How to mill incredibly small slots in a milling machine

[mmagliaro]

No.  Shapeways is not an option.  The wheel centers in that blog look, frankly, pretty bad, even after they are painted.
I applaud the effort and ingenuity, and I'm sure the wheels will roll and work fine, but I will not go through all
this work if the wheels are going to come out like that.

Plus, I am still determined to make these myself, not have them created by somebody else, even from my CAD drawings.

I am still not convinced that they cannot be made by milling out a "mold" on the mill in a plate of brass.  I could then either
pour it myself (with what, I don't know yet, but it needs to come out strong, flexible, and with minimal shrinkage).
or insert hub, tire, and spokes all as separate brass pieces and solder them all together.  Victor cautioned me about that
idea, but I have a hard time believing that such an assembly wouldn't be sturdy.

[peteski]

Victor cautioned me about that idea, but I have a hard time believing that such an assembly wouldn't be sturdy.

There is one way to find out....

BTW, I'm with Victor on this (but for a different reason).  Prove us wrong. 

[victor miranda]

I will be a bit more specific in my caution.

solder is funny stuff.
I tried to make spokes and solder and had a mess.
I cleaned out the extra solder....
and slapped the thing on a lathe.

I didn't give it much thought the tire was easy to cut.
the spokes... curved in the center as the tool passed by
and then it went ping.
 the hub kept  spinning and the spoke stuck on the tool.

I can't recall what happened next...I am not joking.
I have not any parts from that effort.

you may find a grinder can get that delicate job done.
keep an eye on the temp.

 for the same reason, I have not
cleaned up the back side of the good wheel in the photo.

victor

[mmagliaro]

Oh!  That makes more sense.
Yes, I could well imagine that the soldered wheel could not stand up to the force of a milling bit.
I do admit that part gave me pause, as I could see the bit tearing the wheel to pieces like what happened to you.

But once the wheel is done, I cannot see our typical N Scale forces, or handling by even clumsy people,
making that wheel fail. 

Yes, perhaps it would be better not to use a cutter, but a fine diamond stone or file held against the spinning wheel, and
YES keep spraying it with water to keep the temperature down.

[victor miranda]

Max,

I think a soldered driver/spokes assembly is sturdy for operation in n-scale.
after all, I did cut the tire and flange through those spokes. with a single point tool and a file.

what caused my wheel/spokes to fail in the skim cutting I was doing...
Solder is not brass and where the two are stressed (from the skim cutting)
they will crack/fail at the soldered joint.  assuming there was solder in the joint...

I was attempting to model the fact that most spokes taper a bit as they get to the rim.

If you attempt solder, get it in the joint.
do not stress the joints.

it is easier to make a mold.  and it is hard to get a wax casting out in one piece
and I can't find a lost wax caster short of industrial levels.

I have been tried to make a driver using pewter as the center.
ooof  what you are doing is not easy.

if yyou find a caster, let me know, we may be able to make a deal.

victor




victor