Ian_Grant

Impressive! Did you have to fold up that hull somehow, or does it come formed?

The science and tech museum underwent a huge renovation several years ago. Many of the old exhibits were replaced by new stuff. I still like their old bicycle collection, in fact we were there on a day when you could try out a penny-farthing; and they kept their two or three steam locomotives but like many museums nowadays it has been "dumbed down" with interactive displays that convey less information, and many blinking lights e.g. there is a big tunnel with thousands of LEDs that supposedly teaches you about fiber-optic communications. Really just something for the kids to run through.

Underhill mentions that the upper topsail lifts are seized to shackles at each end of the topgallant mast fid (!?), and the upper topsail buntlines pass through a double block seized beneath the cross trees. Bottom line is there are more ways to rig stuff than there are ways to skin a cat. For my Preussen I just look through Underhill, rig it in a reasonable way, and about 0.01% of people would even know what they're looking at. 😄

According to Underhill, the trestle-trees, cross-trees, and spreaders are all lengths of angle-iron. The trestle-trees are riveted along the top edges of cheek pieces which are triangular and are centred on the lower mast i.e. they project both forward and aft of the mast. Hard to see them in your dark revell mast but the shape doesn't look right. They shouldn't have that re-curve along the forward edge like wood cheeks on a wood mast. I'd say that cheeks are required, I can't imagine just riveting angle iron at the single point where it meets the round mast. I agree that those bits of plastic between the cross trees should not be there. Other than the cheeks Underhill agrees with Campbell in all other respects. On the other hand I don't see cheeks in this photo although it's hard to see at all. If they are there then they're painted like the mast.

Beautiful model! I see you like macaws - do you have one?

Yes I have seen a video of a similar design, but the circular stroke is very inefficient and silly looking. If I can't have software-controlled rowing where I can alter oar dynamics as I please then why bother going further with this project....

Being unhappy with the above bulky result I explored reducing the height of the ship. The minimum deck height was dictated by two things (1) the upper reme oar looms' top limit when in the water, and (2) the upper end of the 2-1/4" linear bearing when oar beam is in high position. To address this I decided to reduce the loom length from 2" to 1.5". This increases the force to push two remes from 2lb to 2.6lb. However, the shorter looms require a shorter stroke to move the oars over the same arc; as it turns out a servo moving 120 degrees only needs a 0.866" arm to give the new 1.5" (max) stroke. Max torque is then (2.6)*(0.866) = 2.25 lb-in, the same as before. Since I am now providing a lift servo at each end of the beam I can use shorter 1-1/8" linear bearings with no issue, I think. I will have to build yet another jig to prove this out. Here is the new profile with draft decreased in tandem with deck height. The depth of the outrigger is reduced to match the shorter looms. It is now a scale 24" which I think is enough to have those oarsmen clear of their lower crewmates ie 24" is a reasonable width value for wide-shouldered crewmen. The sweep servo is shown in dotted form on the right. I discovered a "low profile" servo HS-77BB meant for aircraft tail controls etc; it is ideal to use as lift servos and can be mounted above the base beam as shown, which is better than the first scheme of standard servos attached beneath the beams from a maintenance and clearances point of view. Only problem is they cost twice as much as a standard servo, and I already have four standard servos to hand. Will explore more configurations for lift function. I also decided to swivel the mounting clamps on the bearings 90 degrees then I can have the oar beam run along the centre of the base beams instead of the inner edge. This makes a lot more room along the centre of the ship. Here is the new plan view for this cross section. I like it a lot more than the previous ship. It's much leaner and more like a galley. I did add an inch at the bows as mentioned above, just tweaking the space for the electronics here. Still a bit worried about stability. I may add 1/8" back to the draft; on the other hand just look at the midships cross section of the Olympias in post #100.....I have a lot more hull in the water already. One last note - I went to a 3D print shop armed with .stl files for an oar and an oar pivot I quickly drew in TinkerCAD. Fancy materials were too expensive. They said they would print one of each in something cheaper and call me. Well I went over yesterday to see the results, printed in acrylic. The oar is a bit bendy, not sure it would stay straight enough; they're pretty close together in the water. Are we all sitting down? This option would be $11 a set i.e. per oar/pivot set. Just $968 plus tax for all 88 of them. Sheesh! I thought 3D printing was supposed to be cheap. They're printing a set for me in PLA now just to show me. That would be dirt cheap but I'm pretty sure it would not be robust enough. I've already made up my mind to just use wood dowels for oars, with eyes and screws at the loom like I did in my software development jig. Just need to figure out how to jig fitting blades to dowel consistently over 88 instances, say 100 with a few spares.

A 1/32 scale Lancaster! Wow! I'd love to build that, but where to display? If only we had a vaulted ceiling......😄

Zvezda has kits of many unusual models. They have the "Varyag" and a couple of other pre-dreadnoughts. I have their Roman trireme and am impressed with the mold engraving.

I created a plan view based on my midships cross section. See below. It's pretty beefy looking for a quadrireme, thanks to my wanting some draft and adding some extra freeboard to the first reme. Not sure I like it. Maybe I could reduce draft 1/2" (half a grid space in this drawing), reduce freeboard to lower reme by 3/16", and reduce clearance between remes a bit. That last one is a little tricky because some vertical occupation is necessary for making the outriggers sound mechanically. I don't want to just edge-glue thin plywood. On the other hand I could fiberglass them....hmmmm. The oar mechanisms would have to drop down lower to suit but they could also be shifted 3/8" towards the centreline. Just so long as I have my space for the battery pack between them. The curves at bow and stern I just drew with french curves; I don't have access right now to my wife's photocopier at work to enlarge Olympias drawings because my covid is lingering and I can't go in there 😢.

Glen, are you implying that I should get with the 21st century and do it all in CAD rather than on paper? 🤪 It would be great no doubt but I don't want to learn it all with no other foreseeable use. I'm an early 20th century kind of guy plus I loved drafting in high school in the 70's. Mind you we had proper drafting arms. Bedford, I'm open to anything; that contour is from Olympias and it's pretty close to what Pitassi shows at midships. I did decrease the downward flair at the keel per Pitassi. I'm already afraid the hull is too deep in; galleys just skimmed across the water or they'd be too hard to row. I planned to add external ballast if necessary for stability, be it a torpedo or even a short fin keel.

I see what you mean. Will mull it over. Think I need to rig up a drafting table of some sort. Home-made t-square at least and some taped-together grid paper to get going. happy modelling!

Veering back and forth between excitement and hopelessness on this project. Fundamental issue is I do not have a lines plan for a Roman galley. They don't exist. I've always known this but now the rubber is hitting the road. I used Pitassi's quadrireme creation for fundamental length and beam measurements. His top view shows the profile of waterline and deck bulwark and that's it. Problem is that his tiny 4" drawing is hard to measure proportions from. At 1/32 scale I came up with the general top view shown here, drawn at 1/4 size on grid paper. This was an effort to see if I am likely to have the space for all the electronics given that the rowing mechanism takes up most of the interior. It looks a bit tight in the bows for all the connectors sticking out perpendicular to the Arduino PCBs given the looming presence of the giant-scale sweep servos. I may stretch the bow out another inch or so. I've decided to use the Servocity low-flange beam for the bases of the oar beams, with the linear bearings to allow lift movement. I will however revert to the simple eye-screws to mount the oars onto wood like my earlier rowing test jig; no more u-channels and fancy pivots and hinges. As seen the oars require 27" of space, then there is a bit added at each end to accommodate the vertical shafts and linear bearings; then a "no-go" zone at each end required for the beams to do their sweep back and forth. The four lift servos will be mounted beneath the beam bases, screwed to them so they move along with them. I forgot to draw the rudder servo but there's nothing else back there and anyway I'm not sure yet how I will mount them or activate them. Probably will heed my old dad's advice and "you'll never figure out every detail before you start; have a basic plan then solve issues as they arise". So now I know to extend the bows a little. Next was verifying there was space in the central cross-section to do the rowing. I really want a space along the keel to place ballast and the battery. Will be a 5-cell NiMH to provide 6V, and will need to be a "flat-pack" style not a "Hump-Back Pack". The cross section I came up with has an 8" waterline beam which is a little beamier than Pitassi's estimate at 1/32 scale. I got that by enlarging the Olympias midship section drawing, and modifying to a bireme with my desired freeboard and my made-up deck level. Here is the result. Left side shows the oar beam placement and the outrigger for the upper reme. The slides are only 17" long, placed at the centre of the beam. This leaves nothing at the ends to get in the way of the lift servos as shown on the right. Clearance is a bit tight for them; I've shown it notched into the side flange of the metal base beam, or I could omit a frame in their locale. By the way, frame spacing will be 2.5", or double the oar spacing. There is ample room in the centre for the 1" wide battery pack. Tricky part will be constructing the outrigger. I need to somehow provide some sort of framing to reinforce it, without interfering with the cycle of the upper oars. Not a lot of latitude for members. I will have to rely on the plywood bottom face of the outrigger to hold the lower hull's edge in a straight line above the upper oars since no cross-beams can be added to the hull here because of the mechanisms. Just how to make this outrigger solid enough to support the removable deck is another question. I did allow for 3/8" beams for the deck itself. Worried I have too much of the hull under water...but if waterline drops so must oar mechanisms then I'm in trouble with clearances...🤔 Lastly, hull lines. All that is available is the drawings of trireme Olympias. I expected them to be much like other lines plans I have seen but after downloading I was shocked to find the following: He seems to have the cross sections, waterlines, and buttock lines all on a single sheet with the sections drawn right on top of the buttocks. Never seen that before. And I cannot find any indication of station placement and spacing in the general arrangement (below; and just look at how little of it is in the water!). Kudos to Richard Braithewaite for deciphering these for his model. I will have to scratch my head; I wish I had my old drafting table and arm. I need to tweak the bow and stern to my made-up waterline to get ram and rudders correct, and stretch/compress them to my desired lengths. 🤪 I expect I will have to do a card mock-up to verify the lines are anything like correct.

Marc, hope you have a great time! We're booked for Hawaii in September. Already worried about airport fiascos especially here in Canada. Praying there isn't another wave in the fall, although I finally got covid last week so my immunity should be pretty good.

Bruce, sorry to hear that. Best wishes for a full and speedy recovery!

Bill, remember that ropes on ships are sized according to circumference not diameter. A 1.5mm thread would be larger than the lower shrouds. The 6" circumference tye is 1.9" in diameter, 19 thou at 1/100 scale, almost exactly 1/2mm. The 3.5" halliard is about 1.1" in diameter, 11 thou at 1/100 scale, almost exactly 1/4 mm. I thought you were at the beach? 😃

I thought that might be the case! it looks much neater now.....😉

Bill, I don't see a difference?....Please advise.........🤔

She looks nice, Bill. You should be done next week! On to the SR........

Doesn't look much like the real one:

Glen, you're a wizard at miniatures!

Yes I think overhand knots are the answer. On Victory, I tied several widely spaced ratlines along the shrouds, and put glue on them to make them rigid. Then I filled in the intervening ratlines with less fear of hourglassing. Only problem was the glue darkened them, so I matt varnished the lot afterwards.

At this scale a wood thimble would look a bit big against the block. I just trapped a couple of bits of thread under the strop at each end of the block, to form loops around the backstay. Perhaps you could push a needle and thread through between the block and its strop? I've done that before.

What we are concerned with here is getting the length of the tyes right, such that the halyards actually could raise and lower the yard. Because of the way the tyes are rigged at the topmast head, those 26" double blocks move twice as far up or down than the topsail yard moves down or up. If the tyes were too long, the 26" double blocks would collide with the single blocks before the yard could be fully raised. With the yard lowered, the double blocks need to be at least twice as far above the lower single blocks as the expected travel of the yard. Longridge is fully aware of this, and mentions elsewhere in his book about otherwise excellent models being "spoiled" by rigging that could not operate. Thus he gives the guidance that if the double blocks are about level with the cap when the yard is resting on the cap, that would be about right for a properly operable halyard. In Plan 7 the yard is not resting on the cap, therefore the block is necessarily lower down. It would move higher if the yard was in fact on the cap. However I think Longridge was a little off here, because if the yard dropped the remaining "inch" let's call it, the block would have to move up 2" as stated above. I think he forgot about that when he drew this.

Looks very good!