Boring large holes in Oak

[printcom]

I have got to make up a couple of Oak bearing blocks for a ballast roller of mine. Nice easy job until it came to drilling the main shaft holes - that's when I realised that I don't have a bit large enough. The shaft is 65mm and the block is 100mm deep. I can get a 65mm forstner bit but from my experience they don't last long in oak. I was wondering if those adjustable auger bits are any good or if anyone has any other suggestions.

 

[CRB]

?Presumably a lathe is not available?

 

[printcom]

?Presumably a lathe is not available?

I have got a lathe and a Mill but I am reluctant to let wood anywhere near them.

 

[Richardjjj]

Try a Starrett or similar tank cutter.
Sorry, my mistake, they are not tank cutters but tct 'hole saws'.

 

[HughF]

Adjustable auger bits are not particularly nice to use in my experience. I would suggest a flat wood bit (made from a file perhaps)?

Or just buy the Forster bit and sharpen it regularly.

 

[wyn]

I used a holesaw for some hardwood bearings on a roller.

 

[Paul.]

I made this former using a 3" holesaw, the block is deeper than the saw so had to stop halfway and chisel a section out, this is a piece of hardwood door sill, oak will be a bit tougher,

Flat bits can be made quite easily, if only for a couple of holes they don't need to be too hard, this is one I knocked up from a bit of stainless in about 15mins flat to put some holes in a polyethylene bottle drainer I made,

 

[brightspark]

use a starret hole saw on a slow speed.cut and pull out blade every few seconds to remove the sawdust otherwise it will soon clog and burn the wood and heat the saw with the friction .every inch chip out the core with a wood chissel as above post .a bit of patience is all that is needed

 

[Kent]

I should go with the flat bit all the way, too thick for a hole saw
I like the bit that Paul made up it has never occurred to me to make the size needed before and I use these a fair bit to make something from a big block of walnut

 

[mike os]

just turn it.. or bore it, oak is certainly no worse than cast iron .... and at least it will only leave blue/black marks, not grinding paste, and the holes will be the right size and not run off

 

[printcom]

Thanks for all the tips chaps, I decided to do a belt and braces job and ordered a 67mm holesaw and one of those cheap ebay expandable auger bits.
The ebay auger turned up first so I gave it a go - I honestly expected it to go straight in the bin, but no, it did the job - not bad for under a tenner inc the postage. Mind you I would not want to try using one without a drill press.

 

[Turbo]

Mind you I would not want to try using one without a drill press.

You've made a nice job of that.

I've found it's very difficult to bore a straight hole with that type of drill bit as there's no shank to guide it.

I remember when my dad bought his land roller and I was surprised to see it was fitted with oak bearings. I've since discovered that most agricultural rollers are fitted with them - very old technology in a modern piece of farm equipment.

 

[printcom]

I've since discovered that most agricultural rollers are fitted with them - very old technology in a modern piece of farm equipment.

I did think about making them out of nylon block until I priced it up.