Help: 2mm drill in 1/4" collet

[Omnivore]

*** Yes, I know I shouldn't do this. ***

My hobby cnc mdf router has a Ozita router as the "spindle", fitted with a 1/4" collet for standard router bits.

I need to drill a number of 2.0mm and 2.5mm holes in some thin mdf, using the cnc to get accurate placement. (It's actually a part for a 3d printer).

Now I realise that a HSS drill spinning at far_too_fast won't work brilliantly, but I don't have any 1/4" shank router bits smaller than 3.2mm. This will all take place inside a very solid enclosure so if something explodes I don't expect any human damage.

Shall I:

(a) Turn a chunk of steel to 1/4" diameter, drill into it with the 2mm held in the tailstock, then solder the drill (possibly shortened) into it.

(b) Turn a chunk oversize, drill into it with the 2mm, solder in, then hold the drill bit in the chuck and turn the shank down to 1/4" to try and get it more concentric.

(c) Make a sleeve, 2mm ID, 1/4" OD, slit down one side, and clamp the drill with that.

or (d) Turn a sharp point on a chunk of 1/4" steel (or grind it on some hardened music wire), and use the cnc z-axis to drive the point into the mdf, then use the indentation as a guide to drill the holes in a drill press?

Withering criticism, helpful ideas, or any comments welcomed.

[jeffrey001]

They're a lot of mini chuck or micro chuck you can buy anywhere like amazon.

http://www.amazon.com/SE-Micro-Chuck-inch-shank/dp/B001NQP8HU%3FSubscriptionId=AKIAJ2KCCSRYBYAUNNMA&tag=affilamazo0da-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B001NQP8HU]Amazon.com: Micro Chuck 1/4 inch shank: Home Improvement

1-3mm Mini Micro Drill Chuck Pin Vise Set 1/4" Shank | eBay

Or look for Dremel chuck, very inexpensive.

Hope this help.

And don't use anything that is not balanced to high speed.

Jeff

[Omnivore]

Wow. Thanks Jeffrey.

I had assumed (bad me) that anything of that type would be too expensive. I've ordered a unit of ebay - much more professional than my bodge would have been.

[txcncman]

Or there are adapters available to run smaller drill sizes in 1/4" holders.