HMS Bellona 1760 by SJSoane - Scale 1:64 - English 74-gun - as designed

[Siggi52]

Hello Mark,

 

did you see the pictures of the cutter Cheerful from the Rogers Collection? Even at this cutter from 1805 the breech ropes where laid only above the cascable and not turned around it. It seems that the gunners at that time did't  fear that it would slip down.

At least it looked like on a bazaar, everyone who had a picture with a cannon on it, posted it. But none has any historical sources for that! 

So I think we are right to do it like the historical sources, Falconer, the Royal George and also the Cheerful model show it.

 

Your cannons looking pretty good. Greater pictures would show that much better 😉

 

[SJSoane]

Thanks, Siggi, the weight of evidence seems to be pointing in the direction of laying them over the button. Since there is no other evidence we have been able to find for the period of ca. 1760 that is contrary to this, I will go with this solution. Plus, it saves making cut splices in 74 ropes!

 

I am working away on plaster sleeves for my cannon moulds, hope to have something to show in a day or so.

 

Mark

[mtaylor]

Siggi,

Those appear to be carronades in the photo.  Weren't they rigged differently due to the carriages being different?  

[SJSoane]

Hi everyone,

 

I have been working my way through a number of issues fixing the cannon moulds. Following druxey's and Michael's good advice, I have cast plaster sleeves for three of the four masters. I used Hydrostone dental plaster, which worked very differently from plaster of paris. It is a much smoother finish, but it was exceptionally liquid following the recommended mix on the package, of 2:1 plaster to water. I found a manufacturer sheet online which suggested 3:1 plaster to water. I tried this for the second pours and it was better, but still very liquid. The watery mix began to attack the foamcore mould boxes. They are still moist and cold after sitting a day. I will wait until they are bone dry before trying. If I did this again, which I hope I will not have to do, I might try as much as 4:1.

 

But for the 9" long gun, which was not having registration issues as much as the others, I tried drilling for registration pins through the plywood and rubber sandwich on a drill press in two corners. This seemed to work quite well. 

 

And just for fun, I tried pouring with and without first dusting talcum powder into the mould. You can see the fundamental value of the powder (talcum pour on the left, no talcum on the right.) The one on the right goes back into the melting pot.

 

 

Mark

 

 

 

 

 

 

 

 

[druxey]

That's the good thing about poor castings - no waste! Back into the melting pot they go. That is a graphic demonstration of the use of talc, BTW.

 

I think that the stiffer Hydrostone mix would probably be OK. I usually dry my casts in a warming oven. That drives off the moisture more quickly than simple air-drying. Make sure that it is only just warm, not hot!

[vossiewulf]

I assume the talcum powder gives the metal a capillary surface to run down, without it the natural surface tension of the melted metal leads to an uneven surface.

[SJSoane]

Hi vossiewulf, yes, that was my understanding. I wasn't sure just how much a difference it would make until I tried the experiment. Its value is now very obvious to me!

 

Mark

[michael mott]

Nice work with the mold jackets Mark, and this of course applies to all the mold jackets that we want for production runs, not just cannons.

 

Michael

[SJSoane]

Thanks, Michael, you and druxey gave me good advice on this. I admit to being happier working with wood than plaster, though....😀

 

I spent the day building a fixture for the 32# guns, in order to mount the casts in the lathe for drilling and facing the muzzles.

These are shaped so the hind end can go into the Sherline lathe headstock as far as possible, so the fore end does not project too far beyond the jaws of the chuck. This is to keep everything as concentric as possible at the face. Things get tight at the rear of the headstock, due to the Morse taper there. There will obviously be more clearance with the smaller guns.

 

These still have to be drilled so the trunnions can recess into the fixture.

You will see some burning on the inside of the fixtures. This is because I had to make very precise diameter holes to grab the front and rear of the cannon, and these dimensions were not an exact size of drill. So I used the Sherline boring tools in the lathe (see below). I could not get these to work very well. They cut grooves, and burned the boxwood I am using for the fixture (so the chuck jaws don't compress these too much, and throw things out of true). And I was taking such light cuts that it took a long, long time to bore out from the closest drill size I had first used for initial clearance.

 

Does anyone have any thoughts about what I am doing wrong with the boring tool?

 

This is the first time I have used them, so I haven't yet seen them work well.

 

Mark

 

 

 

 

 

 

[druxey]

Silly question: is that tool mounted correctly relative to the direction the stock is turning? Is it rubbing rather than cutting?

[SJSoane]

Hi druxey,

 

Good question, I could not find any instructions on the Sherline pages, except to line up the notch in the top of the boring bar itself, with the top set screw in the boring mount. But it sure does act like it is rubbing. The cutting edge as I have it set up appears to be meaning to cut at the back lower edge of the relief hole, cutting as the wood is starting to climb up around and back to the front. 

 

I also experimented with the angle of the boring bar to the axis of the lathe, because sometimes the bar started to rub at the outer edge of the hole as it got deeper. Didn't seem to make any difference to the quality of the cut.

 

Maybe I should try flipping it upside down, although the flat would not align with the set screw.

 

Mark

[mtaylor]

Is the rotation of the stock such that it's cutting?   The boring bar that I have actually looks like a bit of a short "L" and I to reverse the lathe to use it as it's cutting edge is at slight angle "down".   Run the lathe the other way it scrapes instead of "peels".   I hope that makes sense.  

[Landrotten Highlander]

I think Druxey and MTaylor are on to it.

From my days learning to work the lathe (admittently, many decades ago, and in steel rather than wood) we always aligne our boring too in the horizontal plane (so not vertical as you are doing) and had to have the tailstock running in the opposite direction than for outside turning.

 

The benefit in this setup is also that it is much easier to include a counter pressure to your cutting edge (in other words, if you have tube sticking out a long way, the moment your tool touches the inside of the tube it will always attempt to push the tube out of alignment, leading to an oval shape, rather than a perfect round one - having something gently pushing against the outside will counteract this).

[Gaetan Bordeleau]

Yes they are. The idea is that only the point of the cutter must touch the metal to remove. there must not be other friction from the tool on the metal.

A knife that I used and I added another to show on top

[SJSoane]

Thank you Mark, Landrotten Highlander, and Gaetan, for these ideas. And Gaetan, I look with envy at your full size lathe. I will likely never be able to get one, but I can admire from afar!

 

I woke up in the middle of night, thinking that I should try cutting on the side of the hole towards the operator, rather than away from the operator as  I tried yesterday. But that rubbed even worse.

 

As it turned out, you were all correct. I rotated the cutting edge 90 degrees, and it works perfectly cutting on the side of the hole closest to the operator. Thanks!

 

So it is interesting why the Sherline setup has a flat cut on the top of the boring bar for the set screw, when the bar needs to be 90 degrees to this arrangement. I then realized that they originally sold these for a boring head for the mill, which does use the flat to locate the bar correctly. They say that the bars can be used in the lathe, but as far as I can find, Sherline did not explain to rotate the bar in the lathe setup.

 

There is an interesting lesson here. I knew something wasn't working well yesterday with chattering and burning, but I just kept on going thinking that I might be able to correct with a different feed speed or RPM adjustment. I did not take the time to rethink why this setup was not working well, or try other things like rotating the head. I know that machines speak to you, if only you are willing to listen. I did not listen well yesterday!

 

Thanks again, everyone,

 

Mark

 

Edited March 30, 2019 by SJSoane

[Gaetan Bordeleau]

If the cutting end face the top; you would be able to cut only 1 diameter size.

When the cutting end is forward you can move it towards you with the cart and this way you enlarge the hole as you wish.

[SJSoane]

Thanks, Gaetan, it worked perfectly!

 

So here is the fixture for drilling and facing the 32# cannon. This one is a little ragged inside because of my boring challenges. Now I have that figured out, the 18# and 9# fixtures ought to come out a little more elegantly. This one needed a little adjustment internally with a flexible shaft cutter.

 

Mark

[druxey]

Glad we helped you sort that one out!

[mtaylor]

Great to hear the problem is solved, Mark.   

[SJSoane]

Hi everyone,

 

More casting, I have only 11 of the 32# and 9 of the 18# to go. The 9# in long and short are done.  I couldn't be patient enough to wait until all were cast, to see how they look  lined up in the 32# carriages:

However, I got up this morning to cast the final cannon, and my MicroMark butane burner died. It won't start. The sparker still works, and trying to fill it quickly has the butane coming out at the nozzle, so I assume it is full. There are no instructions for cleaning, so I appear to be dead in the water. I will have to buy another one, or figure out how to melt the pewter another way. I have a stand-up micro butane torch for soldering, but the heat point is too fine to heat up the entire ladle of pewter.

 

So, moving on for a moment, I made the fixture for the 18# cannon, for facing and boring the muzzle. Much cleaner this time, now you helped me with the boring tool. Worked perfectly. This time, I glued thickish paper between two halves of the blanks, so I could easily split these apart when finished turning.

 

 

 

 

 

 

 

 

[druxey]

I use a regular butane torch for melting pewter, not the small size. It's quicker!

 

Looking really nice so far.

Edited April 2, 2019 by druxey

[SJSoane]

The cannon are all cast!

 

It is fascinating to see all of the cannon together. 74 guns provides a lot of firepower, when you see them all in one place. And I am glad at this point that I did not build a first rate ship with 100+ guns. This got very weary after a while.

 

Next, cleaning up with files, facing and boring the muzzles.

And then messing with blacking.

A big step completed!

 

Mark

[Hubac's Historian]

BRAVO!!

[dvm27]

Awesome work, Mark. The only thing that would make it better is if you were to take higher resolution photos so that we might better enjoy all the fine details you incorporate.

[rwiederrich]

Fantastic work..

 

Rob

[Gaetan Bordeleau]

2 hours ago, dvm27 said:

The only thing that would make it better is if you were to take higher resolution photos so that we might better enjoy all the fine details you incorporate.

 

It is possible to include photos 3 times larger in size.

 

[SJSoane]

Thanks, everyone.

 

Here is the largest image my iphone will take. Above this, I need to switch to the DSLR.

 

Mark

[mtaylor]

Sweet work indeed, Mark, and a very impressive arsenal.    So don't think you want to take commissions for cannons?     

[SJSoane]

Thanks, Marc, Greg, Rob, Gaetan and Mark. After working all winter on these cannon, it is very gratifying to get to this milestone.

 

Mark, I have endless admiration for those who make these commercially. I would never have guessed how long this would take. Admittedly, I had a large learning curve, and a few setbacks; and now I know more of what I am doing, it started to go faster.

 

One would have to make multiple masters of each size, so it would be possible to pour in gangs rather than singly. Even so, the most laborious part is dusting with the talcum powder so there is just enough even coverage without blocking up details, and this would still have to be done for every pour. I would have to charge $100 a cannon just to make it worth my sanity!

 

When I started this quest for cannon, I explored the different ways this might be done: a duplicator on the lathe, 3-D printing, and casting. From my perspective now, even if I had been able to make the duplicator work, it would never have achieved the detail and consistency of the casting, and it would have been even more tedious. 3-D printing is still an interesting option, although it turned out to be beyond my budget to have them printed commercially, or to gear up with a 3-D printer of my own. So I defaulted to casting, which in the end gave a very satisfactory outcome. Maybe that is why it has been used for centuries. Now if only I had the equipment to do lost-wax casting....😀

 

Best wishes,

 

Mark

 

 

[mtaylor]

I do understand where you're coming from.  When I made my comment I added the little icon to make sort of a joke.   

 

Oh boy, lost wax casting is a whole different critter as I understand it.