First run of the chassis with the inside motion fitted. Actually it’s the second run I had it running initially last night but realised that I had one of the insulated wheels on the wrong side so I had to strip the rod off and swap it over.

Still working my way through getting the chassis running and I now have the inside motion running forwards at least.

As an aside I have reversed the front crankpin bushes to look more like the prototype and to give additional clearance for the motion. I was wondering about how to tighten the reversed bushes and remembered the late David Smith talking about making peg spanners as he called them. I chose a similar route but instead of pegs I used the same approach as the 4mm scale Romford screwdriver (I still have one in my modelling toolbox).

For those who haven’t a clue what I am talking about this is a Romford screwdriver

This is the leading crankpin bush that I am talking about

This is the custom big boy’s ‘Romford’ Screwdriver that I made to tighten them. The business end is 3/16 silver steel and the end was shaped with a 3mm end mill with the rod held in a square collet block so that I could keep flipping it over to take the same amount off each side.

If I wish to use this method of securing the coupling rods to the front wheels again in the future I will probably need to make another one with a smaller diameter to fit reversed Slaters bushes. The crankpins on this build are 8BA so bigger than most builders make them (the wheels were already tapped 8BA for the crankpins when I received them with the kit). Continuing my current ‘Dremel’ tool theme I used a ball burr in the mill to make the grip. Previously I have used the ball burr in a similar manner to an end mill by cutting into the top of the work piece. This time I did it differently and side milled it. This gave a much better finish and was easier to do. I milled the grooves before turning the taper.

I got around the problem last night by modifying a 12BA screw and soldering the etched covers on, making a small bush from tube threaded 12BA and a small spacer. Once I get them assembled, I may not need the spacer but if I don’t they will go in the spares box.

I still need to add oil corks to the eccentric rods.

Recently there has been much work but not a lot to show for it. I returned to the chassis in an attempt to get that running before carrying on with the body and cab. much of the time has been spent fine tuning the fit of the gearbox so that it doesn’t rub and getting the rear axle to pass through the gearbox and be a tight fit but still be removable for painting etc. This is more interesting because of the wheels being fixed to the axle stubs and the gearbox having ball races which want to grab onto the axle.

I also had a rather frustrating time trying to make a pin for the outer end of the return crank which attaches the eccentric rod. I had tapped the small end of the return crank 12ba and the plan was to make a small shouldered pin threaded 12BA with a large flat head that I could attach an etched cover to.

This gives an idea of the desired pin with the etched covers below

The observant amongst you will note that the threads look very undernourished on the pin. This was possibly my fifth or sixth attempt and I kept putting it down to my having the pin too thin, too thick etc. as each time the thread came out too small for 12BA. Eventually I examined my 12ba die under some magnification and realised that one of the three cutting edges is out of line with the rest and is what I am sure was causing all the failures.

I can’t actually recall if I have used the 12BA die at all (I use the 12 BA tap set regularly but generally for fitting bought hardware) and if I have I would have only used it on brass or nickel so I very much doubt that I have deformed it. It has been consigned to the bin and a new one ordered from Chronos. in the meantime I will probably modify a a couple of 12BA set screws to get on with the job but when the new die arrives I will have to make another to prove once and for all that it’s not something that I am doing wrong.

More detailing of the cab has ensued since my last update. The reverser is a mixture of David Andrews and Ragstone castings. 

The David Andrews Seats are reasonable castings but I was struggling to work out how best to fit them. They look like the idea is that the two pegs fit into holes but I didn’t really want to be drilling holes in the cab side sheets for them. With the pegs removed there is very little to secure them so I made some replacements with a rear strip to solder to the cab side.

What is unclear is whether they fold up or down. At the minute They just drop down but if they fold up I can make a couple of stays to hold them when folded down.