Newman Miniatures Crampton

[TangoOscarMike]

To achieve the flat inside the bore of the gear wheel, I:

 

1. Filed flats on either side of a piece of brass tube, until the flats became slots
2. Opened out the slots with a file, then concentrating on one side, filed the surviving metal from inside, until it was just below 0.5mm thick
3. Tinned the outside of this portion
4. Pushed the tube into the gear, supported by a steel rod up the middle
5. Applied heat to the outside of the boss, to solder the shim to the inside of the gear
6. Removed the steel rod, and cut away the surplus brass

Well, that was the idea, anyway. Steps 1 and 2 went pretty well.

 

 

But around about step 4 it started going wrong, with the thin brass buckling, followed by the usual shameful blundering that occurs whenever I wield a soldering iron.

 

But in the end, after some recovery effort with the broken bits, I have a result that works - the gear fits snugly on the motor's shaft with hardly any play.

 

 

 

[Chas Levin]

20 hours ago, TangoOscarMike said:

To achieve the flat inside the bore of the gear wheel, I:

 

1. Filed flats on either side of a piece of brass tube, until the flats became slots
2. Opened out the slots with a file, then concentrating on one side, filed the surviving metal from inside, until it was just below 0.5mm thick
3. Tinned the outside of this portion
4. Pushed the tube into the gear, supported by a steel rod up the middle
5. Applied heat to the outside of the boss, to solder the shim to the inside of the gear
6. Removed the steel rod, and cut away the surplus brass

Well, that was the idea, anyway. Steps 1 and 2 went pretty well.

 

 

But around about step 4 it started going wrong, with the thin brass buckling, followed by the usual shameful blundering that occurs whenever I wield a soldering iron.

 

But in the end, after some recovery effort with the broken bits, I have a result that works - the gear fits snugly on the motor's shaft with hardly any play.

 

 

 

That's excellent, very nice idea and duly filed away for future copying! I saw your previous reply too, that the gear has no grub screw - which I should of course have realised!

Merry Christmas 👋🏻

[TangoOscarMike]

It's been a while.

 

Fully assembled, the chassis almost works, but it's too weak to overcome its internal friction (or some other internal source of unwillingness).

 

The best case is that a moving part is rubbing against some piece of plastic that I didn't file back enough.

The second best case is that my odd-one-out gear wheel isn't quite compatible enough with the others, and needs replacing.

And the worst case is that my design and construction, between them, are inadequate.

 

It must come apart again, and I hope that an obvious problem will be immediately evident. If not, then I will reassemble it with most of the gears missing, so that only one pair of wheels is driven, in the hope that this provides some insight.

 

Meanwhile, a digression: I need some coaches for this engine to pull. Since I'm leaning towards toy trains, I'm not aiming for historical accuracy. But I would like something vaguely Victorian-ish.

 

A few years ago, I built my first rolling stock kit, one of the Ratio GWR 4 wheel coaches. It did not run well, and so I embarked on a scheme of designing small, toy-like coach bodies to mount on various RTR chassis. Here are my first attempts:

 

 

The first and last are on the Hornby 4-wheel chassis. The middle two are on two different Hornby wagon chassis. The main problem (from my perspective) is the proportions - the closed compartments are simply too huge and generous. The 4 open compartments are a bit more plausible, but closed compartments of this size would be too small.

 

With help from @Gibbo675 (who also generously supplied various types of chassis), I performed an audit of real coach dimensions, and settled on three compartments on the Dapol 10" wagon chassis. I have also designed a brake coach for the Hornby 4 wheel chassis (the brake compartment allows me to play with the dimensions of the passenger compartments).

 

 

Painting is in progress.

 

[Chas Levin]

They look very good to my eye! I have something similar in mind - there are so few kits for very early rolling stock, aren't there? Are the sides / bodies ones you printed yourself?

[TangoOscarMike]

6 hours ago, Chas Levin said:

They look very good to my eye! I have something similar in mind - there are so few kits for very early rolling stock, aren't there? Are the sides / bodies ones you printed yourself?

Thank you!

 

Each body is a single printed piece with a separate roof. They're printed by Shapeways, which accounts for the poor quality. The "white versatile" plastic is the only remotely sane option, price-wise, and even with very crude detail the quality isn't great.

 

I sometimes consider breaking the designs into separate walls, ends and roofs, which I think would make them cheaper to print in a better plastic.

 

The other options are, of course, to get my own printer, or to find an alternative to Shapeways.

 

If you're interested, I would be happy to collaborate to push the project forwards (and maybe increase the realism).

 

 

[TangoOscarMike]

And here they are painted. My first experiments had crude handrails embedded in their ends (like many RTR coaches). For these, I made a gesture towards realism pleasing fiddly detail by making rails from 3D printed knobs and mandolin E string.

 

 

 

[Chas Levin]

20 hours ago, TangoOscarMike said:

Thank you!

 

Each body is a single printed piece with a separate roof. They're printed by Shapeways, which accounts for the poor quality. The "white versatile" plastic is the only remotely sane option, price-wise, and even with very crude detail the quality isn't great.

 

I sometimes consider breaking the designs into separate walls, ends and roofs, which I think would make them cheaper to print in a better plastic.

 

The other options are, of course, to get my own printer, or to find an alternative to Shapeways.

 

If you're interested, I would be happy to collaborate to push the project forwards (and maybe increase the realism).

 

 

Interesting!

I have to admit I'm not too keen on the whole 3D printing thing so I don't think I'd be keen to get involved at the moment. I have a couple of kits that I intend modifying into something suitable in due course but once they're used up, I might dip a toe...

[BernardTPM]

The three compartment coach looks rather like the 'Prusssian' coaches Bachmann did.

[TangoOscarMike]

I tinkered with the chassis, and found that after a bit of backwards and forwards running, and a bit of oil, it started to move much more freely.

 

It's still rather unreliable on track, and the pickups do not make contact with the back wheels. But when it does move it is rather brisk. So I've ordered another motor, with a higher gear ratio, and I'm crossing my fingers.

 

 

[Chas Levin]

Excellent: always good to get something moving under its own steam!