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

November 23, 2024

CNC Mini Mill -7

A few subjects to update, including the mini mill build, the USS Constitution, the 110pr Armstrong gun model, and plans for another ship modelling machine.

The CNC Mini Mill. The mill itself is finished. I had to replace all of the linear bearings and 8mm hardened steel rods because the play was excessive. I knew that the first shipment of 8mm rods from AliExpress were undersized (7.97mm) and all had a detectable bend. AliE offered to refund if I returned them, but I decided to just try a different AliE supplier. The next lot of 6 x400 x8mm were again a bit undersized at 7.98mm, and were not bent, but still the play was excessive. Slow learner, I tried again with another order and called it quits when they came in at 7.99mm (new Mitutoyo micrometer). But there was still excessive play, so I wondered about the linear bearings. Stuart T came to the rescue with some leftovers from his build of the mini mill, and they solved the problem. No detectable play at all. So it was both the steel rods AND the bearings at fault. Anyway, all fixed. And now I have 20 dodgy spare linear bearings, and 12 dodgy steel rods. Stuart said to bin the lot. But I can’t quite do that, so into the workshop supplies for the time being.

Also, I have now copied Stuart’s design for the electronic controls, and set them up in a nice plastic box with a transparent lid. SO many exciting coloured lights that I want to be able to see them at a glance.

There is a power transformer under the alu shelf, and on top are 4 stepper motor modules (foreground), the CNC controller and breakout board, rear. Also a computer fan, power switch and fuse, E stop panic button, 25db connector for the pendant control, and Ethernet port to connect to the computer.

The only things missing are the bits to transport the electrons around the place. Will happen soon! Then have to decide just what this machine is going to be used for. Yeah yeah. Another tool looking for something to do.

Constitution has had a rest while I have working on the mini mill. But in the past week I have been busy making masts and fighting tops, and trying to decide on the order of glueing bits together. Bowsprit and 3 more vertical masts almost finished. But no stays yet in place. The instructions say to totally finish the hull and fittings before commencing the rigging. Oh, have I mentioned that I made a ropewalk for making the models fixed and running rigging, as well as the cables? I forget. Well, the fixed rigging gets installed first, and some of those big ropes are totally served (are totally covered with thin rope to increase their resistance to water ingress, and rotting, and increase longevity. Did you know that a ship of Constitution’s size had approx 50km of rope, and the average life of a rope of the era was only 5 years!

As well as serving the ship’s ropes, there is a process called seizing. Best to look at a picture…

Securing a rope end by doubling it back on itself, and binding the 2 parts together with smaller rope is called seizing.

I tried my hand at seizing, but was totally dissatisfied with the result.

Seizing on the 3 bowsprit stays. Pretty lumpy and crappy. Got to be a better method. Also my effort at micro painting. That stars and stripes is about 10x7mm. A bit sad considering that these hands used to do microsurgery.

So, a machine to do seizing and serving (and worming or snaking and parcelling, but more about those later), is in my plans. Another machine is being planned. CNC again. And the control box listed above will control the seizing/ serving machine. More about that in a future post.

Finally, and incredibly exciting, is that my post about modelling the sights on my 110pr Armstrong cannon in 2022 https://johnsmachines.com/2022/10/25/model-armstrong-110pr-sights/ has prompted a response from a UK reader who has recently purchased a tangent sight from an online auction, and he has identified it as coming from an 1867 Armstrong 110pr cannon. In researching the sight Daryl came across my modelling posts, and he has contacted me, forwarding some photographs. Just to remind you, this is what I modelled, from line drawings published in the 19th century…

Yes, the left hand tangent sight does cant slightly more than the right. As intended.

And here are some photographs taken by and reproduced here with permission by Daryl Pendlebury-Jones of his purchase…..

The rear tangent sight, approx 500mm long. Gunmetal. Daryl notes that the notched top (top left) slides nicely and freely. And the markings are still clear.
Lateral view, notched top at bottom right.

I might have to remake the sights on my model now that I have seen these pics.

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January 5, 2020

?Next Project

I am home after a short holiday at Port Fairy, Victoria.  Port Fairy is on the “shipwreck coast” of Victoria, labelled for the number of ships which were wrecked in the 19th century.  Dozens and dozens of them, including the tragic “Loch Ard”.   Port Fairy was a sealing, whaling, fishing village in the 19th century, but now survives on tourism and dairy farming.  It was also the site of horrendous massacres of aboriginals.

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Port Fairy was part of the coastal defences against a possible Russian invasion in the late 19th century, when Britain was the enemy of Tsarist Russia.  Not that any invasion eventuated, or probably even contemplated by the Russians.  But no doubt they were pretty pissed off by the defeats in the Crimea, so an invasion of a weak but gold rich British colony was not not totally ridiculous.

So Port Fairy, and nearby Warnambool and Portland were fortified with decent shore based artillery.  The coast is incredibly rugged, with few landing places.

Today I saw some of the fortifications.  And my next project?….

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It is a muzzle loading, rifled bore, 80lb, black powder cannon (RML).  The associated machinery is in poor condition, but much of it is present, and its original form can be inferred.  Most of the external brass and bronze fittings such as sights and gauges have been removed, probably stolen.

The barrel itself is in good condition.  It is fired to entertain the tourists every Sunday at 1200, and on New Year Day at 1400.  Just a blank charge of course, about 1/8th of the charge which would have been used to fire a projectile.  I was fortunate enough to be present at the January 1 firing, and it was awesome!  Very loud.  A sharp “crack”, and gout of flame, and air shock wave.  Very impressive.   Rated as an 80lb cannon.  Far from the biggest ever RML, but still awesome.

And our model engineering society has a connection with the gun.  One of our GSMEE members used to prepare the demonstration charge, and conduct the weekly firing.  He operated a stone quarry, and was qualified to handle black powder and other explosives.  He tells a story of one firing which had a funny ending.  Someone else had prepared the charge, inserted it ready for firing, which was done.  Unfortunately he had neglected to remove the powder container, which was a “Milo” tin.  A few minutes after the firing, a very irate cop demanded to know who had fired the gun.  The Milo tin had landed on his patrol car which was about 100 meters away.

No (legal) charges were laid.

And another connection…   my son in law grew up in Port Fairy, and has fond memories of the town.

So I have taken many photographs of the gun and its carriage and machinery, and many measurements using a builder’s tape measure.  The overall length is 4 meters plus protruding barrel, and if I use the same scale as my previous 3 cannons, 1:10, it will be about 400-500mm long.  At this time I am preparing some drawings.  Thinking about materials.  Possibly steel.  With some bronze and brass for the fittings.   But I will finish the Southworth vertical steam pump first.

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Found this photo of a very similar gun which was mounted at Port Jackson, NSW.

 

Back home now, and watching the news about Australia’s climate change fires, politicians posturing, and the president who ordered a murder.  Absolutely appalled. “We got him”.   WTF.

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October 12, 2016

More Scale Stuff

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There is the 1464 Turkish bombard (black), 17 tons, 307kg granite ball;  the 1779 long naval gun off USS Constitution or HMS Victory 24lb balls; and a 32lb carronade.  All 1:10 scale.  Interesting to see them together on my kitchen table?

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May 4, 2016

CANNON BALLS FLOAT IN THIS LIQUID

OK,  so I am not quite ready to post my pics of the scale model carronade, and the number of hits and likes on this site is plummeting, so I am re-posting someone else’s video to retain your interest.  This is interesting!

 

Mercury has a melting point of -38 celsius, and a boiling point of 356 celsius.  It is 13.6  times as dense as water.  It is the only metal which is liquid at room temperature.

Mercury is very poisonous.  However it is a component of dental amalgam, used in tooth fillings, but it is calculated that you would need 490 fillings to reach toxic levels.  I hope so.

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