Retiarius – the making of a 009 Sentinel Tram Loco

tebee sentinel 009 loco body

Sentinel 009 loco body
©Tebee – all rights acknowledged

The inspiration for the resurgence of my modelling bug was seeing an article on a blog about a freelance 009 Sentinel steam tram loco body that had been designed to fit the inexpensive Kato 11-103 tram chassis.

This tram body, by Tebee, was available to buy from Shapeways.com, the on-line 3d printing service.

This was the trigger for an inexpensive model I thought …… little did I know how untrue that was!

The ‘problem’ was that being somewhat of a computer geek I decided that I would try and make this diminutive loco run under DCC control with lights etc.

This was my ‘downfall’ because now I have several DCC controlled locos, Digitrax controller and computer control by use of the free JMRI Decoder3 DCC control software  …. but that is a story for another day.

My copy of this loco, in HD plastic,  was ordered from Shapeways at a cost of about £30 and the Kato 11-103 chassis from Amazon for about £17.00.

Delivery was about 2 working weeks from Shapeways and 24 hours for Amazon!

Hand rails fitted

Hand rails fitted

3d printing speeds are going to need to be a lot faster if they are to compete I think.

As part of this build I also ordered some 2mm warm white LEDs and 1.0 KΩ ballast resisters and a Digitrax DZ125 2-function DCC decoder, one of the smallest on the market and with a higher current capacity than the Lenz Gold Mini etc.

I now awaited the delivery from Shapeways and when it arrived I was pleasantly surprised by the amount and quality of the packaging.

The model was clean and had a fine, almost ‘sandblasted’, finish to the plastic with very little striation in the panels apparent.

Work was now in progress. I have not undertaken such fine detail work for 40 years!

 

As a start I drilled this very fragile kit to fit Nairnshire Modelling Supplies short handrail knobs and 0.45mm brass rod.

Once the handrails were fitted it was time to adapt the Kato 11-103 chassis to fit the body and to install the Digitrax DZ125 DCC decoder.

Liquid Gravity and DCC decoder in place

Liquid Gravity and DCC decoder in place

Before that work was done Liquid Gravity pellets were set into the water tank and boiler, using CA (CyanoAcrylate) glue, to add some much-needed weight to this diminutive model. To facilitate this the top of the boiler was blocked from the chimney using a disc of Plastikard and bulkheads fitted to the ends of the water tank mid-section.

Care was taken to ensure that there was enough room to fit the Digitrax DZ125 decoder chip within the water tank above the Kato chassis.

The Kato 105 chassis was modified by removing the n-gauge couplers and opening up the holes in the chassis to allow me to embed a 3-pin micro plug so that the body can be easily separated from the chassis and DCC decoder without disturbing the wiring in the body for the lighting .

DCC decoder and lighting plug fitted

DCC decoder and lighting plug fitted

 

The next job was to fit front and rear 2mm Warm white LEDS to the front and rear cabs. The front was left white whilst the rear was later over-painted with Tamiya Red acrylic varnish, some I had left over from modelling 30+ years ago!  1KΩ resisters were wired onto the negative pins of each LED. All wiring to the LEDs was insulated with heatshrink tube.

Once the LEDs were in place they were coated with masking fluid and the model went off to the paintshop to be firstly undercoated with Halfords red-oxide acrylic primer  and then airbrushed with Vallejo Black Green acrylic and several coats of Vallejo satin varnish.

After the paintshop

After the paintshop

The reason for choosing red-oxide primer over grey or white was that you get a more intense green for using a red undercoat.

Handrails were picked out with Vallejo acrylic gold and the chimney cap ‘coppered’ with a mixture of gold and Vallejo red-oxide primer. All the paints for application had to be thinned with 50% Vallejo thinners for easy spraying. Several coats were built up before I was satisfied as to the density of colour.

The model was then assembled and weathered and a pair Mike’s Models driver and firemen figures painted and fitted. Custom ‘RETIARIUS’ nameplates by Narrow Planet completed the model.

The finished 009 model Sentinel Tram Loco

The finished 009 model Sentinel Tram Loco

I had the privilege of being able to run this loco on the renowned 009 Cliffhanger layout when I help run it at the Railex NE 2013 exhibition. Here is a little video of it guesting on that layout.

Making a 009/H0e shunter using the Knightwing 0-4-0 kit and a Graham Farish Class 14 chassis

Graham Farish Class 14 n-gauge chassis

Graham Farish Class 14 n-gauge chassis

I wanted to make a shunter for my 009/H0e model railway that looked ‘chunkier’ than the one described in Railway Modeller using the Kato 105 chassis. This conversion, to me, looked wrong because the Knightwing body had to be shortened by 2 grill bays.

I looked at using the Graham Farish Class 08 n-gauge outside-framed shunter chassis so as to have working conrods but, instead, I decided that it may be possible to use the Graham Farish Class 14 n-gauge inside-framed shunter chassis instead as this was, at 61mm, longer and also had the benefit of having working conrods.

I wanted to run this loco using DCC and so I had to fit a Digitrax DZ125 decoder to the chassis.

This presented a few minor problems to be solved. The Farish chassis is live and connected to one set of wheel pickups.

To fit DCC you must isolate the motor completely from the chassis. Farish connect to the chassis using a copper strip screwed to the chassis which is then trapped against the PCB at the rear of the motor by a ‘pin’ cast as part of the chassis block.

Removing chassis contact pin from Farish Class 14 chassis

Removing chassis contact pin from Farish Class 14 chassis

This ‘pin’ has to be removed. For this task I used a burr in my Dremel drill, carefully grinding the pin.and overlying copper strip, away whilst leaving enough copper to enable me to solder the black wire from the DZ125 to it.

At this time I used my solder rework station’s hot air gun to remove the surface mount resistors that were on the circuit board. This completely isolates the motor inputs from each other.

Chassis contact pin removal

Chassis contact pin removal

After de-soldering the existing yellow motor wire you can then solder the DCC decoder to the chassis contact (decoder black wire), the already installed yellow former motor wire (decoder red wire), and the PCB motor contacts (decoder grey and yellow wires).

DCC decoder

DCC decoder fitted

That completes the chassis modifications. An hour on the rolling road ran the chassis in nicely.

Making a start

Welcome to this blog which will aperiodically post news on my modelling efforts to create a  9mm narrow gauge model railway. I shall be showing how I built or converted my locos and set them up to be controlled with DCC decoders.