How do i drill small holes – just ruined my Elmers Tiny Column :(

[Cornish JackParticipant @cornishjack]

David

Just checked and, for some unknown reason, it says the message is 'undeliverable'!! I used the link you included so don't know how to get around that.

Rgds

Bill

[David Clark 13Participant @davidclark13]

Hi Cornish Jack

Make sure you delete the mailto: bit in the email.

That might be the problem.

Copy and paste from below, that might work OK.

regards david

david.clark@myhobbystore.com

Edited By David Clark 1 on 20/03/2012 14:18:18

[Cornish JackParticipant @cornishjack]

Hi David

Have just tried again to email you. Seemed to work … but so did the previous attempt. Fingers crossed.

Rgds

Bill

[Speedy Builder5Participant @speedybuilder5]

Ok, so I have read the above, but I am trying to drill 0.2mm holes in brass on the lathe to make some carb jets. What do you use to start the drill off and stop it wandering. Usually, I would use a centre drill, but even using my smallest centre drill, the 0.2mm drill wanders about such that the hole is not concentric with the jet.

BobH

[jason udallParticipant @jasonudall57142]

The bottom of your drilled hole will at best be a plane surface..at 0.2 mm scale it will probably have a scrape mark across the bottom from where the drill stopped..

This ridge is worse to start on than a plane surface…

Once deflected the drill is off on its own…

I would start on a faced and if needed stoned face…

At 0.2 mm in brass say 250 000 rpm…so inpractice as fast as you have…

Also you need a drill chuck of better or comparable runnout for your drill..

But try dead flat face and fast as possible…

[jason udallParticipant @jasonudall57142]

And woodpeck …lots….0.2 size pecks.( rolls eyes)…coolant will help even in brass..to wash the swarf from drill/hole when retracted

[Speedy Builder5Participant @speedybuilder5]

The spot drills in your link (Bogstandard) are 3mm dia, I need 0.2mm dia. I did in the end, grip the drill in a precision chuck with only a few mm protruding which centred better, but on a 9" lathe, there is still some wobble on the tailstock barrel.

[Michael GilliganParticipant @michaelgilligan61133]

Bob,

I suggest you "catch the centre" in the job, using a watchmaker's graver.

This is probably the only practical way of starting a 0.2mm drill.

… after that, proceed carefully with the drill

MichaelG.

[Speedy Builder5Participant @speedybuilder5]

Humor me – What is a watchmaker's graver ? Looking on the net, it just looks like a lathe tool.

BobH

[John BromleyParticipant @johnbromley78794]

Having a cheapo Clarke drill press myself, I feel your pain when drilling below 2mm. I have however managed to drill down to well under this with some patience. I have used a pin vice to get a start when the run out of the drill becomes just too much to deal with.

For drilling small holes with the lathe tailstock, rather than use a centre drill I just wind a nice sharp dead centre up to the faced stock, just enough to make a small punch mark.

John

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Speedy Builder5 on 27/09/2014 19:59:48:

Humor me – What is a watchmaker's graver ? Looking on the net, it just looks like a lathe tool.

BobH

.

Bob,

Yes, it's a [hand held] lathe tool, very hard and very sharp.

Have a look at this

MichaelG.

[VersabossParticipant @versaboss]

Instead of a standard spot drill you can treat yourself to a carbide centre tool from Eternal tools:

**LINK**

Not cheap I admit, but would solve your problems methinks. Satisfied customer etc., you know…

It would relieve you from learning to 'catch a centre' with a graver, an art in itself!

Kind regards, HansR.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Versaboss on 27/09/2014 23:49:40:

Not cheap I admit, but would solve your problems methinks.

.

With the greatest repect to both John and HansR. …

The tools you propose are designed to be held in the tailstock; and therefore success demands that the alignment of the tailstock is "perfect" [whatevever that might mean in real terms]. …. Any misalignment will result in that sharp point describing a circle on the work instead of the desired conical sink.

Using a graver [tricky as it may be to learn] is quick, cheap, and effective.

MichaelG.

[MuzzerParticipant @muzzer]

Interesting video if you follow the link in the page here. Never used a graver but they look pretty handy for small work.

Murray

[jaCK HobsonParticipant @jackhobson50760]

The runout on the Clarke and the chuck can be too much for small drills. I bought a new chuck and then I bought a Proxxon TBM 220 – I still had trouble.
Make sure the work is held firmly during the drilling, and cannot rock. You need sharp drills, and often 'new' drills are not sharp – particularly cheap small ones. Small drills are easy to sharpen. My new 'secret' is to use a coarser diamond stone (like blue DMT) so you can sharpen a flute with a single stroke. Also, just grind the surface flat, don't worry about the flair you would put on a lager drill. If your flutes get uneven, square off the end to 'start again'. On drills less than 1mm you can still sharpen in a single swipe.
Put most of the drill in the chuck and only leave a few mm sticking out. When drilling, make sure the drill keeps cutting by watching the swarf. Sharpen early. If swarf doesn't show because the drill is badly sharpened, then you are work-hardening the bottom.
Picking up centre with a graver is only easy after you can do it. Use eyeglass to guess the very centre and put the graver there – if it makes a small spot then that may be enough. Another watchmaker's tip is to hold the drill in a pin vice, support the wrong end of the pin vice by the tailstock centre, and feed the drill by hand holding the pin vice.

[jaCK HobsonParticipant @jackhobson50760]

Posted by Muzzer on 28/09/2014 02:52:42:

Interesting video if you follow the link in the page here. Never used a graver but they look pretty handy for small work.

Murray

Those carbide spade drills would be handy – if a bit expensive.

[Ian S CParticipant @iansc]

When trying to start a drill on Alclad aircraft skins, often on repairs, using an air driven drill, put the tip of the drill on the spot, press and rotate the drill backward maybe one turn, then go for it, the tricky ones were the 1/16" holes drilled at the end of a crack in a skin to prevent the crack growing, ideally the drill would be across the cracked section, and could catch. Normally a block of wood was held behind the job, I only missed the block once, six months later a bit of swarf came out from that spot on my finger.

Ian S C

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