As an intermezzo in building the boiler, some machine work was nice to do. Turning the driving and coupled wheels is a straightforward turning job, but requires some planning in set-up and sequence to machine the several faces.
The wheels were bought in England from Mark Wood, in the days before the Brexit customs rules made this very difficult.
The wheel castings are of excellent quality and are fine cast. Mark did some special research on the prototype Y14 locomotive so that they are very close to scale.
Update: Mark told me today that:
Just after Brexit I had problems with long customs delays and even parcels being returned to me - that was with DPD. Now I use UPS and pay the local duties in advance and parcels have been delivered to Europe in about 3 days from posting.
So this gives a good prospect for future model locomotives. 😀 Take a look at his website, because he offers many wheel castings.
First the backside is faced, so there is a reference plane to start with.
With all the wheels faced, the outer flange had to be cleaned up. But the jaws of the chuck were too deep to give enough clearance. So some aluminum strip was bent, so it could be clamped over the inner jaws.
This made it possible to give just enough clearance.
Gripping the wheels on the machined outside rim, the front could now be faced.
The bosses are 3,5mm outside the rim and could also be faced.
Then the backside could be finished and faced to the final thickness of the wheel.
In the same setup, the wheel is bored for the driving axle. By doing this in one setup, the hole and backside are dead square to each other. This way the wheel will run without a sway.
Because the spokes are close to scale (and therefore thin), the wheel was clamped between two aluminum disks. With three bolts the disks are screwed together.
Now the rim could be turned to the final diameter of 133 mm and the flange could made.
It's a job that takes some steps for each wheel. Every step is done for the six wheels, before changing to the next set-up. So a lot of set-up time: clamping in the three-jaw chuck and between the disks and changing the lathe tools, was involved. A few evenings behind the lathe were needed.
For the flange, the top-slide was set to 18 degrees.
Finally, a small radius was made on the flange.
To drill and ream the crankpins, a set-up was made in the milling machine. A short stub was mounted on the milling table from which the center of the wheel was positioned.
The stroke of the crankpin was done first with a center finder used on the stub, setting this to zero and then moving the Y-axis to 26,5 mm.
With a small piece of round brass, that was turned to the same diameter as the boss, the correct position of the crank could be determined by turning it over around the center, after which the wheel was locked down with the clamps.
With two clamps the wheel was fixed to the bed. The hole was centered, pre-drilled with a standard drill, drilled with a three-lip drill and then reamed.
The small brass plate under the wheel is used as protection for the milling table, in case a drill or reamer is going too deep.
The backside of the crankpin hole is countersunk, so a screw can later fix the crankpin.
The axles are a job that could be done by using the collet.
"On its wheels" (well, without the hornblocks yet)
