This week's efforts began by cutting out and installing a cylinder front and bottom. I also added the front and sides of the ashpan from the kit. As I had widened the frames significantly, I had to cut out new ashpan doors and a floor.
When the ashpan was finished, I used the coupling rods as a jig to instal the front driving wheel axleboxes.
The wheelsets were installed and checked for free running, and all was well without any adjustments. I like it when that happens.
Much of the rest of the week was then spent preparing bits for the Stephenson Link motion. I still prefer to use Laurie Griffin castings for the crank webs and eccentric rods. The moulds for the waxes for these parts would surely benefit from a refresh, as the castings are a bit poor now, and require quite a bit of fettling. Etchings for the rods would be preferable, but I suppose fettling the laminations would take just as long. The cast eccentrics available from Laurie are too big for his cast eccentric straps (!) and I had some slightly undersized ones machined ages ago, that make the job much easier.
I installed the etched slide bars provided in the kit. I also used the cast white metal crossheads, and valve rods, provided, even though they were only intended to be used in dummy valve gear. They are a very nice fit and don't bear any load, so I think wear will be minimal when lubricated.
The connecting rod etchings in the kit made some nice components. The big ends did need to be modified slightly to fit round the crankpin journals, and I made the big end eyes too big in diameter. When running the motion made quite a distinctive knocking, similar to an old Triumph 3TA I used to own that had knackered big end bearings. I will adjust or pack with grease later.
I soldered up a crank axle and cut out the axle sections.
The last job before assembly was to make a new weighshaft and counter balances.
I installed the eccentric rods first, and to my delight they worked perfectly first time, without adjustments. I did a little victory dance round my workshop, and installed the con rods. They knocked badly! (see above.) They did however run freely, without any binding, giving rise to victory dance #2.
As I was finishing the second dance the letter box rattled, and a package containing a pair of modified axles and some 3D printed valve chest covers dropped (cheers Mickoo.) I like JIT deliveries (take note ABC!) I quickly installed the wheels in the bogie and fabricated a bogie mount below the cylinders. I popped the finished chassis on the test track (S7, ambitious 5' 6'' rad!) and it worked with only a minor mod to the front of the chassis to give the front bogie wheel a smidge more clearence. I really was on a roll, dance #3 ensued.
You can hear the knocky big end when the loco is running forwards! If it had been a BR Austerity 2-8-0 loco I would leave it as an authentic sound. I understand drivers up here in the North Country referred to Austerities as 'Bump-Clanks!'
I made the steam reverser from the parts in the kit, but ran out of working-week in which to fit the assembly.
This is where I will begin next week.
