **terrydowning** » Tue Feb 12, 2013 11:13 am

Most of the suggestions offered are great.

Drilling straight holes through small stock is definitely a challenge.

Short, sharp bits, and step drilling are recommended (1/8" starter holes centered on either side), 3/16" through and finish with 1/4".

Drill in lathe mode. If you have a Harbor Freight near by they sell a Morse Taper 2 drill chuck for around $15 (Warning run out and/or improper chucking of the dowel in a standard scroll chuck may not lead to the most accurate results) A collett chuck is more accurate. But don't go out and spend $100 on a collett chuck unless you plan on doing this operation often.

As to drill sharpening make sure that any bit used for accurate drilling is sharpened equally well on both sides of the bit. If one side is sharper then the other the result is a bit that does not drill straight.

To test sharpness: On a test piece of plastic examine how the bit is cutting, you should have equal size "shavings" coming off of all cutters. I say test with plastic because because a sharp bit will make nice long ribbon like shavings that are easy to evaluate.

Keep the RPM low (A), slow the feed rate, and clear chips often (1/8" to 1/4"). If accuracy is your desired outcome, take your time.

You may also want to consider a sharp forstner bit if you have one in this size. I have successfully drilled 3/8" holes through 1/2" dowel using my collett chuck, my HF lathe drill chuck, forstner bits and a lot of patience. I used a center starter bit to start the hole, a 1/4" forstner, and finished with the 3/8" forstner.