Spur Gears -1

The model Armstrong cannon has 7 gears, 2 of which are bevel gears, and 5 spur gears, including one quadrant gear.

4 of the original spur gears. These position the carriage on the chassis for loading and firing. There is also a decoupling mechanism on the second shaft. (Portland cannon)

The spur gears will be machined and cut from bronze, brass or steel. I have a set of module 1 cutters, which are close in 1:10 scale to the originals which are close to module 10.

The bevel gears I have made by casting them in bronze, teeth and all, and they are pretty darned good. Not perfect, but they will be hidden from sight in the gear case. They seem to mesh pretty well, but, if they are not up to the job of elevating the barrel I will cut some replacements.

The biggest gear is a spur gear, and it has a brake drum as part of the casting. It is a bit more complicated than a simple cut spur gear. Apart from the brake drum, the gear teeth have flanges at each end of the teeth, which will make them difficult to cut, unless I add the flanges later. I guess that the original was cast, teeth and all.

From below, the biggest gear with the brake drum on the left of the picture. The brake band is a steel band. (Port Fairy cannon)

I have decided to cast this gear also.

You can see the flanges more clearly in this photo. (Port Fairy cannon)
So I have 3D printed casting blanks with teeth and flanges (left) and without teeth and flanges (right). I will cast both, then decide which to use. 58mm diameter, 25mm wide. The prints are colourless PLA. I have had problems with plate adhesion with this PLA.
The bevel gear case. Cast bronze. Some more finishing required.
The cast bevel gears. Since this pic I have machined bores and improved the finish. PLA blanks.
And can you guess what this fingernail size piece is? It will cast in bronze.