Long hole boring

[nunanman]

I want to make 2 lamp stands but don't want it in too many sections as my lathe is short. I have been doing my boring using a drill chuck and extended drill bit. Is there a simple way of long hole boring through the hollow headstock or tailstock?

Nunanman

[oldiephred]

Not much info to work with nun--. What will be the finished length of the pieces and the diameter? You say your lathe is short but you don't want it in too many sections, what would be the length osf each section? Are you making these from one piece or laminated glueups.? I'm sure there is help somewhere here but the additional details would be good to have.

Good luck

[burraboy]

Is there a simple way of long hole boring through the hollow headstock or tailstock?

Yes. You will need a shell auger (also called a lamp auger). They are usually fed thru a hollow tailstock and will drill up to about 3 feet without much deviation. Could be hard to find though!

[nunanman]

The bed is about 1000-1100 between centres. The material will be min about 40mm and max about 75mm, single pieces, rosewood. Total height about 1600, so 2 pieces ideal for me.

For the lamp auger, how is the bit held to prevent wobble and wander?

[RETIRED]

The proper kit for the job is called a long hole boring kit and consists of a hollow live centre with removable pin, a drive centre with a sized pin to fit in the bored hole and an an auger that is used by hand,
Pic here:
http://www.cws.au.com/cgi/index.cgi/shopfront/view_by_category?category_id=1107145003

The method.
Use a normal drive in the headstock for starters and the hollow taiilstock centre with pin fitted.
Mark the centres of the blank.
Mount in lathe to get a mark off the tail stock ring.
Remove blank and reverse so that you now have the indentation of the ring on both ends.
Remove pin from tail stock centre (keep normal drive in head stock) and fit blank with the centre supported at the tail stock end by the ring.
Drill hole with auger through tail stock removing constantly to clear shavings at a speed that feels right.
Drill just over half way.
Remove blank.
Fit the drive with the sized pin in head stock.
Mount blank with previously drilled end into drive and centre on the ring at the tail stock end.
Repeat drilling and if all has gone well the holes should meet.
It takes some practise and is always done prior to turning.

HTH

[RETIRED]

I forgot one thing. If you are joining 2 pieces, drill the mortise prior to mounting in the lathe and use the centre of the hole as centre for the drive and tail stock centres.

[Jim Carroll]

Just a bit more.

When drilling only go about 25mm at a time as the flutes fill up very fast and if not removed will jam up the drill bit in the timber, It will not come out no matter how much persausion you try.

So drill 25mm draw the bit out and clean then go in again and again. Slow process but easiest way.

[rsser]

And hollow centres/augers come in 5/16 and 3/8.

Musical instrument makers will often use a home-made D-bit rather than an auger; they claim it's far less prone to wander. You can make your own; do a Google for instructions if you're interested.

...

Added: I had to do a short std lamp on the cheap -

Hollow cup dead centre from Woodfast, 5/16
60 cm auger from Carbatec
Held the auger in a Jacobs chuck
Over a single pass 40 cm deep hole the drill wandered about a cm off.

Obviously nunanman, coming in from both ends of an 80 cm piece, this degree of wander wouldn't do.

If you were doing a lot then the Vermec auger would be worth a look; IIRC it has a replaceable HSS tip.

[munruben]

Wow, you learn something new every day. Thanks guys very interesting..

[RETIRED]

Just a bit more.

When drilling only go about 25mm at a time as the flutes fill up very fast and if not removed will jam up the drill bit in the timber, It will not come out no matter how much persausion you try.

So drill 25mm draw the bit out and clean then go in again and again. Slow process but easiest way.Who would do that?:B:roll:

[Jim Carroll]

only once:~

quick learner:D

[rsser]

Nothing wrong with brute force and innergrance ...

once.

[orraloon]

There is a way to cheat and will be easier to do. Cut blank down the middle and rout a groove in each half then glue together again. if care is taken to align grain on glue up the joint should be almost not noticeable. Then turn.

[RETIRED]

Another little tip. Hold the shank of the auger with a pair of vyce grips to stop it spinning in the handle. DAMHIK.:rolleyes:

[Tim the Timber Turner]

Many years ago I had a contract to turn Didgeridoo's from Radiata Pine.

The blanks 90x90mm and were 1200mm and 1500mm long.

I turned the outside shape between centers with a chuck spigot on each end.

The spigots were used to drive the blanks and a 10mm pilot hole drilled from each end using a shell auger.

The blank was then set up in the chuck and the other end suported with a 3 point steady.

A special 32mm step drill with a 10mm blind lead and a long 25mm square handle was then shoved down the centre. This was hard yacka and I ended up getting a young bloke to do this.

The chuck spigots were cut off and the hole in the large end was belled out by hand using a large carving gouge and mallet.

Ended up turning about 500 digi's over the space of a couple of years.

This job helped pay the bills when I was starting out full time turning.

Cheers

Tim

[bookend]

Just a bit more.

So drill 25mm draw the bit out and clean then go in again and again. Slow process but easiest way.

Last Christmas I made a couple of 5ft tall floor lamps, made in sections. On one 60cm jarrah blank the 2 holes missed by a mile even though I withdrew the auger and gave it a quick clean every 20mm or so. The culprit was about 10mm of compacted dust. It kept pushing the auger off centre:B. Remember that withdrawing the auger does not mean you have withdrawn all the dust and clean all groove right to their ends.

Another hint is to do with your blank sizes and your design choices for the sections of the lamp. I have the Hamlet shell auger Rsser mentioned. At 60cm long, by the time it had passed through the tailstock and the hollow centre, I only had 30 odd centimetres of shaft to drill with (ie drill from each end = 60cm odd blank). Assuming you want your joins to be invisible in that they disappear at a fillet ect, designing your sections to fit the drill becomes important.

I have seen a standard drill bit machined, tapped and screwed onto longer steel bars for drilling longer holes, but these always seemed so flimsy to me that I doubted I had the skill/ patience/ luck to get the hole straight down the middle.

[joe greiner]

Not yet mentioned, AFAICT, is the use of an electrician's drill, which I've seen in the electrical department at Home Depot (model for Bunnings) and Lowes. These drills are quite long, up to about 4 feet (1.2m +). I couldn't find them by that name at McMaster-Carr ( http://www.mcmaster.com/ ), but with reference to an old paper catalog, I found the nomenclature of "bell hangers' drills," which can be used in McMaster's search box for recognition.

According to my very imperfect understanding, such drills are used in retrofit work to drill through wall sill plates and firestops/noggings from a proposed outlet box, because the bit can flex a little to reach its target. Thus, wall facings need not be removed. Google wasn't much help on usage, and flexure may, or may not, be a problem for the intended application. A sparkie might have a better explanation about usage and suitability.

Joe - purveyour of useless information