Cutting a 3" hole in oak.

[graduate_owner]

I've been asked to make some oak bearings for an agricultural roller. The farmer has given me some chain-sawn oak 'cubes' which are anything but cubic. I need to get 2 rectangular blocks, one out of each chunk of would-be firewood, and then make a 3" diameter hole through each of them.

I have planed one side flat on my Axminster planer and I thought to screw the planed side to a faceplate and turn off the opposite face to the correct thickness which will bring the block down to a thickness that my table saw can cut through - then I can square it all round by sawing. If anyone has better ideas then please let me know.

Then I will have to get a 3" hole through (not end grain, thankfully). I thought perhaps a hole saw might help me to take out the bulk of the waste, so I could leave it on the faceplate and fit a holesaw in the tail stock. Then after about 1" depth I could back off the hole saw and gouge out or perhaps use a parting tool or scraper to remove the 'plug' before continuing drilling. That would give me an accurate 3". So that's the plan.

Any comments?
Would a forstner bit be better? I have a 2" one, and could perhaps widen the hole into 3".
Would it be easier to take out the entire hole with a gouge or scraper / parting tool and not bother with drilling? I'm no expert at the lathe - far from it.

K

 

[CHJ]

You will struggle to cut that big a diameter hole in good Oak with a Forstener Bit.

The only way you will do it is to drill a succession of ever increasing sized holes, but of course the chances of the final hole being true to size would be small due to lack of central location for the largest bit, so I think it will need to be bored with a tungsten tipped boring bar or maybe a very stiff scraper in boring mode.

Personally I would square up the blocks to fit the housings and then mount these on a faceplate/Cole jaw system to bore out the central hole.

If you cone the lead into the hole then the unsupported/located Forstener bits will centralise at the start of the cut.

 

[Dalboy]

I think a diagram might be useful. There are different possibilities depending exactly how the blocks fit. For example there is the split type wooden bearing block there is also a blind hole type and then there is the through hole block.
I have made a steering drum for a large model steam engine this had to be made in two halves as this was only the pattern for the casting process

 

[bellringer]

There is a 3 inch Forster bit for sale in the for sale section

 

[dickm]

Just out of interest, why oak? Would have thought this could lead to all sorts of rust problems if it's an iron axle that it running in it. In an ideal world, it would be lignum, but being sensible might elm be better than oak?

 

[andersonec]

There's some guys not far from me who make wine racks out of old oak beams and they cut the holes with core drilling bits, if you know someone who's got some.

http://www.thefallentree.co.uk/products/wine-racks

Andy

 

[Dalboy]

Bimey I think I'll go into wine rack productionj

 

[finneyb]

Bimey I think I'll go into wine rack productionj

Hope that you've not cut those branches in your 'roughing out wet wood' thread :lol: make wine racks
roughing-out-wet-wood-t78478.html

Brian

 

[Dalboy]

Bimey I think I'll go into wine rack productionj

Hope that you've not cut those branches in your 'roughing out wet wood' thread :lol: make wine racks
roughing-out-wet-wood-t78478.html

Brian

It would be a wine rack for miniature bottles then :lol: :lol: :lol:

 

[graduate_owner]

Hi Dickm,
The farmer asked for oak and that's what he brought for me to use, so that's what I've used. I see your point about rusting but if that's what he wants, well that's it. (Loads of grease perhaps).
I've 'ordered' a 2 3/4" forstner from Russell in the 'for sale' section (thanks to Bellringer for pointing that out), and I'll give that a go - feeding slowly !! I thought I'd clean the hole out to 3" with a side cutting scraper and see how it goes.

K

 

[finneyb]

Bimey I think I'll go into wine rack productionj

Hope that you've not cut those branches in your 'roughing out wet wood' thread :lol: make wine racks
roughing-out-wet-wood-t78478.html

Brian

It would be a wine rack for miniature bottles then :lol: :lol: :lol:

Up north we have proper branches that would make a decent wine rack :lol: :lol:
I've used branches to turn mushrooms with a natural edge to the base and the bottom edge of the cup

Brian