Pride of Baltimore by Jerry Todd - 1:20 scale - as she appeared in Fall 1981 - RADIO

[JerryTodd]

The paint dry, things can be put in their places to check fit and alignments.

Then on to the forward winch-tray.

Reusing the blocks that were epoxied in for the rudder to sit on, I needed them taller and the angle change so the plane of this tray is level with the one aft.  I also need them a little longer because this tray will get slots cut into it so I can adjust it fore-and-aft to set the tension on the loop, and so the screw that hold it are accessible through the hatch.

The battery lays just aft of here as well, so I shaped the pieces like knees to over hang it a little while not interfering with access to it.  The added pieces are glued to the old rudder-servo mounts, but not having a good way to clamp them, I put a couple of bugle-head screws in, which I think I'll leave in there, since they're epoxy coated.

 

Here's a pic of the model with sub-deck laid in to show the access hatch openings as they'll be in the finished model.  The little hatch forward will most likely get decked over when the time comes as it's not really for anything.

The "engine room hatch" over the aft winch and the main hatch will be screwed down with rubber gaskets to prevent leakage since I expect this boat to be as wet as the real one was.

[JerryTodd]

I found a nice pulley wheel, sheave, whatever it ought to be called in this context, at Thingiverse, scaled it to 1 inch diameter and printed 4 of them.

 

 

I mounted them on their blocks with #8 x 1" wood screws with a brass washer under each as a bearing.

 

I cut slots in the forward tray so it'll have 3/8" of adjustment, fore-and-aft.  With all that in place, I couldn't resist running some loops with some Nylon line.  I need to get the radio gear together and charged up to do a real test.

I have a little over 20 inches of travel.  Some fancy block magic and I can get up to 40 inches.

Edited July 3, 2022 by JerryTodd

[JerryTodd]

I sat down last night to modify Tim Bowman's Blomefield 18 pdr barrel to fit Pride, but removing the cascable ring, ER cartouche, and rearranging the barrel bands was more work than starting from scratch, so I started from scratch. Making a gun barrel in 3D is generally pretty straight forward, make a cylinder with a lot of segments and resize and move each segment to create bands, slope, etc.

I had made a new carriage for Macedonian's guns and rearranged it here for Pride. Since these guns are basically static displays, I modeled them in one piece, rather than print the parts and assemble them. I think I spent about 3 hours making the barrel, and another hour redoing the carriage.

  

I saved the STL file, started the print, and went to bed. When I got up this morning I was actually surprised to find they printed great.



Cleaned them up and sat them on the boat to see how they look.
I hoped the rings would be loose, like the anchor chain I made for Constellation, but it wasn't, so I'll probably replace the eye and ring with brass.


Mini-Me (a photo from 1980 scaled to 1:20) and one of my "babies." When I was on Pride, I was put in charge of her guns. I was told they were my "babies" and I should take care of them. My experience with black-powder cannon was one reason I was hired, because the Yorktown Bicentennial was coming up and Pride was going to attend.


Here's the real thing. This was all the rigging they had. No breaching, retrieving tackle, just training tackle. This is all the model will get as well, since it's a model of a particular boat as she was at a particular time, not how it was supposed to be.

[JerryTodd]

Pride also mounted a pair of 1 pounder swivel guns on the rail, port and starboard.  Examining all the pictures I could find, these guns were basically scaled down versions of the 6 pounders; all the shapes match, bands, everything.  That made my job much easier, I simply scaled down the 3D model 6 pounder barrel, made the iron fitting on the cascable, and put a stock on it.  I made the yoke, and posed it all in the position you'd usually see the gun in, and printed two of them.  I don't intend then to function or move.

 

The pin of one of the yokes broke trying to free it from the supports, but I'll probably trim them both and use a brass pin instead.  As this is a working RC model, there's a fair chance of these items getting broken or snapped off by a line snagging, or handing in general.  The nice thing about 3D printing though, is the ability to print a replacement. 

 

 

 

Edited July 18, 2023 by JerryTodd

[JerryTodd]

A test run of the loops went pretty well, but I felt it needed some suspension in it, so I figured to put a pair of blocks connected by a spring to put tension in the system.



A little more thinking and it seemed tensioning the two loops together like that wasn't a good idea, so I figured to mount a post on the fin trunk and hang the spring on that, keeping the two loops independent. I rigged up one loop and ran it back and forth hauling the weight of a can of spray paint up and down, and it seemed to be up to the task. I did wind up switching to a harder spring than I had started with.



The tensioning blocks will use the same pulley used for the idlers, and I made some slab sides to hold them, then printed all that with a barrel I found on Thingiverse.
The barrel is modeled with wood banding instead of iron, so I need to see if I can change that on the model. The circle on the end is the plug for a drain hole so it wont be filled with liquid resin trapped inside.
Pride had three of these on their sides in front of the house blocking the hand-pump. There was sometimes a 55 gallon drum parked there as well, but I don't recall that being there when I was aboard - got look through the photos again.

 

I ordered some braided line to use on the loops. What I have is too fat, and the rest is twisted line. I figure braided line will be less likely to kink than twisted line in this situation.  I also need some #4 nuts and bolts for those blocks.  Then it'll be time to plan all the fairleads.

The main sheet is pretty straight-forward, though it won't be on an arm; I'll detail that arrangement when I get to it.



The heads'ls and the squares will all on one loop, the fore and main on the other.  I'm hoping the main-forestays and the running backstays will also be on the loop.  I don't need them to sail the model, but they were a big part of the procedure for tacking and no one that sailed on this boat will soon forget that.

I'll detail all that when I get there as well.

[JerryTodd]

In 1981, Pride kept three casks for water forward of the cabin trunk, surrounding the hand pump which wasn't used.

I found a "whiskey barrel" on Thingiverse I though to use, but it was modeled as a barrel with wooden banding, so I subdued the bands on the 3D model, covered them with "iron bands," resized the barrel to 40mm and printed three of them.

Apparently resizing them made the ends too thin and they printed perfectly except for lacking any ends.  I may use these as napkin holders, but most likely I'll glue some ends into them.

 
I also wanted the flap on top represented, and the bands a little more pronounced.  Editing the original file to fix the end walls wasn't working, so I made a new 3D model from scratch, and print three of these.

 

 

Getting back to the sail controls, I got some braided polyester 1.5mm line for the loops and rigged them up.  For tension on the loops, I used pre-made brass blocks on springs mounted on a screw-eye on a wood block on top of the fin trunk.

The video is some of my running the loops back and forth waiting for a failure.  The squeaking is coming from the idler pulleys, so I'll be putting some brass bushings in them.  The aft winch is perfect, the little tab of blue tape runs from end to end as it should.  The other winch needs a new drum (a crack in that home-made one keeps catching the line.  That channel also needs to be reprogrammed in the transmitter as it's not making it's full 3.5 revolutions.

 

 

One loop will control the heads'ls and squares, the other will control the main-sheet, fores'l, main-stays, and main top-mast running back-stays.  There were running backs stays on the foremast, but I don't need them to operate, nor do I need the main-stays and running backs to operate either, but those main stays are a signature item on a Baltimore Clipper, and a major part of the tacking process on Pride, so I want them to operate on the model.

[JerryTodd]

Been away for a few days, so back into the sauna/shop to figure out how to translate those winch driven loops into sail control.

 

I took pictures of the model to use to figure out how the sheets and such will need to run.  This is a draft as some lines will need to run to fairleads in order to get the most efficient use of the loop's travel.  The diagram also doesn't show the main topmast running backs stays or braces for the squares - yet.

 

On the image below, the black spots are where the lines go through the deck.  These places are where wood blocking and brass tubing needs to be installed for that.

 

The first task is to work out where they actually will be with a combination of where the lines ran on the real boat combined with just holding the lines where they go on the model and making a mark.  That means figuring out how I will handle the mainstay's operation. 

 

The main stay is a split-stay, port and starboard, that run forward to a block and tackle at the deck just forward of the foremast.  When sailing, the windward one is taken up taught, and the lee one is loose (usually carried aft and tied to a main shroud).  This way one stay is always working to support that highly raked mast.  The line from the tackle leads aft so the winch can be used to make it taught.  A length of flat braided line on a ring on deck was used to hold the stay taught as the line was transferred from the winch to a cleat on deck and made fast.  I have to decide if I want it's thru-deck to be at the cleat, or forward at the tackle, as shown in the diagram.
I'm leaning towards the thru-deck forward, as shown, but this is one of the things I'll have to jury rig to test and see what works best.  The stays function on the model are mostly aesthetic as the masts are strong enough to sail without shrouds.  They are also a signature detail, and an important part of the procedure when tacking a Baltimore Clipper.

One set of fairleads below deck are the turning blocks for the steering cables.  These are placed where they are to get the best use of the servo-arm's travel.  Two of the temporary brace blocks I made for Constellation were used here.  The eyes used here will be replaced with screw-eyes as in Constellation because the wire eyes I made aren't strong enough.
 

[JerryTodd]

Not a lot going on in my shops for months now, at least, not for me; but I did get some equipment for Pride...

 

The real Pride of Baltimore was a wet boat.  It wasn't unusual for her decks to be awash in a seaway, and I figure the model will be no different, maybe more-so.

To that end I decided to install a bilge-pump.  I searched forums, Facebook, YouTube, and anywhere I could think of to get some idea which pump would be best for the job, and all I really learned was while there's a great deal of information on the Internet, a great deal of that is useless.

 

I finally settled on the little impeller pump pictured, which should fit nicely deep in the model's bilges and pump out any excess.  I think I'll also use the electronics set-up in the next pic provided by Dan Lewandowski over on the RCGroups forums a few years back.

[Mic_Nao]

Very nice work, bravo.

[JerryTodd]

I was going to slap together a temporary trough to float the model in to determine what the weight the bulb on her fin would need to be, but I'm either up to my neck with other stuff or too worn out to motivate myself through the shop door.

I finally put the model in the tub, in which she barely fit, and figured out the bulb will need to be 25 pounds (11kg) to sit about 1/2" below her painted water line. Adding the battery and some lead-shot bean-bags will trim her where I want her for sailing.


I'm still up in the air on how to make the bulb; whether to melt and cast the lead, or cast the lead in epoxy. I'm leaning toward the epoxy casting, and have ordered the epoxy to do the job (and to do some other jobs like repair the pram).

In either case it will be made in two halves and somewhat "wing" shaped; something like this model's, though Pride's fin is longer, wider?


Meanwhile, the masts are back in and I've been playing with the sail controls again. I seized dress hook loops to the winch lines (red arrows) to attach the sheets and figure out how to keep everything neat and untangled.

[JerryTodd]

Most of the model's ballast weight will be in a bulb on a fin at the bottom of the boat.  The fin slides into a sort of center-board trunk built into the model some years ago, back around post #7 of this log.  The fin itself is an aluminum plate measuring about 153mm x 245mm x 4mm.

The fin is placed at the hull's center of lateral plane.  Last post I used a brute force method to determine the amount of weight the bulb will need to be (25pds/11kg)

I intended to sand cast the lead bulb in two halves, but that would require getting the tools and equipment for the job; a pot and burner to melt the lead, a ladle, casting sand, gloves and an apron, etc.  Simpler yet, is to cast the lead shot in epoxy, but I would still need a form.  Years ago, I would put the lead in some sort of container, like a 35mm film can, or in the case of Constellation a PVC pipe.  That's got to be the safest way to handle this without requiring special equipment.

 

Suitable containers that can hold 25 pounds of lead shot aren't readily available, but 3D printing is...
So I started making a 3D model ball with inward facing surfaces, pulled and stretched it into a nice symmetrical ellipsoid, and went surfing for how to determine it's volume.  I found a great web site that does just that, and played with the numbers till I got a volume of about 60.62 cubic inches, which multiplied by lead's weigh of .41 pounds per cubic inch, gave me 24.9 pounds.

I adjusted my 3D model to those dimensions (a=50mm, b=105mm, c=45mm).  I built a model of the fin plate as a reference, then cut the bulb into left and right halves, deleting one of them.  I copied the remaining half and pasted it over the original, enlarged it, and flipped the surfaced so it was facing outward.  The gaps between the two shells were closed up so it was a solid shell about 4mm thick.  I built some structure to seat the fin inside the bulb, them cut the completed half shell into halves again, ie, quarters to wind up with 4 identical quarters , two of which will fit the volume of my 3D printer.

 

As I write this, the first two pieces are on the printer with just 4 out of 6 hours left to print; then I'll print the other two quarters.
When done, I'll bond two quarters each into a right and left half; fill each half with lead shot; pour in epoxy to solidify everything, then bond the two halves on the fin.

[JerryTodd]

Finally all four parts are printed and two quarters bonded together to make two halves, left and right.  There'll be some sanding involved, but that was expected.

Now it's time to load it up with lead.

     

[mtaylor]

Sheer brilliance to use the 3D printer.   

[Mark P]

Congratulations Jerry, on a real working model which is a reflection of both the real vessel, and also your many hours of dedication and effort to bring her to life in miniature.

 

Great model, well done indeed!

 

All the best,

 

Mark P

[JerryTodd]

The lead shot I have is reclaimed material and has a lot of dirt in it.  I shook it through a sieve several times today, but I'm not washing it because it takes a very long time to get it dry, and I don't want to seal moisture inside this thing.

So here's both halves mostly filled with lead, and a pic with the fin on it.  It was too cold tonight to pour epoxy, but if it gets above 55°f tomorrow, I'll give it a try.

 

Edited December 1, 2023 by JerryTodd