Drilling on lathe

[Woodchipper]

I know this forum has been worn out with similar questions. I have a setup to drill on the DP and have seen some drift on some woods. OK, to continue. I just finished drilling a round blank on the lathe with the Teknatool pen jaws. Followed with a synthetic blank, using the same bit. This blank was as square as can be. So far, so good. I have noticed that not all blanks are perfectly 3/4x3/4. Does drilling on the lathe center the bit so the out-of-square doesn't matter? Cures bit drift? The only thing, to me, is turning the blank round and then drilling seems to take a lot of time to set up the lathe, especially if you are only doing one pen. Several blanks at once- turn and then drill? I'm not a production turner. Your experience, expertise, etc. are most welcome.

 

[wolf creek knives]

I use my DP for drilling my blanks also. I've noticed in the past that I would get some drifting with Brad Point drill bits. I'm not exactly sure why but once I stopped using them the drift went away. Also, if the blank is not square and tapers down a bit you could get a blank that is not "square" and could look like drift when in fact, if the taper is on the exit end of the blank, it's just following the contour of the blank (hope this makes sense).

 

[Woodchipper]

WCK, thanks.

 

[Chippa]

If you're having trouble with your bits hitting center and you know your lathe is aligned, you can try using a skew chisel to true the ends and make a small dimple to guide the bit in.

 

[jttheclockman]

The only time it really matters that the bit is drilling dead center is if doing a segmented blank. The the hole needs to be dead center of the design. Other than that if there is enough meat left to accept the pen components then the blank will center when turned round. When you true the ends you do so in relation to the tube and not edge of blank. I think too much is made about centering tubes in blanks from drilling on drill press or lathe. If your drill press is set up properly and you have a secure means to hold the blank you will do just fine. But I would stay away from brad point bits drilling into end grain.

 

[Jarod888]

So, depending on the amount of effort you want to put into it:
Buy a set of centering drill bits from Amazon. They are about 12-15$. Pick a size that is slightly smaller than the drill bit you are going to use. Chuck the square blank into your chuck and drill a hole, partially into the blank. Stop once the bit changes from a cone to a round shank. Centering drill bits have a hardened tip that is designed to not wonder and the shape is a perfect 60 degree cone. Take the blank out and do the same to the opposite side. Then using a 60 degree dead center in the head stock and a 60 degree live center in the tail stock, turn the blank down to round and to a nominal size, about 1/32 under 3/4 of an inch. Then, chuck the now rounded blank into a collet chuck and drill your hole for your pen tube. Once you've glued the tube in, you can use "turn between center bushings" to shape the blank. Your blake will be perfectly concentric because of the 60 degree taper in the bushings.

Option 2 is to use the centering bit to drill your starter hole and then complete the rest with a 118 or 135 degree drill bit. Dont use a brad point. Buy quality drill bits, I suggest norse or viking, but they are more pricey than others. Drill slow, clear your chips often and develop a smooth drilling technique.

 

[Woodchipper]

If you're having trouble with your bits hitting center and you know your lathe is aligned, you can try using a skew chisel to true the ends and make a small dimple to guide the bit in.

Thanks for the tip. No problem there but I do keep a sharpened nail on hand- tap with a hammer for the drive spur and the live center. Just concerned about not-square blanks drilling with the hole centered. I don't worry about Slimlines as there ia a ton of wiggle room. Some pens I'm working on for a juried museum selection don't leave a lot of extra material.

 

[Dehn0045]

I turn round then drill on the lathe using pin jaws to hold the blank. I use my skew to make a center for the drill bit. I'm normally making just one or two pens at a time, if I was doing large batches I would probably use my DP. I see a couple of advantages with turning round first - less risk of blowing up when knocking corners, better preview of the blank for choosing where to position, allows me to TBC the rest of the way with no bushings, allows me to easily square on the lathe after gluing tubes, eventually it has to be turned round anyway. Also I don't really have much trouble with drift, so kills a lot of small issues with only a small amount of extra effort, so it's worth it for me.

 

[Woodchipper]

Sam, thanks for the info. Makes sense. I'm starting to TBC. Mentioned it to my grandson this past week. "Using the calipers, huh." I have a ton of wood and cut blanks. Might cut and turn some round in anticipation of future pens; mark the length and wood type.
Speaking of skew, went to a club demo...the guy roughed the square piece with a skew!

 

[eharri446]

If your blank is more of a rectangle than a square the Nova pen plus jaws will allow you to drill a hole straight thru the blank as nearly centered as it can be.

 

[howsitwork]

I use my drill press and hold the blank in a compound vice having lined it up with the drill bit first.

Hmm that doesn't make it clear so ...

The engineering vice I use has an X and Y axis adjustment like this

so you can pit the blank in the jaws and , having,locked the drill quill down next to the blank ensure the dill is entering parallel to the long axis of the blank. You then release the drill quill ( let it up ) and adjust the drill bit using the x and y handles below the voice itself to set the drill where you want it on the blank.
I find it helps to wrap more fragile blanks in tape to help prevent splitting. Drill slowly and carefully using a quality drill bit and frequently lifting it to clear chips out. Oh and it helps to rest the bottom of the blank on a scrap of flat plywood to prevent blowout in either wood or plastics. This also stops you drilling the base of your vice don't ask how I know that.

If you drill on the lathe the bit usually self centres as end grain tends to deflect bits lathe action tends to allow them to " bore" rather than drill true if used slowly. What ever you do DONT let the drill get hot. It will expand and depending upon the wood may jam causing you much heartache or exploding the blank.

For speed it can be worth making a clothes peg type hand vice to hold blanks to drill but I do like to use my drill press for the control it gives.

 

[dogcatcher]

I turn my blanks round for 2 main reasons, first when turned I get to see the real wood grain, second, I because I get better drilling results holding the blank in my collet chuck. I mainly make wood pens, so getting a look at the grain in the round is important.

 

[Woodchipper]

I turn my blanks round for 2 main reasons, first when turned I get to see the real wood grain, second, I because I get better drilling results holding the blank in my collet chuck. I mainly make wood pens, so getting a look at the grain in the round is important.

It makes sense for wood blanks or even synthetic (too many types so I don't want to call them acrylic). Seems I need to regroup in the future.
howitswork, have a similar setup- HF machinist's vise.

 

[leehljp]

It has been said already but I will repeat it: it depends on the type of blank you have. This must be kept in mind,

1. if it is an ordinary but nice looking wood or cast blank, it does not matter if it is square, round or rectangular.

2. If it is a certain kind of segmented design, precision is paramount.* Getting it square or round before drilling is a necessity. But not all kinds of segments require precision.

3. Trying to get a hole through the center of odd shaped wood or material can be accomplished like this:

The problem arises when we do not understand the different kinds of issues/situations (not that many).

* Look at the pin stripe:

SS Baron PenStripe

I was experimenting in making pin stripes and made a PenStripe. Sterling Silver Baron; 1.5 mm plastic. It is OK and I will make more in the future. For now, I am just going to look at this one. It challenged me. The Photo part is challenging me also. Not as sharp as I want it but I will live...

www.penturners.org

ANY off center, even as much as .5mm or even .1 will show up in uneven spacing of the stripes.

 

[Woodchipper]

Hank, thanks. I have some antler that can be a complement to some of the "gun" kits.

 

[MiteyF]

So, depending on the amount of effort you want to put into it:
Buy a set of centering drill bits from Amazon. They are about 12-15$. Pick a size that is slightly smaller than the drill bit you are going to use. Chuck the square blank into your chuck and drill a hole, partially into the blank. Stop once the bit changes from a cone to a round shank. Centering drill bits have a hardened tip that is designed to not wonder and the shape is a perfect 60 degree cone. Take the blank out and do the same to the opposite side. Then using a 60 degree dead center in the head stock and a 60 degree live center in the tail stock, turn the blank down to round and to a nominal size, about 1/32 under 3/4 of an inch. Then, chuck the now rounded blank into a collet chuck and drill your hole for your pen tube. Once you've glued the tube in, you can use "turn between center bushings" to shape the blank. Your blake will be perfectly concentric because of the 60 degree taper in the bushings.

Option 2 is to use the centering bit to drill your starter hole and then complete the rest with a 118 or 135 degree drill bit. Dont use a brad point. Buy quality drill bits, I suggest norse or viking, but they are more pricey than others. Drill slow, clear your chips often and develop a smooth drilling technique.

What you're describing is not a "centering bit", it's a "center drill" (semantics I suppose). While one of its uses is to put a little "divot" where you want the center of your hole to be, its primary purpose is putting centers in a work piece for either a live or dead center on a metal lathe, hence the 60* like you described (and the name). I haven't ever seen one with a hardened tip, they're almost always straight HSS, though I'm sure makeups can be had. They don't resist wandering because of their hardened tip, they resist wandering because they're very short and wide.

Using a center drill before drilling for the tube MAY help with the bit wandering, but the issue (I'd guess) is more likely incorrect setup or a bad bit. Not sure why you suggest against brad point bits though, as they tend to drill much more straight than a regular twist drill, AND leave a cleaner exit. Brad points have the "brad" for the same reason forstner bits have them... it helps keep them centered. Drill bits cannot "cut" at the very tip, they must PUSH the material out of the way, until the cutting edge can start working. Brad points can start cutting sooner than twist bits can thanks to their geometry. Drill bits will always wander to some degree, but regular twist bits are generally the worst of the bunch.

 

[dogcatcher]

It makes sense for wood blanks or even synthetic (too many types so I don't want to call them acrylic). Seems I need to regroup in the future.
howitswork, have a similar setup- HF machinist's vise.

Fix a mount for your lathe chuck out of a block of 2x6, the as needed set ip up and center on your drill press. On a 2x5 or a 2x8 drill a hole for a blot the size of the spindle threads. When ready to use screw the chuck onto the board, then center it with the chuck and clamp it down.

 

[Woodchipper]

Adding this to my original post! Getting seven pens (so far) for the juried show for a local museum. I sorted the blanks according to the bit needed for each blank. I kept the pen jaws in the chuck. Some of the blanks were fairly square to the 3/4x3/4 typical for blanks. I had to cut some on the BS as accurately as I could. Even with a couple not exactly square, I drilled on the lathe and they came out great! Didn't turn any of the blanks before drilling. Had one blank that was round- got it on sale at Woodcraft. My thanks to all. Only thing is changing the jaws when turning. Another chuck (SuperNova2) is out of the question and the budget for now.