This first section is all about sorting the wheels out.

The wheels are Alan Gibon plastic centered wheels. We use these in our 7mm Scale models and actually produce FR pattern wheels for Fairlies and England Engines ourselves. The result is that I have some experience of getting them right.

First important bit is countersinking the back of the wheels to clear the head of the countersunk screw as used as the crankpin. The trick here is to be gentle with it and use a bluntish 2mm drill as a sharp one will catch and drag itself straight through the plastic.

Once countersunk using the drill the back of the wheel is rubbed on a sanding block to make sure its flat before a 1mm tap is run though the hole from the front.

The key to all this is to make sure its perpendicular to the wheek so I use a tapping fixure which is basically and mini pillar drill but with a handle on top of the shaft.

Once this is all done the screw are put in from the rear but left a smidge loose whilst a crankpin bush and a nut are put on the front. Once they're all in that state some slow setting [and stronger] Araldite is mixed up and the merest smidge wiped under the head of the screws with a piece of wire. The screw is then screwed the rest of the way in distributing the glue right around the head. The nut on the front is tightened to pull it all up tight tight and sqaure.

When the Araldite is fully set the bacl of the wheel will again be rubbed on an emery block to make sure its flat

This section is about getting the frames true and sqaure.

I wouldn't expect everyone to have one of these but having got an Avon Works Chassis Pro2 jig it made sense to use it. The frames you had put together were undone and all the solder cleaned off. The edges were then all filed and cleaned to remove the etching cusp and the holes opened out so the bushes were a loose fit.The jig was then used to erect the frames. It goes like this.

• The coupling rods are used to set the wheelbase in the jig.
• The jig rods are then changed to the 2mm axle rods.
• One frame is fitted, outside facing up, and the bushes placed on the rods and into the holes in the frame. The frame is then held down with clamps whilst some flux and then solder is run into the joins.
• Frame one is removed and the same done to frame 2
• The frame stetchers are then soldered to one frame.
• The second frame is applied and soldered to the stretchers

The result is a joined up chassis in which the axles must be the right spacing, parallel and level. Next it all gets a big clean up of the joints removing excess solder with Gravers [sort of mini scrapers], files and emery

Next Up was to sort out the Cylinders

You had blobbed way too much solder on to them and from the way it worked I suspect it was electrical solder. Basically it didnt flow in to the joints and had pooled in big blobs

One of the cylinders fell to bits as I was cleaning it up. This made more work but in some ways it also helped clean it up. Some wicks were made from some electrical cable impregnated with flux so that excess solder flowed into the wire and off the cylinders.

It was back to more cleaning and filing then plus a scrub in `shiny sinks' in the bathroom to clean it up (A wise old hand told me years ago to clean up after every op as you'll forget or you fasten a bit on that stops you getting in to clean. I probably though "yeah right" and ingnored him in my youth but he was right]. The cylinder wrappers aren't perfect as I couldn't get all the wrinkles out before wrapping them again.

Thats the chassis as of about 3pm today.

I had to do some christmassy crap them [bah humbug] but it is cleaned up with the bearings in for the gears, the bogie centre on and the brake hanger in.

Next up was making bits up ready to add on to the chassis as detailed below

Making up Chassis Bits

This was interesting from a kit designers point of view. Peter does his kit artwork by hand drawing it to about 8mm / foot scale and then photo reducing it. It means, for example that for the four parts that make up the two brake blocks he has to draw four with the attendant risk he draws the four all slightly different to each other. These are different!

Its only minor differences as reducing the artwork to 4mm/foot also reduces the error. Its a lot more serious in the 009 kits he's now done to 7mm scale - on the NGG16 the cranks are made up from three layers and you struggle to find two the same.

Us computer age designers draw one, cut and paste to get the second and mirror the pair to get the two opposite hand ones and they are all the same!

I was on to doing the crossheads and recessing the backs of them for the connecting rods when I spotted the problem with the casting. I have been trying to figure out a way of resolving it without success so i think it will have to be a new one