Monthly Archives: October 2013

Making a 4mm Radio Control Truck Pt5


I did some tests with the truck on mains power and found that there could be a problem with traction. I did some experiments with elastic bands wrapped around the tyres and this really increased the traction, so I have decided to have a go at making some tyres out of silicon rubber using an alginate mould. I was quite excited about this until I realised that the rubber isn’t black!!! I decided to go ahead with the moulding anyway… annoying!

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I also tried translating the instructions using Google translate, which made me feel a bit more confident in approaching the wiring. I was very confused about which wires to solder the capacitor on to. Based on images from one of the German forums I eventually soldered the capacitor across both the black and red wires on the motor (I’m far from an electrics wiz).
Finally, I cut away some of the flooring and fitted the servo, and the on/off switch.

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Here is a video of the cars first trial run on mains power (with no steering).

Visit to Model Rail Live 2013

On 21st September, I visited Newark Showground in Nottinghamshire for Model Rail Magazines exhibition. The venue was a large metal industrial-type unit, which afforded lots of space for layouts and traders.

There were lots of models on display, with some really impressive large layouts. I must admit that some of my favourites were of the smaller variety. Sparkle, was probably my favourite: which is a HO Gauge, German layout set in winter. The barren trees are very effective, and the subtle use of glitter also adds a lot to the overall winter scene. Plus there were some nice little steam locos on show.

It was also nice to see Deepcar again, which now features some newer motive power in the form of Olivia’s Trains EM1s. One of the highlights of the exhibition was seeing two LMS garratt’s passing each other on Radford Mill; I was lucky enough to film it (does this make me a model-train spotter?).

My second favourite layout was ‘The end of the line’ which featured a standard gauge siding with a narrow gauge system loading up the trucks. There was even a moving flat-loader truck (which inspired my current workbench project: a 4mm radio control car).
Exhibiting at a show like this must be quite a challenge. It is something that I have considered doing, but I’m in no rush to dive-in.

Below is my video of the show.

Making a 4mm Radio Control Truck Pt4

Over the weekend I commenced work on my miniature RC car.

I eventually settled on the Oxford Die-cast AEC pick-up truck, mainly because of the ground clearance beneath the chassis. The main risk of using this truck is the difference in size of the AEC trucks wheels compared to those provided with the conversion RC kit.

Wheel removal

The first job was to remove the wheels and axles from the die-cast model. I wanted to see if it was possible to use the original wheels, so I knew I had to be careful. The Oxford Die-cast wheels are held onto the axle with an abrasive tipped axle (not quite a thread, but more a cross hatching).

The axle of the AEC truck with cross hatched tip.

The axle of the AEC truck with cross hatched tip.

This meant that a bit of gradual pulling (using a pin vice and brute strength) releases the wheels. I also realised that the Oxford Die-cast tyres are made of a similar rubber to those provided in my kit, which should be great for traction.

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Motor positioning

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The next job was to provide enough space for the motor on the die-cast chassis. I cut away at the rear of the chassis with a mini drill armed with a disc cutter. After losing about five disc cutters, I managed to clear a nice space for the motor.

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I soldered a small bit of wire to the brass gearbox, which acts as a simple harness to keep the motor inside the chassis.

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Building the front axle

The steering axle is a lovely, simple kit. I didn’t realise that the kit is made so that the axle will move across the x, y and z axes, so I am very pleased (as I thought I would have to adapt it for up/down movement). The plastic is also very rigid, with little chance of distortion, it looks laser cut. The wheels supplied are quite small and the rear wheels are constructed to take a double tyre (which would look a bit silly on non-lorry models). In order to fit the AEC’s original wheels I replaced the kits brass axle pins and converted new ones out of the AEC axles. I didn’t want to risk widening the holes in the steering kit to take the wider AEC axles, so I milled down the AEC axles with a mini drill and a file.

To the left - newly milled axles, made out of the AEC axle. To the right - the kits original brass plunger axle.

To the left – newly milled axles, made out of the AEC axle. To the right – the kits original brass plunger axle.

The new axles fitted to the wheels

The new axles fitted to the wheels

Fitting the steering axle

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I decided that the steering column needed so much space beneath the body that it would be better to cut away the front of the AEC chassis and fit it directly to the cab. I also removed the mud guards, so the wheels wouldn’t collide with them.

Thoughts on progress so far

It was at this stage that I started to realise that the wheels were too far stretched out from the steering axle. This gives the impression of some monster truck adaptation, which I quite like.

Converted truck (to the right0 with widely spaced wheels.

Converted truck (to the right0 with widely spaced wheels.

The problem is that the rear axle is fixed in the motor gear box, and is nowhere near as lengthy as the front one. Thus when the back wheels go on, the final product will look a bit stupid. So my next task will be to carefully de-construct the steering axle and re-mill the front axles until they are a bit closer to the body.

I have ordered some spare axles (just in case).

Expect an update soon.