Drill a hole close to opposite surface but not go through...

[adamr7747]

Hi All,

I want to make a 2cm hole part way through a 3cm piece of pine. The hole must stop within 1mm of the opposite face of the wood but must not break through at all.

Can anyone suggest a method/tool to achieve this? Obviously a flat wood drill bit has a big spike in the middle which would pop through, and even normal drill bits are too "pointy" for this task. I'm assuming I'll need to use a pillar drill for the depth accuracy.

I'd be grateful for any thoughts/ideas/suggestions/alternatives!

Adam

 

[joe-90]

Never tried it but a pillar drill with a suitable router bit should do it.

Or a router of course.

 

[TheVictorian]

Something like this maybe on a router/pillar drill?

http://www.thatcable.com/product/Straight-Metric-Cutter-20-x-20mm

 

[Harbourwoodwork]

why?

 

[Burnerman]

A forstner bit is what you want for this - again using a pillar drill.
John

 

[adamr7747]

Thanks. I've not heard of Forstner bits but it looks like they've still got a central guide. I'll investigate the router bit suggestion

Why?

I've got a wooden shelf structured a bit like this. I want to place magnets behind it and use the vertical section as a knife rack. The magnets need to be very near the surface!

Adam

 

[big-all]

will not work for less than around 5mm as the wood grain is not flat and level and requires around 5mm to resist the cutting action and force off the cutter

you could double up on the wood to support the surface but the force off the "twist" will not allow a thin amount
remember the cutting edge is in front and normally 2 or 3mm in front off the finished face /depth

 

[Harbourwoodwork]

can you set the magnets flush then veneer over

 

[Burnerman]

If you don't go down the veneering route, it will be very difficult to centre a router bit in the exact position, which would ideally require an indexing drill table.
Why not give it a go on a piece of scrap timber, and see how strong the magnets actually are? A large surface area magnet should give quite a pull.
John

 

[Harbourwoodwork]

Or use a straight fluted router bit with bottom cut and top follow bearing with smaller diameter than the magnet and use a jig with the size of hole you need, job done

 

[big-all]

duplicate please remove

 

[big-all]

the veneer route is the only sensible one unless-------
30mm timber will actually be 44mm[2" planed ] router your hole and pass through a table saw to 31.5mm then sand

but keep in mind you will have to sand with very very fine cabinet paper on a flat/shaped block with the magnet glued in to give support
you will need to choose you glue carefully as all glues i know will penetrate the wood more than 1mm so effecting the finished surface

 

[adamr7747]

Thanks for the ideas. Looks like I'll need to do a bit of experimenting - I'll buy the magnets and see how I get on...

Adam

 

[joinerjohn]

Some of the rare earth magnets, are extremely strong (magnetically) and wouldn't require the hole to be drilled to only leave a 1mm thickness. Google neodymium magnets.
(you'd probably get away with leaving 5mm thickness, which would be a lot better)