I finished the escape wheel by using the time-tested method of inserting it into a wooden box. The box is a piece of wood screwed to the lathe faceplate, into which is carefully cut a pocket to hold the wheel. The wheel must be tight in the box, or it can come out. If it's too tight, it doesn't fit well. I remove wood with a boring bar in the tool post of the lathe, at the rate of a few thousandths at a time, until the pocket is just right. The final cuts in the box are only made a thousandth at a time.

(The faint of heart may press the wheel into the pocket with a piece of pegwood while operations are being performed.)

Then, the center hole of the wheel is trued with the boring bar. This ensures that the hole is exactly centered in the wheel. The wooden box method is quite accurate in this regard.

Next, I thinned the wheel between the teeth ring and the hub ring with a round-nosed bit which is made from a #31 high-speed steel drill-blank. The round-nosed bit makes a very smooth cut, and also permits cutting in both directions, both in and out. It also leaves a roundosity on the hub and tooth rings which is attractive.

The web which results is only about .015" thick, which is plenty thick enough to support the tooth ring of the wheel, but lightens the wheel considerably. It's necessary to monitor the depth of the cutting with a micrometer.

We think that clock wheels should have spokes because wagon wheels do. Wagon wheels are what they are because of the properties of wood. Clock wheels don't need spokes because they're made of brass not wood. What clock wheels do need is to be light in weight, since the wheel must start and stop with each tick.

I prefer to thin the wheels, using a thin web of metal instead of spokes. Thinning lessens weight, without providing the hassle of spoking out wheels. No matter how careful you are, hand-spoked wheels always have a certain lumpy appearance.

Finally, the wheel is polished while still in the box, using Scotchbrite and steel wool. My favorite fine-line finish for working parts.

Next, I'll calculate the train and cut the train wheels.

Todays' links:

Escape in box I
Escape in box II
Round-nosed bit
Escape finished