2020 October Virtual Meeting

Once again we are having to hold a virtual club meeting. Members have submitted photos and videos of their models for viewing and discussion. We will not allow Covid-19 to spoil the enjoyment of our hobby, so please enjoy the contributions below.

David Northcott is showing his 'Vintage  4 2 2  Steam Locomotive.

John Day has built a Hole-in-One machine.  He acquired the plans from Ron Mitchell at Skegex in 2019. The balls are not ping pong balls but are balls removed from roll on deodorants.

John's next model is from Model Plan no. 172 Endless Ball Chute designed by Peter Matthews. This model does use ping pong balls.

John has also built the Linde Side Loader - a fork lift truck for use in timber yards.

Pete Evans: Here is a Lattice boom truck crane manufactured by P&H. The model was originally intended for display at Skegex 2020. It is fully functional with jib raise, lower and slew, plus the truck can move forward and reverse and steer with its four wheel front steering.

The jib folds back on itself for transportation as per the real machine. It also has an operational electromagnetic grab supported by the hook.

This controller is fed by a standard transformer and utilises individual joysticks for each of the motions.

The next model is a Euclid R-105 Rear Dump Truck. It features a tipping bed, forward and reverse and steering. The steering is achieved with articulation between the forward and rear sets of wheels as can be seen in the short video.

Here is another dumper truck - the M-100 Lectra Haul. This truck featured a diesel electric drive system.

The diesel engine drove a generator which supplied power to two separate electric motors, one for each rear wheel. Truck turning assistance could be achieved without a differential by powering each motor at different speeds.

Lastly, this is a simple jig for creating hanks of cord from loose cord. The rods are spaced 4" apart, and when wound with enough cord, the hank is bound manually with the end of the cord.

Sam Medworth

The Harwich Treadwheel Crane

During a recent holiday I came across this interesting piece of historical archaeology. Built in 1667, it is the only example of a double treadwheel crane left in the UK. (There is a single-wheel one in Guildford). At the time Britain was engaged in a maritime war with Holland, and Harwich was the only deep-water port between the Thames and the Humber. Samuel Pepys, the famous diarist, was MP for the town and in charge of the Admiralty; he arranged for the port to be upgraded. I understand, however, that this technology was hardly cutting edge, since such cranes were in use by the Romans and the Mediaeval Cathedral builders.

A wooden house, 26ft 3in by 14ft 10in, provides the frame for the crane, from which the jib (12” by 10” timber) projects 17ft 10in. Some of the timbers have clearly been reused from dismantled ships. The mechanism was two men walking inside a pair of 16’ diameter x 3’10” wide treadwheels, set 4ft apart on a common axle, itself 14” square timber. (Treadwheels in prisons were generally worked from the outside). The lifting chain wound around this axle to pass over a horizontal roller, between two vertical rollers, along the jib and over a wheel. There was no brake, so a piece of wood had to be kept handy to jam the treadwheels. The only mechanical advantage in the mechanism was the ratio between the radius of the axle and that of the wheel; thus 2 men could lift no more than 3 tons, depending on their combined weight! I can find no evidence that pulley blocks were even used to increase the possible load – but it is likely that loads heavier than this would have been impossible to handle on board the ships of the day anyway.

The cost of the crane was £392 to build and it served the docks for 260 years, even throughout World War 1. The Naval dockyard closed in 1928 and in 1932 the crane was moved to Harwich Green overlooking the North Sea, where the photograph above was taken.

The model is at a scale of roughly ½” to the foot, and requires a pair of hamsters for motive power. I don’t think they were ever marketed by Meccano ltd. Hoisting and slewing are the only movements possible. Can you spot the brake?

Steve Briancourt

The build of the Penny Falls Machine continues. Beta testing threw up some minor issues with the coin drop which have now been addressed.

The coin table may have other things put onto it like small packets of sweets, key rings etc., to encourage play. These would have to be positioned before play or introduced by a chute.

One of the problems found was an occasional jam of a coin under a flipper. An auto-reverse mechanism has been introduced on the back panel which detects the jam and backs off the flippers a little to allow the coin to clear. It then continues onwards in the proper direction.

The motorized drive for the plungers and flippers is in place.

The back panel with all the mechanisms is removable as a module simply by removing two bolts.

Eric Pentecost has some photos of his block setting crane. This is modelled on the Titan Crane in Table Bay.  See Eric's Page for more details.

Michael Morris has been building a tram.

The yellow tram is: 46cm long, 12cm wide and 20cm high.

It runs on 3 sets of bogies each with 6 wheels.

It has 14 yellow double seats and a blue conductor’s chair at the front.

Each of the windows is glazed.

Although not a technically advanced model creating the curves and the rounded sections proved challenging.

I started to make a yellow emergency  air ambulance, hence the rounded nose. But somehow it morphed into the much larger tram.

It was not made to a plan only from good memories of holidays spent in the cities of California and the Far East.

A future development will be to add lights, a drive and to create a track or roadway.

Alan Perry brought his 1/24 scale post mill which supersedes his 1/12 scale replica of the Danzy Green windmill at Avoncraft Museum in Bromsgrove.

The current model is far more manageable both in size and weight.  It is within a short time of completion so all the mechanisms are functioning.  These include the grinding stones and the tentering levers to adjust the distance between the stones and thus the grade of the flour.  Also operational is the sack hoist.

The whole assembly is powered not by the wind but a Meccano Powerdrive Motor/ gearbox set to 1:60 ratio to give maximum torque.

This motor is controlled through a variable voltage model railway unit.  Power is transmitted through the made-up pinion to the brake wheel and thus the sails via a chain drive and bevel gearing.

Saturday’s display was its first outing and one or two problems became apparent.  He hopes these will soon be rectified.

 

Chris Bates showed his model 'Percy'.  The model is Chris's version of Chris Shute's Percy the Ping Pong Porter.  Building it was not a problem, but adjusting it to get the timing right was difficult.  The model has a speed controller for the motor which is almost essential for this kind of model.

Philip Bond showed the beginnings of a VW camper van. This build was prompted by his daughter building a smaller version from an alternative Construction toy kit. He has scaled up pictures of the van such that the wheels correspond to the appropriate Meccano size. Pictures of this new model will be available in due course.

Rob Curling showed the members a circuit he is building to give a soft start to motors. This would be a useful addition to many models to prevent jerky movements. Details of how to build this unit will be added to the website when he has finished the design.