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

[SJSoane]

 

Thanks, Michael, it is always fun to think of a simple way to do something repetitive, and in this case I can adjust it to mark several decks!

 

Mark

[Remcohe]

Very very clever marking tool!
 

Remco

[SJSoane]

 

Hi everyone,

 

As I started working on the upper deck clamps, I was quickly reminded that I had no way to clamp the clamps. My hull is solid and offers no places to clamp except through the gunports. And that does not help at the bow.

 

So, inspired by Ed T, I built some long reach clamps. Just for fun, I used up some old padouk left over from my workbench, with maple handles.

I was stumped for a bit by how to turn down the end of the threaded rod for a smooth engagement into a blind hole for the top screw. In the end, I just wrapped the rod in masking tape and clamped it in the three jaw chuck. It held firm enough for this light machining, and did not hurt the threads.

 

I will have to work out some specially shaped pads at the end of the clamps, to deal with the angle of the wales and the curve of the bow. But I'll deal with that later, using double sided tape to affix temporary pads.

 

Thanks, Ed, you inspired me to make what I am sure will be very useful tools as I start planking the upper works.

 

Best wishes,

 

Mark

 

 

 

 

 

 

[alangr4]

 

Mark

 

The clamps match the Bellona - all class.

 

Thinking of putting in an order for some made of Madagascan ebony with white oak handles please.

 

Great stuff well done.

 

Alan

[Remcohe]

That sure is a fine set of clamps.

 

Remco

[dgbot]

Mark, I came onto your build late. I am learning many things.

David B

[EdT]

Nice work on the clamps, Mark.  I like the measuring tool and especially the use of the ports to set the deck height.  Beautiful craftsmanship as always.

 

Ed

[SJSoane]

 

Thanks, everyone, for your comments. Alan, black and white clamps sound like an equally nice idea. Maybe the next set! David, thanks for looking in. I have learned a lot through trial and error and learning from others on this site; I hope some of what I learned can be of use to you as well.

 

Remco and Ed, I aspire to your levels of craftsmanship, so your comments are particularly meaningful. And Ed, thanks again for the diagram in your book on making clamps. It gave me confidence to try. I am starting to think about your more complex right and left hand thread clamps, now these are under my belt. Did you get the taps and dies from Contenti?

 

Mark

[EdT]

Mark, I believe I bought mine from Small Parts Inc, since taken over by Amazon, I believe. Amazon has some. A much bigger, almost too big, selction is here:

 

http://www1.mscdirect.com/cgi/nnsrhm

 

These people have everything. I believe you can still get there print catalog which is like a set of encyclopedias. Good supplier.

 

 

Ed

Edited June 18, 2014 by EdT

[dgbot]

I use MSC all the time.  Since I worked next door to their facility I would call it in and drop by after work.

David B

[SJSoane]

 

Hi everyone,

 

I got more work done on the upper deck clamps. I am showing first of all my scarph jig, which I haven't used in several years. The first image shows how the stick of wood is pushed into a notch on the right, and up against the projecting arm. This ensures that both pieces are exactly the same angle, no matter what the width (both pieces have to be the same width, of course, to match). The second photo shows the clamp holding it in place. A first cut is taken the thickness of the thin plywood above the maple jig, and then the cutter is lowered to the maple jig to cut the notch. I use the dials to move the cutter exactly the right distance in the X direction.

 

The third photo shows some pieces of poplar run through the gun ports, held firmly up to the top sill by wedges underneath. This allows me to fit the clamps so their lower edges are exactly at the height of the sill (my sills were cut many years ago to include the upper stop in the sill, so strictly speaking, this allows me to align the lower edge of the clamp with the lower surface of the upper sill stop, which I believe is the correct location).

 

With these in place, I was able to plane the lower edge of the clamp until it fit exactly against the poplar pieces, including getting the acute angle right (it changes down the length, so this helped me see what was going on as I trimmed the edge). Then, I could measure up the side at each gunport location to the marked line of the top of the clamp. I transferred this to the clamps and trimmed the top edge accordingly. The fifth photo shows marking the top edge on the foremost piece.

 

This method allowed me to fit these clamps precisely between two very critical locations--the top of the gunports, and the marked line of the top edge. And it helped me accurately shape the acute angle of the top and bottom edges as they twist with the sides.

 

Interestingly, I found that the clamps are not the same width along their length. They are somewhat wider in the bow than in the stern. I double checked my original Admiralty drawings several times; there is no doubt that the line of the upper deck as shown at the sides in the sheer drawing rises gently in relation to the gun deck ports below as it goes forward, causing the clamps in-between to widen towards the bow. Another one of those subtleties of 18th century ship design. I can imagine no reason for this--keeping the decks parallel would have been easier, and it is independent of the sheer which gives the ship its beauty. It is only a couple of inches, but very intentional.

 

The third photo shows a caul I used to bend the foremost clamps in place after boiling for an hour. The caul helped even out the pressure, so the wood did not snap at the location of the first clamp applied. It worked well, although I still get significant spring-back after sitting all night. I have had problems bending this South American boxwood before. Any thoughts from anyone on how long to boil, and how long to let it sit, so I don't get this spring-back?

 

Best wishes,

 

Mark

 

 

 

 

 

[dvm27]

Love the scarph jig and everything else, Mark! I don't think you can prevent all spring-back. I've always followed Harold Hahn's advice of boiling and clamping over a shaped mold that has too much curve. This allows for natural spring-back after the piece has dried.

[michael mott]

Mark your tools and workmanship show what a fine craftsman you are. Beautiful work.

 

michael

[gjdale]

Beautifully done Mark. Love that scarph jig - do you have any more details (pictures or drawings) of how it is constructed?

[EdT]

Extraordinary work as always, Mark. Your precision always knocks me out.

 

Ed

[alangr4]

Stunning work Mark.

 

Like Grant wouldn't mind more info on the Scarph jig. What is anchoring the steel thread or how does that run through your Sherline?

 

Very clever and like your other tools beautifully designed and constructed.

 

Cheers

 

Alan

[SJSoane]

Thanks everyone. 

 

Here are more details of the scarph jig. The first drawing, number 1, shows the basic geometry of the scarph. The two long cuts, labeled "L", are equal; and all of the depth cuts are the same and are marked "t".

 

Drawing 2 shows the scarph turned so  the angle side will be flat to the mill.

 

Drawing 3 shows the jig, with a spacer arm on a piece of plywood the thickness of "t"; and a notch piece with the same thickness "t" sticking up above the top of the maple block. The piece to be cut is pushed against the notch, and up against the spacer arm. This ensures that all pieces will be in the same location to ensure the same cuts. Also notice that the end of the blank needs to be trimmed to the angle of the scarph before inserting into the jig. I use a sanding disc for this.

 

Drawing 4 shows a mill cutter making the first cut. It is "t" distance above the top of the maple block. In reality, I trim the top of the blank close to this line before putting it in the jig, to save multiple cuts with the mill down to this final cut.

 

Drawing 5 shows the mill cutter making the second cut. Now it is down the distance "t" to the top of the maple block. And it is measured in with the dials of the mill the exact distance "L" from the edge of the notch piece. In my case, the diameter of the cutter was not the full size of "L", and so I needed to move it over a slight distance to complete the second length "L". Using the dials and double checking before cutting ensures that I don't cut into my jig!

 

The photos show the jig with, and without, the clamp. The clamp is simply a T-bolt run through the maple block (you can see the T in the photo from behind), using those cute cam clamps from Rocklers. From behind, you can also see that the plywood spacer on top is glued to a another piece of ply held to the maple block with a nylon screw. This allows me to adjust the spacer arm back and forth to accommodate different lengths of scarphs, or 2 times "L".

 

The whole thing is held in the Sherline milling vise.

 

I hope this helps clarify. If not, let me know and I will draw more diagrams!

 

Best wishes,

 

Mark

 

 

[alangr4]

 

Many thanks Mark for sharing this with us.

 

Very clever.

 

Regards

 

 

Alan

[gjdale]

Thank you Mark for taking the time and trouble to share these details with us. I'm shamelessly copying your drawings and filing them for later use!

[Trussben]

Much thanks Mark for the illustrations!

 

Ben

[SJSoane]

 

Thanks, Alan, Grant and Ben. Please feel free to use, and if you improve upon it, pass it on. It is fun to think about the basic geometry of a process, and automate it.

 

Having said that, I have learned from Gaetan, Remco, Ed T, and David Antscherl about the virtues of hand tools. Gaetan convinced me to keep cutting the carlings mortises by hand, and sure enough, I got fairly consistent and accurate with repetition.

 

Perhaps life is most fun with both.....

 

Mark

[SJSoane]

 

Hi everyone,

 

I just completed fitting the upper deck clamps, from stem to stern. I was reminded of Remco's quote about treating every piece as if it is a model by itself. The last piece had to hook over the helm port transom, and fair into the forward face of the lower counter planking, while twisting from an acute angle forward, to almost vertical at the counter. Many pleasant hours were spent shaping and fitting these... I can also see that the spirketting right under the wing transom is going to be equally fun, as it curves along that knee while sloping back further up.

 

I had an ah hah moment, which notching the clamp over the helm port transom. To stop the saw cuts at exactly the right depth, I stuck two pieces of wood to either side of the blank with double sided carpet tape. I then clamped this in my vise, and used the wood stops to indicate when to end sawing with the razor saw. I don't know why I did not think of this earlier. It is now in my tool box of techniques.

 

Best wishes,

 

Mark

 

 

[michael mott]

Nicely Done Mark.

 

Michael

[druxey]

Oh, neatly and adroitly done, Mark!

[gjdale]

Very nice Mark. Sometimes the simple solutions really are the best!

[mtaylor]

Beautifully done and a great tip on making cuts.

[SJSoane]

 

Thanks, Michael, druxey, Grant and Mark. Those angled clamps at the upper deck level were definitely one of those projects that seemed straightforward starting into it, only to realize just how complex it really is. These really increase one's appreciation of the original model-makers. It really connects one with the past, to realize that someone made and fitted exactly these same parts 250 years ago.

[SJSoane]

Hi everyone,

 

I finally managed to finish the upper deck clamps, with a side tour to rearrange my wall of tools for the table saw, mill and lathe (it is like cleaning the closets or filing papers when you can't get going on something else).

 

I decided to color the clamps and quickwork red, and spirketting black, like many of the admiralty models I admire. So here is a nice ribbon of red around the hull until more inner works come in.

 

My long clamps came in very handy. I wish I had made more.

 

On the the quarterdeck and forecastle clamps...

 

Mark

 

 

[druxey]

Always a treat to see your progress, Mark. Color choice looks great.

[michael mott]

Mark your precision and clean work are a joy to follow, those long reach clamps must be wonderful to work with.

 

Michael