Thread: Brad bit, Gimlet, Shell Auger?

Sebastiaan

Just to give you some idea of what is out there, (sadly generally not available in Australia), http://www.fine-tools.com/bohr4.htm look at the 250mm long brad bits, there are 300mm brad bits on Ebay (sold as 12" long).

It wouldn't surprise me if a conventional twist bit made a straighter hole than a brad point bit in this situation. The wood itself would also have to be very straight grained for flute making. Any irregularities from one side of the hole to the other would tend to send the drill bit off at a slight angle.

These are purely theoretical ideas: I've never actually drilled such a hole, so would be interested to hear from someone with experience.

What's the diameter of the hole you're making?

Could maybe look out for an old hand auger, should be long enough & could possibly be adapted to drill on the lathe after modification & a tune up.

Are you using a steady rest? For a significant length, the lathe chuck alone might not hold it rigid enough. Also, what is your diameter? If 3/8" or less, there's a current thread in Woodturning - General on Deep Hole Boring, regarding drilling through the tailstock.

Joe

An auger nor a brad point bit will not work. The reason is that the sharp point of either tends to follow the grain. If the grain is not perfectly straight then the hole will not be striaght.

Have you tried using a lathe? I think that even using a long twist drill bit and a lathe you would have better results.

You'll need bits that are of a far better quality than could ever be found at bunnings. I think the brads are the best option. You want a bit that will cut the fibers from the outside edge cleanly and then remove them. So a good quality brad that will maintain a keen edge is a must. If they can't cut the fibers cleanly and easily they'll wander with the grain - especially in the woods you'll be drilling. The higher quality bits will also be more robust and resistant to bending with the grain like cheap ones. Forstners maybe another good option if you can find a long enough one but they can generate a fair bit of heat.

Originally Posted by joe greiner

Are you using a steady rest? For a significant length, the lathe chuck alone might not hold it rigid enough. Also, what is your diameter? If 3/8" or less, there's a current thread in Woodturning - General on Deep Hole Boring, regarding drilling through the tailstock.

Joe

Hi Joe,

Yes, Ive kept an eye on that tread, even added to it. Have a few phone calls to make today.

Hi rrich,

Yes the lathe is what I have been using. Issues come from the flex on auger bits as well as the wandering caused by strong grain. If I can get the bit for the Record, I will try the methods described in the other thread.

Sebastiaan

Sebastiaan,
A friend suggested starting with a larger block of wood than you need. Then drill the hole. Finally put a bushing through the hole and turn the outside to be concentric.

Sebastiaan56

I don't know much about making flutes and the like, but perhaps someone at "The Musical Instrument Makers Forum" has the experience / knowledge and might be able to help.

http://www.mimf.com/index.htm

Hi everyone,

Well there is no one dealing in Record Power parts in Australia, so back to square one. There is a kit to do what I want CWA13, now... how to get one.

MIMF has helped, Terry on Flutemakers at Yahoo has been amazing, and I have been turning down larger blocks. The issue is that the holes always end up curved to some degree, I have a number of blanks with veerry loonnng finger holes in the middle of the blank. Hole needs to be straight with 2mm walls,

Sebastiaan

No music content (apart from a persistent hum from the computer ), but I used a 19mm auger bit, 400mm long, to drill the beam bolt holes for my catamaran. The hole was through 7mm ply + 2 x 40mm oregon side grain + 40mm western red cedar + more I've forgotten . Used a brace (a la bit-'n-brace) and slowly hand-drilled with one person checking upright and angles continuously. Given the position of the holes on the boat, it wasn't possible to use a drill press (unless someone had held a swivel one on it's side while it was going ). In end-grain and shortish lengths, I'd be tempted to put the drill press on really slow and clamp the piece to b*ggery.

Rob