cutting a 45mm hole in 3 inches of walnut

[davidthomson]

Hi There

I am a bit of a newbie to woodworking. My father had a lathe many years ago in our family home which I used to try may hand at.
Some 20 + year later I now have a shed and have got the wood bug again.

Here is where I bow to the greater collectives knowledge
I am working on a little project to make a lamp I need to bore a 45mm hole through 3 inches of Walnut.

I have tried with a forstner bit in a black and decker drill stand but the bit jumps a bit when going into the wood subsequently I am not getting a perfectly round hole.

I drilled several holes at varying width with a selection of spade bits to open the hole up so as the forstner bit dod not have to so much work but still the same story.

I am now inclined to go down the router route but I cant seem to find how to make a jig to cut such a small hole

Any suggestions.

Cheers

David

 

[siggy_7]

Is the problem with the hole accuracy due to your setup or the high forces you need to get through the walnut? If you can get the Forstner bit to go through easier material and leave a good finish, then just drill a hole through a piece of plywood or MDF and then clamp this onto the walnut and use a top bearing guided cutter.

 

[jasonB]

Drill it with a holesaw, stopping every inch to remove the waste with a chisel, done it many times for newel post spigots.

Router as above if you need a better finish

J

 

[foxhunter]

If the hole is to go all the way through then first drill a pilot hole through (6mm) and use a hole saw from both sides.

 

[AndyT]

Can you explain in more detail just what you want to do?

For instance, it makes a huge difference which way of the grain your hole is. If it is into end grain, a Forstner bit won't work very well. A sawtooth bit might be better. What quality was the bit you tried? Was it truly sharp?

In general, large holes are difficult, just because of the amount to be cut. Do you mind spending some cash on a big drill bit for just this one job?

Might it be possible to split the workpiece in two, cut out two grooves, and reassemble it? Is the hole to go all the way through, or stop within the wood?

If the hole is going to be three inches deep, you would need a very substantial router and bit, but the general principle for using a powered router on a job like this is to use a guide bush on the router working inside a ring cut from plywood or mdf which is your target size + the extra for the bush.

 

[davidthomson]

I am cutting into side grain. and the Forstner bit was brand new.

Can anyone recommend a hole saw, I do like the idea of a 6mm pilot hole and drilling from both sides but the timber i am using is 80mm
and the hole cutters I have seen have a maximum cutting depth of 34mm.

I really want to keep the timber as a whole pice so spiting it and cutting two halves is not an option.

As I understand it with a router I would need to make a hole bigger than 45mm for the bush to sit in and then slowly par down the hole with the router eventually revealing a large hole, but as i said I am having difficulty finding a guide to make such a small hole.

Cheers
D

 

[wallace]

Have you got a lathe? If so just put the wood in the chuck and hollow out
Mark

 

[RogerP]

I would expect a Famag to cope. I've used them for deep holes in oak without problem.

 

[AndyT]

As I understand it with a router I would need to make a hole bigger than 45mm for the bush to sit in and then slowly par down the hole with the router eventually revealing a large hole, but as i said I am having difficulty finding a guide to make such a small hole.

Cheers
D

Yes, but the bigger hole is not in the workpiece, it's in a template which is temporarily attached to the workpiece. This video was the first one Google offered, and shows the general idea. You'll need a neat circular hole in some thin ply or MDF - but you can work that with a rasp or sandpaper round a stick, until it's a clean circle.

http://www.woodsmith.com/magazine/extras/158/using-router-guide-bushings/

Unless you have a heavy duty router and bit, getting 3" depth might be impractical.

 

[foxhunter]

If you want to use a router then a template used as below

Identify the centre of the hole you want to make, drill a short pilot hole and place the template on it using a drill bit. Attach the template using double sided tape remove the centre disc and rout the hole as required.

The calculations for the hole are Jig Size less the difference between the guide bush and the cutter. In my example above I used a 64mm jig with a 18mm guide bush and a 14mm cutter. Resulting in a 60mm hole. Cut by plunging the router at first randomly then round off to achieve a smooth finish.

The only problem with this is that you would need a very long cutter and a 1/2in router.

 

[marcros]

Is hole size critical? If you are wanting an oversized hole, to run a router guide bearing round, then somebody on here may have a scrap of ply and a holesaw that is a near enough size. Do you have a guide bit for your router already, and if so what size?

 

[davidthomson]

I am somewhat overwhelmed with the amount or responses.

To answer a few questions I took these pics of what I have managed today.
The cutouts could be prettier but I am going to cover them with a aluminum plate similar to the one in the gallery.



The depth of the hole going all the way through is 80mm the second hole stops 7mm shy of the bottom of the hole.
The cut outs were done with a router with a 60mm cutter

I just have to make a jig to be 3mm deep to accomodate the aluminum plate

Thanks for the input I will put up more pics as I progress

Cheers
D

Apparently I am not able to post a link to my photobucket??

 

[AndyT]

Apparently I am not able to post a link to my photobucket??

You need five posts first - it stops automated spambots abusing the site.

 

[davidthomson]

I shall make another post to avoid the spam bot

 

[davidthomson]

and one more so as I can post the link

 

[Paul Hannaby]

I think I would stick with the drill press and forstner bit. Slow down the speed of the drill, clamp the workpiece down securely and feed slowly until the bit is running securely in the hole it is creating.

 

[davidthomson]

here is the link to the photos

http://s1147.photobucket.com/albums/o54 ... otobucket/

 

[Jacob]

Spade bit would do it no prob. Cheapest and simplest drill bit you can get, but highly effective.
One size drills available or adjustable variety here:
http://www.mtmc.co.uk/product.aspx?Prod ... googlebase
The only essential detail is that you must not have had a go first with another drill - a spade bit needs good solid wood to keep it in a straight line.

PS just had a search for one size versions but couldn't see one above 38mm. They do exist though!

 

[Cheshirechappie]

Hi There

I am a bit of a newbie to woodworking. My father had a lathe many years ago in our family home which I used to try may hand at.
Some 20 + year later I now have a shed and have got the wood bug again.

Here is where I bow to the greater collectives knowledge
I am working on a little project to make a lamp I need to bore a 45mm hole through 3 inches of Walnut.

I have tried with a forstner bit in a black and decker drill stand but the bit jumps a bit when going into the wood subsequently I am not getting a perfectly round hole.

I drilled several holes at varying width with a selection of spade bits to open the hole up so as the forstner bit dod not have to so much work but still the same story.

I am now inclined to go down the router route but I cant seem to find how to make a jig to cut such a small hole

Any suggestions.

Cheers

David

I think the problem is that that's too large a drill for the (fairly flimsy) Black & Decker drill stand to cope with. With the better rigidity of something more industrial, you'd whizz through (as long as your workpiece was securely clamped down).

That leaves us with the problem of how to create a 1 3/4" hole through 3" of walnut. Others have suggested a holesaw, which would work, but if you don't have one (and don't want to shell out for one), try chain-drilling small holes inside the circumference of the big one, and clearing the waste with chisels. Then clean up with a paring gouge or rasp, followed by coarse the fine sandpaper wrapped round a length of broom-handle.

 

[jasonB]

Can anyone recommend a hole saw, I do like the idea of a 6mm pilot hole and drilling from both sides but the timber i am using is 80mm
and the hole cutters I have seen have a maximum cutting depth of 34mm.

Thats why I said stop every inch to clear out teh waste with a chisel, that way you can drill 150mm depth quite easily.

Screwfix holesaw and arbor will do fine