Drilling on the lathe

[Rangertrek]

Well, I converted to drilling my blanks on the lathe last weekend. I scr...up two blanks trying to drill a 10.5mm hole in Blackwood for a Jr. Retro Christian Fish pen. The blanks were in a pen drill vise and the bit 'wandered' off center anyway. The bench top drill press is a little sloppy and the combination caused a bad start to drilling the blank. The bushing barely even covered the hole.

My question is ... What tips do you have for drilling on the lathe?

I am using a drill chuck on the live center and a baracuda chuck to hold the blank on the business end. I can adjust the blank in and out of the chuck to expose more or the blank. Is there a better way, or preferred way to do this?
Thanks for any comments.

 

[leehljp]

John,

I am interested in other peoples responses also. I use this method on special occasions when I need pin point entry and exit. I square my blanks as best as possible, but if one side is 1/32 wider than the other, I try to go from there rather than trying to square any more.

I put the squarest end on the chuck end. But I check, mark and double check where I think the center point is on the unsquare end. IF I am using a brad point, I can start the hole just where I want. If the hole is a size that I don't have a brad point, I ream out the starting point and then use my bit.

This helps me adjust the blank to be perfectly in line with the bit.

I use a centering square for marking, and mark from all four corners. I also use a scribe because that is more accurate than a pencil lead. (I do have .03mm markers here that I use on occasion, and they do well also.)

 

[mick]

I drill all my blanks on the lathe and when I need something to be perfectly centered I will square it up on the TS if its terribly out.
Otherwise like Hank I'll mark the center and use a small countersink to start a center hole in most blanks the bit will seat into the depression and start correctly. Of course you can't be far out of square or the bit will start binding and you'll end up flexing the bit enough that your entry hole will be too large. Another way I've dealt with this is to not really crank the jaws tight until I've turned the blank by hand a few rounds with the bit touching it. once the bit seats into the depression tighten down on the chuck. YMMV but this is what works foe me

 

[pipecrafter]

I use a Oneway chuck with the #1 spigot jaws and have never had a problem. You mentioned using a live center jacobs chuck - is that true? If so, how the heck do you drill without holding the jacobs chuck steady in your hand? I use a jacobs chuck in the tailstock, but it's a "dead center" chuck and doesn't turn at all.

 

[leehljp]

Another way I've dealt with this is to not really crank the jaws tight until I've turned the blank by hand a few rounds with the bit touching it. once the bit seats into the depression tighten down on the chuck. YMMV but this is what works foe me

That was what I was wanted to say! :biggrin: Japanese thinking in a US mind is "on me" today. :wink:

 

[JerryS]

I use a Oneway chuck with the #1 spigot jaws and have never had a problem. You mentioned using a live center jacobs chuck - is that true? If so, how the heck do you drill without holding the jacobs chuck steady in your hand? I use a jacobs chuck in the tailstock, but it's a "dead center" chuck and doesn't turn at all.

I use the same exact setup . I can't see how using a scroll chuck ( In Headstock ) like the Oneway and a Live center drill chuck ( in Tail stock)would work . Please correct me if my setup is wrong .

 

[jskeen]

I find that if I am really concerned about dead center drilling of a particular blank on the lathe, I am better off turning it round (or almost round) between centers, then chucking it and drilling. This seems to offer better contact and more exact centering of a blank in my chuck than trying to grip it on the flat sides. I usually grip the rounded blank firmly in the chuck about 3/4 max depth, and use the live center in the tailstock to push the blank in to almost full depth (but not quite, bottoming a workpiece in a holder is generally not considered quite pukka). This serves to center the blank and the drive center divot. I then remove the live center and replace with the jacobs chuck and drill bit. I also almost always hold my air hose in my left hand, resting on the tool rest and blow a stream of air across the drill bit as it enters the blank, helping to eject chips and also cool the blank. Having a mark on the drill bit at the length of the blank allows one to sneak up on the end of the blank and advance that last little bit dead slow to avoid blowing out the end. Not 1000% foolproof like drilling into a oversized blank and then cutting off the excess, but it works for me so far.

 

[Texatdurango]

I use a Beall collet chuck to hold the blank and a mt2 jacobs chuck in the tailstock to hold the drill bit.

One thing I have started doing that I believe has increased my accuracy is to pre-drill the hole with a center drill. For those unfamiliar with a center drill, here is a photo of a few... http://cgi.ebay.com/5-Lathe-Mill-CENTER-DRILL-COUNTERSINK-Bit-Tooling-SET_W0QQitemZ270333845946QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item270333845946&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

The center drill does not flex like a jobber length drill bit so odds of being dead center are increased. With the hole started with a 60 degree countersink, the regular bit follows it right to the center of the blank.

 

[JerryS]

Using those center drills is a nifty little thick , thanks for sharing it .

 

[Rangertrek]

Setup correction

I mistated my set up. Drill chuck in tail stock, drill is fixed, not turning.
Barracuda chuck in head stock. You can tell how new I am to this.:biggrin:

Another question, how far out from the chuck do you extend the blank?
I dia mine wiht about 1/2 of it exposed. The other 1/2 was in the chuck.
On mine, I could see thru the spinning chuck to see the bit emerge from the blank.
Again, thanks for the comments.

 

[panini]

I use a PSI Barracuda CS3000 chuck in the headstock and Drill chuck in the tail. I start with a drill center bit then replace with the appropriate bit of what kit I'm turning. So 99% centered when drilling.

 

[Fred]

I cut my blanks square, also square the ends with a sanding jig on the ET sander.

Then, I use a center marker and mark the center of both ends.

I use a spring loaded center punch to dimple the center of one end and mount this end deep as possible into a FOUR Jawed chuck with the dimpled end facing the drill bit (Duh!). BTW, It is rather hard to center a four sided square blank in a three jaw chuck and keep it centered.

I turn it for a second or two and ensure the blank turns square to the drill bit, adjusting IF necessary.

Then I drill it using a sharp drill bit ... A Drill Doctor ensures that I have sharp bits.

Looking at the opposite end I can immediately tell if the bit wandered off center at all. But why worry if it does wandeer around a bit? The blank will be turned round according to wherever the bushings are mounted.

I might worry a lot about being centered if this were rocket science, but it's not, so ....! Now if the bit wandered out the side or too close to the edge then there must be other problems to worry about. :biggrin:

 

[Sylvanite]

I use a center bit also. Likewise, if the hole has to be perfectly concentric, I will turn the piece round first and mount it in a Beall chuck.

Regards,
Eric

 

[davinci27]

I turn the blank round between centers the use a collet chuck to hold the blanks. I generally turn 5-10 blanks round at a time then have them sitting around when needed. I cut the blanks and then slide them into the collet chuck. I leave just a little bit out of the chuck maybe 1/16 - 1/8 of an inch.

My favorite part about doing it this way is that I can use smaller blanks to make my pens. The collet chuck distributes the pressure more evenly over the whole blank, so you can leave a pretty thin wall.

 

[pipecrafter]

If you're having a lot of problems with the drill bit wandering, check to make sure the bit is sharp. I've found that, with smaller bits up to about 1/4", if the bit isn't sharp it can wander, especially in harder materials. Also, I hate brad point bits for the exact same reason. I find they tend to wander, and I prefer plain jane HSS twist bits for 99% of the holes I make.

 

[ribanett]

I drill all my blanks on a metal lathe.

I bore a 1/4" hole using my DP, and use a mandral to true it up on the metal lathe. Remove the mandrel and mount the blank in a three-point chuck, and bore to the size I need. I can drill dead-center because the 1/4' hole acts a pilot.

 

[Glass Scratcher]

I use the same exact setup . I can't see how using a scroll chuck ( In Headstock ) like the Oneway and a Live center drill chuck ( in Tail stock)would work . Please correct me if my setup is wrong .

Drill chucks aren't "Live".

 

[cnirenberg]

I have an old PSI econmy chuck that has aluminum jaws somewhat like those on a metal lathe for turning square or close to sqare blanks. I use a centering bit as well, keeps things from straying out of plumb. I recently upgraded my nova chuck from a paperweight to a everyday piece of equpment by getting pin and #1 jaws for it. Works fine. There is many ways to skin this cat, unfortunately for the cat, he doesn't like any.

 

[Blind_Squirrel]

I use a Beall collet chuck to hold the blank and a mt2 jacobs chuck in the tailstock to hold the drill bit.

One thing I have started doing that I believe has increased my accuracy is to pre-drill the hole with a center drill.

The center drill does not flex like a jobber length drill bit so odds of being dead center are increased. With the hole started with a 60 degree countersink, the regular bit follows it right to the center of the blank.

I do the same thing. Additionally, if I am drilling a large hole I drill it in stages i.e. 1/8", then 1/4", then 3/8" etc.

 

[SuperDave]

... I use a Stronghold chuck with the 1" spigot jaws. You can center a somewhat out of square blank in the jaws by placing the right angled edges in the gaps between each jaw, and as you close the jaws, you can twist the edges back and forth to get the blank centered equally on each jaw... the flat sides of the blank do not need to be dead center on each jaw.

...of course, a severely out of square blank is another question.

D

 

[rherrell]

Drill chucks aren't "Live".

Here's one that is!

 

[Glass Scratcher]

Hmm. Is the chuck on a live arbor? Or is it a live adaptor for the chuck and arbor? Regardless, where did you acquire such a thing?

 

[devowoodworking]

Here's one that is!

Nice set-up Rick

 

[rherrell]

Here it is....... http://tinyurl.com/cbkjk2
Yes Charles, it's on a live arbor and can be used for all kinds of things. I mostly use it with homemade Delrin centers like in the photo. I apply my CA finish with this set-up since CA won't stick to Delrin, at least not very well.:wink: