Centre drilling a timber column

[Dengue]

What is the best way to drill a 50mm hole straight down the centreline of a 300 x 300 timber column to a depth of about 300mm?

regards,
Dengue

[wheelinround]

Using a Forstner bit an extension for it once depth limit has been reached if using a hand held power drill hang on tight. Oh and slow clearing the waste out often

[Dengue]

Hi wheelinaround, how would you keep this bit "straight down the centreline "of the timber post?

[wheelinround]

same as any other bit

[joe greiner]

same as any other bit
Very correct, Ray, but not much help.:p

With the timber mounted horizontally:
Easy to maintain lateral alignment by eyeball sighting from above, and easy to maintain vertical alignment by eyeball sighting from the side. Difficult to do both simultaneously, without remote eyeballs. To create a remote eyeball, use a table-top shaving mirror, set up to allow an occasional glimpse from the other drilling position.

Cheers,
Joe

[scooter]

Maybe have a read of a method I've used here (http://www.woodworkforums.com/f87/simple-wooden-box-hinges-32590/#post316175), might be of some use for a starter or pilot hole.



Cheers................Sean

Edit: just reread original post, might have some trouble fitting a largish column under the quill.:- Anyway, there it is.:)

[Dengue]

Thanks for your advice, Joe.

I was hoping that there would be some type of jig that could be chained to the timber posts as they lay horizontal, which would deliver a straight and true hole.

regards,
Jill

[joe greiner]

Thanks for your advice, Joe.

I was hoping that there would be some type of jig that could be chained to the timber posts as they lay horizontal, which would deliver a straight and true hole.

regards,
Jill
There is such a "jig," Jill. It's called a "lathe." :D But without the chains.

The post is secured in a chuck at the headstock, and a circular clamp is mounted at the drilling end, to engage a steady rest (like my avatar). A stationary drill bit is mounted in a drill chuck at the tailstock. With the post spinning, the tailstock is advanced toward the headstock, occasionally withdrawn to remove shavings. has probably made a few like this. I've only made smaller versions (tool handles and vases).

Cheers,
Joe