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View Full Version : Making accurate holes in pen blanks - How?



David LaRue
11-24-2004, 8:17 AM
I just launched myself into turing pens on my Jet mini lathe. Lot's 'O' fun so far. My results at dilling perpendicular holes in the pen blank were not so good! :mad:

Procedure followed:
I marked the centers by drawing an "X" I used my floor standing drill press and a machinist vice to drill the holes. I was not able to hole the blank straignt up and down, or my drilling technique allowed the bit to flex, but the result was an off center hole on the bottom.

Question::confused:
What technique do you find sucessful?

And is there a homemade jig that would assit? ( Really don't want to purchase one, and would rather put that money twords a chuck in the future)

Dave

Terry Quiram
11-24-2004, 9:05 AM
Dave

Two things helped me to drill straight holes. I am now using a pilot bit. It stays straighter as the drill enters the wood. If you watch the point of the bit as you start to drill a blank you will see it drift in the direction of rotation. That angle will continue till you reach the end of the blank. Have you ever heard the drill skreeching? That is the length of the bit rubbing against a hole that is not parallel to the bit. You could use a scrap of wood and "push" the bit as it enters the wood to keep it from drifting. The other thing that helped me was to slow down and woodpecker the bit to remove chips.

Terry

David LaRue
11-24-2004, 9:08 AM
Terry,


I guilty of being impatient, and I likely contributed to drill flex by not 'woodpeckering' as much as I should have. Is there a jig you use to hold the blanks?

Dave

Kent Cori
11-24-2004, 9:46 AM
David,

I made a set of two scrap wood blocks with vees cut in them for my 4" drill press vice. I then used double sided tape to affix them to the jaws of the vice making sure the vee was perpendicular. When I clamp the blank in here it is automatically aligned along the axis of the drill bit. You can also buy commercial jigs with a similar concept that are allso self centering for about $50.

I use parabolic drill bits from Berea for drilling my blanks. For me they tend to keep the hole centered better than almost any other style.

Ray Dockrey
11-24-2004, 10:14 AM
I use the centering jig from Woodcraft. It is pricey but I have never regretted buying it. As long as you end mill the ends after drilling the holes your holes don't have to be perfectly straight anyway. I think the biggest thing is taking your time and backing out often to clear the chips.

Dick Parr
11-24-2004, 10:34 AM
Dave I made myself a jig using any type of small hinge. Split a 2x4 and cut a notch on each side and put the hinge on the end. This will hold all sizes of blanks. I don't need to mark the center anymore, just line it up with the end of a brad point bit. I raised the speed of the drill press up to 990 and I back out of the hole after every 1/8-1/4" to remove the chips.

Since I made this jig all is well. No more throwing away bad blanks with the hole to close to the edge of the wood. :D

Randy Meijer
11-24-2004, 10:51 AM
Dave:

I use exactly the same method as you have described and get satisfactory results......not perfect.....but satisfactory. Depending upon the type of wood used, there sometimes is a little tilt to the holes; but as long as you are not blowing out the sides and have enough wood thickness left for your pen, it really doesn't matter.

It is kinda basic; but I always be sure to use very sharp drill bits. Right now, i'm just using plain old twist drills; but plan on trying a couple of the parabolic bits shortly based on recommendations by guys on this board. Another basic....the table on my DP moves sometimes so I check it before each job with a 6" drafting triangle to make sure it is perpendicular to the axis of the drill. I don't use the gage on the table.....just don't trust it.

Ken Salisbury
11-24-2004, 12:45 PM
Procedure followed:
I marked the centers by drawing an "X" I used my floor standing drill press and a machinist vice to drill the holes. I was not able to hole the blank straignt up and down, or my drilling technique allowed the bit to flex, but the result was an off center hole on the bottom.

And is there a homemade jig that would assit? ( Really don't want to purchase one, and would rather put that money twords a chuck in the future)

Dave

It is more important for the hole to be perpendicular to the sides of the blank than to be in the center. For years I used a very simple block with a "V" cut and my drill press vice - see photo link below. In order to prevent dill bit wandering it is important to start the hole with a very very slow feed, backing the bit out 4 or 5 times to help remove chips as you continue to the bottom. I also cut my blanks 1/4" longer than required, set my drill press stop at 1/8" from the bottom of the baln to prevent blowout. I then trim the blanks to the required length. If the hole is slanted then a pen mill will square the ends to fix the problem.


http://www.sawmillcreek.org/attachment.php?attachmentid=5512&stc=1

Note the filed mark on the front jaw of the vise. It was used to line up the position of the next blank to be drilled.

I drilled more then 1,000 blanks with this technique and setup in the photo and rarely had to resort to using a pen mill.

Joe Judge
11-24-2004, 12:50 PM
My method is crude ...

I took 2 pieces of 1x4 wood scrap (cut about 4" long) and attached them at right angles. Basically, this looks like a drawer corner :-)

This is my 'jig' -- just stick the pen blank vertically against the inside corner. I use a clamp to hold it against the jig.

Then, my non-drill-press owning self "eyeballs" my drill vertically and puts a hole in it. I go fast until about 3/4 of the way down. Then I clear the hole and go slow for the remainder (to reduce blowouts).

-- joe
(I MUST get a drill press someday soon)

Keith Outten
11-24-2004, 2:37 PM
David,

Here is the method I have been using to drill blanks. I also keep my vac running and keep the nozzle right up next to the drill bit to vacumn the chips right at the source and believe it or not it makes a difference in how straight the holes will be.

http://www.sawmillcreek.org/showthread.php?t=8365&highlight=drill+press

John Shuk
11-24-2004, 5:39 PM
I just try to make mmy blanks big enough that I have room for error. Then I use the drill press vise. When I start paying for blanks I'll have to be more careful but what I am doing seems to work for me.

David LaRue
11-24-2004, 8:34 PM
Great ideas! :)

Keith I was wondering about the the 'perfect' use for the MicroJig Grrriper. I have a bunch of 3/4" Jotoba left over from my floor project, and I think I need to get a gripper for the job of making pen blanks.

I need to get started on a jig, since I ordered some pretty neat pen blanks. I'll let you know on my progress. (Christmas gifts)

BTW: Where do you get parabolic bits? I purchased a 7mm from Woodcraft that is sold as a penmaker's bit. How is a parabolic differenet?

David

Keith Outten
11-24-2004, 9:29 PM
David,

The MicroJig is invaluable on my table saw and works perfectly for ripping 1/2" strips of Corian. Note that the sink cutout will produce literally hundreds of pen blanks safely using the MicroJig. I got some Jotoba scraps from the Residence Hall we just finished and it has made lots of pens to date. Jotoba also engraves nicely and although it will darken over time and the engraving contrast is reduced I love to turn Jotoba pens.

My source for parabolic bits is Berea Hardwoods, most bits are priced at $6.00 each and must be purchased in the size required the pen kit. These work well in wood, acrylic and Corian and will outlast and outperform standard twist bits when drilling pen blanks.