Sunday, March 25, 2012

Ingenious loco drive mechanism

Clever mechanism

50p on the Nottingham second hand stall. Bought out of curiosity, this American loco is to be powered by a AAA battery fitted in a box on the top. The box is missing its lid but I didn't care. I wanted to know what was inside.

The wheels are horrible. Traction tyres and flanges to cut pizza. Overall standards that make 1960's Triang look MRJ-worthy. Presumably the model came in a box with plastic track and a few wagons. Actually, I know that last bit is true as I couldn't resit buying one (there was only one) from the same stand for the same money. Heaven knows what I can do with it but that doesn't matter. It was cheap and bright orange so worth every penny.

Bogie gutsInside the beast is a very interesting mechanism. The double reduction drive (yes, double reduction, like posh loco kits have) powers a shaft that goes through the bogie pivot. This then drives the wheels. Both axles. Hidden behind a very Triang like set of sideframes.

This might be cheap and tacky but the engineering is pretty nifty. I'm surprised that the real RTR makers haven't looked at a similar thing. In fact I'm amazed they didn't try it long ago in preference to pancake motors. This thing is built down to a price yet it's got all this clever stuff going on and "proper" locos had much more horrible drive systems.

What I think, is that the wheels could be replaced with something decent and maybe the motor swapped for something capable of surviving 12v, and then this could be the basis for a decent model. For the minute I'll screw it all back together and put it in the maturing drawer. But ideas will form in the back of my mind.


James Finister said...

Crying out for conversion to Gn15 for use in the garden - a pastiche of Lady Wakefield perhaps

Anonymous said...

Hello again Phil,
That mechanism reminds me very much of what's inside my collection of ugly old Jouef/Playcraft Class 21 diesels (why should I have a collection of such 'orrible things? 'Cos I'm a modeller of BR in H0, remember!). Anyway a huge double-ended can motor lurks at the heart of these toys, driving two gear 'towers' just like the one in your pictures.
This arrangement was also used in several of Jouef's contemporary continental offerings as well, way back in the sixties. So, there's truly nothing new under the sun!
All the best,
David Alexander,
Rochester, Kent

Phil Parker said...

I'd forgotten Playcraft. Of course they used this sort of mech. It still doesn't explain why no one else did though. After all, both examples are on ranges where cost is a important - in other words they were cheap - is it not high-fi enough ?

Anonymous said...

I've heard it said that this type of mech allows childish hands to push the loco up and down, without damaging the wheels or drive. Maybe that's why it was chosen for this toy-like application.
David of Rochester