Shop Made Long Hole Boring Tools

[RoyG]

Greetings,

I've been asked to make some table lamps and standard lamps for a client. I've been considering buying a commercially made tool (e.g this Hamlet Long Hole Boring Tool (http://www.hamletcrafttools.co.uk/long-hole-bore.html)), which is sold by a few outlets in AU.

But before I went and bought a commercial tool, I thought I'd ask whether anyone on the forum has made their own Long Hole Boring Tool, and if so:

How, and
How successful was your shop made long hole boring tool ?


Thanks,

RoyG

[Rippa]

I have a home made long hole borer which is quiet successful. I just welded a length of mild steel the same size as the drill on the end of the drill ground off my rough welding and have been using it for years
Cheers Rippa

[RoyG]

Thanks Rippa.

What sort of drill bit did you use ? Twist drill, Auger Bit, something else ?

RoyG

[Enfield Guy]

I bought the Vermec item. Works well for me.

[issatree]

Hi RoyG,
How long is the Hole to be.
If not too long, then you can end for end it.
Nothing says it has to be dead straight, as you will use a mouse to go through the hole, or some light wire.
3/8 - 1/2in. is quite big enough.
You may have an old Auger Bit long enough to do the job.
Don't forget, you do the hole first.

[QC Inspector]

One option is to cut the stock In half and route or saw with dado blades a groove down the length. Glue back together and turn.

[RoyG]

Thanks very much for the many suggestions.

The Standard Lamps will be made up from three sections of 600mm length each. I plan to drill half way from each end to reduce the length of drill bit/auger that I'll need. So, with just over half of the timber length being say 325mm, plus the 320mm taken up by the hollow tail stock, and hollow live centre, I need a drill/auger length of around 650mm. I only need a hole around 3/8" or 10mm.

I've thought about making the tall standard lamps by assembling say four x 450mm lengths, (instead of 3 x 600 mm lengths) but the less number of joints the better, as the joints really show up any grain differences where the joins are. Ideally, I'd like to use longer pieces (~800mm) so that any joins are lower down out of direct eye line, but I don't like my chances of keeping an such a long hole on centre.

I did one standard lamp by splitting the pieces, cutting a 10mm wide by 5 mm deep slot with the dado blade in each half, and then gluing them back together. Unfortunately, the glue lines are hard to hide, and as a result the glue lines are very obvious.

I've looked at many antique standard lamps over the last year or so. I've never seen an antique one where the wood has been split to make the hole in the centre and then glued back together and turned to shape - I think that approach might be a modern manufacturing technique.

I've also seen many tall standard lamps (around the 6 and 7 feet tall mark) that are obviously turned (and bored) in one long length, as there are no discernible joints (i.e. no discernible discontinuity in the grain) over the entire length. I'd love to know how the previous generations of Wood Turners bored such long holes without the hole running off centre too much. And, I'll bet they made their own tools to do the job.

Once again - thanks very much for your input. It's all greatly appreciated.

Regards,

RoyG

[burraboy]

It's not hard to make a D bit for long hole boring, much the same as gun drills. Quite accurate too.

[RoyG]

Thanks Burraboy.

I just Googled "D Bit" and drew a blank on anything meaningful. Can anyone provide a link or a photo of a D Bit ?

EDITED ------- I just tried searching on "How to make a D-Bit", and found a few relevant posts. Time to do some reading..

Thanks,

RoyG

[QC Inspector]

"I've also seen many tall standard lamps (around the 6 and 7 feet tall mark) that are obviously turned (and bored) in one long length, as there are no discernible joints (i.e. no discernible discontinuity in the grain) over the entire length. I'd love to know how the previous generations of Wood Turners bored such long holes without the hole running off centre too much. And, I'll bet they made their own tools to do the job."

They used the "D" bit as mentioned earlier and it was done through a hollow tailstock. The cup centre point was removed while the cup held the end of the piece and the long bit was feed through the hollow tailstock to make the hole. An alternative was a special cup centre that was mounted in a post in the tool rest that also had a removable point. That centred the bit and aligned it until it was cutting true on its own.

Pete

[Mobyturns]

I also have the Vermec unit which has served me well.

[chuck1]

I have 2 long hole drills 3/8 &1/2 . The 1/2 inch is handy when holes start to run off as there is less flex.
Mine are about 1 metre long.
To hide the joins in my lamps I place join at the bottom of a bead slightly under cut both faces to be joined.
also I turn about a 32 mm dowel joined to one Turning and 32mm hole first then bore long hole.
it is important to draw it up full size to workout placement of joins.
I have seen older lamps where they thread tap the dowel and hole.
once you have done a few you will get a feel for what the hole is doing.
I have had a few where the holes don't meet properly and had to run a string through lamp then tie the cord on and drag it through lamp, due to miss alignment of hole.
Buy your electrical fittings first that also governs lamp length.
today's standard lamps are not as long as antique ones.
I get all my lamp fittings from a small lighting place. Long leads with moulded 2 pin plugs are hard to find.
I hope mentioning some traps I found help you!?

[RoyG]

Well, thanks again for all the advice.

Now that I know the terminology to search for, I've found some useful articles and videos that address what I'd like to do.

The first video that I found is one where a bloke is making a Native American Flute, which requires various diameter holes (up to ~20mm) all the way through a blank that looks to be around 600 or 700 mm long. He uses Gun Drills to do the boring, and uses a modified hollow tail stock to enable the larger Gun Drill to pass through. His Gun Drill is impressively quick, but I believe it must be a commercial product with the cutting face modified for wood. The Gun Drill has a small hole (maybe 3mm diameter) running the full length of the Gun Drill (roughly a meter long), and compressed air is blown through the 3mm hole to help clear the chips (and I expect that the compressed air also helps to cool the bit). I should imagine that drilling a 1 meter long, 3mm diameter hole, is something of a challenge requiring some pretty specialised equipment, which is why expect that his gun drill is a commercially made item.

https://www.youtube.com/watch?v=W3H5o2DHloc

The next link is to a fairly detailed article by Woodturning Magazine from back in October 2009 titled "The Fundamentals of Long-Hole Drilling", and provides a few pointers to techniques that I hadn't thought of.

http://www.woodworkersinstitute.com/page.asp?p=1109

The next link is probably going to be the most useful link for me, as it describes in words and a few photographs, "How to Make a D-Bit for Woodturning". Most importantly to me, it shows clearly the cutting edge geometry that that this author used. The section about how to make the D-Bit starts about 2/3 of the way through the article - search for the Paragraph starting with the words "So what we need here is a shell auger! Here is how I made one."

http://toolmakingart.com/2011/02/27/how-to-make-an-octagonal-handle-shell-auger-and-straight-drilling-guide/

It looks like it would be possible to make a D-Bit by grinding and hand filing as per the above video, although I assume it would be a much easier job and a far more accurate job, if it was done on a milling machine, so I might have a talk to our local metal machinist.

In the above video, the author says that he leaves the drill rod in it's annealed state when he's drilling wood. But with tough Australian hardwoods, I think I will need to harden and temper the drill rod before using it, so I might try the hardening and tempering techniques that are used in ClickSpring's Youtube videos (http://www.woodworkforums.com/showthread.php?t=198383&p=1895431#post1895431) to heat treat the tip (approx 100mm) of the D-Bit.

I'll post some updates in this thread, or maybe in a new thread, as I proceed with this little project over the next few months.

Once again, thanks for the input.

Regards,

RoyG

[soundman]

One option you may not have considered is drilling the blanks in short sections, then assembling them before turning.

If the same piece of wood is used and the ends are tracked and matched you should be able to hide the joins in a grove as there should be 2 to 4mm missing depending on how you square and match the ends.

hollow dowels and epoxy should do for joining the sections.

you may also put in a slip of brass or a feature timber where the sections are joined before turning ..... brass turns reasonably well with a sharp scraper.

cheers