Drilling on lathe question

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Talltim

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We finally got a nova g3 Chuck and pen jaws to try drilling on our lathe.

My question has to do with the tailstock. (For reference we use the jet 1221 vs lathe). We move the tailstock up so the bit is close to the blank and then lock the tailstock to the bed. We leave the spindle lock loose so we can advance it with the wheel.

The problem seems to be when the spindle is not locked the is a lot of play in it as it moves forward on the shaft.

Is this normal or how do you avoid it?
 
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This is .... semi-normal. You'll want to tighten the spindle lock just enough to take out most of the play ...

You will also NEED to keep your left hand ON THE DRILL CHUCK as it advances in order to keep it from spinning in the tailstock taper and scratching it up ... also, you'll need to keep it tight against the tailstock in order to keep it from pulling out of the taper and spinning as you retract the bit by backing the wheel on the tailstock. This is a safety consideration, as you DO NOT want that tailstock chuck coming out and then getting flung across the room or right into you.


On a metal turning lathe, the tailstock is on it's own bed that can be moved forward/backward for drilling operations. The tailstock's spindle is locked, and the drill chuck is secured by a device called a "draw bar" ... this item is screwed into the base of the taper from the back side of the tailstock and locked in place with a nut, drawing the chuck securely into the tailstock's taper and eliminating any possibility of it coming loose or spinning.

You then turn the crank that advances the entire tailstock as a unit or retracts it as a unit, with one hand, while the other is free to control delivery of coolant/lubricant to the item being machined.

(added a bit here)
You can simulate this effect on your wood lathe by beginning your drilling operation as described above in the first paragraph ... and then once you have gone an inch or two into your blank you can lock down the spindle and then UNLOCK THE TAILSTOCK ... you then keep one hand on the tailstock and move it back and forth to drill the hole and clear the chips, while keeping the other hand on the drill chuck to guide it. This method has the added benefit of being able to drill MUCH FASTER through softer materials or with sharp bits, as you can clear the drill's flutes much more quickly and then get back to drilling much more quickly. It is more difficult to do with harder materials, as you are using your own muscle power (your arms) to push the bit into the work, rather than the mechanical advantage of a screw feed.



Before any drilling operation, ensure that the stock is SECURELY FASTENED in the chuck assembly. Pen Jaws are somewhat long, so they are easy to overtighten and bend ... bend them back if you can, and/or help secure them by wrapping with duct tape or good rope so that you have good contact all the way down the sides of your blank.

There are only 2 jaws for grabbing the blank, because if your blank is out of round or out of square (rectangular or some other odd shape) then the chuck jaws SHOULD still be able to grab it and center it for drilling. If you wish to drill "off center" then wrap the blank with something else along the side you wish to bias and then clamp it in the jaws, and wrap the jaws well to prevent slippage.


Always remember .... as long as the drill chuck's taper is still well within the morse taper of the tailstock, you should easily be able to stop the lathe safely, or just GRAB the drill chuck and push it back into the taper before it starts wobbling loose. This works even if the bit gets grabbed by your material and the whole drill chuck is spinning. DO NOT let your drill chuck's taper spin against the interior of your tailstock's morse taper ... you do not want it getting scratched up.
 
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Talltim said:
We finally got a nova g3 Chuck and pen jaws to try drilling on our lathe.

My question has to do with the tailstock. (For reference we use the jet 1221 vs lathe). We move the tailstock up so the bit is close to the blank and then lock the tailstock to the bed. We leave the spindle lock loose so we can advance it with the wheel.

The problem seems to be when the spindle is not locked the is a lot of play in it as it moves forward on the shaft.

Is this normal or how do you avoid it?
Click to expand...

Make sure your drill chuck is snug in the spindle and then snug the spindle lock but not tight so that it still can advance. Then as you advance the drill bit hold the drill chuck with your left hand to steady it as you get it started. It will find its own pathe after it gets started.
 
Thank you both for giving very complete answers. I am always impressed with the time people here take to take others.
 
Tim--I used to move the tailstock to "close" like you described. Enough play in mine before locking it down that if could start slightly off center. I now advance the bit about a half turn, move the tailstock up to my center mark, lock down, then retract the bit that half turn (so i'm not in contact when I turn on the motor. Gets me dead center every time.

Hope that made some sense. I had to drill a few blanks on my drill press last week--now that I've been using the lathe for the past year, I don't know how I ever thought the DP was functional!!

earl
 
Did you put a divot dead center on the end of the blank with a skew? It will guide the bit instead of it wanting to follow the grain. I'm not a fan of brad point bits either because I think they tend to wander, especially when drilling into endgrain. A standard HSS bit works great when the divot closely matches the tip.
 
My experience with drilling is that there can be backlash in the tailstock, and there are a few simple things that will help avoid problems:

1. Start by putting a small dimple exactly on the center of rotation before starting to drill. Mount the blank in a chuck on the headstock, face off the end, and use a skew to cut that dimple exactly on the center of rotation.

2. Make sure that the Jacobs chuck taper is firmly seated in the tailstock quill. My lathe has the automatic ejection feature, and there is a gap between the point where the taper is fully seated, and the point where it ejects. I always start by advancing the quill to the point where the taper is fully engaged. In my case, that seems to be very close to the zero point on the calibrations engraved on the side of the quill, but I don't know if you can always trust those engravings to determine the depth of the hole being drilled. (In his book on pen turning, the late Richard Kleinheinz recommended measuring how far the quill advances for each revolution of the handle, and then counting revolutions rather than using the calibration marks.) But the key is that if the chuck taper isn't fully engaged with the taper in the tailstock, there will be some sloppiness.

3. Move the tailstock up to the point where the drill bit almost touches the workpiece, and then center the bit on the dimple BEFORE locking the tailstock down to the bedways. There can be some 'wiggle' caused by a slight mismatch between the spacing between the bedways and the width of the alignment block on the bottom of the tailstock - in the case of my lathe (a 12" Turncrafter), I have less than 1 degree of rotation, but that's enough to cause a hole to be off center unless I carefully align the bit to the dimple before locking the tailstock down.
 
philipff said:
Sorry, but I think UNLOCKING the tail stock is asking for Big Trouble! What's so difficult that you can not turn the handle to move the bit into and out of the wood!! Philip
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Interesting thought.

It's not unusual to use a loose bit held in vice grips, or embedded in a handle, to drill a depth hole in a hollow form. I don't see any problem with that.

But if you want to drill a precise hole - that is, one where the diameter is consistent throughout its depth - I think the bit needs to be held in a Jacobs chuck in the tailstock. If the bit is not aligned with the axis of rotation, and goes in at a slight angle, the diameter of the hole can vary along its depth.

That said, however, I think Skie's point was that if you start the bit with the tailstock locked down and drill part of the hole, you can then loosen the tailstock and drill the rest of the hole by simply pushing the tailstock toward the headstock. The idea is that bit will be kept on axis by the initial portion of the hole. While that may theoretically be true, the objective of that approach is to speed up the process of drilling the hole, and my experience is that if you want a straight, precise hole, you have to take your time and drill slowly. Do it too fast, and you get to do it over.

By the way, I've seen a few videos where people have put a bit in a Jacobs chuck mounted in the headstock, and then drilled the hole by pushing the blank onto the spinning bit. That's scarry - if that bit wanders off axis, it can go through the side of the blank and into the hand holding it.
 
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As you can see, there's more than one way to skin a cat! :) Or a less macabre way to put it, more than one way to drill a hole.


The least precise version would be .... to grab a hand-cranked or power drill and drill the blank freehand ... Is it POSSIBLE to drill a straight hole? sure .... might be a little wavy or wobbly inside for the first few centimeters as you straighten your bit to go somewhat down the center. Will it be straight down the center of the blank? probably not.

The next step up would be to use a holding fixture for your power drill, such as a portable drill press attachment ... or to step up to using an actual drill press. This method CAN drill a very straight hole, and IF YOU LINE IT UP PROPERLY 90 degrees to your table and use a proper clamp/vice setup to hold your blank, you CAN POSSIBLY drill right down the center of the blank. The problem is ... is your table properly set up that way? Does your drill travel exactly 90 degrees in direction from the plane of the table? Is your material properly clamped?


The next step up from there would be the lathe. Why is the lathe more accurate? If your blank is spinning on center of axis WHERE YOU WANT THE HOLE TO GO and your bit is positioned properly, you will get a dead center hole right down the middle of the blank ... if your bit does not BEND. To keep it from bending, you can drill a starter hole and then drill with the full diameter bore rather than using a small thin pilot hole bit.

Another measure to keep the bit from deflecting or wandering is to make sure it is SHARP! (use a drill doctor!)


Any method that makes use of putting the drill bit in the headstock side and drilling their blank on the tailstock will TYPICALLY FAIL unless your blank simply CAN NOT BE HELD ON CENTER. (antler, horn, bone, out of round material that you just can"t center up on your lathe's clamping fixtures). For things like this, a drill press or a pair of vice grips can be used (or both together), but you CAN use your lathe for this operation with the vice grips.

Mark and center drill (any way you choose) both ends of the antler round. You'll use this center drill mark with your tailstock to try to keep things properly centered during drilling. Use a 60 degree center (doesn't need to be a live center) in the tailstock, or something similar that wont mar your work piece. Use of a draw bar with the drill chuck mounted in the headstock is probably a requirement. :P

Hold the piece of antler with one side centered on the tailstock center and USE THE TAILSTOCK WHEEL to push the antler up and onto the bit for your drilling operation .... drill slowly, holding the antler with your vice grips. Once you are about halfway through the blank, completely back it out and drill the rest of the hole from the other side .... this ensures that even if you are a TINY bit off where the two holes meet, each end will have it's hole perfectly centered. Make sure your bit can pass completely through, and use a good gap filling glue inside (as antler is likely to have interior voids to fill anyways, from the marrow pockets).


So ... that's a lot of ways to drill! We didn't even cover reaming, broaching, milling, or using an offset cutter to enlarge an existing hole!

In short ... there's a lot of ways to make a hole. Find one that you are comfortable with and gives you the results you desire. No one person is always right all the time, because it's only human to make mistakes. (don't forget to learn from them, though, ok?? :) )
 
farmer said:
Gun drills normally drill extremely straight
https://www.bing.com/images/search?q=gun+drill+bit&qpvt=gun+drill+bit&FORM=IGRE
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which is done on a gun lathe or barrel lathe ... :)

First you drill the barrel, then you bore it out to the correct diameter, then you button ream it to harden the interior layer, then you ream it with the rifling buttons to give it the rifling grooves ... all of this is generally done right on the barrel lathe. Sometimes they use a press for the reaming, as the rod pushing the button simply needs to be pressed straight through the barrel.

Some versions don't use a button, but instead use a reaming die at the end of the rod.
 
there's more than one way to skin a cat! :)
Click to expand...
FWIW, that is a reference to a catfish, not a four-footed feline.
Tried drilling on the lathe. It was more trouble than drilling on the DP. I have a Supernova 2 chuck and pen jaws. Unless the blank is perfectly square, you have trouble. To me, turning the blank to round is adding extra time and another operation. JMHO.
 
Gun drilling can be done on a regular lather and do drill a good hole. Not real practical for pen turning due to the various sizes of holes required. The gun drill in a lathe also needs a pilot hole. The bits are single flute which is off center. (I gun drill a lot at work, but on a dedicated gun drilling machine)
The suggestion of sliding the tail stock in and out to drill is not a good idea, IMHO. drill bits tend to want to 'screw' in once the tip breaks through. That could pull the tail stock into the blank/chuck and damage or ruin a blank. If your blanks are long and you drill short, could get away with it.
 
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For me, turning the blank round and then drilling makes the job much more accurate. Unless you are making a square pen, you will have to turn it round at some point. I just could never get the blank perfectly square so it would spin on center in the pen jaws.
Also, some of my bits are what is called mechanic's length. I have a 12.5 mm that has a drill depth of 2" and it doesn't wiggle at all.
 
Drilling on the lathe is not a problem in and of itself. Overall, it is more accurate than a drill press for the average person. The problem arises with technique, and chancy technique has been mentioned above. NEVER drill while sliding the tail stock with the bit in it - forward. It "can" be done, but that is where error is usually introduced and problems begin - assuming the head stock and tail stock are aligned and stay aligned - but one has to KNOW his lathe for strengths and weaknesses for this to work. If an unexperienced person has some slop or wobble and does not know that this is unacceptable, he will assume that this is normal. On the other hand, one who does not know this, and forceable pushes and bumps the tail stock forcing it to move when "locked down", and then saying his lathe tail stock has "slop" - that is not acceptable either. (Trying to cover the bases for all kinds of "not knowing" proper tool use on the tail stock.)

Advance the tail stock and LOCK it down. Use the rear wheel to advance the bit into the blank. When the bit is extended as far as it will go, withdraw the bit with the rear wheel, loosen the tail stock and advance it. Turn on lathe and advance the bit with the rear wheel again, not moving the tail stock.

Drilling should be done using the intended method of the lathe itself. Advancing the bit DURING the TURNING process by sliding the tail stock on rails is NOT what was intended in the design of pen turning wood lathes.
 
Thanks again for all of your comments. We have incorporated a number of your suggestions and they have helped a lot.
 
I am a game call turner, and have been for over 54 years, on game calls the drilling is important, but the accuracy doesn't have to be as precise as on pens. For my calls, I drill blanks on the lathe, rodeo cold or hand grenade close works. For pens I want the drilling to be as close as possible. I turn my pen blanks to 3/4, 5/8 0r 1/2 inch diameters. I then use my collet chuck, I start with a center bit, then use the drill bits. If it is a material that is prone to blowouts, I drill from both ends and meet in the middle. I lock down my tailstock, and use only the quill to feed the bit, I also hold on to the drill chuck.

Having the rounded blank also allows me to use my lathe for milling the ends after the tubes are glued in. I can stick the barrel in the collet chuck knowing that it is square and use a drill chuck to hold either my mill sander or pen mill to square the ends.

Rounding the blanks take time and I was a production turner and time was money. But I found this to be the most efficient method, my missed drilled blanks were minimal and usually salvageable.

But the best part was that some of those wood blanks that looked plain and were destined for a Slimline pen, suddenly became a blank for a better pen. As I turned the blanks round I graded and sorted them, A, B, C and Slimline quality.
 
dogcatcher said:
I am a game call turner, and have been for over 54 years, on game calls the drilling is important, but the accuracy doesn't have to be as precise as on pens. For my calls, I drill blanks on the lathe, rodeo cold or hand grenade close works. For pens I want the drilling to be as close as possible. I turn my pen blanks to 3/4, 5/8 0r 1/2 inch diameters. I then use my collet chuck, I start with a center bit, then use the drill bits. If it is a material that is prone to blowouts, I drill from both ends and meet in the middle. I lock down my tailstock, and use only the quill to feed the bit, I also hold on to the drill chuck.

Having the rounded blank also allows me to use my lathe for milling the ends after the tubes are glued in. I can stick the barrel in the collet chuck knowing that it is square and use a drill chuck to hold either my mill sander or pen mill to square the ends.

Rounding the blanks take time and I was a production turner and time was money. But I found this to be the most efficient method, my missed drilled blanks were minimal and usually salvageable.

But the best part was that some of those wood blanks that looked plain and were destined for a Slimline pen, suddenly became a blank for a better pen. As I turned the blanks round I graded and sorted them, A, B, C and Slimline quality.
Click to expand...

I like the madness to your method, there .... and I'ld really like to point out that NOT ONE SINGLE TIME in this entire thread did I mention turning a blank round BEFORE the drilling, though that happens to be what I do every time on my own lathe. When I mentioned "antler rounds" ... it is because, obviously, when you go to drill your antler blank they have rounded sides. :)

I do understand that a lot of people would prefer not to have to take that extra step before drilling their blanks, because it does take some extra time that they'ld rather use for other things. I do it mostly because I had no real way to reliably hold a square blank for drilling, and I mostly keep up with it because everybody who has seen my pre-rounded blanks get to see much of what it would look like once it's on a pen and finished... sort of a preview effect, and they like it. Your mileage may vary, of course ... :)


I'm sorry if I happened to "recommend" procedures on the lathe that may not be 100% safe. I really should go back and edit my post to reflect that these are techniques that I've tried out and found to work for me, but may not be the safest techniques in the world. Then again, we all work with lathes, and we know them to be not the safest machines in the world for the uninitiated to work with. Use caution when using new and untried techniques, use caution when using new and unfamiliar materials, and use caution when turning on your lathe. :)


(edit) ahh, nope ... looks like I can't edit that first post I put in this thread.
 
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