Drilling blanks on your lathe?

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Rcd567

Rcd567

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Sep 22, 2007
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Location
Glenwood, Iowa, USA.
I've got a drill press but am experiencing some oblong or oversized holes. Would like to try drilling on the lathe but am curious how you folks that drill that way...what do you use to hold the blank?

I've got a Nova Midi but would probably need smaller jaws?

Thanks.
 
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I personally use the nova chuck for the blanks and have had nearly no issues. I have cracked 1 acrylic blank this way, but I think it was my fault, maybe tightened it too much.
 
Turn blank round between centers and get a set of collet chucks. It will be one of the best tool investments you make. Put the blank in the collet chuck and start the hole with a centering bit. A set of centering bits is only about $5-6. You will be amazed how accurate you can drill.
 
you can hold a blank in your midi...just need jaws that will hold 3/4 or 7/8 or so...collet chucks are great, but they are expensive if this is just a hobby
 
You will still probably get oblong and wobbly holes.
The problem is (more than likely) that you are using the wrong kind of drill bit.
Use either brad points or spit point bits. Standard twist bits will wander and nothing you can do will hold them in place until they start cutting.
To get split points, invest in a Drill Doctor. Sharpen your own then use the split point feature. You will turn good bits into great bits.
 
Rifleman1776 said:
You will still probably get oblong and wobbly holes.
The problem is (more than likely) that you are using the wrong kind of drill bit.
Use either brad points or spit point bits. Standard twist bits will wander and nothing you can do will hold them in place until they start cutting.
To get split points, invest in a Drill Doctor. Sharpen your own then use the split point feature. You will turn good bits into great bits.
Click to expand...

I'd have to disagree. If his problem was a bit wandering off center then you would be correct, but since his holes are oval shaped it's obvious he has a run out problem with his drill press.

Using a collet chuck, centering bit and a quality drill chuck in the tailstock will solve 99% of his problems.
 
Rcd567 said:
I've got a drill press but am experiencing some oblong or oversized holes.
Click to expand...

By how much? What are you using to hold the blanks? Are you trying to run a cheap and/or dull bit through too quickly?

If you have a long piece of straight rod, try chucking it in the drill press and turning by hand to see if you can tell whether the chuck is a bit off.

Even if you find the problem, boring a hole down the center of a piece is something the lathe is pretty much ideally suited for. Then again, the drill press is too useful to not find and fix the issue if possible.
 
Wood or Acrylic? I was experiencing oversized holes drilling acrylics on my drill press, but not wood. The issue seems to be heat related. I can avoid it by taking smaller bites and letting the chips out or by drilling out first with a smaller diameter bit followed by the correct diameter bit. The second pass doesn't have much work to do and goes very smoothly. Maybe my bits need sharpening too.
If you are seeing this issue with wood blanks, then I agree, you should look into the runout on the drill press.
 
I use a Nova chuck, and soft jaws to hold my blanks while i drill them. The jaws were super cheap, and come in handy for all kinds of stuff. I even have a slot turned into the face of the jaws to hold bottle stoppers for drilling!

A little piece of advice for when you do start drilling on the lathe, true up the blank, and tur a slight indention to the center. This is what i do, and my drill bits go straight to the center and through. VERY LITTLE slop.
 
This may not help for the direction of drilling on the lathe....

I have drilled on both my little drill press and on the lathe. I have done a lot more on the drill press though, because I find it to be more faster, even though I do still take my time and relieve it every 1/4"-1/2" or so. I am not sure what you use to hold the blank on the DP, but I have one of the common centering vices; I believe I got it at Woodcraft about two years ago. A lot of my pens seemed to be a little oval or a bit too big. After some time I realized that the vice flexed to one side when downward pressure was applied when drilling. It appears to be due to the cantilevered design of the vice. I simple shimmed the one side of the vice with a piece of scrap wood and it now works fine.

Not sure if this is a similar problem as yours, but thought I would throw it out there.
 
jleiwig said:
I'd have to disagree. If his problem was a bit wandering off center then you would be correct, but since his holes are oval shaped it's obvious he has a run out problem with his drill press.

Using a collet chuck, centering bit and a quality drill chuck in the tailstock will solve 99% of his problems.
Click to expand...

Using a 'centering bit' (center drill, or combined drill and counter sink, as they are called) will help the problem with drilling with the drill press. I am guesing that the holes are mostly oval at the top, which would indicate the drill bit wondering at the start, but it will follow the hole from there. Make sure the top of the blank is a s square as possible before you start drilling. If you 'peck' the drill when you start (just touch the top of the blank by gently bumping it as you start a few times) this can help as well. Clear chips often, even every 1/8 inch. Type of bit, well that is personal preference. I use regular old drill bits with no problem.
 
I use standard twist drills after using a center drill with drilling on the lathe with excellent results but agree with Paul that it would also help using a drill press as well. The Little Machine Shop sells a set of 5 center drills for under $6 http://littlemachineshop.com/products/product_view.php?ProductID=1230

I just did a little write up which includes drilling on the lathe and has some photos of using a collet chuck, it might give you some ideas. I have several collet chucks and the Beall chuck which I show photos of is no better than a good morse taper collet chuck, just handier since it screws onto the spindle.

A decent full set of er-32 collets and a mt-2 chuck can be found on ebay for under $70, just look for watt800 (I think) AND watch his prices, he often will sell identical items for $20 difference.

To see the write up on drilling, check out http://www.penturners.org/forum/showthread.php?t=54760
 
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I do as Bruce has described. And I usually drill from both sides.
You don't get any blowout issues this way.

Horst
 
Thanks for all the replies. Yes, it happens in acrylics and not wood. And yep, it's usually only on one end. I use bits I've bought from Woodcraft, and they weren't the cheap ones. You folks have given me some tips to try. Thanks.
 
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