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CMC Meeting, May 08

The next meeting of the Christchurch Meccano Club is Friday 6th June.

The challenge

Last month's challenge was to make a model powered only by a bottle of Speight's beer, and race it across the floor of the club rooms.  We only had two entries for this challenge, but it might have been something to do with the dreadful weather (and the rugby being on at the time of the meeting!)

Charles' entry was a simple design with the intention of being lightweight and fast accelerating.  Wheels of 7½'' circular strips were driven by sprocket and chain from the drive axle.  The weight was suspended round this axle, and then run around threaded pins mounted on a 4'' circular plate on this axle.

The initial acceleration is provided by the cord pulling on the threaded pins, and once the bottle drops near the bottom the run continues unwinding from the axle.  It's important to wind it correctly for the distance required, and although it managed one very good run it wasn't quite good enough on the day.

Hugh's entry (above and right) was a very similar design, but taller and had the drive directly to the single driven wheel.  Four pulleys on this axle allow five different gearings to be used! Careful winding from the smallest to the largest pulley enables the operator to balance acceleration against speed.

A very close-run first round win proved enough to win after the second and third runs were shared out, giving Hugh the win for the second month in a row.  A good job too, since he'd forgotten to bring the cup to the meeting!

Controversial non-Meccano 'tyres' around the hub discs were allegedly to protect the floor (or the paintwork on the wheels, it wasn't certain).  On the other hand, it may have been the use of Speight's "Distinction" Ale that gave it the crucial edge!

A bit of a disappointment in the number of models this month, with many of the members shown up by Neil's nine-year-old grandson Finn, who brought this whole range of models shown to the right.  It's a nice change to see one of the modern tuning cars getting a Kiwi-style trailer to make it do something useful.  Other than the car itself, all of these models were freelanced.

Shown above and right are a first attempt at an Orrery, based on the June 1957 Meccano Magazine "model of the month".  The instructions for this model have been converted to a PDF and are available for download in the gallery by clicking here.

Instead of providing power through a flanged ring to an E20, this model uses a small Meccparts motor and a 12V lead-acid battery as a counterweight.  Another modification is to the circular plate supporting the moon.  This was more than a bit wobbly in the original design, and so a small sprung 'fork' sporting a pair of half-inch pulleys and tyres pushes up on this plate to support it and dampen the wobbles a bit.

The sun is a $3 find from the local toyshop, the earth was a yellow sponge ball from the same place (sprayed with primer then painted with model enamels).  It's important to have the earth very light as it is the one that's spinning.  The moon is from modelling clay hardened in the oven.

The CMC Challenge – "Bridging the gap"

The Challenge

Build a bridge from Meccano, to span between two tables exactly two feet apart.  There are no other specifications to adhere to, but votes are likely to be gained by models showing particular elegance, strength, lightness, design features or any combination of these.

The Competition

At the CMC meeting in June, each model will be displayed in place between the two tables usually provided in the club rooms.  All club members present will vote for their favourite, and the winner is the model with the most votes.  In the event of a tie, the most senior disinterested party will choose.

Definition of 'Meccano model'

As usual, you can use any Meccano part ever made and sold as Meccano, or any reproduction part that is structurally identical to a Meccano part.  Parts may not be cut or deformed such that they cannot be used for their intended function again.  You can cut a 2 down into a 2a (it becomes a reproduction part), but not down to a 5'' long strip (which has no Meccano equivalent).

Cord, driving bands, and springs may be of any type.  Motors must be genuine Meccano.  Non-Meccano washers may be used in your model solely to protect the paintwork (these don't count as a part).

The June meeting

The next meeting is Friday 6th June, 2008, at St Johns Church, Ferry Road, Woolston.  Bring a friend! And, as usual, bring whatever Meccano model or curiosity you're currently working on, whether it's finished or not!