Many years ago I decided to build a Rider Ericsson hot air engine. To me it was a fascinating engine because of its geometry of the working parts, it was built as per drawings except for the fly wheel which was alloy, this was changed to cast iron.

It was eventually installed into a pumping house workshop, the building was complete with a real slate roof, gutters - a skylight window etc., the model was an intermittent project which was built over a period of 18 years, in between I built a five inch gauge locomotive and a four inch scale showman’s engine.

When the pumping house was finally completed it was exhibited at a Model Engineer Exhibition where it was awarded a Gold Medal and the Bradbury Winter Memorial Trophy, shortly afterwards it appeared at the Harrogate show where it was awarded a first certificate and the Barry Jordan Trophy for the best in show.

The model featured a number of very interesting items apart from the pumping engine, which in themselves proved to be a tremendous challenge.

The model and accessories were all built to quarter scale, one major item was a bench hand drilling machine complete with an automatic vertical feed, this miniature proved to be a challenging project, no castings were used. Everything was cut from the solid, it has a working 3 Jaw chuck fitted to a 3/16 inch diameter spindle, the thrust race has 10 tiny balls 0.038 inch diameter, the spindle was screw cut 80 TPIx.055 inch deep as is the chuck body to receive it, and the bevel gears were all machined on my Dore Westbury milling machine.

The workshop is fitted with an old-fashioned blacksmith’s vice. I was able to borrow the real item in order to measure it, again no castings were used, everything was cut and machined from the solid.

In one comer of the building there is a Belfast sink with working water taps, there is also a coal fired iron stove. I was able to copy the latter from drawings which were available to me.

The model was an open invitation for a considerable multitude of detailed accessories, the old style batteries, OXO tins, cigarette box, oil can, petrol can, mop bucket and mop, bucket for sticks and coal-oil tin, to name but a few.

The various boxes and tins were all copied from the full size article which were then scanned into the computer, they were then re-scaled and reproduced in miniature. There is a complete miniature copy of the Model Engineer on the workbench, the main difficulty was finding thin enough paper on which to print it.
The petrol Can was another challenge. I had the real item which I was able to copy; the model is made up from tin plate with correctly flanged upper and lower panels. I made up a
steel die for the Shell motif, this was sandwiched between a piece of steel, a piece of rubber and brass shim. The assembly was mounted in a 6inch vice, under pressure the shell imprint was embossed into the brass shim, after which it was carefully cut out and glued into place. The lettering was cut out from a plastic strip letter embossing machine, two sizes were available to me, the embossed letters were carefully cut away from the surface of the tape with a scalpel, and then stuck in place using superglue.

The most difficult challenge no doubt was the electrical system all of which was faithfully reproduced in miniature. Everything all works right down to the wall switches and the brass light switches, each switch is made up of eleven parts with its own circuit, there is a working radio which is also home made along with an angle poise lamp, all the light bulbs and their sockets have bayonet fittings faithfully reproduced.



HEARD AT THE HARROGATE SHOW:

Oh! You have a Belfast sink! -My God, mother had one when I was a boy!


Your KitKat is melting!


I'll bet even the dog has fleas!

Is that a model of your workshop?

Are the glasses bi focal?

There are no cuttings on the floor!

These two jokers want to know if the radio works?

There should be a bird in the roof space!

You can stand and just look at it - it is better than the TV!

I have a drilling machine like that at home!

You have got to be insane to make that!

There is no dirt on the towel!

There is no dog pooh on the floor!

I see you have taken up forgery!

Where is the bowl for the dog?


Do the matches work?

There should be wood worm in the roof beams!

Do the water taps work?

Can you get the Home - Light and Third programme on the radio?

Is that the view from your workshop window?

Is the KitKat bar real chocolate?

Did you make that?

I suppose you have Ajax in the Ajax tin?

I want one! I want one! The lady exclaimed - he is not taking orders my wife replied.

Why don't you make another and spot the difference!

It's one Hell of a model!

The RSPCA will be after you if you don't let the dog out!

It's too clean - my workshop is not like that!

Look! He even has Fairy soap in the soap dish!

 
THE PUMPING HOUSE
A moment in time
By Raymond McMahon