drill small holes at an angle?

I would like to make a series of 3mm angled holes (20,22,24 degrees) in a small piece of Tufnol, around 12 mm deep.

I have quite a few hand tools (both woodworking and metalworking), but my only powertool is a drill in a wolf stand.

The angle is enough to make starting a 3mm drill at all "interesting", and getting the hole in the right place "more interesting".

My approach so far is to use a piece of 2x4 sliced off at the desired angle with my Nobex mitre saw, as an angled table, with a drill vise holding the workpiece.

I used this as the drill:

formatting link
I would welcome hints or tips.

(I'm making a more-engineered version of the gadget discussed here

formatting link
is just a piece of scrap hardwood)

BugBear

Reply to
bugbear
Loading thread data ...

formatting link

Cool drill!

When I have to drill accurately angled holes I get a dremel or something and make a flat spot to drill into, so I'm starting off into the flat rather than starting off into an angle.

-- Peter Fairbrother

Reply to
Peter Fairbrother

formatting link

Why, thank you!

Here's more, in a thread where I eventually identified it.

formatting link
BugBear

Reply to
bugbear

Simples. Start the hole with either a centre drill or a small end milling cutter (slot drill).

The other way is to use sacrificial material. Cut two slices of summat similarly hard, wood will do, at the desired angle and clamp the tufnol between them. You now have horizontal surfaces top and bottom and the Tufnol at the desired angle in the middle. Much more buggering about than using a centre drill though.

Reply to
Dave Baker

bugbear laid this down on his screen :

formatting link

I would start the drill vertically into the material at the required centre, then tilt either the drill or the material over to the required angle once it is deep enough not to skittle off centre.

Reply to
Harry Bloomfield

That's frankly, and sorry to be blunt, asinine advice which is about the best way of breaking drill bits and ensuring the hole won't be on centre I've ever heard.

Reply to
Dave Baker

message

required

Don't hold back man - say what you mean !!!

AWEM

Reply to
Andrew Mawson

I like the drill stand as well (GRIN)

Why not just drill your hole square to the magnet face and insert a bit of 3mm rod that you have bent to the required angle?

Richard

Reply to
Richard Edwards

Frankly Dave, I don't understand the difference between your earlier advice and Harry's. Both seem to advise starting the hole by making a dimple or tiny hole then changing the angle of the drill. Please explain what I am missing.

Cliff Coggin.

Reply to
Cliff Coggin

Nowhere in my post did I advise changing the angle of the drill nor can I see how it could be read like that. Having already set up the Tufnol at the required angle I said simply to start the hole with a centre drill or a milling cutter, neither of which would drift off centre like an ordinary drill when starting into an angled surface. Personally, having both tools, I'd use a 3mm milling cutter to generate a small flat perpendicular to the drilling axis, then start the hole with a small centre drill as is normal practice and finish with the ordinary drill. No need to move the workpiece or the drilling angle again during any of this.

Reply to
Dave Baker

Yup. What he said.

Regards, Tony.

Reply to
Tony Jeffree

I want multiple angles. I actually want multiple block with multiple holes, giving me angles from around 4-30 degrees.

I thought I had a better chance of making angled holes; the blocks are also small and easy to store.

Oh - I'm using a bamboo (kebab) skewer as my pointer.

BugBear

Reply to
bugbear

Sorry if I misunderstood you. Why would a centre drill at an angle to the work not drift off centre when it has the same angled cutting edges as a full size drill which does drift? I don't see the difference, because, except for the change in size, the geometry of tool and work are the same and so the forces involved are the same.

Cliff.

Reply to
Cliff Coggin

I think the shorter, thicker (for much of its length) centre drill will drift less, under the same forces.

BugBear

Reply to
bugbear

So make a flat so there are no deflective forces, and then use a deflection resistant drill anyway!

Belt and braces.

BugBear

Reply to
bugbear

Exactly.

I use a centre drill to start holes a lot, simply because they go where they are put. I've also made use of a slot drill too, that works well for the workpiece set an angle.

Reply to
Steve

Exactly.

Regards, Tony

Reply to
Tony Jeffree

Not really. Twist drills are not designed for starting accurate holes or to be self centering even when running into a perpendicular surface. Good practice is to always start a hole with either a centre drill or a spotting drill. Having an angled surface to work against only adds the single step of milling a perpendicular flat before starting to drill. All of this is very basic workshop practice - no rocket surgery involved.

Reply to
Dave Baker

formatting link

I'd make a metal jig with guide holes at the required angles. Clamp the jig to the Tufnol and drill through the guide hole. Marks on the jig would enable accurate alignment.

Reply to
lemel_man

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.