Q: How to make a micro sized nut driver?

[u18b]

Max,

Sorry it wasn't clear.

Unless you REALLY need to torque these down, couldn't you just cut a slot in a flat blade screwdriver?
I went ahead and followed my suggestion with one that is a bit large for typical N scale use.

Since I don't have one of your screws, I just did a rough approximation.

Here is .045" by the calliper.



Then, I used a diamond cutoff wheel I got from harbor freight. 



Wouldn't this do?

[haasmarc]

Couldn't you make something similar to those universal sockets.  Take your oversized tubing about an inch long, place it over the bolt head, fill the tube with small diameter brass rods.  Some of which will go down beside the head and some will sit on top of the head.  Now flood the top of the tube with solder to hold all the rods in place.  Custom made socket.

[mmagliaro]

Ron,
I like the slot idea.  It's like the wrench idea.  But I'm really trying to make something that will spin these buggers in and out a little easier.

[mmagliaro]

Couldn't you make something similar to those universal sockets.  Take your oversized tubing about an inch long, place it over the bolt head, fill the tube with small diameter brass rods.  Some of which will go down beside the head and some will sit on top of the head.  Now flood the top of the tube with solder to hold all the rods in place.  Custom made socket.

The problem is the sheer small size of what we're trying to make here.  1.1mm across the flats, only .045".
So even .008" wires would be too big to slip down the sides, at least getting a few of them next to each flat, to form some approximation of a wall on each of the 6 sides, and that's what those universal things do.

I

[up1950s]

Take a brass tube and put your nuts in it then convince the tube to be be a hex tube with this .

http://g01.a.alicdn.com/kf/HTB1M7ZsIFXXXXXvXpXXq6xXFXXXy/Coaxial-font-b-crimper-b-font-crimping-Tool-LS-02H1-for-coaxial-cable-BNC-fiber-optic.jpg

[mmagliaro]

Take a brass tube and put your nuts in it then convince the tube to be be a hex tube with this .

http://g01.a.alicdn.com/kf/HTB1M7ZsIFXXXXXvXpXXq6xXFXXXy/Coaxial-font-b-crimper-b-font-crimping-Tool-LS-02H1-for-coaxial-cable-BNC-fiber-optic.jpg

There's a 1.72mm crimp size on that thing, I see.
1.72 - 1.1 = .62mm = .024"
Hmmm.... Not quite .014" wall thickness of the standard K&S tubing, but it might fly.

[PGE_Modeller]

There's a 1.72mm crimp size on that thing, I see.
1.72 - 1.1 = .62mm = .024"
Hmmm.... Not quite .014" wall thickness of the standard K&S tubing, but it might fly.

But probably close enough to the 0.028" of two wall thicknesses which is what you will have!

Cheers

[mmagliaro]

Well, first time's a charm I guess.

I tried a "what the heck" easy approach, akin to the various suggestions on here from narrowminded
and LemoSteam, although much more simplistic than their instructions.

Took a piece of brass tube with an ID somewhat less than the head of my bolt.  Drilled it out with a pin vise
to .046" (just about 1.1mm).  Then I clamped one of the bolts under the mill head, put my brass tube in the chuck and just pressed it down like a ram, forcing the open end of the tube over the head of the bolt.

Voila!   

Wow... after all this hard thinking.. it was much easier to do than I thought it would be.

Fits the bolts *perfectly* and works like a charm.  I don't know how much torque it could really take before the brass stripped out.  But think it is adequate.

[Chris333]

Glad we could help 

[narrowminded]

That's what I'm talking about!!!!

That bolt head is a machined head, not cold headed like most fasteners we see in larger sizes, isn't it?  It gave you a decent edge and honest dimension.  Flowed that metal right up into the hole just like a.... socket.

NOW... get the small hex key sizes that don't need to be reworked, cut off and grind the end nice and square, push that into a mild steel blank, and you've got a punch and die set for thin aluminum or brass sheet, simulating small hex bolt heads for your models.  A "stripper" that helps hold the material flat and allows you to draw the punch back out of the material is needed too.  That would be a hole on a plate that clears the corners by a very precise metric measurement known as "enough".  This what I meant about adding another trick to your bag of tricks.  Works with squares, too. 

[up1950s]

Cool , and when the hole gets a bit sloppy you can put it in a chuck and squeeze it a bit .

[u18b]

For long term use....

In order to reduce the chance the thinner brass will flare, I wonder if you could flare the tip of next size tube and slide it over your new nut driver.  This would give you a thicker wall.

[mmagliaro]

For long term use....

In order to reduce the chance the thinner brass will flare, I wonder if you could flare the tip of next size tube and slide it over your new nut driver.  This would give you a thicker wall.

I did think about this (reenforcing my nut driver with another layer of tube around the outside wall).
I wonder.... is that how it will really give, or will the straight faces on the inside just kind of round off over time?

[Lemosteam]

I did think about this (reenforcing my nut driver with another layer of tube around the outside wall).
I wonder.... is that how it will really give, or will the straight faces on the inside just kind of round off over time?

Heat the thing up and quench it in oil.  I think sometimes we overplay wear on these tiny devices that do not see grease monkey torques or real life loads.  It sounded like it was so easy to make you could make a lifetime's supply anyhow.

I do think however, had you heated the brass in advance, it would not have shaved material into the tube as the picture shows.

[Missaberoad]

I think sometimes we overplay wear on these tiny devices that do not see grease monkey torques or real life loads. 

This, Typically the torque applied with a "prototype" nut driver (in the 8-10mm range) is measured in inch lbs and that's with a big rubber grippy handle... I think the torque applied with a couple fingers and a piece of brass rod will be negligible.
Especially since a pair of tweezers are capable of applying sufficient force for the fastener.