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.

NBN. At Last!

And about the last.  The fibre optic network was commenced about 3 years ago, and I applied for a connection shortly after.

Despite living in the centre of Victoria’s second biggest city, my house was not connected to the National Broadband Network until today.

Until then I have coped with download speeds as low as 1mb/sec, and uploads as slow as 60kb/sec.  Do you wonder why I upload so few videos?

Today, the NBN was finally connected.  The download speed is a blistering 50mb/sec, and uploads 25mb/sec.  Wow!

Just to celebrate, I am posting some pictures.  Not much to report from the workshop, but I am accumulating some items in readiness for rifling the model cannon bore.

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This photograph would typically have taken 60-120 seconds to upload previously.  Today it took about 5 seconds!    As you can see it is a cold saw blade which has seen better days.  My bad, unfortunately.   But I saved the pieces,  because these blades are made of high quality tool steel.  I have had some parts laser cut .

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The laser cutter left the tabs intact so the tiny parts would not be lost.

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The 2.5mm thick part popped out with a bit of finger pressure.  Not much tidying up required here, but I will sharpen the cutting edge.  This will be the cutter for the rifling of the model cannon.

This is the first time I have had parts laser cut, and I am impressed by the accuracy and smoothness of the cut and the narrow kerf (0.2mm).    Oh, and the cost.  It was surprisingly inexpensive.  ($AUD26).

 

Repairing Failed 3D Prints

As a beginner, I have a fair percentage of unsatisfactory prints.

Print breaks free of plate.

Supports fall over.

Overhanging areas insufficiently supported.

Holes appearing due to wrong settings.

etc. etc. etc.

Most of the time I just bin the failure, change the settings or setup, and make another print. And wait another 2, 9, 12 or 24 hours……  Not a huge financial cost, but does involve waiting.  And I am not very good at that.

I used to grow olives and make olive oil.

Sometimes the bottles of oil were sealed with wax.  Melting point 85ºc.

After a failed print of 6 items today, due to inadequate supports of overhanging areas, I wondered if the holes and thin areas could be fixed with the bottle sealing wax.  After all, lost PLA casting is just a descendant of the lost wax method in the metal casting process.

So I found the left over remnants of the bottle sealing wax, and heated up a soldering iron.

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One of the failed prints.  This is a wheel trolley bracket for the model Armstrong cannon.  The moth eaten area was overhanging, and the support had fallen over.  The area was thinned and the holes were not properly formed.   If a brass or bronze casting was made from this, it would have been unusable.

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The 850g slab of bottle sealing wax, and soldering iron.  I do not know if this supplier is still available.  It was not expensive.

The soldering iron is heated, dipped into the wax, and the molten wax carefully dripped onto the deficient area of the print, gradually building it up.

The wax can then be shaped with the soldering iron, or a heated knife, or even a finger or thumb.  I also tried a blade shaver and sharp knife.  I think that my soldering iron, and finger were the best tools.

 

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The repaired area.  It looks unsightly, but of course the wax will all disappear during the casting process, along with the PLA.

I am probably reinventing the wheel with this idea.  Again.  But have not seen it used anywhere else.  So there it is.  I think that it will be useful to me.

PS>. 12 hours later.  I now realise that this is so old hat that I embarrassed that I posted this.  Reinventing the wheel,… that’s me.

 

 

Bronze Casting. 1.

My model Armstrong cannon has some components which will be difficult to machine, and would involve silver soldering many tiny pieces.

For example, the steel brackets in which the wheels are supported, and the centre column.

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There are 4 trolleys like this.  Each one has 2 or 3  wheels.  It is a Z shaped profile with 3 gussets visible and 2 more inside.

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The centre column.  It could be fabricated.  

But being basically lazy and always looking for the easy way out, I have decided to investigate the possibility of casting these parts.  And some others.

So I have printed them in PLA filament, with a view to a “lost wax” type of casting process.  It will be “lost PLA” of course.  Maybe doing the casting myself.  But also checking the possibility of having it done professionally.

The PLA printed parts which will be melted and burned away in the casting process, have to be as well finished as possible.  So I have been experimenting with various settings in 3D printing.  One problem is that the molten plastic thread has to be supported.  Overhangs up to 45º or even 60º can self support.  And even horizontal overhangs can self support if the gap is not too big.

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But this gap, about 20mm, proved to be too big…

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The threads are partly bridging the gap…

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Horrible.  It is the underside, but even out of sight, it is unusable.

So, I am printing up some supported versions, even as I type this.  And I am going to look at some casting equipment which I might be able to borrow.  Apparently the gas furnace is very noisy, and it needs a home with no close neighbours.   List…. a furnace capable of melting bronze, a crucible, investment casting powder,  protective gloves, helmet or face mask, leather apron, tongs, slag ladle, a casting box.   There are many YouTube videos on the subject of lost PLA casting.    Watch this space.  But if the quote for professional casting from my printed molds is not too fierce, I will probably take that path.

3D Printing Question

3D printing is really slow.  So slow, that the machine is left unattended to continue the print, overnight in many instances.  The print head is set at 205ºc and the table at 60ºc, and it does bother me that this hot machine is left unattended, unwatched.  I do not know if any fires have resulted, but fires are of some concern, particularly here in Oz.

A substantial component of the printing time is the hidden, internal structure of the object being printed, the “infill”.

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In this photo I set the infill at only 3%, but to compensate for that I increased the wall thickness.  The result was a nicely rigid article, but it was a 24 hour print.

My question.   At this point in the print job could I have paused the printing, and filled the cavities with a substance which set hard.  It would have to be done carefully of course, and keeping the level below the printing edge.  It would also have to be cool or cold, so the PLA did not melt or distort.  It would also need to be able to be poured, or injected.  Plaster of Paris comes to mind.  Car filler bog would be too viscous.

Any suggestions?

Model Cannon Barrel. (T)rifling Thoughts.

My aim (as it were) in making this model cannon is to have a high visual quality exhibition piece.

It is a 1:10 scale model, 1866 Armstrong 80lb, rifled muzzle loader, blackpowder cannon.

One question which always arises is whether it will be actually fired.  My answer is that if it could be fired legally, it would be nice so I could make a video.  However, Australia has very strict gun control laws, (with which I totally agree), and I do not intend to flout those laws.  So this gun will not be capable of being fired.  It will have no touch hole.

To satisfy the visual appearance of a touch hole there will be a laser printed dot at the location.  Along with laser engraved Queen Victoria insignia, sight lines, etc.

But, it IS a rifled cannon, so I do intend to rifle the barrel.  And that needs to accomplished before the trunnions are fitted, and after the cascabel is fitted, so the orientation of the rifling is as per the original.

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The original rifling.  The 3 grooves are each 30mm wide, (clockwise or anticlockwise, not sure) and extend up to the edge of the powder chamber.  They are about 2 mm deep.  The powder chamber is slightly wider than the barrel bore, being continuous with the depth of the rifling grooves.  It is academic, because it will not be visible, but I will make it (the powder chamber, and the whole model) as accurately as I can, for my own satisfaction.  Fortunately the powder chamber is accessible to machining from the breech end, because the cascabel is screwed into position, and is removable.

Yesterday I started making the cascabel.  It was difficult.  The steel thread is lathe cut first, then the shape is lathe CNC’d.  Then there is milling the insides, and making a removable pinned rope retainer.  The third attempt was the most successful, but I am still not satisfied, and so there will be another one made today.   This is what I have so far…

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The turned barrel, threaded to accept the cascabel.  More work is required on the cascabel.

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The cascabel is mounted in an ER40 chuck.  It has been drilled and milled, and a removable insert is temporarily glued into place pending more machining.

 

Rifling.  Searching YouTube reveals multiple tools and setups from US sites.  Here are a few screen shots to show you some varieties.

From the sublime ….

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to the other extreme…

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No.  I will not be using a PVC pipe lash up.

The amateur designed and built machines are interesting….

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Sine bar on the right.

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Then there is the method of pressing a button cutter through the bore.  My bore is an odd size, so if I used this method I would need to make my own cutter.

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This one is a computer animation of a 19th century rifling machine, now a museum exhibit.   Can you see the barrel?   Armstrong probably used a much larger version of this type to rifle his cannons.

 

But I think that I will use none of these methods.  I have a CNC mill and a CNC rotary table.  Mach3 can control both of these machines simultaneously.   If I mount the cutter assembly in the rotary table, and the cannon barrel to the mill quill, I should be able to cut the rifling grooves.  Still working on this one.

Naval Gunnery. A Book Review.

Naval Gunnery.  A Description.  by Captain H. Garbett.  R.N.  360 pages.

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Was originally published in 1897, and is a book which has been considered by academicians and scholars as being of great significance and value to literature.  As such, it has been reproduced by Alpha Editions in an inexpensive, facsimile, paper back edition.

I came across an article about rifled muzzle loading cannons which referenced the book, and led me to purchase it from the Book Depository for $AUD20.

It, the book, is fascinating.  1897 English, is beautiful to read, non ambiguous, and unusually, does not provoke the grammar Nazi in me.

And the book has answered my questions about cannon construction.  Not completely, mind you.  I still do not know how they managed blind rifling.  But most of the first 78 pages are about muzzle loaders, particularly Armstrong muzzle loaders.  With diagrams.

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One question which was answered was about the “recoil tube” located below the barrel of the Port Fairy 80 lb RML’s.  I wondered whether it was like a gas shock absorber.  The book explains that these long cylinders had a piston, and were filled with “Rangoon Oil”, (look it up.  It is in Wikipedia), and they were indeed designed to moderate the rate of recoil of the cannon.

Another fact about rifled cannons…   the rifling causes the projectile to emerge from the cannon slightly to the left or the right of the cannon axis, depending on whether the rifling is clockwise or anti-clockwise.

The book has chapters on breech loaders, naval mountings, quick firing guns, magazines, shell rooms, loading arrangements, sights, powder, cordite, projectiles fuzes, battleship development (up to 1897), battleship organisation and manning.

360 pages, 12 plates (black and white), 113 text illustrations.

If you have an interest in pre-dreadnought naval guns, this book is highly recommended.

 

Another Model Cannon Builder

One of my US readers has made a model rifled cannon, an Armstrong 110lb breech loader, 1:9 scale.  And it looks superb!  Best of all, he has made 2 videos of firing it.  I definitely recommend checking out the build and the firing in the link below.

I will substantially copy the rifling setup which Jeff used.  My sincere thanks to him for the information.

http://jefenry.com/main/110PounderArmstrong.php

Armstrong RML barrel

After 3D printing a plastic 1:10 barrel I decided to have a go at turning one in steel.  I had a length of steel 70mm diameter and 290mm long, which was just too short to turn the entire barrel, so I decided to make one of the breech reduction rings separately, when I make the cascabel.

I did not know what the steel grade was, but it was off a machine so I thought that there would be a good chance that it would be reasonable quality.

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The length of rod next to the printed barrel.

The turning was initially fairly routine.

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and I was really pleased with the finish which was appearing.

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Mountains of hot swarf.

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The roughed out barrel.  I used the 16mm drill bit to drill the bore from both ends, but there was still 50mm or so beyond the reach of the bit.  So I silver soldered the drill bit into a length of silver steel (drill rod).

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And quickly completed the drilled hole. 

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Then transferred the piece to the CNC lathe, and shaped the barrel exterior.

I experienced 2 problems with the CNC turning.  The tapered chase of the barrel, and the rounded fillets came out really well, but the straight sections of the breech developed chatter marks.  I was preparing to take a skim to remove the chatter marks when I bumped the manual CNC control, the cutter dug in, and I got a deep score in the breech.  And broke the carbide cutter.  I turned away the dig in, but it left the breech diameter 3.5mm undersize.

I have no more steel of that size, and it will be quite a while before I get an opportunity to buy some.  So I persisted with the slightly undersized barrel.  It will be 62mm diameter rather than the intended 65.5mm.   I still have not decided whether to scrap it and start again.  But if I can get some more suitable steel I will remake it.  I might even use the undersized barrel to make a 64lb Armstrong RML, which had a smaller diameter breech than the 80lb RML which I am making.

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I showed it to SWMBO.  “That is beautiful” she said, somewhat to my surprise, and being surprised by its 3.5kg weight. 

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Ah…  if only…

Armstrong RML. Roughing Out the Barrel

Today was humid.  But I hardly noticed.  I was attacking a piece of 72mm diameter steel rod for the Armstrong 80lb model cannon barrel.   Enough of the plastic printed shit.  Now for the real material..

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It was a piece of an axle.  No idea of the exact material.  But it is magnetic, turned beautifully.  So not stainless.

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The roughed blank, and the plastic printed model.

Next problem was to produce the 16mm bore, through 285mm.

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None of my 5/8″ (15.87mm) or 16mm drill bits were long enough, so I drilled from both ends.  Still have a substantial chunk in the middle.  The cutting fluid is my own mixture of olive oil and kerosene.   I used to grow and make olive oil and I have quite a bit left over.

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The roughed barrel, ready for CNC finishing.  And a 16mm drill bit which I turned down to a 10mm shank, and a piece of 5/8″ drill rod/silver steel drilled to 10mm, which I will silver solder to the drill bit to make it adequately long to drill through the whole barrel tomorrow.

 

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The roughed barrel, and the 16mm drill bit ready for silver soldering.  Yeah.  It is a bit longer than necessary.

Turning cannon barrels is really satisfying.  Still considering how to manage the rifling.

BTW.  I am not feeling the love lately.  If you want these posts to continue, you need to hit the “like” button occasionally, or better still, make a comment.  If I continue to feel unappreciated I will just stop.

3D Printing a Cannon Barrel

There is quite a learning curve to 3D printing, and most of my prints so far have exhibited considerable room for improvement.  There are some helpful YouTube videos on the subject, but at my beginners level there is still a lot of trial and error.

I am still planning my next cannon model build, and printed some cannon barrels to improve my printing skills, and also to have a plastic model of the barrel to help decide about construction methods of the metal model.

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This is a 1:20 print, but was unsatisfactory because the cascable, and the rifling did not print.

The next prints took 22 hours (vertical orientation) and 24 hours (horizontal orientation) each.

Firstly the vertical orientation..

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It starts with a thin line which marks a little beyond the outside outline of the model to ensure that it is properly located on the printing plate.  Then a thin base to ensure adherence of the model to the printing plate, for the duration of the printing.  My plate is heated to 60ºc, which is not essential with the PLA filament which I am using.  I changed the filament colour for aesthetic reasons.

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Each layer of filament adds another 0.2mm of height.  The rectangular columns support the overhanging parts, and increase the overall support of the model during printing.

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The printing is finished after 22 hours.  I can already see some mistakes.  The barrel should be smoothly rounded, instead of faceted.

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After breaking off the supports.  Next to a bit of workshop rod  which I will use to make the actual cannon model.   Not quite long enough, but the rifled gun tube and cascabel will be made separately so the steel rod will be long enough for the rest of the cannon.

The next print was horizontal…

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I made the supports more densely placed to improve the support.  The cannon barrel is just appearing in the centre.

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I left the printer to continue overnight, and this is what I saw next morning.  Note the longitudinal placement of the plastic fibres.  Infill set at only 3%, which was adequate.  I increased the outside wall thickness to 5 layers, which was plenty thick enough.

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The finished horizontal print on its supports (front) and the vertical version (behind).   Apart from the facets, the appearance of the vertical version was better IMO.

Now I am ready to turn the barrel in steel.  I have obtained a facsimile book about naval artillery which was written in the late 19th century, it reveals that the Armstrong barrels were made in concentric pieces, and heat shrunk together.  I will adopt a similar method, making the cascabel and the central rifled tube separately from the breech sections.   Not decided whether to heat shrink them together, or silver solder, or Loctite. (ps. a week later.  Changed my mind.  Making the barrel from a single piece of steel)

The artillery book also answered my question about 64 -80 lb cannon and bore sizes.  When round shot was replaced by pointy cylindrical projectiles, the projectile weight could increase by increasing the length rather than the diameter of the projectile.  And some 64lb cannons were redesignated as 80 lb cannons, after modifications which did not necessarily alter the bore.  Unfortunately the book does not answer how the rifling was accomplished with a closed breech.

And I made another workshop tool.   This one is a lathe tool height gauge.

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I expect that the tough PLA will stand up to workshop treatment quite well.  It is light, very visible, will test upright and upside down tool bits, and will hang on a conveniently placed hook. Also, it is within 0.01mm of the required 38.05mm tool height.  A light rub of the base over fine emery paper will get the dimension right on.

 

 

3D Printing is FUN! (but still slow)

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My 3D printer.  Bought from Amazon on a special offer.  $AUD279.  Worked straight out of the box after minimal assembly, and using the supplied plastic filament (PLA).  You can see the large gear on the platten which I drew up using a CAD program.  I used the software (Cura) supplied by the printer manufacturer (Creality).   The printer is a Creality CR -10S.  The “S” refers to a “filament out” sensor which I have not yet installed.  I read some reviews of the printer before spending my money, and so far I am very happy with it.  You might notice some bracing bars which I bought separately on Ebay.  Not sure if they are necessary, but they might improve the print quality by reducing vibration in the printer.

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These gears and shafts were printed.  They were used to check the sizes of parts for my next model cannon build.  I used a program called “Gearotic” to plan the gear module, teeth numbers, distance between centres etc.  Gearotic is also great fun.

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The printed gear and pinion quadrant on a background of a photo of the real cannon.  On my model the gear and pinion will be made of steel or brass, machined from bar stock.

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Another part sitting on a photo of the original.  This demonstrated that I had got the corner chamfer a bit wrong.  Much better to discover the fault at this stage! 

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A half size print of the barrel.  This was just for fun.  The final part will be ~300mm long, and will be machined from steel.  This print took almost 4 hours.

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A print of the centre column which the cannon chassis sits on and traverses around.  It is ~60mm tall.  It will be tricky to machine from solid bar.  Could be fabricated in pieces and silver soldered together, but I am considering using the printed part to make a mould and cast the part in brass or bronze……   The original cannon column has an 5-600mm extension into the concrete base which my model will not need.

So far all of these prints have been made from PLA filament, which I read is easy to use, tough, rather brittle, and has a low melting point.  It is also inexpensive (about $20-25 for 1 kg).  I am still on the supplied small roll which came with the printer.  Future prints will be in colour!

The weather is a bit cooler today, so I might get back into the workshop and make some metal swarf.

 

 

Armstrong RML

Some images of what I am planning to be my next model build.  As mentioned in a recent post, I photographed and took lots of measurements of this Rifled Muzzle Loader at Port Fairy, and have been searching the web for more information.  It is said to be an 80 pounder, but the bore (6.3″) is more consistent with a 64 pounder.  Can anyone shed any light on the discrepancy?

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Yes, there will be some interesting machining challenges.

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Not looking forward to all of that riveting.  Considering options.

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Most of the photos were taken with a Panasonic Lumix camera, but some, like this one, were with my iphone, using an App named “My Measures” which accepts annotations and measurements.  The barrel “diameters” above are actually circumferences.  And the “19” is the plate thickness.

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The emblem on the barrel surface.  I am hoping to engrave this on the model, but there would be a lot of time cleaning up the image.

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A web search turned up this image, which will be easier to clean up for laser engraving on the model.

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And some basic diagrams of similar design

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The rifling grooves are 1″ wide.  3 of them.  How to make them?

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I asked about rifling grooves at a GSMEE meeting, and Rudi showed me how it is done.  He made these 2 rifling tools.   They are pushed through the bore to create the grooves.  The bottom tool was most succesful, because it has a pilot diameter.  But, the tools cannot be pulled backwards, so both ends of the bore must be open.  But what about the cascable end of the cannon.  It is not a breach loader.

Then the penny dropped…..I remembered seeing this diagram…

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The cascabel screws into the barrel.  That opening will allow me to broach the rifling.  I do not know how the rifling was made in 1866!  (does any reader have information on that point?)  Note also that these barrels were usually made with some concentric tubes of steel.  I expect that the model will be one piece of steel, with the trunnions silver soldered.

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And I have started drawing up the cannon, massaging the field measured dimensions (which were obtained with a builders’s tape measure)…

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And doing gear calculations for the gear train and rack.  Lots more detail to go into the drawing and plans.   And thinking about construction methods meanwhile.  Now who has a metal sintering 3D printer for loan?

 

3D Printing is SLOW

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Crealty CR-10s 3D printer.  The machinists parallels were my solution to ensuring that the horizontal arm is parallel to the base frame.

So, I took delivery of the 14kg box, and spent a couple of hours assembling the printer.  It was partly assembled, as delivered, and if I had known what I was doing the final assembly would have been done in a fraction of the time.  The assembly instructions were adequate.  The wiring connections were well labelled.  The wiring connectors were delicate, and I took care not to bend or break them.

The vertical frame bolts to the base frame, and it is surprisingly rigid.  There are 2 Z axis stepper motors, and when not powered up, they can be individually turned.  It occurred to me that the horizontal arm which the Z axis motors raise and lower should be exactly parallel to the base, so I placed the machinist’s parallels as shown in the above photo and screwed the horizontal arm down onto the parallels to set the horizontal position.  I assume that the Z steppers will move the arm equally. (Hmm… I will check that assumption later.)

Next day, I downloaded the operating software.  An older version was supplied with the machine, and the newer version would not work on my old XP Pro Windows computer, so I used the old version.

I spent some time manually levelling the bed, then ran the automatic bed levelling software.

The printed operating instructions are very basic.  An Internet connection is assumed, and I did not have one available, so my first printed object was with default settings and the supplied white filament.

Somewhat to my surprise, it worked.

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The platten is aluminium.  A glass plate was also supplied, so I used that on top of the aluminium.

The filename was “dog”.  I had no idea whether “dog” was a 3D dog, a picture, or whatever.  Neither did I have any idea of its size.  After an hour, I had printed a disk about 125mm diameter and 1.1mm thick.  Then the disk came off the platten, so I aborted the print.

Today, after getting some advice from Stuart T regarding print adhesion I removed the glass platten cover and applied some special adhesive 3D printer cover.  It is called “3M double coated tissue tape 9080A”.  Then I printed 2 more items.  Neither broke free.  in fact they were difficult to remove at the conclusion of the prints.

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This tiny Tyranosaurus was printed from a 3D file which I found on my computer.  It printed in about 20 minutes.  Default settings again.  The supports were too big for the object, and when I broke them free I also broke off the T Rex arms.  Some settings for supports need to be changed.

The next print was a tool which I planned for the 3D printer…..

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The item is a speed handle for a milling vise.  It is 80mm diameter with some grippy indentations on the circumference.  The tricky feature to make is the hex hole, to fit a 19mm hex shaft.  This is the 3D drawing, imported into the Creality software, so the G code can be generated.

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First layers.  Each layer is 0.2mm thick

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The internal framework is a bit lighter than I wanted.  I thought that I had chosen 90% density.  (ps.  a couple of weeks later.  The speed handle seems to be standing up to the usual rough treatment in my workshop, despite my misgivings about its lightness.)

 

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The speed handle on the vise.  Nice fit.  The print took over 2 hours.

Not perfect, but too bad at all.

 

?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.

So Many Mistakes! Am I Too Old for this hobby? Or is it the heat?

Having completed the model Trevithick dredger engine, and not having an inspiration to start another major build, I decided to make another steam driven boiler feed pump.

Earlier this year (2019) I made a horizontal, duplex, twin cylinder feed pump for the 6″ vertical boiler, but I had also purchased the castings and plans for a vertical, single cylinder feed pump, not having decided which version to fit to the boiler.  The horizontal twin version fits and functions very well, but I decided to make the vertical version while I am thinking about another major build.

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This is what it will look like.  Hopefully.  Single acting 3/4″ steam cylinder top, and 1/2″ water pump bottom.

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The plans, O rings and castings.  The castings have been cleaned up on the RadiusMaster, and the steam cylinder (top) is almost finished.

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The 7 pages of plans are excellent.  Imperial measurements and fasteners.  I will use metric fasteners.

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But I work in metric.

So over the past few days, excluding the ones over 38ºc (100ºf), I have been machining the gun metal castings.  And making a real mess of it.

The Mess.

  1. The steam cylinder bore.  Bored with a boring head on the milling machine.  Turned out nicely, but I decided to run a 3/4″ reamer while it was set up on the mill, thinking that the dimension would be more accurate.  I did not notice until too late that the reamer was damaged.  It badly scored the bore.  I considered making a new cylinder from bar stock, but used the boring head to remove the scores.  Now 0.75mm oversize.  Annoying but not fatal.
  2. Steam passage not centered.
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    The steam passage in the cylinder cutout is meant to be centered.  It is off at a 15º angle, and is centered with the cylinder top, but not the bottom of the cutout where it should be.   OK, it will not be seen, will not affect the function.  Just a trivial mistake.  That is the final oversize bore.

    3.  This one could have been fatal.  All of the center drill holes for the screws and steam passages in the cylinder valve face were off by about 1mm.  The workpiece had moved in the milling vice between setup and machining.  I really thought that this would probably require a new part, but I decided to proceed and see what eventuated.

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    The middle 6 holes are the steam inlet and exhaust passages.  Fortunately they are in the correct vertical position, and have just been widened horizontally by the incorrect centre drill holes, which should not effect the function.  The screw holes merged into the incorrect holes, and were pulled a fraction laterally, but should be OK.   At final assembly I will fill the incorrect holes with something, probably epoxy or gasket goo.

    4. This was the most obvious error.  Moved the mill table in the wrong direction, and the rectangular hole ended up with an extension.  I don’t think that it will effect the function.  And it wont be seen by anyone except me, and all of you blog readers.  Oh, and now I have to kill you.

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    Bugger bugger bugger

    5.  This was another mill problem.  I had changed the tools to a 1.6mm drill bit, and reset the Z axis zero.  Or had I?  Maybe I had neglected to hit <enter> after the reset.  Anyway, the chuck crashed at high speed into the job, impaling and snapping off the drill bit, gouging the steam chest, and the drill chuck gouged the milling vice.  The chuck survived but required some remodelling on the belt sander and then a diamond file.   The vice jaw also needed some impact craters to be flattened, then swapped out to another less critical vice.

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    I flattened the gouges in the steam chest face, and I will make sure to fill those with something at final assembly.  The embedded drill bit can stay there, after flattening it with emery paper.

 

There were some other more minor issues, which do not bear repeating and prolonging this missive.  This all happened over 2 days.  Mistakes are made, and I console myself with my father’s advice “he who makes no mistakes makes nothing”.  But, this is the worst run of blues which I can remember.   It IS hot, which is not ideal machining conditions.  So what do I do?

Well, maybe it is just a bad patch, and things will be better next session.  And, I will try to be not SO impatient to get things finished that I don’t double check.  I (and you) will just have to wait and see.

BTW, have a safe and happy new year. 2020.  It is 101 years since we had a double number year (1919), and most of us will not see the next one (2121).  So make the most of it!

 

 

 

30 watt Laser in action.

Not mine, unfortunately.  This one is Stuart Tankard’s.  It is a Ytterbium generated, 30w, fibre laser, and the wavelength is such that the 0.01mm diameter beam will burn holes in metal.  Ytterbium, for those who can’t be bothered to look it up,  is a rare earth metal, atomic number 70,  Stuart has used the laser to cut parts from a 1.2mm thick hacksaw blade.  And in the following video he is making marks in a work-tool rest which I will use on my Radius Master sander grinder.

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It is a 360º protractor, and grid lines at 10mm intervals.   Looks purposeful.  Time will tell if it is useful.

Watch the video.  I am experiencing tool envy.

 

Listening to my own voice is pretty painful.  I hope that it doesn’t grate too much on you.

 

Melbourne Society of Model and Experimental Engineers. Xmas meeting.

The December meeting includes the competition for best model, best workshop tooling, and best engine.  The 3 happy winners were all from Geelong.

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Stuart Tankard, John Viggers, Swen Pettig

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Trevithick dredger engine model by John

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CNC lathe tools, toolholders and toolpost milling attachment by Stuart.

Following is a video of Stuart’s toolpost milling attachment in action.  It has been posted before, but is worth watching again.  It is quite remarkable.

(Photo of the flame gulper to be added.)

But, the best part of the meeting was this demo of a model aeroplane which was made by Don.  The plane weighs 2.5 grams!!!   The wing material is mylar which is 1 micron thick!!!  The flight was cut short by hitting a ceiling projector, but apparently the world record for a flight by a similar plane lasted for over an hour!  This YouTube video has had 360,000+ views in 5 days!

 

 

A modification to the Radius Master

The Radius Master is a quality 48″ x 2″ belt sander which is impressively versatile with its 7 work stations.

The work station which is vertical, and against a platten is the one which I expect to use most often.

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Vertical belt, and using the backing platten.

But the supplied work – tool rest is a bit narrow for my taste, and I decided to make another one.

I really like the one which was supplied with the Acute Tool Sharpening System (ATSS).

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The Acute Tool Sharpening System from Eccentric Engineering.

So I bought some 4mm steel plate and cut it to size (150 x 150mm), and CNC milled a support bracket to fit the Radius Master.

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The Radius Master with larger work-tool rest.

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The rest is adjustable for angle and distance from the belt.  Copied from the original.  The bracket is screwed to the plate.  I did not want to risk heat distortion by welding the join.

Then the penny dropped.

Why not use all of the ATSS fittings and fixtures on the Radius Master?  So that is what I have done.

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The ATSS system looks quite at home, yes?

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Hey Gary Sneezby, maybe you should do a deal with Radius Master.

I can quickly swap the ATSS fittings and fixtures between the CBN grinding wheel and the Radius Master.  It will be interesting to see whether the cubic boron nitride wheel or the belt is preferred for different applications.  I expect that the belt will be best for quick removal of material and the CBN wheel for tool sharpening, but we will see.

Oh, and by the way, the bigger work plate does not interfere with any of the other work stations.

And I will ask my friend Stuart to laser engrave some guide lines on the plate.  I have a new design to try.

And finally, here is a link to the video of using the ATSS, by Eccentric Engineering.  It is worth considering.  If you have not done so, I suggest that you look at Eccentric Engineering’s other tools too.  They are very interesting.  The lathe parting tool is the best one which I have used.  And the Diamond lathe tool gets more use on my lathe than any other.

 

 

 

Between the Classical Greeks and the Romans. The Hellenistic Kingdoms!

OK, now I realise that few of my metalworking, engine modelling, machinist friends will be interested, but just in case……a history book review….

THE RISE OF THE HELLENISTIC KINGDOMS 336-250BC

Philip Matyszak

Hardcover.  £20 RRP

It is satisfying to read a book which plugs a gap in the history timeline.  I chose this title because Philip Matyszak is a terrific author and I always enjoy his books, but once I had read the initial chapters I realized that I knew very little about the kingdoms which remained after the split of the empire of Alexander the Great.

The first third of the book summarises the career of Alexander and his wars of conquest.  Then the maneuvering and wars which determined how the empire was to be divided, and who the rulers would be.  Then a closer look at each kingdom.   The west (Greece, Macedonia), the Seleucid empire (Syria, Persia, parts of India and Afghanistan), and Ptolemaic Egypt.

Matyszak emphasizes that the Hellenistic kingdoms period was not just an interregnum between classical Greece and Rome, but a period with its own significance in warfare, the arts, philosophy, etc.  Three of the seven wonders of the ancient world originated in the Hellenistic kingdoms.

Unfortunately, there are many place names in the text which do not appear on the four simple maps.   Why can’t decent maps be considered an essential component of history books?

(If any of my metal working, modelling, machinist friends would like to borrow this book, just ask.)

 

 

 

 

Bucket List. A Book Review leading to..

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GLASGOW MUSEUMS THE SHIP MODELS

A HISTORY AND COMPLETE ILLUSTRATED CATALOGUE

Emily Malcolm and Michael R Harrison

Large format, hardcover.  £35 RRP

 

Doesn’t sound particularly interesting?  That was my thought when I read that this book is a catalogue.  After all, who reads a catalogue?

 

However, the artwork on the covers is attractive and interesting, and I do have an interest in ships, models, modelling and history, so I opened a few pages at random.   And was transfixed!  This book is glorious!   Back to page one, read a few pages, then worked through every one of the 373 pages.

 

The photographs of the models are beautiful and expert.  Most are laterals, but some are of smaller details.  There are many historical photographs, pictures of modelers in action, previous exhibitions.  To describe the pictures as “lavish” would be an understatement.

 

Glasgow and the River Clyde was (and is?) famous for ship building.  Most of the 676 models in the Glasgow Museum’s collection are of ships built or owned in this region, over the past 150 years.  So this book includes models from the age of clippers and steam dredges, through the age of steam and dreadnoughts, to Queens Mary and Elizabeth, and later.  A wonderful historical tour.

 

Chapter 1.  Models in Shipbuilding (the whys and wherefores of making model ships)

Chapter 2. Professional Model Making (there were companies which made models for ship builders and owners for industrial and marketing reasons)

Chapter 3.  Amateur Models.  (including models made by French prisoners of the Napoleonic wars)

Chapter 4.  Ship Models and Exhibitions

Chapter 5. Building the Collection

The Catalogue  (220 pages)

 

Glasgow is now on my bucket list.

A few random pages to tempt you.

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Yes, I do find dredgers interesting.  Note who bought this one.

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