Drilling large diameter long holes

[emabear]

I am struggling to find a way to drill / bore a 30mm dia hole into a 35cm long piece of wood. Grateful for any thoughts. Many attempts have led to o=verheating, problems with chip dispersal and drill wandering.

 

[Phil Pascoe]

Using what?

 

[--Tom--]

Auger in a brace would chomp through

 

[Myfordman]

Give us some clues and we might be able to help!
What sort of bit are you using?, what sort of quality bit?, Is it sharp? what is the wood type?, along or across the grain? what sort of machine are you using to turn the bit? and what power is available?. What sort of speed are you using ( slow medium or high)?

 

[Lazurus]

I am struggling to find a way to drill / bore a 30mm dia hole into a 35cm long piece of wood. Grateful for any thoughts. Many attempts have led to o=verheating, problems with chip dispersal and drill wandering.

Find a local turner to assist?

 

[Phil Pascoe]

Auger in a brace would chomp through

A 350mm x 30mm hole in endgrain? It would get through, but I doubt it would "chomp".

 

[Sheffield Tony]

If you are going into end grain, Gedge pattern augurs work best. You'll be in luck if you find one that size though !

 

[AndyT]

Have you tried one of these? :lol:

(From the not-boring http://www.lowtechmagazine.com/2010/12/ ... hines.html )

(Seriously, this is how miles of elm water pipes used to be made. For a sensible answer, we need to know a bit more.)

 

[Geoff_S]

I'm with Lazarus on this one, a local woodturner. Which may sound strange as you are drilling a hole and
not turning the piece of wood. However, a woodturner might have a long hole boring tools and setup to do this.

If not, your only option is to find a 40cm wood drill bit of some description, a powerful enough drill, and a rock steady clamp
and pair of hands.

I take it that it's some sort of lamp stand?

 

[nev]

How about one of these? and go slowly, and you may want to rig up a block or two of wood to guide the shaft level/ straight.

https://www.ffx.co.uk/tools/product/Dew ... -Extension

and one of these
https://www.ffx.co.uk/tools/product/Tre ... r-Bit-30Mm

or these
https://www.ffx.co.uk/tools/product/Fes ... 3EQAvD_BwE

 

[Mike Jordan]

Cut the material down the centre lengthwise, machine a half round using router and box core cutter or spindle moulder.
Glue the halves together again.,job done!

 

[Beau]

How about one of these? and go slowly, and you may want to rig up a block or two of wood to guide the shaft level/ straight.

https://www.ffx.co.uk/tools/product/Dew ... -Extension

and one of these
https://www.ffx.co.uk/tools/product/Tre ... r-Bit-30Mm

or these
https://www.ffx.co.uk/tools/product/Fes ... 3EQAvD_BwE

Had to drill a long hole for a propshaft through a boat hull. We used something similar to the above but to improve accuracy we had a custom made extension which was pretty heafty. Once the hole was started set a guide that held the extension in line and buy using the leverage of the long extension could counteract any attempt the bit made to run off line.

Hope that makes sense

 

[Phil Pascoe]

If you are having to buy an extension, you'd just as well buy a long enough bit.

www.amazon.co.uk/Irwin-10502781-400mm-A ... long+auger

 

[AndyT]

That's all very practical Phil, but I am sure the OP would enjoy building a waterwheel, and you're taking away his excuse!

 

[emabear]

Thanks for all of the ideas and apologies for not replying but have been abroad. A lot of the suggestions i have thought of / tried but to no avail. I am a turner and have tried but all methods are veering off. Problem is the combination of heat and chaff dispersal (if that is the right expression) when using a lathe. I did find someone in Oxfordshire with an old huge industrial drill press with correct diameter drill bit, but the company no longer exist. I havent been able to find one on line though and not sure what to ask for.

 

[MusicMan]

As AndyT said, this was a well-known method a couple of hundred years ago, not only for metal but also for gun barrels. Nowadays, if you can't afford or locate a gun drill (by far the easiest way), you can do it like musical instrument makers do. I had instruction from a man who made baroque bassoons, who could drill two parallel holes a metre long and a few mm apart without damage. He used a D-bit as shown below for a 22 mm drill, but a spoon bit would also do. He had a pretty big lathe to hold the drill and to clamp the work down. Think big Wadkin. It needs a headstock that will take the diameter of the drill. For 35 mm you'd need about 5 HP I think, hence the water wheel! You drill a few cm (using the screw drive on the carriage) then pull out to clear the clippings. Then pull the drill further out of the chuck and repeat. These are for very high quality holes, with a virtually polished finish inside, which need no further work to suit woodwind instruments.

Beau's method is more practical for holes with more tolerance.

Whatever drill you use, lubricate it with beeswax. Makes a huge difference.

Keith

D bits in top and side view.

 

[MusicMan]

http://www.drillandhone.com/index.htm do gun drilling, probably costs a bit though!

 

[custard]

I needed to drill a hole through a pair of these for the electric cable.

Instead of drilling I split the stem blank in two, cut a groove on each side then reglued the two halves together. The stem was fastened to the base with twin tenons, and the hole ran between the two tenons where it mated with a corresponding hole in the base. After that the octagonal profile was formed with a spokeshave.

Unless there was a specific reason why you needed a perfect hole I'd recommend this method rather than drilling.

 

[Sawdust=manglitter]

When fitting the vice on my workbench (solid top) i used a long-ish forstner bit for as long as it could go, then just used the same diameter spade bit on an extension. It got there in the end...