Two types of drive cylinder


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2nd March 2012 Rubber track drive

Plastic 19t pinion will fit inside the cylinder and locate on the integral moulded teeth. The brass pinion is too big!

A short while ago, someone on the Spanner II list or on the Rust Bucket Forum (can't remember which) pointed out that a plastic 19-tooth pinion fits inside the plastic drive ‘sprocket’ (cylinder) and engaging with pre moulded teeth making a non-slip union between the parts.  As far as I can see Meccano have not used this design feature in any of their instruction book models. Drilling rigThe part (moulded in grey) originates from the short-lived ‘Future Master’ sets and specifically the  drilling machine, shown here. This picture is taken fom an old American advert - I am not even sure this model was available here in the UK. A similar (but not identical) part, moulded in green, can be found in the ‘Crazy Inventor’ Rattletrap set. If you know of any other sources of this part please let me know. You can contact me HERE.

This may not be new to some of you but it was to me. Inspecting the drive cylinders there are two different parts. The grey ones have a full lattice of ridges on the cylinder’s surface but have only three teeth internally that will locate with the gear wheel. The bright Green cylinders have a full compliment of teeth and a broken lattice of ridges on their face. As far as performance goes this seems to make little or no difference.

The moulded teeth can clearly be seen in the green version. The rubber 'pulleys' hold the gears in place. Not shown here but pinions are inserted on both sides of the cylinder to balance the strain on the moulded teeth.

Mounting axles 4 inches apart (e.g. holes 2 and 9 in an 11 hole strip) allows the rubber tracks (from the 15 model Multimodel set) to be mounted with enough tension to be driven very successfully.

Both tri axle and brassed bossed 19t pinions fit into the hubs
Truck The works

The first prototype was hurriedly put together using French tri-axle parts as it has no steering capacity. A more sophisticated version of the tracked drive using two motors, conventional axles and the yellow plastic, brass bossed pulleys makes the second prototype. Free wheeling hubs are made making good use of the brass boss and knurled extension that we all get left with when the yellow pinion degrades and splits away. Arranging one fixed hub on each side of the chassis and at opposite ends, means that steering can be achieved by driving the axles in different directions or simply stopping one track. More work to be done here…



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