Ian_Grant

Thanks Bill; it's been quite a saga but now that the finishing stages have arrived I'm really looking forward to painting it up nice. I joined the local RC model boat group; apart from monthly meetings in the winter, I think they usually have one session at a local indoor pool. I'm hoping to be ready for that evening.

I'm building up the hull sides above the outrigger so we can now see how the hull looks with wood added to deck level. I think it looks proportional. My one doubt is that I began the upsweep of the bow bulwarks too early; I may revisit the curve though it will be painful to cut off my painstakingly laminated false top rails. Here are some pics. I used the library's laser cutter (60W Epilog Mini) to etch some planking for the outrigger tops. My mind is opening to the possibilities of this machine. I didn't want to form all the "X" shapes in the ventilation course with bits of wood; thought I might 3D print it in sections; finally used the laser to cut them out. I ordered some decorative brass strips from Etsy to dress up the hull but now I'm wondering if I could just laser etch patterns. The ventilation is lasered out of 1/8" cherry and will be painted white. The pine wood behind will be painted black to simulate openings into the hull. I'm wondering how to finish the planking; spar varnish would look like a bowling alley lane. I'm reluctant to use water-based because it will bring up the plywood skin's grain and I don't want to sand much and perhaps damage the etching. Also pondering dry-brushing another colour on the planks for some aging. Does anyone have any ideas?

Back in the 70's I was into RC boats. Here is an old Dumas speed controller, with proportional forward, stop, reverse (complete with a blob of epoxy from almost 50 years ago!). I remember dismantling it to clean the exposed element in the wire-wound ceramic resistor, and the contact arm, to keep current flow steady. What wasted power in the resistor! As I mentioned you had to have a throttle servo to run it, unlike today's ESC's plugging directly into the Receiver. I pity my kids who'll have to sort through all my old hobby junk when I'm gone. Or maybe I will one day dispose of stuff to ease their load. I seem to recall there's an apple basket somewhere full of old 0.049 airplane engines and parts, and I also have two 0.35 Enya engines which the hobby shop tells me are worth zero now. He did say the 0.049 engines are in demand though! 🤔 Fond memories .............

Especially at this scale !!!!

There are several videos in my rather long build log; those at the start showing the process of refining the oar mechanism and writing software for it, while the last two or three are sea trials in the pool. Now I am satisfied it will work I am working on finishing, painting, and decorating the hull. Below is the build log. I got through about 5 pages before even starting to build a ship. 😊🙄 The most recent video is here:

Yes, I have an SR in my stash. I was going to build it after the "Preussen" but that build stalled when I became distracted for the past two years by my Radio-Controlled Roman Galley; designing and refining an oar drive mechanism, writing Arduino software for it, and for the past six months designing and building the hull, culminating in "sea trials" where I had it rowing around our pool. Now that I know it works I am starting to complete and pretty-up the hull. I can even laser-etch decking boards using our library's laser cutter, and the more I use it the more possibilities open up before me .... it's an amazing machine! Will also be using the library's 3D printer to print a ram for the bow, once I draw it in CAD.

Looking really great, Bill. Bow is already looking intricate with some of the head rigging done. Gunport lids really nice too. Nice work!

Yes, modern ESC's are vastly superior to the old big clunky rheostatic speed controllers used in the 70's, which needed a servo to move their control arm and wasted a lot of battery power. And remember cleaning their contacts? 🙄 Re fiberglassing - when I made my cedar strip canoe I had an ultra smooth sanded cedar hull which became lumpy plastic after three coats fiberglass resin with cloth. It was a letdown but it comes up beautifully with sanding. Even the guy who wrote the how-to book ("Canoecraft") wrote not to be discouraged when you first see the dried resin. HaHa. Going to be a great model. Looking forward to seeing the painted hull!

HaHaHa!!!

Hi Kevin; Those are the buntlines for the (absent) course sail. As you say, without sails they are just tied off neatly in a representative location. Modellers do the same when going "bare poles", and sometimes do something similar for the bowlines. Buntlines are used to pull the foot of a sail up when furling or reefing. At sea there would have been buntline blocks where they have them tied off and the buntlines would be spaced along the sail's foot. Bowlines are used to pull the windward leech (side) of a square sail forward when beating to windward, They attach to the leech in two or three locations with a little "crowsfoot". Modellers without sails clinch them to the yard about where they would be with the sail furled but I think by Cutty Sark's day they were obsolete. On Cutty Sark today, they also have those tidy-looking triple iron rings dangling in mid-air, representing the bottom corners of the course sails to which they tie off the sheet, the tack, and the leech lines.

It's your model, you can be as bold or conservative as you like. I made it with the plastic pins with no problems. Perhaps the plastic now is "softer" than in the 70's though? Nice job with the copper paint!

Was going to refrain from posting for a while, BUT I just went to the library and used the laser etcher to make some decking patterns for the two steering platforms, as a test of whether to do the same for the main deck too. I'm thrilled by the result. Going to "plank" the tops of the outriggers too now. You can just see a few "test" planks at the left that were etched to select the raster speed for a good darkness level. Marcus is thankful to have a good solid deck to stand on instead of water ...... 😏

Despite my previous comment, here is another short post. Hadn't got around to stripping the interior parts until today. Before doing this, I borrowed a cat weigh scale from my wife's clinic. Weight of hull/mechanisms/oars/servos/arduino (no battery) .......... 5.5 kg Total lead ballast .......... 5.2 kg Total displacement ...... 10.7 kg (!) you can see why carrying with a midships handle would be problematic... ************************************************************************************************************************* In post #127 I estimated hull + mechanisms would be 7.9 kg. That was before I thought of cutting the metal drawer slides shorter. So the actual at 5.5 kg is about 30% less than estimated. Actually, a bit more because the 5.5 kg includes servos and all. My estimated total displacement, with battery, was 8.34 kg. I designed the hull to give me some extra displacement over and above this, which would be met using ballast. I ended up with extra displacement of (10.7 - 8.34)/8.34 = 28% . Given that it's still a little sensitive to ballast distribution I wouldn't want to reduce it, so no hull re-work is I think the correct call. So the overall result is not bad. If I did rebuild the hull, I'd just be losing ballast and maybe it would be too tippy. Thanks for following. Toodle-ooh!

All the way to the keel, Bill.

John, I see a train layout there; how extensive is it? I've seen setups that run around the entire room.

Yes, I paid a fortune to case my Heller Victory, but after five years of working on it it's an investment in keeping it safe and free of dust.

Since you are not going to have visible planking, I urge you to use f/g cloth, if you're not already planning to. Wood around moisture always changes and cracks will appear in an unclothed hull. The cloth helps stitch the planks together.

Tomorrow I will be taking the mechanisms, electronics, and ballast out of the hull to return to just working on a wooden ship. Changes I have in mind for the mechanisms include: 1) Have vertical mounting slots for the upper oar beams to facilitate adjustment relative to the lower beams. 2) Since I will not have the central handle, move the lift servos closer to midships to reduce the disparity between the link lengths to each end, and move the servo mounts slightly closer to the keel line to allow slightly longer servo arms to be used. 3) Cut a notch in the u-channel where the bellcranks are mounted to allow them to tilt further down. This change combined with the longer lift servo arms will give a greater range of lift movement which I think I need to keep oars well out of water during return strokes. The existing range of movement barely meets the theoretical requirement from the oar geometry drawing. I can use the Arduino "Map" command to select whatever sub-range I want, later. I rejected the idea of tearing the hull apart to change the bilge shape, so I will just have to live with the weight of the thing. One factor contributing to the amount of ballast is that I thought of cutting off the excess ends of the drawer slides well after designing the bilge curve. As a historical footnote, here is a pic of the metal thus removed. A not inconsiderable weight.... I probably won't be posting for a while, until I have some meaningful work done on the hull, but I will enjoy reading all your build logs. Thanks for following this build. More later.

Thanks Steven; Draw a level bulwark between bow and stern bulwarks and that's the hull. Perhaps you are right. I'll consider it over the winter. I do see that my bow and stern bulwarks sweep up earlier than for example those in the gentleman's ship in #335; they could be reworked. Consider the following pic from the cover of Conway's book on galleys. This Greek ship is pretty tall even without bulwarks.....

Pat - Yes both oars were used. In fact, on Hellenic triremes such as "Olympias" a single helmsman handles both, one tiller in each hand, one hand going forward and the other back depending on which way she is turning. Roman quadriremes were bigger and wider, requiring two helmsmen. See the fantastically beautiful, manned, model quinquereme in the video below (I'm hoping to paint and decorate my ship much like his although I have no actual planking to leave "natural" coloured). 🤞 At time 11:17 the two helmsmen are clearly seen, even wearing green and red to delineate their side, HaHa! https://www.youtube.com/watch?v=bLiGM6MOBL0 If interested, his completion video is here: https://www.youtube.com/watch?v=LuYBk0znbB8&list=PLN8dHnRD0y61NWWulgdXo7fMLYSnjZ943&index=11

Hi Steven, thanks for taking the time to discuss the boat on water! To your first point, yes it's true, I've been running it at full throttle, most of the time. More relaxed rowing is available; indeed I probably should reduce software variable "MSR" (Maximum Sweep Rate) and re-compile. All this is still in experimental/development stage. Everything is open. Except cutting the bottom off the hull and rebuilding it with smaller displacement (!); I've decided that I couldn't face the work involved. You've put your finger on the classic RC "scale problem". Let's call this ship 1/30 for round values; scale oar blades would be 1/30 as long and 1/30 as wide, for a total of 1/900 actual area. My oar blades are ridiculous for the scale, but hey, we need some traction here! Model sailing ships have it worse - for scale factor "n" they end up with, as you say, 1/(n**3) the displacement for 1/(n**2) the sail area, meaning "n" times as much sail area for the displacement. Hence all the dagger keels with lead bulbs. Over the weekend at the cottage I decided I **must** have some form of effective rudder control, even if it relies on stopping the inside oars (I'll save backstroking oars for emergencies; not sure they could even do it). I looked at my 30 degree dummy rudders, and when viewed from straight ahead the 1.25" wide blades presented an apparent 5/8" wide strip 2" long as resistance to the water. Now I see why they couldn't do much. To that end I played around today with larger blades clamped to my dummy rudders. With 2" x 3" blades I get pretty decent response. Two inches is as deep in the water as I want them to get; that's the limit for no rudder damage when sitting the boat on a flat surface with the resulting tilt because of the external keel. Three inches is wildly large. I will follow a convention I've seen in RC modelling mags where one paints a scale rudder on the over-large blade, then fills in the rest with black paint to "hide" the excess when in water. With that sort of dimension I may balance it a little too. Depends on aesthetics. Regarding the height, yes my first drawing here looked like an overweight guppy. There are two factors (1) scale appearance would have the lower oar ports just 3/4" clear of water. I decided that was too risky so I added 1/2" for peace of mind (relatively). This extra 1/2" shifts everything up, obviously; and (2) the oar loom ends rise in the hull as the blades bite water. The deck beams must clear the oar mechanisms' beams when they hit their highest point. I reworked the oar geometry a couple of times with this in mind. Way back I reduced loom to 1.5" for this reason, but I had to change back to 2" for mechanical clearances when I decided to increase the outrigger projection to 1.25" because to my eye 3/4" was too paltry for the hull. In retrospect I could have lowered the deck somewhat by allowing for thinner beams, but I did not want the separate lift-off long deck to warp in future so decided 1/2" beams was the number. No one today really knows how tall these ships were; Pitassi quotes various classical sources and gives approx 10 feet as a quadrireme's deck height over WL. There's a pic below of "Marcus" standing on water by the break in the forward bulwark for boarding bridge deployment from the deck. Deck height looks fairly ok, even bearing in mind that Marcus is a scale 6'-2" giant of a Roman. 😏 One reason Olympias looks so low is that there are no bulwarks on the upper deck. Here are pics of the giant rudders, and Marcus walking on water. Note, the real rudders won't be massive above waterline !!!

Bill, see Anderson pg 143 on lower yard parrels.

Hi Pat; my Conway book of galleys has reproductions of ancient drawings showing Egyptian, Phoenician, and Hellenic galleys with twin steering oars. The trireme "Olympias", launched around 1990, had twins which were very effective as shown in videos available on youtube. My Pitassi book on Roman galleys also shows them with twin steering oars, as gleaned from surviving stone relief carvings and even wall paintings uncovered in Pompeii. There's a place on my bucket list! I realized that in the video, or maybe after it was shot, I had it rowing with oars on one side stopped (out of water) and it didn't turn much even then so my plan of shortening the inside stroke probably won't work. Maybe I'll have to put exaggeratedly large rudders on her after all. It will look awkward if I have to keep doing reverse strokes to steer.

A day to remember - Sea Trial #3 with all 86 oars!! My conclusions from this trial: 1) The upper oar blades hang lower than my geometry drawing, which is ok for power stroke but they nearly drag on the water during return stroke. Any slight ripple on the water will be a bother. Checking on the bench again, they do seem to be about 1/4" lower than planned. Will need to revisit the upper oar bars this winter and mount them again more carefully. Probably would be a good idea to change their mounting holes in the beam to vertical slots to allow adjustments on the fly. Would need to, I guess, find a 5/32" milling bit and use my drill press and some jigs. It probably doesn't help that I made those oars 1/2" longer....thinking I will take the extra length off, and make the lower oar blades the same slightly larger size, over the winter. 2) She is very sensitive to ballast amount and distribution, surprising me given her size and full, rounded bilge. Will need to adjust the whole ballast scheme when model is complete and final weight is known. 3) Realistically proportioned rudders have very little effect; there's no prop wash to apply force to them. I don't want hugely exaggerated rudders on the model so I'm wondering whether to even bother having them servo-controlled! Also, now considering rewriting the software, over the winter, to have the inside oars on a turn go to a shorter stroke, still in time with the outer oars as far as power/return goes. This would make her turn for sure. As rudder moves over more the inside stroke could get even shorter, at some point simply stopping out of the water, and going to reverse stroke at rudder hard over. Haven't thought about code but this sounds pretty complex to me since there would be different "delta-X" increments for the two sweep oars; plus we already have the new requirement of varying the sweep servo rotation rate to try to maintain a constant sweep velocity, as mentioned in a previous post. 4) She's damn heavy and awkward to carry through doorways. My initial scheme of having a central handle is an EPIC FAIL. 😭 You know that exercise where you have a dumb-bell in your hand and lift your arm straight out to the side .... that's what it would be like since you must keep the oars clear of your hip. 🙄 I'm now considering a very solidly built handle across the hull very near the stern, beneath the front edge of the fixed portion of the aft deck. One would grasp this and lift up stern first, then place other hand under the hull at mid-keel and carry it like that to the cradle. Will be an interesting winter. With all that, here is the video. Thanks to all for following me thus far!!!

Thanks, but they don't look heavy-duty to me, almost as thin as mine. I DID find some very sturdy 9v-connector-to-5mm-jack adapters in a music store, used to power up guitar pedals apparently. They were American made, thick and solid because a band can't afford to have them fall apart. I had a 9V battery with me and loved the solid feel of plugging and unplugging and I thought I had it solved. Unfortunately the standard in the music industry is that the jack is tip-negative whereas any Arduino is tip-positive in keeping with the electronics industry. I could buy one and cut the wires up but it's just one more joint to fail. I ordered a thick-looking part on Amazon, made by "Pacific Science Supply", so we'll see how it is when it arrives.