This jig is used to mark out for crossing out clock wheels to form the ‘spokes’. I had previously done this on a milling machine and it is no coincidence that the two clockmakers that saw my wheels commented on the lack of taper on the spoke. There are a variety of plans available for this type of jig.
I used a scrap piece of brass plate that had been heavily scribed on one face but had a clean upper face. The brass is approximately 1/8″ thick. It was roughed to size with a piercing saw and then screwed to an aluminium back plate in what will turn into the centre holes and the four holes in the first circumference.
Ok, a little more done and this should show how it works. It’s nothing mind blowing, just a simple jig to quickly cross out wheels.
So I’ve turned up a few stubs and pins but I need to turn up more, the idea is you build up a collection as time goes by so it isn’t something you need to keep doing.
The wheel is mounted on a central stub that is tight fitting:
There is a tiny centre pop in the centre stub to mark out the inner centre and outer rim:
Then if you want 1/8″ spokes, you machine up two 1/8 pins, put them in the appropriate dividing holes and mark up.
This can easily be done marking out in other ways but it’s fast and I hope to maintain an interest in clocks, it should be a useful tool. The real benefit is that using different size pins, you can achieve taper on the spokes… More pics to follow.,,