Thread: Drill bits - which are the best for very neat holes

what size of hole?

Upcut router bits do a pretty decent job of making nice holes. provided the holes are not going to be too deep otherwise any vibration in the piece will just let the router bit cut a bigger odd shaped hole.

I'm making more of my Maxifigs, wooden robots and spaceships.

They are very popular, but tricky to make. Several of the parts are eyes, portals, rocket tubes and gun nozzles.

I'd need mostly from ~5mm up to 15mm in 0.5mm diameters.

Carbatec seems to have a good set for about $85, but I'm hoping someone can definitively say "buy these, they are excellent".

Don't get me started on the Drill Doctor...

My advice is to learn how to sharpen them yourself. You could spend $500 on the best set of bits in the world, but once they're blunt they're useless.

Video here: https://www.youtube.com/watch?v=VcwOBL0tTbc not quite the way I was taught, but there are many ways to skin a cat.

Once you've go your technique sorted, you can go and buy any set of twist drills and re-grind them. That's what we do at work.

If you are looking for accurate sizes in brad point bits I would not be buying the carbatec set, Like Elan says, learn to sharpen, or, most good saw doctors can put a brad point on any bit.

Cheers

I wish they made Forstner bits in 1/2mm increments from 6 to 12.5 mm as they make the neatest holes. I'd buy them just to drill ally

Elanjacobs video suggestion is excellent. I've a huge pile of spare drill bits to test on. There is also a 180 CBN here, so it should prove an interesting test tomorrow.

I saw on another thread that BobL has a diamond plate attached to his grinder. This would make a very nice way of getting a trim sharp angle close in to the centre.

Originally Posted by Evanism

I've many drill bits, dozens, but they don't drill very neat holes - free of slight tearout or lightly nasty edges.

The ones I have have been thoroughly sharpened with a Drill Doctor.

I need to drill many neat holes in almost finished curved things, so sanding back errors isn't an option.

Anyone know of a particularly good set of brad point bits?

i have found the brad point bits from lee valley excellent ... i don't believe you can get the equivalent style in australia though ...

depending on the size you want ... the colt 7mm pen drill cuts a very nice hole ... something to do with its spiral design i believe ... that you can get in australia

regards david

I agree with what David said. I have had the Lee valley brad points for about 10 years now and they drill very clean holes for a long time. They do not have all the metric sizes but some of the imperial sizes will get you very close and the imperial bits are a little cheaper than the equivalent metric sizes.
Les

ElconJacobs' idea to hand sharpen is a good one. The CBN is probably a bit too fat, so I emailed BobL and he suggested these: http://stores.ebay.com/THK-Diamond-T...sub=3920503013

I bought the 600 grit and 1200... that should give me a very fine edge.

With the drill doctor, its irritating that they are only 80 and 180 grit. The edges arent smooth and nowhere what Id call "sharp". Ive teaspoons with better edges. They should seriously make a 600 grit stone so regular touchups get a frequent and very fine edge. The 180 is fine for fixing up old/rough bits, but for fine edges its damn hopeless.

Thanks to everyone for the assistance. Attached is a sample of the types of hole I need to drill. The heads and bodies are mostly done on the lathe and a belt sander jury-rigged to work on the lathe. All very low tech! There are 12 new designs and getting the eyes and portals (guns, holes, smoke stacks, etc) are particularly troublesome.

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Hi Evanism- nice work on the robots.

The laps in your link have a ½" arbor. Anyone know if these could these be enlarged to ⅝" with a stepped drill bit?

Originally Posted by jack620

The laps in your link have a ½" arbor. Anyone know if these could these be enlarged to ⅝" with a stepped drill bit?

BobL suggested a reamer, but said you need to be dead accurate to prevent wobble. He also suggested getting some steel backing plates made that match the diameter, as the wheels are very thin and can't hack side pressure (they are mounted on some type of polishing wheel for jewellery apparently)

I thought a circ/table saw blade service could do it. They did this previously for a flat bottomed circ blade they made for me. I'm going to talk with Ueee to ask him if he could do it for me (he's making some Riving knives currently).

Thanks for the reply. I don't have a ⅝ reamer. The stepped drill bit ought to do it as long as the metal isn't too hard. I can easily turn up a backing plate/spacer. I reckon I would use aluminium tho instead of steel.

Originally Posted by elanjacobs

Don't get me started on the Drill Doctor...

I bought one, it is still in the cupboard after a few failed attempts to use it and will likely go in the bin eventually unless someone is silly enough to offer me money for it. Sorry, off topic but I feel better now.

Originally Posted by Chris Parks

I bought one, it is still in the cupboard after a few failed attempts to use it and will likely go in the bin eventually unless someone is silly enough to offer me money for it. Sorry, off topic but I feel better now.

After watching a Youtube video review, I can see why so many people hate the Drill Doctor. The amount of slack / movement when spinning the chuck is ridiculous.