How do you make a 0.4mm hole in brass?

[ImagineRobots]

I have a cheapo MakerBot 3D printer. It's essentially a 3D CNC hot glue gun. There's a heated brass nozzle with a 0.4mm hole. How do they make such a small hole? There's no way a drill bit could be that small or am I wrong?

Here is the nozzle:
MakerBot® MK7 .4mm Nozzle - MakerBot Industries

They want 20 bucks for the nozzle. Seems expensive.

thx

[underthetire]

Thats actually a rather large size hole. We have them down to .05mm.

Here is a handy chart
Drill Chart

[ImagineRobots]

Thats actually a rather large size hole. We have them down to .05mm.

Here is a handy chart
Drill Chart

I wonder if these small bits require a special precision drill chuck with really small runout. Someone also mentioned that the nozzle parts were most likely made using EDM. Maybe that's why they cost $20 each.

[fizzissist]

.4mm is a piece of cake. In brass? It's almost cheating.
Run it as fast as you can, good air blast, in a sensitive drill chuck.
Easy.

[max_imum2000]

yep , i have done it several times before and for the same purpose
0.3mm , but i used a lathe
very easy

[ImagineRobots]

.4mm is a piece of cake. In brass? It's almost cheating.
Run it as fast as you can, good air blast, in a sensitive drill chuck.
Easy.

All of my drill chucks have a small hole in the center even with the jaws completely closed. My friend just told me to use something called a pin vise to hold small bits.

[underthetire]

You just need a smaller chuck. A hand feed chuck is ideal for small stuff.

[fizzissist]

A pin vise isn't designed to run concentric. If it does, you're lucky.
If it don't, your hole size is whatever it ends up being along with the bellmouth you get as an extra, along with the potential for breaking the drill.

You're right, $20 is outrageous. You should make one yourself, and keep track of the hours you spend on it..allowing yourself a minimum wage rate.

Let us know how long it takes.

[cyclestart]

All of my drill chucks have a small hole in the center even with the jaws completely closed.

Stick the drill in a cigarette filter and clamp the filter in the chuck. Not the best or most accurate solution but it will spin the drill.

[RomanLini]

Buy a brass "carburettor jet" available in many very small sizes, for a couple of bucks.

That is already a screw-in brass orifice. Then you might have to turn a bit off its face on the lathe (as most have a countersunk top to the hole).

[neilw20]

My trick with holding small drills is to get a strip of thin paper, wet my fingers and wrap it around the drill in a rolling action, much the same as a women magically threads a needle.
When enough paper, even doubling the drill diameter or more I rip off the end, stuff it in the chuck and tighten it.
Real easy with a bit of practice. Been doin' it that way for 40 years.

[ImagineRobots]

Buy a brass "carburettor jet" available in many very small sizes, for a couple of bucks.

That is already a screw-in brass orifice. Then you might have to turn a bit off its face on the lathe (as most have a countersunk top to the hole).

I was also thinking of turning a brass shoulder bolt and then drilling a center hole ($2.50 from McMaster-Carr). I just found another place that sells a slightly different nozzle for $10.

MakerGear.com - Nozzles

The site says it's made on "high end Swiss CNC equipment"