Back to loco design

[rue_d_etropal]

Needed a change so decided to design that large Decauville Mallet that ran in Morocco. I had found some very poor quality images /plans online, and suspected that it was basically two standard Decauville 8 ton locos as I had already done. Using the images and resizing them to roughly 1/35, I compared measurements, and I think I an right. The cab, sideways is same size, with roof going back further, but it is wider. Interestingly the spectacle windows in front are in same place as the 8ton version. Decauville obviously used a lot of standard parts.
This all means I should be able to use my design as a start point.

Mind you as a freelance loco for Gn15 with taller cab etc

[henrix72se]

Could you show a picture please, so we can see better which version you are referring to.

Henrik

[tebee]

[rue_d_etropal]

Tom, that is the only drawing I have found, although I do remember an article in Voie Libre. It took a bit of manipulation, to make it clearer.


here is pic from CAD program. got the basic shape, based on other design. Lots to add, also not sure how to do front unit). would need to cut away under boiler, but there is a lot of daylight at front.


I found the boiler is very slightly wider, and chimney is a bit bigger. The cab was more difficult as getting relative positions was tricky. It worked out in end.

[henrix72se]

That was a rather big one! I was hoping for the smaller 0-4-4-0 mallet from 1889 event in Paris.

Henrik

[henrix72se]

Which motor chassis did you had in mind for this ?

Henrik

[rue_d_etropal]

Pre-empted what I was about to talk about.
For 1/35 I had hoped the Bachmann chassis I used for the smaller Decauville might do, but the rear axle on the Mallet is further back , under the cab, so fitting chassis in is a problem.It might be possible to reverse the chassis. I am also looking at the Fleischmann and Lima chassis, but both have motor that won't fit out of sight. Ideally I am looking for a scrap chassis with everything OK except motor. Another option is to put motor in tender. With motor in tender, I could use any of above chassis with motor removed.

The Bachmann On30 might fit but it is not a cheap option.

For 016.5, I think the Mantua Mallet will fit. I had hoped it might be OK for the bigger scale, but the wheels are too small. I had one to try, but sold it before I started on this design.

I myself am not bothered that the rear drive unit is outside framed, but some might want to scratchbuild chassis to do this.
I am thinking the front unit would have a 3D printed top on it , in effect the bottom part of my other Decauville design.

OO9 I think has been attemted elsewhere. I think there are some possible N gauge Mallet chassis out there.
As I am drifting bvack up to 1/19th(SM32) , I might look at a simplified Faller ETrain chassis. Going even bigger might be easiest as the Piko G gauge chassis would fit a 1/12th scale one.

[rue_d_etropal]

some more ideas on a chassis. Getting a motorised chassis into cab end is tricky as most chassis have motor at back. The various HO Mallet locos are 2-6-6-2 so driving wheel in in front of cab and suspect motor goes that far back. I think the rear unit has to be a dummy. A Fleischmann (possibly a Lima unit) would fit in front space as there should be enough room for it to swing a bit. Not sure though.
The other option is a powered tender, and that might be a simple Black Beetle in one bogie, of a bigger(cheaper ) unit powering two central wheels, and have pony trucks as outside wheels. With dummy bogie sides it might not be too obvious.
I think I will make underside of loco and tender basic so it is easier to adapt.

Another possibility is a modified Hornby Bill/Ben chassis, using the extra axle from the Toby chassis. It might be possible to cobble up coupling rods etc from Hornby spares(old type as they are stronger). I have been thinking of that for a small Decauville Mallet(the original as shown at Paris exhibition ), and have a couple of units with wheels on shorter wheelbase.

For an outside framed unit, possible an 08 diesel shunter chassis. No getting away without then adding coupling rods etc.

[Willow Creek Traction]

Part of the fun of creation is the conquering of the odds against you, but there are times one sure wishes those odds were rather more easily conquered, ya know.

[rue_d_etropal]

this is one model I might actually make, but that does not stop me designing it. it was only when I had started that I realised the position of the rear axle.
As with other designs it will be resized, and I am thinking a 1/32 version might be easier. The slightly larger wheels are nearer to those found on some British OO locos. The gauge is not right, but I am working on layout ideas for 1/32 anyway.

Having got this far, i have taken a short break to think. Best way of working for me. See other threads.

[rue_d_etropal]

Got a bit diverted, but finding out chassis might be a problem slowed me down. Always find it better to leave something then come back later.
Just had a thought and checked by Rivarossi/Jouef/Hornb USA tank loco. It looks about right for the 1/35 version, but more importantly the motor is in middle not at the back as Bachmann do, so I think that is way forward. Not a cheap option, especially as I would want two, although one does not need motor.

[rue_d_etropal]

just sent off for first version of the big Decauville. But in 1/76 as it is a lot cheaper , just to see how it comes out. A bit rough at edges, but little point spending too much more time on it yet and can add it to existing order.

Might think about the small Decauville next then the C2.
Odd thing is, I have a calendar on wall with French impressionist paintings, and current one is of the Paris exhibition. No train, but it does include a short section of the track with Eiffel Tower in background. It has to be the narrow gauge as no conduit or wires up for trams and lots of people wandering around.
paris painting

[Gerry Bullock]

Odd thing is, I have a calendar on wall with French impressionist paintings, and current one is of the Paris exhibition. No train, but it does include a short section of the track with Eiffel Tower in background. It has to be the narrow gauge as no conduit or wires up for trams and lots of people wandering around.
paris painting

Possibly not Simon :
http://www.messynessychic.com/2014/09/1 ... is-forgot/

[rue_d_etropal]

Not so sure Gerry, the tracks do look like narrow gauge and scene looks similar to photos of the narrow gauge.
Fascinating piece about the station though. Reminds me a bit of the Crystal Palace and how it was moved after its short stay in Hyde Park , and then sadly destroyed by fire. Hopefully this building can be saved and used for something new.

[KEG]

The painting seems to refer to the 1889 World Expo.

Messrs. Decauville had a 600mm line running.
I think, the locomotive was a Mallet type. The white station can be seen in this photograph.
https://de.wikipedia.org/wiki/Weltausstellung_Paris_1889#/media/File:Paris_Exposition_train_1889.jpg

Have Fun

Juergen

[rue_d_etropal]

That is the photo I was thinking off. Also it will probably be the next loco I will design for 3d printing.

[KEG]

The Paris Exibition Mallet was built 1887 after Paul Decauville designs. Scroll here and find a plan:
https://www.youtube.com/watch?v=gjtOsUFa8SY

If you look for "Lessebo" you can find a short Swedish film at YouTube of a loco of this type. They imported a few and built some themselves after the Decauville plans.

Have Fun

Juergen

[rue_d_etropal]

I have the drawings for the original Decauville Mallet. It is published in loads of places. Getting a chassis sorted is difficult, but I would prefer now to get locos designed. Different scales throw up different problems.
One thing I am thinking is that if I use components in design it should be possible to produce model with different cabs(as the ones sold elsewhere) and other fittings. Just wish I had been more confident with software to do that with other locos, but can still go back through some designs. I can make job of resizing more complicated, but for some designs is worth while.

[KEG]

Getting a chassis sorted is difficult, but I would prefer now to get locos designed

Why don´t you design chassi as well. In case of the Decauville Mallet you need one with outside frame and one with an inside frame.

Over at Shapeways there are quite a few body and parts kits in various scales available already.

Have Fun

Juergen

[rue_d_etropal]

Designing loco bodies is fun. Designing chassis is far too hard for me. I prefer to leave it up to modellers to have the fun.
From comments I have had, most are happy to do chassis themselves.
My original Decauville was designed for a specific chassis. Always a risk when chassis becomes not available as has happened with many of the kits out there. I think that when someone starts designing a chassis for 3D printing, they quite often don't do that many designs. I am aiming for models that get people over the first hurdle, and a complete loco body is quite an incentive to those wanting a model of that loco. Also means different people can build locos for different standards of track, in particular what minimum radius of curves, and getting 3D printed items to work properly takes a lot of time, and tweaking to make sure it is strong enough. I have done a lot of this with my door/gate/window opening mechanisms.
Not bothered about outside frames, it is difficult enough to get bogies balanced. It might sound like a cop out, but I know what I can do, and don't like it when people try to get me to do what I know I can't do.

[rue_d_etropal]

versions of the big Decauville Mallet now available. Biggest is 1/32, smallest is 1/220. I want to do some bigger scaled ones, but need to spend time working out extra detailing required. Now for that small Mallet and the ex Chinese C2. Now also thinking about another Simplex, the ones that evolved from the ww1 40hp protected ones. Looks like there were more used for standard gauge than narrow gauge though. There are drawings of a 6ton version in the Simplex book, but there was also an 8ton version, and it is this version, I think which was adapted to standard gauge. Some have been preserved so might be able to measure one up.

[rue_d_etropal]

I find jumping between projects keeps me from getting bored. Also I find I get requests just as time becomes free so I can get on with those suggestions straight away. Possibly not the best way to project manage, but so far it has worked OK.
anyway after making the Mallet available, and getting stuck into the building design, then some more tram track, I saw something about the Chinese C2 loco, one of the ones on my list, dug out the sketchy drawings and started on a basic design yesterday. It is also a chance to start looking at using more components in loco design, so it is easier to do variations and start new designs.
I am not sure I now want to build a Chinese themed layout in 1/35(surprisingly difficult to suitable figures), so may just get a test sample in OO9, as I did with the Mallet. Given the size of the cab on the C2, I also wonder if it could be extended upwards for a miniature/minimum gauge version.

[Nevadablue]

Lots of 1/24 figures available from China. Let's see the minimum gauge version!

[docnjoj]

Those ubiquitous Chinese plastic figures are actually closer to 1/30 so would be fine for 1/32 scale.
otherDoc

[rue_d_etropal]

I was searching for some for my Bangers and MASH layout(Korean war), but could not find any. The Vietnam figures might be close enough, as might some Japanese ones, but it is surprising how few there are in 1/35 or near.
I have first very basic version of the C2, given how many variations and how bashed they were I don't think it is worth adding too much detail


I only had photos for detail on tender, and made a guess at width, as the windows at back of cab have a clear view backwards, there was a basic side drawing online, and a couple of years ago when I first thought about doing this loco, I tracked down a front end drawing, and an inside cab one, but I don't plan to add cab detail. 3D printing was once described to me as an aid to scratchbuilding, and that is the way that suits me, especially for this loco. The tender and cab are separate components so can be changed easily.
They are almost beautiful for being so ugly!