David Andrews Princess Royal - 6206 Princess Marie Louise

After a bit of fiddling about I got the cylinder front and motion plate for the inside motion made and assembled.

The fiddling about was my own fault, I initially made the motion plate too shallow and therefore it would only accept the slide bars at their very ends and I needed to mount it further along. I was also considering adding the valve guides and after spending some time fettling the rather misshapen castings I realised that they wouldn't actually be seen so decided not to go any further. After considering them I had started to remake the cylinder front plate in order to accept them but in the end used it for the replacement motion plate so it worked out perfect in the end if a little convoluted getting there.

One beauty of having a mill is that cutting out the centre section of the motion plate was so much easier than using a piercing saw and files as I have done in the past.





I may yet need to cut the ends off the slide bars but I won't know for certain until I start assembling the chassis.

 

Thanks Steve,

It shouldn't be too long now before I can think about assembling the chassis.

 

A little more miniature madness this morning. The LG Cross heads are supplied with really nice cast castle nuts on pins for attaching the connecting rods.

The David Andrews castings have something similar but it's a plain nut (I would guess that the pattern maker used either a 14 or 16 ba nut) rather than a castle nut specifically.

A quick search online for photos of castle nuts and off I went. These are very cruel close ups but I am happy with how they have turned out and now I know how to make them knocking more up in the future will be relatively simple. To give a better idea of scale the pin through the nut is 0.8mm. You will note that one of them has a thick stem to the pin? That's because I made the first one with a 0.8mm pin right through but it's a bit sloppy in the cross head hole and it's well and truly stuck so the other two I made by turning a piece of 1.2mm rod down to 0.8 for a couple of mm on each end.

 

Mmm, I think that I might just pass on that one Brian.

 

Are you sure that shouldn't read, "I can't believe how nuts you are."

 

The rest of yesterday was spent fitting the replacement driving wheels springs. Due to fitting Alan Harris wheels, I thought it necessary to make the springs and hangers removable so that the horn blocks can be dropped out for maintenance. With Slaters wheels it's easy to loosen the screw and ease the wheel from the axle to wiggle them out around the brakes. When using telescopic axles there isn't the flexibility to wiggle the wheels so alternatives need to be sought.

 

The last few days have been spent assembling the chassis frames ready for detailing.

As I mentioned in Torry's thread, I had to trim away sections of some the frame spacers to accommodate the thicker cast spring hangers, the horn guides and the gearbox. Most of this adjustment was done prior to assembling the frames but the cut out for the gear box was done afterwards. The mill came in handy for removing the bulk of the cut out, I just needed to square up the round corners of the slot with a file.

 

The last few days have been one step forward and two steps back...

The wheels have been drilled 8BA as the guy that I am building it for prefers the thicker material.

I didn't have any steel 8BA screws so I turned some rod down and threaded it 8BA. Next on auto pilot I made some 8BA crankpin nuts.



Then of course I did what I should have done first and looked at photos...



So far I have made a pair for the rear.


I have also made some rear plates for the balance weights but I haven't taken any photos yet.

 

While I was at the lathe I decided to make a replacement vacuum cylinder. The casting supplied was actually one of the better castings but it was not quite the right shape and undernourished when compared to the drawing.









So a fun time was had turning a new one an dressing it with studs/nuts. Those who are paying attention will note the odd arrangement of studs which I took from the drawing. I had an interesting time working out all the different angles which equated to: four at 45 degrees and the other three at 56.25 degrees from those.