Category Archives: New Releases

Dummy Locomotive Chassis Kits

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With the EMD DD35 kit being released earlier this year you may recall I designed a 3D printed chassis to be used with the spare EMD DDA40X shell.  Well the kit is now finished and complete with the correct trucks, as shown below, and available on Shapeways which led to a new section in the shop as well as on the blog site.

DDA40X Dummy Kit

The new section is ‘Dummy Locomotive Chassis Kits’ and can be found by clicking here or through the drop down menus at the top of the page.  Currently there are two kits available, one for an EMD DD35 which fits my 3D printed shells and one for an EMD DDA40X which fits a third generation Bachmann shell.

The kits are designed to fit directly under the shells, without the need for modifications, and include the chassis, trucks and bolster pins.  Wheels and couplings are the only extra things required and I also recommend some additional weight.  The wheel size and make depends on the model and that information will be available on the individual kit pages along with the coupling specification.

I recommend adding weight to the dummy locomotives as this will help them track better through turnouts/points and if you are using them between powered locomotives and a long or heavy train it will prevent them from pulling off the track on tight curves.  For the weights I often use old motorcycle wheel balancing weights; not only are these set weights but they are also very compact compared to car ones and fit nicely inside N scale shells.  Below is a selection of used weights from my local motorcycle mechanic, the bottom three are car ones so you can see how much better the motorcycle ones are.

Motorcycle Wheel Weigts 2

If you are lucky enough get new ones they have a sticky strip on the back that you just need to peel off.

Here you can see where I have used some of the weights to weigh down a Con Cor Alco PB dummy chassis which I fitted with a through wiring harness for DCC.  I did a similar thing with a set of Con Cor EMD E7s which you can read about here.

Motorcycle Wheel Weights

As I recommend metal wheels for the trucks it is also easy to add power pickups if required.  Some locomotives, like the DDA40X, have a flashing top light which will require power or, if the locomotive is going to be used at the rear of the train, red tail lights.

If, when using a power chassis for another project, your spare shell has details like a detachable fuel tank that are not required with your project, the new 3D printed chassis will have the same fixings so the details can then be attached in the same way.

The next dummy locomotive chassis kit will be for a Alco C-628 from Atlas. This is because I will be using the powered chassis form my new Baldwin DT6-6-2000 Center Cab and once again I will have a spare shell.  There will also be a dummy chassis for the DT6-6-200.

I also plan to do some dummy locomotive chassis kits for the odd shells I have laying around from other scratch build projects and they will be in a later posts.

Completing the DD35 Set

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Happy New Year!

With all the New Year festivities I haven’t gotten round to painting the new log cars, so for this post I will show you the new DD35 dummy unit which was made available just before Christmas.

When I set out to design and make the DD35 I always intended to have two, as with EMD’s original concept, top and tailed by a GP35 or something similar.  However, as is often the case with model railroading, having all the locos powered in a 4 loco lash-up is overkill, not to mention expensive.  So my second DD35 is to be a dummy unit.

The shell for the powered DD35 was designed to fit over the Bachmann DD40AX chassis so I wanted to design a printable chassis that could be used with the same shell.  This chassis would also incorporate the fuel tank, which was separate on the powered unit, giving it rigidity.

DD35 Chassis 1

It would have been easy to draw a large flat plate  which would have made it incredibly strong, but also very expensive due to the large amount of material it would need to print it. The challenge was to design the chassis so that it is strong but also economical on material as I intended to print it in the FUD material along with a shell and trucks.

DD35 Chassis 2

I decided to draw the trucks in the style used on the DD35 rather than copying the DD40AX.  Although this would mean the trucks would look different from the ones on my powered unit I decided it would be worth it because it would be easy to change the truck sides on the powered unit at a later stage.  I originally intended to use Micro Trains plastic wheels with this unit but on reflection I decided to go with Fox Vally 36″ metal wheels; this was because I wanted to add plenty of weight to the unit to withstand locomotives pulling at one end and pushing at the other and figured that metal wheels would run a lot better with this.

DD35 Truck 1

As with Bachmann’s DD40AX the steps and couplings are part of the truck, totally non prototypical, but as that was the power chassis I have used, the dummy would have to be the same to look right.  The coupler will be a Micro Trains body mount coupler and a pocket will be provided along with a pilot hole for the screw.  The bolster pin will also be printed and is based on a typical freight car pin.

DD35 chassis 3

With the chassis and trucks ready it was time to order the print.  The chassis came out very well and was very strong, and incorporating the fuel tank definitely added to the strength.

EMD DD35 Chassis Kit

The shell which was printed with the chassis is exactly the same as a powered unit. Here you can see it after I had cut out the handrails.

EMD DD35 Dummy Kit

All the parts fitted together perfectly. Next it was time to paint them.

EMD DD35 Dummy

The painting was done by Bob Norris and went very well, the only issue he had was with the trucks.  Due to the FUD material being a bit thin around the neck, which supports the coupling, the end of the truck with the ladders drooped.

DD35 Truck 2

This was remedied by installing a strip of metal under the neck of the truck thereby strengthening it.

DD35 Truck 3

This has now also been corrected in the 3D model by adding a lot more material in that area, removing the need for a metal plate.  With the correction made it was time for testing and the unit ran very well. After a lap of the layout the FW wheels freed up and spun freely. I think there was still some wax residue it the wheel pocket.

Here is the painted DD35 dummy unit. DD35 Dummy

And again with the powered unit, the dummy still needs to be weathered.

DD35s 1

And with a cab unit.

DD35s 2

And finally in a 4 loco lash-up headed by a U50.

DD35s and U50

These units will be going to the NMRA model show this weekend at Benson, in the UK, working hard pulling trains on the GAMRG club layout. If you’re in the area drop in and come and have a chat.