Nothing new to report. I wanted to buy a Dremel tool last weekend, trim the hull height down by 3/16" and make the 'wavy' forecastle deck line before I took photos. The Dremels were out of stock and mine has failed so I'm waiting for a replacement. The mold has been gelcoated for a second hull but won't be glassed until next week. I'm trying to figure out how to mold the forecastle deck with its 'wavy' shape and pronounced turtleback. There has to be an access hatch the width of the barbette and 2-3" longer. I may have to tack a thick piece of balsa in the hull, shape it to match the contours of the deck and take a mold from it. Bob
cool, glad to hear of some progress. My sorrow for your poor Dremel, worked to death, it never had a chance. hahaha
The Sri Ayuthia's 'wavy' and turtlebacked forecastle deck is posing a design problem. It covers the front third of the hull, but the hull is very short so there has to be access to install equipment in the bow. Options are: 1) Don't cut the curved deck profile, leaving the forecastle deck flat. This allows a standard subdeck/deck installation, or my usual fiberglass deck with molded in access hatch. Unfortunately the 'wavy' deck line is a major visual feature of the Japanese built Sri Ayuthia Class. 2) Make a separate mold of the curved part of the forecastle deck that will be a push fit and secured by screws at the bow and aft ends. This could be a problem due to potential for warping with changes in temperature, plus leakage around the edges (a BIG problem with a 3 pound, low freeboard model) but would give a good visual result. 3) Permanently install the curved forward section and lift off the level aft half of the forecastle deck for access. Install all equipment on shaped modular bases that can be dropped in through the access hole and pushed forward into position from there. Advice is welcome! Bob
David R., Your Sri Ayuthia hull was removed from the mold this morning. Please advise whether you want the forecastle deck left flat or trimmed down to produce the 'wavy' deck line. Hull #3 will be made this week for another NATCF member. If we can build the things at 3 pounds or less the fleet will have the Sri Ayuthia and sistership Dhonburi. If we can't build them within the weight limit we can use them as towed targets, simulating Sri Ayuthia under tow to Japan after being sunk in shallow water by a French Naval force. (Dhonburi was sunk too but not salvaged in WWII.) That should make an interesting scenario. (We'll need a 1/144 ocean going tug too!) Bob
Leave it flat, I will look at the pictures, and after I add the subdeck, maybe just sand the sides down a bit to give the appearance of the wavey deck lines, should be good enough I think.
I've been looking for a more accurate set of plans than the ones I bought before making the SRi Ayuthia hull plug. That set had rather crude hull lines so I redrew the hull and deepened it to allow for the extra displacement Class 1 models can have (+25% or +1 lb, whichever is greater). Going through my files recently I found a very detailed side and top view drawing downloaded years ago, but only from the front of the bridge aft. (My computer wouldn't print the entire drawing). I forget where I found it on line and havn't been to locate it again. I suspect it came from the old free 'Warship International' website (gone for many years), and found a reference to an article about Sri Ayuthia and Dhonburi in WI magazine's 1990(2) issue. Off I went tonight to the library at Dalhousie University where I knew there was a bound set of WI I'd used for info on other ships. To my dismay the entire set of WI journals had been placed in storage somewhere. The library computer indicated it was at a branch library a couple of miles away so off I went again. At the branch library they'd never heard of it and said it was showing as in the first place I went to. If Warship International is where the drawing came from the front half of it will remain a mystery. One problem with that drawing is that when enlarged to 1/144 scale for beam, there's too little length left for the absent bow, which all other sources indicate was at least as long as the quarterdeck. (There were similar problems with the WI drawings of heavy cruiser SNS Canarias I used when building that model.) I think the only solution is too modify the drawing, shortening both the superstructure and q-deck to allow for a longer hull ahead of the bridge. Another point that arose is that in the better drawn plan the freeboard aft is 5/8" vs 7/16" for the first plan I had. Due to the extra 3/16" freeboard in the better drawing I no longer recommend trimming the hull's deck edge down by 3/16". The deep displacement given in the 1999 plan is only ~15% more than standard, which is low compared to other coastal defence ships (i.e. the Chinese Ning Hai Class). It isn't mentioned anywhere else so is suspect IMO. I'm still trying to decide what to do about the 'wavy' deck profile. David Ranier isn't going to trim his hull to match it, which will make construiction of the deck straight forward. I'd still like to make it wavy! Bob
A new set of drawings has been completed for the Sri Ayuthia and Dhonburi after reviewing 4 others (which all differed in relative lengths of quarterdeck, forecastle deck and superstructure). The new set appears to be a good match to the few available photos. David Ranier's and John Coffill's hulls and plans are ready for delivery. Now the question is can the models be built within a 3 lb limit? John should have no problem because his ship won't be armed. David and I will collaborate on light weight construction ideas. Ralph Coles has a spare Mogami turret mold and a few turrets left over after selling the hull. They're similar enough to the turrets on the Sri Ayuthia Class (which was built in Japan) to be used until I can make a more detailed RTV turret mold. Bob
After getting my hands on one of Ralph's Mogami turrts today they'e not a good enough match for Sri Ayuthia's. I'll have to do a turret mold, probably in RTV so it can be highly detailed. Bob
Well Bob I received the hull yesterday, Friday, It came Wednesday, but they would not leave it since it had to be signed for. Due to work it waited till Friday. I started today on it, and after 5 hours of steady work, I have the windows cut out, subdeck made and installed. Installed the cutdown BC rudder post. I will grind it down some more just to try to reduce the weight even more, including the subdeck edge. My front impentrable area is 1 inch, instaed of 2, and the stern is 5/8 inch, instead of 1 inch. That allowed me enough for 6, 1/4 inch ribs. I made up some light weight stuffing tubes, question is do I want to use the gearbox, or just go with some small motors, will decide tomorrow. I purchased a Mtronics 10 amp mini ESC, now when you say small, this thing is tiny. At Ricks tomorrow I will pick up a micro pump, and use one of my 1/2 unit outlets, so it should work pretty well. For the gun, I decided on a 25 shot 1/2 unit, and will try one of the Clippard solenoids that Chris K has been using, if I remember right it was only around 4 ounces. It will be a bow gun ship. With a 5 inch barrel, it will just about hang over the bow so it should be great for convoy duty to shoot at those pesky LST's the Allieds use. Right now, with the rudder servo, ESC, 2 motors and mounts, its right at 1 pound 4 ounces. So I have 2 pounds to go. I really need to get a new battery for my Camera, or a new Camera.
One motor driving two shafts should be the lightest system. Either the BC 2 two 1 gear box or like Peter & Tyler did in their DDs make your own gear box. If you make a large accumulation tank how big would it need to be to fire 25 bbs. You might be able to make a large tank then pressurize it from a regulator & bottle with a one way or turn off valve. No regulator needed. The tank might be the same weight as the bottle.
Well the stuffing tubes got installed today, and I made up the rudder. I went with 2 small motors, I weighed 2 motors, or 1 motor and gearbox, and they weighed just about the same amount, the 2 motors will sit lower when mounted. I also cut and fitted both the fore and aft Decks. I also installed the stuffing tubes in a Mississippi that I'm working on for Tim K.
David, You're making good progress. I've yet to install anything in my Sri Ayuthia, being tied up by the HMCS Uganda rebuild. I reduced the SA's bow and stern solid areas by similar amounts but used 3/16" ribs, giving me 8 instead of 6 ribs. I think 2 small motors is the way to go as long as the model isn't over-powered/too fast. My I-400 sub weighs twice as much as an SA and was running at 28 sec/100' with 2 x 360 motors and 1" props. I think the SA will need very small props to stay within its speed limit. Bob
Bob 2 partial days of work on her so far. I fitted her so that 1 inch props will fit, and have the 10 amp speed control for her, but if necessary I can go down to 3/4 inch props if needed. Motor mounts are installed. The 1 1/2 sq inch inch rudder looks small on other ships, but I put it on at Ricks, and Don C looked at it and said that my rudder was too large, but we measured it, and if anything I'm just a tad small, boy will this baby be able to turn I think when shes done. So far I have to admit, I'm having a great time making her, she is going fast just because of the size of course. Latest pic, she is at 1 pound 4 ounces, got the micro pump sitting in her, and 2 Suffren turrets. They are the same basic shape, I will have to add some to the back side to make them deaper, but they are close.
Bob Here is what I have come up with so far, it looks like I'm right at 2 pounds 2 ounce so far. All I need to add is the wiring, receiver, and battery, and superstructure, which will need to weigh no more than 1 pound 2 ounces, and I should be golden. Bottle - Going with the threaded 16 gram bottle, and Palmer Regulator with the 16 gram adapter, total weight is around 7 ounces. Visit this site I was looking at that 30 gram refillable, but it is just too heavy for this boat. Pump controller - Dimension Engineering - BattleSwitch radio controlled 10A relay, its only .72 ounces. It works very well, I use it in my Kumamo for the pump. Lighter than a servo, and switch combo. Visit this site
Update - With the deck added, and all internals, she is coming in right on 3 pounds. So the super max weight will have to be 4 oz or less. Should be doable, my complete center section of the Kumano was 7 oz, with the deck material. I may be forced to have Frank build it, he makes them super light. Right now I have a set of SubC batteries in it, with 4500 mah capacity, at 11 oz. If I really need it, I can go to a set of AA, 2600 mah batteries and save 6 ounces, but they are not high output cells, but should do the job I think, since she is a one sortie wonder.
