Is there a good way to drill a 12" long 3/8" dia hole in a lamp turning..?

Meant to say drill the hole on drill press not the lathe before turning..

On Sat, 2 Jan 2010 11:20:36 -0600, Jim Hall wrote (in message ):

A 12" long (or deep) hole is a very reasonable job for the home hobby turner. Certainly, drilling the hole before mounting the wood for turning is a great way to insure the hole is nicely centered in the lamp. There will likely be as many ways to do this as there are turners who visit this newsgroup. Assuming that you drill the hole first, your next concern is mounting the wood to your lathe. In my own case I would use my spur center at the headstock (instead of a faceplate or chuck), eyeballing the center to be concentric with the drilled hole. You can easily get within 1/16" of dead center this way. Assuming a spur center with 4 spurs, you can square the end of your wood, and then mark where you want the hole to be drilled. Make 2 saw cuts at right angles to each other, centering the cuts over the desired hole center. These cuts will later locate your spur center in the middle of your hole. This is assuming you will accurately start your drilled hole at this marked center.

Depending on the length of drill bits you have, a reasonable method is to drill from both ends towards the middle. The holes may not meet exactly, but is no serious matter. If the bit is long enough, the holes drilled from each end will meet and overlap in the middle, and allow the cord to be fed through the lamp. You will likely not want to run the pipe all the way through the lamp. In most hardware stores you can get short pieces of this threaded material, maybe an inch or so in length, adequate to screw snugly into the top of your turning. At the bottom of your lamp you will want to drill a hole maybe an inch in diameter and about an inch deep, on the same center axis as your long hole. Then, drill a hole about 5/16" or 3/8" in diameter into the base rim of your lamp, into and intersecting the 1" hole. This allows you to feed the cord into the base of the lamp, make the 90 degree turn and upwards into the long hole and to the top of your lamp. A forstner bit will make a neater job of the 1" hole than a spade bit will.

The diameter of your deep hole will be dictated by the outside diameter of the threaded pipe - or threaded nipple - and whether you want to slip a piece of pipe through the whole length of the deep hole, or just screw a threaded nipple into the top inch of deep hole. If you wish to use a full-length pipe, you will really want to use a long bit and drill a single hole the full length (rather than a short bit and drilling from each end)

These are some tips I have learned from my own mistakes on projects of this kind. (This includes making sure your chunk of wood is long enough to allow for trimming and waste when you square off the ends while turning.)

Sorry this was so darn long. I just got carried away. I hope some of it will be useful.

tom koehler

Turn the lamp between centers. Turn a tenon on one end. Mount that tenon in a chuck, using a cone center in the tail stock to ensure perfect alignment. Drill the hole with a long bit. You can do this holding the bit either in a Jacobs chuck, by hand, or even through a the hollow tail stock if your lathe has one.

Actually, I think the fastest is with a paddle bit in a Jacobs chuck. With a twist bit you must withdraw the bit every inch or so to clear the chips. Not quite so bad with a wood bit, but still not as easy as a paddle. The paddle could drift in some situations, however.

Paul Gilbert Dallas, TX

on my lathe, I turn the lamp between centers, then just feed a long enough bit through the tailstock, I hold it by hand in a drill chuck, and pull it out every inch or so to clear chips. It doesn't stay perfectly centered, but it doesn't wander far if the bit is sharpened correctly.

I would use steel not brass pipe - why pay the extra $$ for brass when it's not visible - and if it were me, I'd hollow a spot in the base for a switch and turn a wooden handle for the switch. a rotary switch with a 1/4 inch shaft works well

I have a mono tube lathe that takes a # 1 taper . I ran a 3/8 "drill through the head stock shaft hole so I can run all thread threw my blank and face plate on large bowl blanks so I can turn out of balance chunks of wood. I center drilled the end of the all thread for my live center in my tail stock I got a 3/8 drill with a 24" shaft from an electrical company for running tv coaxial wire in houses..Maybe you can give that a try. Sorta like a large pen arbor. Hay I gotta go and turn some really beg pens now.

Jerry

If you are going to be doing several (or are just a tool nut) . There is special tooling you can use The drill

The center All you do is use the center, then take the "tip" out and drill up through it (of course you have to have a hollow tail stock)

I have had the best luck drilling longer holes (over 4") in wood using Forstner bits. Depending on the size of the wood piece I would either place the Forstner bit in the chuck with the tailpiece directly on center and then just keep adding extensions to the Forstner bit till halfway thru then flip it end for end. The Forstner bits do not wander off center like any other bits do in wood. Of course you are limited by the dimensions of your lathe with this method.

DL

Great suggestions and advice. Thank you.

I did this by routing a groove down the center of two 2x4 pieces of oak, large enough to accommodate the wire, stopping about 1" short of each end. Then glued the pieces together, groove-side in (taking care not to have glue squeeze into the channel), turned the lamp, and when done drilling in to the center of each end to "find" the pre-existing groove. Drill the top end for the diameter of a short piece of pipe to mount the light fitting.

HTH.

/M

Hello Jim,

I recently turned a 25" flag pole for a friend's son that had to have a hole its full length. My long hole drill was one that I had made many years ago when I was doing a set of Newel Posts for a stairway in a new house under construction. I needed a 5/16 inch diameter hole that was drilled deep enough that I needed a 36? shaft. I had a welder set up the drill and my 36? length of 5/16 inch rod in a lathe and weld the rod to the drill end. This worked very well for those seven foot Newel Posts that I had to drill. I had drilled each of them from each end and the holes had met nicely in the center. This time the piece was smaller in diameter than those 5 inch Newel Posts, so I wanted to make sure the drill entered the piece as straight as possible. A part of my Christmas present from Mildred, my wife, was the Colt Five Star HSSM2 Pen Drill Set. Since these drills will drill a very straight hole, I used the ?O? size drill, the closest to the

5/16 inch size to drill a hole the full depth of the drill; i.e., about 5 inches.

Once I had a pilot hole, I needed something in the tailstock to help center the drill. A quick measurement showed that once the center point was removed from the Nova Live Center the drill was a snug fit through the hole. I was now set to drill the hole half way through the work piece. I put a mark on the drill shaft at slightly over half the length of the wood to be drilled. That would mark the depth of drilling from the first end. On the second end it would give me an idea as to whether I had intercepted the hole from the other end or was about to drill through the side.

I highly ecommend that you drill from both ends. With a 12" drill you should be able to drill half way, reverse the wood and drill from the other end. This way you always ensure that the hole is in the center of each end.

Fred Holder