After turning the wheels and axles, making the hornblocks, axle boxes, and coupling rods, there are now enough parts to assemble and test. See the video at the end of this page.
First, the axles were glued to the left wheels
In SolidWorks, a measurement was taken of the height of the crank pin to the top of the milling table, where the wheels are positioned in the T-slot. A support bar was then made on which the crank pins can rest while the axle and wheels are in the table's groove. The height of these support bars ensures that the cranks are set at 90 degrees.
There is about a minute before the Loctite 648 glue begins to cure. This is enough time to check that the wheels and axle are aligned in the T-slot groove, and both crank pins are resting on the top of these support brass rods.
Leave it for a few hours, before the next set of wheels is glued.
The crank pins are straightforward, but the right side have a right-handed screw thread, and the left side have a left-handed thread.
On the rear axle, a small eccentric is needed to drive the mechanical lubricator
A simple straightforward turning job. Drilling and reaming was done in the milling machine.
With this centre locator, a line can be scribed on the excenter. Knowing the diameter of the hole (16mm), a piece of 8 mm rod is used to position the excenter so the middle can be marked.
This line is needed to align the drill and tap for making an M4 threaded hole for the grub screw.
Tapping, done by hand.
All wheels are glued to their axles.
The day after, the motion could be assembled and tested. The 0.02 mm play on the bearing bushes made it hard to assemble, and the motion was too stiff. Although it was possible to rotate the wheels without binding, it wasn't smooth. If left like that, running on an uneven track would be difficult. So, the play was increased to 0.05 mm with a hand reamer.
Now everything is moving fine.
The locknuts for the crank pins, with the dummy cotter pins.
This is also the first test of my specially made rolling road. After years of testing my locomotives by simply putting them on wooden blocks, I decided to make a rolling road. My son has one for his 5" gauge 'City of Truro' class loco, which he used to demonstrate the loco under its own steam at an exhibition.
The drawing has been updated. With the aid of photos and a small sketch, I finally got the height of the tender correct. It's only 7.5 mm higher, but it makes a difference and looks more like the historic black-and-white photographs of the real loco.
