It's Probably Been Asked 1000 Times, But...

[Spec Grade]

I'm having problems drilling straight holes in my pen blanks. Here's my setup: I have a bench mounted heavy duty drill press. (3/4 hp, all cast iron, etc.) It has been leveled, shimmed, checked 3 ways from Sunday, etc.
It's bolted down to a 4" thick rock maple bench top, with 3/4" carriage bolts.

The drill plate is dead level. I'm using a machinist's drill press vise, which is machined perfectly flat. I also use a Speed Square to align the blanks in the vise, to make sure they are perfectly plumb. I have also changed the drive belts, had the sheaves machined & balanced, etc.

I use a laser calibrated chop saw to cut my blanks, so I know that's square & plumb as well.
I have checked all my drill bits, none are bent or warped. I have used brad point bits, spade bits, you name it, and yet my blanks have significant drift in them. I drill very slowly at low speeds (~350-500 RPM's). I relieve the drill hole at 1/8" intervals.
(Meaning: I drill like Grandpa drives.)

I have checked my drill press for wobble, bearing warp, etc., nothing there. But, whenever I drill a pen blank, it invariably comes out at a different point than when it entered the blank. I mark both ends with an "X" to see where it comes out at.

I have even went so far as to have a professional come out & adjust my table saw for perfect squareness.
(That wasn't cheap by any means.)

Yet, the problem persists.

Does anyone have some insight as to why I still have drift when drilling a 2.5" wood blank for making pens?

It's baffling the hell out of me.

 

[terryf]

If your press has a taper fit chuck it might be misaligned or damaged. Also try holding a straight piece of wood against the side of the turning bit, if its not turning true you should feel it in the wood.

Bit of a mind boggler considering what lengths you've already been to.
Good luck.

 

[hanau]

regular drill bits or a braid point drill bits?

 

[jttheclockman]

I'm having problems drilling straight holes in my pen blanks. Here's my setup: I have a bench mounted heavy duty drill press. (3/4 hp, all cast iron, etc.) It has been leveled, shimmed, checked 3 ways from Sunday, etc.
It's bolted down to a 4" thick rock maple bench top, with 3/4" carriage bolts.

The drill plate is dead level. I'm using a machinist's drill press vise, which is machined perfectly flat. I also use a Speed Square to align the blanks in the vise, to make sure they are perfectly plumb. I have also changed the drive belts, had the sheaves machined & balanced, etc.

I use a laser calibrated chop saw to cut my blanks, so I know that's square & plumb as well.
I have checked all my drill bits, none are bent or warped. I have used brad point bits, spade bits, you name it, and yet my blanks have significant drift in them. I drill very slowly at low speeds (~350-500 RPM's). I relieve the drill hole at 1/8" intervals.
(Meaning: I drill like Grandpa drives.)

I have checked my drill press for wobble, bearing warp, etc., nothing there. But, whenever I drill a pen blank, it invariably comes out at a different point than when it entered the blank. I mark both ends with an "X" to see where it comes out at.

I have even went so far as to have a professional come out & adjust my table saw for perfect squareness.
(That wasn't cheap by any means.)

Yet, the problem persists.

Does anyone have some insight as to why I still have drift when drilling a 2.5" wood blank for making pens?

It's baffling the hell out of me.

Boy that is alot of work when you could just as well drill your blanks on the lathe and be dead on all the time. When you are drilling with a drill press there are many variables and even though you think you address them they still can show up. You do not say weather you are drilling wood or acrylic. When drilling wood grain is your enemy. Especially with a brad point bit. That point can walk to an edge of grain and then will continue on that path all the way through the blank. The vice holding the blank may not have grabbed the blank perfectlt 90 degrees and just a slight variation is all it takes. Round the blanks off use a collet chuck and drill on the lathe and all your problems go away unless you have bad equipment for the lathe.

 

[Hucifer]

Make sure your bits are very sharp. Especially with 7mm bits. New bits made all the difference for me....

 

[Chasper]

Is this happening with larger diameter bits or just with 7mm bits? Thicker bits will not bend and drift as easily. Push the 7mm bit as far up into the chuck as possible to make it shorter with less flex. Try drilling without tightening the clamp that controls the left/right swing of the table, start very slowly so it doesn't drift in the initial penetration, then let the table bounce a little to the left and right as you drill the rest of the hole.

 

[Spec Grade]

Just a quick answer so far. I have chucked the bit up into the drill press head, no difference. I am drilling wood, not plastic.
I have used every bit imaginable, including spade bits, brad bits, split point bits, metal bits, exchangable bits, you name it.
I have over 500 drill bits, all are as sharp as a razor blade.
(I have a friend who runs a machine shop & sharpens my bits), yet the problem persists.

I have tried drilling at least 40+ species of wood, and the problem is still there.

The problem seems to exist with 7mm bits only.

 

[Mack C.]

But, whenever I drill a pen blank, it invariably comes out at a different point than when it entered the blank.

Yup, that's what happens when you drill anything. The point comes out at a different location than where it entered. (just adding a little levity to the situation)

Seriously though, what's the big deal? When you turn the blank the hole is in the centre! You don't mention how much the exit hole is off centre. So long as it leaves enough wood or whatever for the nib or clip end, it's good to go. You are working with wood! Don't be anal about it. Penturning is supposed to be fun. Keep it that way or you will end up in the looney bin! (which is not a good place to be, I hear!)
Something else to consider, the blank itself must be perfectly square along it's length.

 

[monophoto]

You seemed to have checked everything except the one thing that matters - is the drill bit absolutely perpendicular to the the table in both directions (side to side, and front to back)?

 

[gr8danish]

Quick question... Are you using a center drill first? I always get more precision out of my 7mm bits by giving a good starting path with a 60 degree center drill.

By nature, there's almost no way to get an absolutley perfect hole through the center of a blank. I even c/d my blanks on a heavy duty milling machine, and I still get some run-out.

As previously mentioned the most precise method of drilling is going to be on a lathe...

Exactly how much run-out are you getting on say a 5/8" blank?

 

[KenV]

I found that the alignment of the blank in the vise, or the jaws of the vise was causing my distortion from center. Now using a PHS vise that I clamp to a 3/8 inch piece of steel rod in the drill press and then lock down the PHS vise in the clamps so it is true.

That gets me as close to center as the opposite edges of the blank fit into the PHS centering vise.

I do a fair amount of drilling on the lathe too -- drill press is for production work (run of 10 or 20 pens).

 

[fernhills]

RPM to slow, go about 1000 RPM. No need to peck with drill bit in out in out. go at one steady speed ,maybe once to clear chips. Your DP is made to drill accurate holes, thats what it does.

 

[hilltopper46]

Make sure your bits are very sharp. Especially with 7mm bits. New bits made all the difference for me....

RPM to slow, go about 1000 RPM.

IMHO, these two guys got it right. If not 1000 RPM, at least double the speed you are currently drilling.

 

[Spec Grade]

Quick question... Are you using a center drill first? I always get more precision out of my 7mm bits by giving a good starting path with a 60 degree center drill.

By nature, there's almost no way to get an absolutley perfect hole through the center of a blank. I even c/d my blanks on a heavy duty milling machine, and I still get some run-out.

As previously mentioned the most precise method of drilling is going to be on a lathe...

Exactly how much run-out are you getting on say a 5/8" blank?

As much as 1/8" in 2.5" run. I'm thinking of buying a laser that will drill a perfectly perpendicular 7mm hole in whatever I decide to drill.

 

[Chasper]

Drilling with a laser? That sounds like a new idea, I've cut 3/4" wood but it took a long time, unless lasers have improved greatly a 2 1/2 inch hole would be a challenge.

If I really need a perfectly centered hold I use the lathe, but for 99%+ of the thousands of holes I drill the nearly perfectly centered hole from a drill press works fine.

 

[its_virgil]

Making pens is not rocket science. Blanks do not have to be perfectly square with parallel sides and square ends. Holes do not have to be dead center on entrance and exit. As long as there is enough wood around the circumference of the hole for the kit being made all is fine. Cut blanks, drill holes and make pens.

If the holes must be dead center then drill on the lathe. Drilling on the lathe is much more accurate than any drill press and vice combination I have ever used.

Do a good turn daily!
Don

 

[penfancy]

I'm with Ken. I had the same problem when drilling blanks held in my machinist's vise. When I used a pen blank vise it all went away. Magically!:biggrin:

 

[polarbear1]

I agree with Marc and Don. You really can not see inside to know the grain pattern and where the hole with will make the prettiest pen. As long as there is enough wood around the outside of the tube for the diameter of the pen you are making, it does not matter how centered the hole is, your lathe will take care of making sure your hole becomes the center. Every wood pen is unique, and a surprise, have fund making the holes at any angle. Unless your drill press is so out of line, or your bit is bent so the hole is too big for the tube to sit snug, it doesn't matter where the hole starts and ends, Unless your mandrel is bent the hole will be the center before your done.

 

[jttheclockman]

The times it is dead necessary to have a drilled hole centered on a pattern such as knots or other fancy designs. Other than that as mentioned if there is enough material on the sides for the kit being used all will be worked out with turning and trueing ends. Do not make this harder than it is. You have 10 year old kids doing this.