johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most. n.b. There is a list of my first 800 posts in my post of 17 June 2021, titled "800 Posts"

Tag: Cannon carriage wheels

February 23, 2022

Carriage Wheels-2

The Armstrong 80pr rifled muzzle loader at Hopetoun Gardens, Elsternwick, Victoria. One of two.
On the Elsternwick guns the slides have been covered with sheet metal covers to protect them.

The carriage wheels are at the front of the carriage. They do not actually contact the slides unless the rear of the carriage is levered up a few millimetres, to assist with rolling the gun down to the firing position.

They are constructed of bronze.

On my model, the gap between the wheels and the slide would be about 0.3mm.

Today I attached the wheel brackets to the carriage cheeks (the sides of the carriage).

I had deliberately made them with a slightly large diameter, knowing that I would need to reduce the diameters after they had been fitted.

This is how I reduced the diameters…..

…on a belt sander, holding the oiled shaft in my fingers and using my thumbnail to hold the wheels in position. After a few seconds sanding, and being careful not to sand my fingers, I tried the wheels on the carriage, rolling it up and down the slide. That was repeated multiple times until the wheels were just clear of the metal slides.

The single axle will be replaced by more authentic appearing separate axles with dome heads and pins. The brackets will be let into rebates in the carriage cheeks, and tapered in their upper halves.

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February 22, 2022

Carriage Wheels

The Armstrong 80pr cannon on the dwarf carriage and wooden traversing platform, slides wood on metal slides. But, when the carriage and its heavy barrel (4+ tons) are returned to the firing position, there are two small bronze wheels to make the return easier.

Two strong gunners lever the rear of the carriage and barrel slightly, so the two small wheels at the front of the carriage take some of the weight, and the carriage runs forward. In fact, the return was a bit uncontrolled, so a rope was added to the rear of the carriage, thrown around the bollard at the rear of the slide, and a third gunner added some control to the return.

Today I made the 1:10 scale wheels. They are 20mm diameter, and 10mm wide. 13mm wide if the hubs are included. I spent a couple of hours with the design. And another couple experimenting with various CNC processes. Not many photos of all of this I am afraid. I learned some new V Carve Pro commands, including nesting commands using the same milling cutter, but there was some trial and error. The first two wheels took a couple of hours. The final two took only 30″.

The original wheels, and brackets.
The brackets are partially recessed into the carriage cheeks. The wheels do not contact the slides unless the rear of the carriage is levered up slightly.
A wheel, and brackets ready to be fitted to the carriage. The dished section was milled with a ball nose cutter.
I will fit them next workshop session. The brackets need a lengthy chamfer first, as per the second photograph.

NB. these parts are not finished. Sharp edges remain. I will probably put them in the gemstone tumbler to smooth the edges.

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