Steam Loco Spoked Wheel Making

[victor miranda]

any one here have the etching talent?

I have a jeweler's lathe.  we can try that while Max gives his idea a run.

that just leaves what wheel/driver.   replacements for blown MP Pacifics?

victor

hmmmmmmm I have an idea....

[mmagliaro]

Andrew (and Chris333),
Yes, I'm surprised the chuck is better than the collet.  That's exactly the opposite of what you would expect.  But it is.
Andrew, yes, I completely understand now about your concern about the danger of milling with a chuck.
I expect that since the stock is small, the speeds are low, and the stock is relatively soft, I haven't had any problem
with it vibrating loose while turning.

I have thought through making a tapered mandril to press my tires back onto to cut out that little relief groove.
I will experiment and report back in here what happens.

[Sokramiketes]

Throwing my vote in for etched centers. A lot of the European steam scratchbuilders go the etched route and get much finer detail and relief.

The S.

I think everyone is missing the big point that Max wants to DO THIS ALL HIMSELF, man and machine as one. 

[victor miranda]

I understand what he wants to do.

.... having tried a similar path,  I am considering alternates.

I do not want to discourage him, for he may well succeed where I failed.
Max has a knack. I marvel at his abilities.

so far the posts he has (as replies) are pointing out safety concerns
as well as answers to issues he may face.

I can be very informative about how to fail...
wearing goggles while machining is not why I did not make a brass and solder driver.

following in Max's footsteps can be quite a challenge.

cheers!
victor

[bbussey]

any one here have the etching talent? ...

The etching can be farmed out at minimal expense.

[peteski]

The etching can be farmed out at minimal expense.

I'm smelling a dead equine again.  Max doesn't want to farm anything out (even if he does the artwork himself).  He, for some personal reason, wants to do all the work himself in his workshop.  But he is not making his own metal - he is willing to buy it, even though he didn't mine and smeltered it. 

[mmagliaro]

I'm smelling a dead equine again.  Max doesn't want to farm anything out (even if he does the artwork himself).  He, for some personal reason, wants to do all the work himself in his workshop.  But he is not making his own metal - he is willing to buy it, even though he didn't mine and smeltered it. 

My great great grandfather,  TOMBSTONE Magliaro, could make his own brass in a forge, but I,
shamed though I am, admit that I am incapable of such a feat.   

[garethashenden]

Here's another method.


The tyre, hub, and two spokes are all machined as one from the same steel rod. The two spokes are cut to size with a piecing saw. The rest of the spokes are filled in with plasticard.

[victor miranda]

Here's another method.


The tyre, hub, and two spokes are all machined as one from the same steel rod. The two spokes are cut to size with a piecing saw. The rest of the spokes are filled in with plasticard.

!!!! danged good idea!!!!

I wish 17 spokes was divisible by something...
I am thinking 15 and do 5 spokes.

victor

[mmagliaro]

Yes, a VERY good idea.  I was just pondering this as I went to sleep last night... why not make just
4 spokes (you made 2, but... )  by machining them out with the rim and hub as one piece, and make the
rest out of styrene, or even brass, but they could just be plunked in with epoxy.  Then you don't need
to use a micro machining bit because the spokes you are cutting aren't so close together.  A little hand file
work in the corners and you've got it.

That's a might fine looking piece of work on that engine there!

So...
6 tossed-out attempts later, here is a new tire with the relief groove cut into it so that when the spokes
are fitted, they will look like they have their own rim inside the tire rim.  The inner relief groove is only
.007 wide and about .010" deep.  I tried shallower, but it's just not enough to really show.



I did make a tapered arbor, pressed it into my already-made tires, and then I attempted to cut
these grooves in them.  But I cannot get the accuracy I need to make it work.  The tire would always have
just the slightest bit of wobble on that arbor and that dashed any hope of getting a concentric groove.

... so, I made a whole new tire, and cut the groove before parting it off.  I like it.  Now I just have to make 7 more.   Just like before, I'm hoping that now that I have everything positioned just right under
the mill, I can make the rest more easily.

[peteski]

That looks good Max (for your original method).  But if you now want to mill out 4 spokes, wouldn't you have to start with a bar stock instead of tubing?  You will need a solid center to mill the spokes out.

[mmagliaro]

That looks good Max (for your original method).  But if you now want to mill out 4 spokes, wouldn't you have to start with a bar stock instead of tubing?  You will need a solid center to mill the spokes out.

Yes. If I decide to go that way, I would abandon this and use a solid brass rod.
But the soldered spokes approach is still my front-runner.  I think I have the best chance of making that so that it
looks right and runs true.  But I WILL now probably only solder 4 of the spokes in place, or perhaps 6 at the most.
The rest can be epoxied in for show.

First things first.  I need to machine 9 more wheels, including two with TT grooves.    As before, I mill a bunch of them,
toss our the outright failures as I go, and then choose the best 6 using my eye and a caliper as the judge.

This first one came out really good.   .023" flange depth, .319" tread diameter, total tread width .048, total wheel thickness
.065.    If I can make them all to those measurements within .001", I'm happy.  (Frankly, I've seen more variation than
that on commercial wheels!)

[peteski]

This first one came out really good.   .023" flange depth, .319" tread diameter, total tread width .048, total wheel thickness
.065.    If I can make them all to those measurements within .001", I'm happy.  (Frankly, I've seen more variation than
that on commercial wheels!)

Well sure!  This is one-of-a-kind model, hand-made by a master craftsman!  No commercial stuff.   

[garethashenden]

!!!! danged good idea!!!!

I wish 17 spokes was divisible by something...
I am thinking 15 and do 5 spokes.

victor

When using the piecing saw, cut to the hub, then go off at whatever angle is appropriate. The two spokes don't have to be exactly opposite each other.

BTW, I didn't make that Stirling Single although I do know the man who did.

[mmagliaro]

By the way, remember for this engine, as it turns out, I don't need 17 spokes.
There are 17 on a Rivarossi 4-6-2 wheel, but on this little 0-6-0, there are, as best I can determine from prototype
photos, 12 or 14.  The brass engine Chris showed was a straight-on side shot, so they can be counted more easily.
But I'm trying to count the spokes on the real thing, and so far, I haven't found anything like a nice "builder's photo"
that would be taked straight-on.

I think regardless of how many spokes there are, you could just machine out (or in my case, solder in)
4 spokes spaced "somewhere" around the wheel, and then fill in the rest.  I don't think it would be especially critical
that they be a nice 90-degree cross.

I will bore out a solid brass rod for the axle, say 1.5mm.  Press an axle in, chuck the axle, and turn the hub down to its final size, so it is perfect concentric with the axle.   Do the same for a smaller-diameter rod that will be the crank/rod boss.
Solder the two rods together, standing side-by-side.  They can be filled in along their sides with epoxy later, so they
look just like the semi-oblong shape of that solid area in the wheel here the hub and crank boss are.

The crank boss can be drilled out by hand with a pin vise and tapped for an M1.0 hole (or not tapped and just use
press-in friction crank pins).  It's a very short, small hole.  A slight centering error there isn't going to matter
unless it's horrendous.  The rods will have to be made to fit however these wheels end up when they are all sitting in bearings in a frame anyway.

Leave the axle through the hub.
The trick is now just coming up with a jig that will hold that axle still, with the driver tire placed around it, so the
two are perfectly concentric, and then solder in a few spokes to make the whole thing solid and round.
The tire really has to be held down and perfectly located, relative to the axle, while you solder in the first few spokes.
After that, it's home free.   Then you glue in some more spokes and glue on a faux "counterweight" from some
thin brass sheet or even styrene sheet.

That "perfectly located" is the hard part.

But first... I've got 6 more groove-reliefed wheels to turn.   They are coming easier now.  I've got all the parameters
and widgets figured out to place the work and cutters just-so under the mill now, so they are coming out consistently.