Iron Pigs
 

Iron Pigs took a step forwards yesterday with the making of a tap to cut some rather important threads. In order for the project to procede I need to re-furbish my home CNC machine mainly by replacing the existing screwed rods with proper machine screws. The screws are no problem but to buy a 12 mm X 3 mm pitch Trapezoidal thread tap costs £100, I can buy nuts at £20 each but I need 6 however £100 is a bit of a chunk out of the pension so to test it I made my own tap. If all goes well then later in the year the tap will be bought so no pocket money for a good few months for me.
The machine is needed for making polystyrene foam chassis patterns which I would rather make in one piece than assemble from smaller components and as more than one loco is envisaged accurate repetition calls for me to use the computer. The machine has already been tried for making 25 mm wheel patterns with 6 spokes and 6 stacked on top of each other only look as one when viewed from the top of the stack, once the weather improves casting can continue outdoors since I do not think melting metal in the kitchen will be approved of by management.
John (G)
PS Perhaps due to the small size Steam Guineas might be a better name.

I think some Iron Pig pics might be in order John. What do you say?

For those unnacustomed to Iron Pigs and that means all except Trev and myself a short history. We have this absurd idea of an individual style of railway in the garden which uses standard basic components. Much internet surfing and a local (for me anyway) expedition to Buzzrail resulted in numerous pictures of Motor rail Simplex machines being gathered together ending with picrures of much beloved Tin Turtles. Later a steam tramcar came to light which confirmed our fears that it has been done before. We have dubbed the project as Iron Pigs.
The heart of these is a common chassis that can be fitted with electric motor, steam, ex R/C car infernal confusion engine (nicked from the son's car) or even sail if there is enough wind. Said Pigs it is thought will have a cast chassis of the general proportions of the Simplex and need minimal machine work to be done to get it rolling on something like 30 mm wheels and to be about 7/8n2 scale (2 foot on 45 mm track).
Progress to date is a basic chassis drawing suitable for me to cut the foam patterns using CNC machine. A slight pause is needed since I am upgrading my machine and if anyone can give me a 12 mm diameter by 3 mm pitch Trapezoidal thread tap the sun will shine for ever more (they cost about £100 new) and the pension will then allow us to eat for another few weeks. Having got this far I will now stop since I cannot see how to attach a photo of a typical Porcus Ferrus nor a Tin Turtle or any other of these narrow gauge machines.
Too wet to go to the workshop so a nap instead.
John (G)

A Porcus Ferrus...

Iron Pigs
 

OK this is the second attempt on showing what has inspired the exercise.
Tin Turtles used in the trenches in WW1 should be the first picture followed by a Motor rail Simplex obviously for a Naturist colony as it is suitably unclothed. Finally Victoria with a steam engine. You will see the similarity in proportions with the picture Trev posted and all of which can be fitted to the same basic chassis with only minor modifications. Being lazy to me a cast aluminium chassis that will save many hours of work seems a good idea.
Iron Pigs are not intended to be copies of anything original but a basic part we can adapt to our own ideas and depending on what is fancied can be gear, chain or side rod driven. Bodywork can be as whimsical as imagination dictates and not alltogether without precedent in the real world where custom finished machgines could be ordered at will or out in the backwoods locos cobbled together from whatever was around at the time. As long as the end product is proportioned for a scale of 1/12 or 7/8n2 we will be reasonably content.
But a Daddy Longlegs crossing my fish pond has interesting possibilites.
John (G)