Stephenson’s Rocket

[Richard Carlstedt]

Nice Work !...no Awesome !

Rich

 

[pamw]

Nice Work !...no Awesome !

Rich

Hello Richard..... has been along time..... I've finally started finishing everything thats been started over the years.

 

[Richard Carlstedt]

Great to hear from you Pam, It has been a few years (Eight, I think)
I spent the past 7 years writing two books on the USS Monitor
and hope to get back in the shop shortly. The Rocket has been on my mind for years
and is a real challenge in miniature engineering as seen in Bob's work here.

 

[Bob Wild]

Hi Richard. Thanks for your kind comments. I still consider myself a beginner (as witnessed by my scrap bin), especially when I see the work of many accomplished members of this forum. But I do appreciate the hints and tips that they give. My next problem is the wheels. I haven't a clue as to the best approach - see attached drawing. I don't mind making a few deviations, but I'd like to stick as near as possible. I think the spokes will have to be round.

 

[Bob Wild]

Well it’s been a while since I reported any progress. That’s because we were due to move house so I packed away all my tools and machinery. Then, would you believe it, our purchasers pulled out (b******ards). So we are not moving. So I’m back in business once I can find which packing case has the tools I need.

Anyway I made some pipe fittings while I waited for some material for the wheels:

 

[stevehuckss396]

Glad your back. I don't usually post much unless I have something of value to add but I've missed the updates on this one.

 

[Bob Wild]

Thanks Steve. Next progress report will be more interesting; the wheels are coming on nicely.

Bob

 

[Bob Wild]

Thanks Steve. Next progress report will be more interesting; the wheels are coming on nicely.

Bob

Nice progress with the wheels. First I made the rims and hubs. Each had 12 slots milled radially to take the spokes. I made a fixture to hold the rim and hub concentric. A ring was added to the rim to hold the spokes in place. It is not clear from the photos, but the spokes on the driving wheels are actually tapered. Not very happy with the black circles. I didn’t manage to trim the masking tape very cleanly. Hence the edges are not very regular. I may spray with yellow again and then apply the black manually.

Next up are the con rods, and who knows, I might even have an engine that moves!

 

[stevehuckss396]

Wheels are beautiful. Love the square spokes.

 

[Basil]

Looking good. Going to be a beauty when completed.

 

[Steamchick]

I agree.

 

[Bob Wild]

Thanks chaps for your kind words. Need some help. Starting to think about the tender and in particular the water barrel. How on earth am I going to model the tapered planks? Can’t think for a simple way.

Bob

 

[Steamchick]

Hi Bob,
Hmmm. How about: glue a dozen parallel planks together, flat-t-flat with a simple water-based glue, clamped, then plane the "wood bar" with a small plane to get the plank shape desired, while holding the bar in the vice. Then soak to soften the glue and dismantle the planks?
Do not use PVA, as once cured it doe not dissolve in water. Wallpaper paste may be OK? - or simple "flour and water" mixture?
Just a thought...
K2

 

[Mark_1984]

Does your barrel need to be functional? I think I'd make 3 discs of wood. One the major diameter less the thickness of the planks, then 2 the barrel end diameter, less the thickness of the planks of course. Mount them on a fairly thick bar to hold the 3 discs rigid in the right position. This will give you a frame to plank, in a similar style to a ship's hull. A bit of maths will give you the width of the planks as the middle and ends, which will also need to be tapered so you don't get gaps. Sand them to shape, glue in place and you'll need to fettle them to fit to the adjacent plank. Work on both sides simultaneously, or the force of the planks trying to straighten will give you a lopsided barrel. I.e. Do 2 planks on one side, then 2 planks diametrically opposite. Finally, just put decorative caps over the ends.

 

[Bob Wild]

Thanks Steamchick and Mark. The barrel doesn't need to be functional. I was thinking of making a solid former rather than three discs. Then glue the tapered planks to that. My biggest worry is getting the taper on the planks correct. I can do the maths, and make a former so that they are all the same size. But with so many pieces any small error will be compounded. So it's probably a bit of trial and error.

Bob

 

[Sprocket]

As long as it isn't to be functional, you could turn the barrel shape from a solid, then score the joint lines on it after, maybe burn the lines to look more like joints. Stretch Nichrome wire where you want the joint, then apply current. Sort of like cutting foam for a model airplane wing.
It could be made functional by hollowing it out and sealing the wood.
Other options.

Doug

 

[Mark_1984]

Use planks about 1.5mm thick. I'd choose something fairly soft like basswood. It's easy to work and is very forgiving to fit. I'm assuming it will be painted, but if you need a particular wood finish, start with the 1.5mm basswood planks, then give it a second layer of whatever wood you want, choosing something thinner, say 1mm which will be easier to work with. That's how I plank model boat hulls.

 

[Steamchick]

Sounds like Mark is the expert!
For Model steam engine cylinders my Father used - and I copied - the "solid" idea, as explained by Sprocket:
" turn the barrel shape from a solid, then score the joint lines on it after, " - But I use a black ball pen in the scored lines. Except on one engine, where I stained the wood (a piece from my Cherry tree) with Dark Oak stain and it is nearly black! - So it has been painted Black as it looked just horrible...
My (Functional) lagging planks on (Functional) boilers are strips of modelling Balsa wood. Stained and varnished, the "scale" joints are simply where the glue causes a discontinuity between the surface of the stained wood. Also the change of grain shows it is planked. Unfortunately, my tin of "Mahogany red" varnish is less like mahogany... a bit Orange!
Photos of 2 of my planked boilers. 1 in 1/8th in Balsa, the other 1/2" Balsa. BOTH applied over a double radiant heat barrier (like a thermos flask) over the boiler shell.
My boilers are parallel, so I didn't need to shape for the taper, but I do set a circular saw "off 90 degrees" so the planks abut correctly as they pass around the cylinder. This makes the planks trapezoidal in section. The planks are assembled into "2-halves" by not glueing a couple of joints, This permits movement of the wood, and makes stripping and re-fitting of "half-cylinder shells" easy. (1 joint is conveniently where the water gauge fits). The Balsa is very easy to replace if damaged, sands the corners off, to form a cylinder, very easily, and has very good insulating properties. These boilers can easily be held by the insulation when in steam, as long as the hot pipework and fittings are avoided! (just warm like a baby's leg!).
Does this help? First a 2 1/2" boiler: 1/8" Balsa planks

Next a 3" boiler. - 1/2" Balsa planks.

Sorry, this close-up is a bit out of focus.
Here's the same 1/2" Balsa cladding on a 3" boat boiler. (Deck raised to show the "workings").

But I think you can see the effect of proper planking. "Solid" with scribed grooves is "not to scale" and looks crude on my models (probably my skill!). At 1/12 scale, a 1/8" joint (or less!) becomes 1/96" (0.010") so the scribing must be very fine and accurate to look right. But plank joints simply show as differences in the wood grain, etc. - I think that's the way for you.
K2