Drilling with accuracy on a wood lathe

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penfetish

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I would like to know how some of you drill (accurately) on a wood lathe. I use a drill chuck that fits into the MT2 on the tail stock. As soon as I loosen the quill to advance the drill, it chatters and wobbles all over the place, even if I am holding it at the base of the chuck to steady it.

The other alternative I have tried is to keep the quill locked, and just manually push the tail stock in slowly. But it's the same issue... once the tail stock is loosened, there is too much play and the end of the drill dances back and forth making a very inaccurate hole.

I use a 60 degree center starter before I drill. But I am not happy with these results. This kind of wobble is not nearly precise enough for the close tolerances needed to make a kitless pen. Is there a better way to secure a drill, than using this MT chuck?
 
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What has worked for me is to lock the tailstock with the bit real close to the blank.
Then tighten the quill down and then back it off just slightly to allow the handwheel to advance the bit. You need to go real slow here so the bit is barely digging in. Once the bit has advanced about 3/16" you can loosen the quill more and advance faster.
I also pre-start the holes either with a center bit or with a round flat tool. It is important that there is no material in the center of the started hole to allow the end of the bit to go off center.
 
Dale Allen said:
What has worked for me is to lock the tailstock with the bit real close to the blank.
Then tighten the quill down and then back it off just slightly to allow the handwheel to advance the bit. You need to go real slow here so the bit is barely digging in. Once the bit has advanced about 3/16" you can loosen the quill more and advance faster.
I also pre-start the holes either with a center bit or with a round flat tool. It is important that there is no material in the center of the started hole to allow the end of the bit to go off center.
Click to expand...
That's about what I do. But what do you mean by starting the hole with a round flat tool?

About the only other thing I do when I really want a good true hole is to drill a pilot hole about 1/16" smaller than the final hole.
 
Thanks Dale. I think part of the problem is the length of the drill + the length of the chuck holding the drill, makes for a very long extension and the vibration gets magnified. I have tried your method, but perhaps I loosened the quill too much at first. It seems the taper in the tail stock has a lot of play in it as soon as the quill is loosened.
 
I put the blank between centers and turn it round then cut into the needed two (or one) parts. i hold the blank with my collet chuck then drill. I make a lot of one piece slim lines and drill from both ends with a standard size bit and the two holes meet dead on. Drilling on the lathe is a very accurate way to drill. I also use a center drill.
Do a good turn daily!
Don
 
This issue has driven me crazy for years. So crazy that I finally bought a metal lathe. With the metal lathe I can drill with complete accuracy. I suggest that if accuracy is as important to you as it is to me, you might want to bite the bullet and purchase a metal lathe.

While using a wood lathe, I found that using a collet chuck helps, but only if you have the blank very evenly rounded. Center drills, pilot holes, slow speed, sharpened bits, and reamers, will help also. A center drill will also help with drifting when using a drill press.

The bottom line is that wood lathes are just not made for the kind of accuracy needed for kitless pen making. Yes, it can be done, much better by some than others, (and no doubt we'll hear from a few directly after I post this), but if you are asking this question, I'm guessing you won't be happy until you have a metal lathe. IMHO.

Lauren
 
Laurenr said:
This issue has driven me crazy for years. So crazy that I finally bought a metal lathe.

Lauren
Click to expand...

I have been thinking about this very same thing, and spent the last hour looking at metal lathes. It's a whole other animal! But I agree, the lack of precision is driving me crazy, too.

I have spent days making fountain pen sections, and every one of them comes out differently - using the same tools - because there is too much play in the tail stock when drilling. It affects the threads when tapping, it enlarges the 1/4" bore where the converter fits in, and where the nib housing meets - the opening is oval. Measure, measure, measure, drill ... start over.

I suspect this what they call chasing the dragon.
 
You haven't said what brand or model lathe you own, but there's a possibility you could improve things by fixing your tailstock so it doesn't have nearly so much play.

For example, you could add shims to the guide plate under the tailstock (the one that's supposed to keep it perfectly centered and aligned along the axis). Then at least you'd have it starting out pointing the right direction.
 
The lathe question is a good one.

What are you using to hold the blank?

Except for kitness style stuff, I don't see why extreme accuracy is so vital.

I get good accuracy. With my nova chuck.

And epoxy always makes up any difference. For gluing tubes in that is.
 
I use to have the same problem, I had excess play in the tailstock, with the colt long 7mm in the drill chuck, I had about 1/2" movement.:eek: I drilled and tapped for small bolts and adjusted them so that it was on centre.
Kryn
 
There is no need for a metal lathe for precision drilling. A properly set up good quality wood lathe is all you need.
It would be helpful if you provided some more information.
What lathe are you using?
How are your blanks held?
What type drill bits are you using?
Are they sharp?
The more information that you can provide the better the answers you will get.
 
I should have been more informative earlier.
This image shows a round nose scraper that I use to start the 'dimple' for the drill bit. I should also say here that I turn all of my blanks round first and get then the same diameter all along the length. This seems to help with alignment in the scroll chuck.
The 4 blanks shown have been turned round after drilling them with a center drill and turning them between centers. I typically bore from the cut end so I need to align it in the chuck prior to drilling.
With the cut end out when held in the chuck I clean up the end with a flat square scraper and then start the hole with the round scraper.
When everything is centered using a dial indicator the hole stays on target.
If I feel any vibration at all then something is out of whack and the hole may never be centered and true.
 

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I pretty much follow Dale's example (less the scraper) but I do use the Nova Pen Plus Jaws. Since switching to the Pen Plus Jaws, my drilling accuracy has been spot on.
 
I am using a Jet1014 lathe. I have checked the accuracy of the centers meeting, and it is very accurate. I use a collet chuck to hold the piece I am working on. When the tail stock is locked down, there is no chatter. It only starts to vibrate when I have a long drill in the chuck and I loosen the quill.

If I were drilling for tubes it would be no issue. The problem happens when I am step drilling, or trying to make small, precise holes, as in a fountain pen section.
 
Whaler said:
What lathe are you using?
How are your blanks held?
What type drill bits are you using?
Are they sharp?
The more information that you can provide the better the answers you will get.
Click to expand...

The lathe is a Jet 1014.
Alumilite blanks are rounded between centers, then a short piece is held in a collet chuck.
Standard length drills, all sharp.

I center drill a small hole first. This helps with the first drilling. But often times I need to drill a second or third size. If the drill wobbles even 1 mm, then the end result is not acceptable for following with a tap or die.
 
penfetish said:
I am using a Jet1014 lathe. I have checked the accuracy of the centers meeting, and it is very accurate.
Click to expand...

Have you tested the accuracy with the quill at full extension?

(Just because the points meet with the quill retracted doesn't mean they'll meet when it's extended.)

Try this further test:

- put a thin (1/8" or less) drill bit in your Jacobs chuck, and put that in the tailstock;

- put a spur drive or dead center in the headstock

- with the quill racked all the way back (just before it auto-ejects the Jacobs chuck) bring the tailstock up and check that the tip of the drill meets the point of the spur drive

- slightly loosen the Jacobs chuck in the tailstock, rotate 180 degrees, and tighten up again ... still aligned?

- loosen the tailstock and draw it back a couple of inches, then clamp it again

- rack the quill forwards till the tip of the drill bit meets the spur drive ... still aligned?

- rotate the Jacobs chuck 180 degrees again ... still aligned?

- spin the headstock 180 degrees ... still aligned?

These tests verify that the head and tailstock are on the same axis (the axis of rotation of the lathe).
 
Well, it looks like you are doing things very similar to what many here do.
One other step that I did not mention because many here would not think it necessary.
When I have the blank in the chuck and before doing anything else to it, I use a dial indicator to be sure it is turning as near to perfect that I can get it. By putting the indicator on the outside of the blank and turning the chuck by hand you can see if the blank is running dead center. For me, this is probably the most important step and it usually takes me some time to get it right by moving the blank in different positions within the chuck.
One other aspect that is much more difficult to determine is if the centerline of the chuck is straight with the centerline of the tailstock. Just making sure the points of the centers meet does not necessarily make that true.
One last thing to check is the runout on the spindle. I deal with a .002" runout on my HF lathe and never could get rid of it, so when I check a drilled blank and the wall thickness is within .002" measured in 3 places, I know that is as good as it gets for my setup.
 
One piece of debris in the tailstock morse taper makes all the other steps to achieve precision worth very little. It causesvibration too.
 
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