Thread: Deep boring help.

Gidday Damien,

I've got a bunch of Soundman's bits that'd be 400-ish... we could have a bash from both ends if you're game. I love learning how to do things at someone else's expense!

If you get a better offer from someone who knows what they are doing.... take it!

On the other hand, if you think you do..... well you're welcome to have a crack!

cheers,

P

That's it, Damien and midge. It's even called a "lamp auger." Drill from both ends, well beyond the centre. Even though the two holes might not meet exactly, there should be enough overlap to allow passage of the wiring tube (or whatever IT's called), with slight flexing.

Joe

Thanks fellas. I'm hoping someone can spin it on a lathe and use the hollow tailstock to drill out the center.

It's generally advisable to reverse mount and drill from both ends, because the drill bit will try to follow the grain and may even daylight away from the far end otherwise. If it's already turned, mounting or re-mounting could be dicey unless accommodation was made in advance. I'd suggest the lathe is not the best tool at this stage.

Joe

So Damien,

Have you already turned it, carved it, or what?

My mini lathe has an extended bed, so length shouldn't be a problem, but I agree with Joe as far as degree of difficulty goes. Drilling into a wobbly bit of timber just won't work!

If it's some of your cedar, or you want to true it up first it shouldn't be a problem though!

I don't have an extension bar for the forstners, which would be the best way I think, but in the absence of the proper gear I'd start with a forstner each end, that'd get rid of 200 in a reasonably accurate way, then if the balance was done with an auger bit also from each end, there's not much room for wandering too far.

Your comments Joe?

Cheers,

P

This is probably irrelevant at this stage; but I have found the easiest way to accommodate the cable when making a tall lamp is to make the column in two halves, cut matching dadoes with a dado set, and then glue the two halves together.

Rocker

I'm with you Rocker, I did a power boat prop shaft like that once too, about three feet long. Perfect it was, with a perfectly straight pipe in it set in epoxy bog.

Then along came a boat-chippy, shrugged his shoulders and just whacked a big long hole through a lump of timber using a hand auger with a bit of reo welded on it! The hole was a bit wavy, but the shaft only had to line up between bearings at each end.

Sometimes I think we spend too much time thinking about how to do stuff, when all we need is a big lump of ignorance and a bit of brute strength!

Cheers,

P

You need to get yourself one of these, they are surprisingly accurate when you set the job up properly

That's what goodwoody's tying to find! Someone who has one!

cheers,

P

Originally Posted by bitingmidge

I don't have an extension bar for the forstners, which would be the best way I think, but in the absence of the proper gear I'd start with a forstner each end, that'd get rid of 200 in a reasonably accurate way, then if the balance was done with an auger bit also from each end, there's not much room for wandering too far.

Your comments Joe?

Cheers,

P

G'day midge.

I think the hole only needs to be about 10mm (3/8") so a Forstner extension wouldn't fit anyway; the shank alone is 3/8" and the barrel would be close to 5/8" or more. An ordinary ship auger of the right size would probably be less dear than the gear in dj's link. Ship augers are about 300-400mm long IIRC.

Like these:
http://www.mcmaster.com/ Enter 2414 in the search field for catalog page. Several styles available.

A few years ago, Nawm (Abrams; New Yankee Workshop) made a few lamps; turned on the lathe, then drilled from each end with the lamp held in a padded vise. That's sorta what I had in mind.

Joe

Originally Posted by djstimber

You need to get yourself one of these, they are surprisingly accurate when you set the job up properly

DJS,

So I take it you have one..... This issue is relevant to my flute neurosis. How do you set the job up properly? How deep can you go straight? What bore diameter are you achieving?

Sebastiaan

Originally Posted by goodwoody

Thanks fellas. I'm hoping someone can spin it on a lathe and use the hollow tailstock to drill out the center.

My lathe will take about a 1/4 drill bit through the tail stock and can handle about 5 1/2 feet. I just don't have any bits to do the long boring. I think Midge said he had some bits so we can probably combine something.

Originally Posted by Sebastiaan56

DJS,

So I take it you have one..... This issue is relevant to my flute neurosis. How do you set the job up properly? How deep can you go straight? What bore diameter are you achieving?

Sebastiaan

The main thing is to have spur drive and live centre with removable centres. I have done from memory about 700mm or 800mm bore which was done from each end, the 2 meet up pretty close to each other, only a slight lip was felt.

Have done some that were a bit out but was still able to see daylight thru them. I think that those ones didn't have the time and effort put into them to get them right.

I have an old 3/8" one that was given to me which I need to replace as it has had a hard life and is wandering a bit and is not really suited for my lathe as it doesn't fit thru my centres<!-- / message --><!-- sig -->

A hollow spur drive with a removable centre sounds like a rare bird. [Also, you'd need reverse turning capability to drill through the headstock, or a power drill with the lathe stationary.] Reverse mounting to use the cup centre on the tailstock for both cuts seems simpler to me. For drilling the holes after removal from the lathe and then re-mounted, neither end would be perfectly centred, but shouldn't matter much as long as the speed is at minimum to reduce vibration. I just dismantled my MT2 live centre, and it passes a 3/8" rod. I didn't check any larger drill bits, so I'm not sure of the maximum it'd take - not much larger though.

Joe