Steam Loco Spoked Wheel Making

[mmagliaro]

Randy...
Now I'm sorry I got you so excited about this because I won't be getting to the spoke work any time soon.
This was a diversion from my NP 2-8-2 W-5 project.   I will be going back to that and revisit the spoke work
afterward.  I have come up with so many possible ways to bore/true/jig something up for soldering in the spokes
that I know I want to think about this for a while before I decide how to proceed.

In general, however, I expect to be able to solder this just with an iron, flux, and conventional solder.
Remember, this is just a little brass wheel.  A little flux and I bet I can make those spoke joints.
The wheel will be face down.  Put a spoke in, put some flux on the joint, then solder.

The thing that could make it hard is if the jig requires lots of metal and heavy clamping.  That will provide too
much metal to sink the heat away.  That's one of the things I want to think through before I proceed.
If only there were something as rigid and stable as metal, that isn't metal.   Ha ha.

[Chris333]

I've read about soldering jigs made out of counter top material. I don't remember what it was though, maybe Corian.

[Sokramiketes]

If only there were something as rigid and stable as metal, that isn't metal.   Ha ha.

That would be phenolic material, often used for soldering jigs.

http://www.usplastic.com/catalog/default.aspx?catid=679

[peteski]

I am riveted!

You know, you should really be soldered!   

[Chris333]

That would be phenolic material, often used for soldering jigs.

http://www.usplastic.com/catalog/default.aspx?catid=679

Didn't know that stuff could take the heat. We have some at work...

[mmagliaro]

Didn't know that stuff could take the heat. We have some at work...

Great idea, but unfortunately, no.  That page, if you click for specs, shows that the maximum temp for those phenolic materials to
be around 275 - 288 F.   It will never stand up to soldering heat.

[Lemosteam]

Max, you might be able to get these parts chromed in black chrome.  Chroming the wheels would absolutely solve the wear issue and provide blackening as desired. Chrome is a very durable plating method.

[peteski]

I really do not see using bare brass for wheels as being a problem.  Most of the currently manufactured models use brass wheels with plating that is basically cosmetic. I've seen lots of locos with the plating worn off (especially Atlas diesel locos)  The brass is still plenty hard to withstand hundreds of running-hours without any appreciable wear. FVM wheels also appear to be brass under the plating.

[mmagliaro]

Yeah, I agree.  I don't think it worth getting side-tracked on the issue of brass wear.
Now, there's brass and then there's brass.  It could be that the brass that loco makers use is harder than what
I have, but I still don't think it is going to wear enough in my lifetime to worry about.   Chemical blackener on
straight brass looks really good.  It blackens very thoroughly and very durably - more so than on nickel-plated wheels.
And it is conductive, but that is also a lesser concern since after many moons have passed and I actually start working on
this engine, it will have all-wheel tender pickup.

Other things I have in the distant future for the design here:
The frame will be split-frame, all brass.  I figure on milling out the axle bearing slots with the whole thing as a solid chunk,
and then mill it down the center to separate the halves and then join them back together with nylon screws and plastic spacers.
I want to try those natty Boca 1.5mm ball bearings on the axles - no friction bearings.   Each driver will have
a piece of axle shaft pressed into it, and the axle halves will be joined together in the center by some sort of plastic
tube.  One axle geared, the others rod-driven.  I think it will be easier to quarter up drivers and make some rods than
it would be for me mount gears on all the axles and mill the frame slots so the gears all mesh, not to mention having to
bore for pins and idlers.  Yikes. 

[Lemosteam]

Peter, no argument here, just laying that out as a potential option.

Max, I am trying to understand your design.

Are you trying to fit the ends of the spokes into the tire? If so that's kind of contrary to the real thing. 

Forgive me if you've already considered this;

The cast wheels had a rim around the end of the spokes that was machined.  Then a machined steel "tire" was heated to expand its ID, and then hammered onto the wheel.  As it cooled it formed a press-fit, that even under the load of the driver, would not slip on the rim. After the assembly, I think the driver was then turned/trued. Why not go that route? You could cool the rim, and heat the tire to slip it over, just like the real thing.

[mmagliaro]

Peter, no argument here, just laying that out as a potential option.

Max, I am trying to understand your design.

Are you trying to fit the ends of the spokes into the tire? If so that's kind of contrary to the real thing. 

Forgive me if you've already considered this;

The cast wheels had a rim around the end of the spokes that was machined.  Then a machined steel "tire" was heated to expand its ID, and then hammered onto the wheel.  As it cooled it formed a press-fit, that even under the load of the driver, would not slip on the rim. After the assembly, I think the driver was then turned/trued. Why not go that route? You could cool the rim, and heat the tire to slip it over, just like the real thing.

John,
Yes, that's how real steam drivers are
made.
But actually doing it that way is far more complicated than necessary. 
It occurred to me that the only thing that really matters is that the
axle hole at the center of the hub, and the surface of the outer tire tread, be perfectly concentric.  Everything else -
the spokes and the "counterweight", are really just window dressing.

So yes, I am going to simply fit spokes between the hub and the tire and solder them.  As long as I can hold the hub and tire in their correct, precise location while doing that, I no longer have to worry about the exact length and location of the spokes.  They just have to be close enough to look good.  i.e. They can't be so bad that they look weird or irregularly-spaced as the wheel rolls along.

[peteski]

J
So yes, I am going to simply fit spokes between the hub and the tire and solder them.  As long as I can hold the hub and tire in their correct, precise location while doing that, I no longer have to worry about the exact length and location of the spokes.  They just have to be close enough to look good.  i.e. They can't be so bad that they look weird or irregularly-spaced as the wheel rolls along.

Max, even the least detailed N scale steamers have drivers with a distinct tire and wheel center.

If you spend all that time scratchbuilding drivers just to have the spokes ending at the tire will make them look weird and unrealistic.

Unless you make the tire so thick that it will simulate the prototype tire and the outside rim of the spoked center.  Maybe a groove cut into the face of the tire would simulate the separate tire and wheel center.

[nickelplate759]

I'm looking forward to seeing the the fire ring Max constructs to mount the tire on the wheel.  Saw it being done on a real 4-8-4 here in Portland - WOW!

[Chris333]

I still say etch the spokes 

[mmagliaro]

Curses.... a thin rim around the edge of the spokes?   Okay, okay.  I'll work on it.