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SAIT Brass Cannon

PeterT

Ultra Member
Premium Member
#1
You guys might get a kick out of this. I took a Continuing Ed machining class during the evenings at SAIT when I was in high school. I believe I was in grade 11, which would make it '76 or so, yikes! The cost was something crazy like $55 or $75. That might buy the brass for the barrel these days LOL. I had no prior machining experience & I recall it was pretty fast paced. Gather around the instructor to watch a setup & operation. Then go back & do it on your lathe. I think the machines were Standard Moderns, lantern style toolpost, HSS cutters, screw on chucks, taper attachment. You got 5 brass tokens to check out your tools from Mr. Big behind the cage. Ah, I remember chuck keys whizzing by my ear, real slate blackboards, smoke break at 8:00 LOL.

We started with layout & handwork on the frames, sawing & filing. The barrel was taper turning setup & I remember having to deal with those those pesky decorative rings mid way. Drilling the spoke holes for wheels used a fixture on an sector dividing head which intimidated me. I distinctly remember a recycle bin in close range containing buggered up ones. Like a graveyard reminder of what happens if you lose count or forget to move the sector or put the pin in the wrong hole. The steel outer tires were heated in an oven & then quickly slipped over the inner brass ring for shrink fit. Mine have faded but it was a neat look when they were dark blue. The metalworking shops were these ancient, war era buildings close by the main (castle) building before the 'new' trades & technology building was completed.

The canon has been at my dads place all these years & it was time to bring it home. One day I'll polish up all purdy again.
 

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#2
Pretty cool.

Please explain in detail how the wheels were made. I can't picture making spoked wheels like that in the way you described making them.

Were they bored to the breach with a fuse hole?
 
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PeterT

Ultra Member
Premium Member
#3
You DO realize its been almost 40 years right? LOL

I seem to recall the spoke holes in brass axle hubs were drilled blind to some depth & possibly reamed to size. The spokes themselves passed through the outer brass rim into these holes. Possibly the ends of the spokes were turned down on axle end to fit these holes. The steel rim then was heat shrunk over the assembly & I have vague recollection of an alignment fixture to keep everything centered in position. If you dilly-dallied with the steel at temperature from the oven, it might seize up half way down.

I can check the bore length, but no, it only goes to somewhere around that first decorative ring. It wasn't meant to go boom by design, just a bookshelf queen. A buddy of mine was into live miniature cannons & shot one of his smaller ones off for me. Holy crap that thing made a bang. Might be something I would build one day but too many other projects in the que.

Speaking of years, after taking this machining 'appetizer' course, it took me another 20-odd years before I had the space & funds to get lathe.
 
#4
That explains it thanks. I was looking at your image, the spokes are staggered inside/outside, and wondering how do you do that.

Your cannon turned out pretty good for a first time one off. I find brass fickle/sticky to turn. You must have had some pretty sharp tooling to get that finish.
 
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PeterT

Ultra Member
Premium Member
#5
re spokes, I'll take a better pic for you. Might be an optical illusion.

re brass (and its equally evil cousin, bearing bronze) I'm having to make some things lately & had a few WTF surprises. They can be very grabby materials, at least on drilling operations. So I bought a set of HSS drills & have altered the tips (dubbed is the term I hear) to change the rake angle. Made a huge difference, no more drama. Which got me thinking about the brass canon course. Nobody had snatch-and-grab issues drilling that I recall, even on the barrel bore. They were the nicest chips. So I can only assume the instructor 'fixed' the drills behind the scene & we were either naïve or didn't pay attention to this detail... until later in life. Small drills aren't quite as bad. Tapping you need to pay attention too, they make different chips that can clog & bind.

Straight turning brass isn't a big deal. Yes sharp tooling helps & again as I reflect back, I don't recall altering the top of HSS cutters then which infers a more neutral rake. Today I use the same inserts I use on aluminum. I haven't figured out how to plunge a ball end mill into bronze. My first tests did not give me the warm & fuzzy. Might have to make one of those D-bit tools or modify the design.
 

Alexander

Super User
Moderator
Premium Member
#6
Sait made the brass cannon project for a long time. During my apprenticeship there was still a guy in the tool crib and you had to hand him the silly tags to sign cutting tools out. I have fond memories of sait. It was an easy and enjoyable program they put together i did second third and fourth year of my apprenticeship there.
 

PeterT

Ultra Member
Premium Member
#7
YYC, I confirmed the spokes are all in 1 plane, centered on the rim. They are not angled like a bicycle wheel. They look to be a close fit to the hub holes, but not necked down. So basically straight rod stock through the outer brass rim & into the blind holes in the hub.