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Old Dec 28, 2012, 08:48 AM
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Yalex,
Many ways to control yards, but I think the simpler the better. Maybe the biggest question at this point is the design priority of prototypical rigging vs. simply functional rigging.
If not prototypical, given all the yards you need to control, maybe rotating masts is the best way to go. A real departure from current approaches, but a very simple drive setup and all yard rotations issues are resolved.
I've seen tube-in- tube mast designs where only the inner mast rotates so that the outer mast shell can be rigged.
The other approach - simple pairing yards by stringing them together, is pretty simple and should work great. An aproach Ray Paratrooper and I used early on was to have one active brace come up thru the deck and have additional braces tied to that. As that main brace travelled, all the attached braces moved in unison. A bit of bungee on the "slave" braces would take care of geometry differences, or do as Ray did - attach every driven brace to a yard at the same distance from the mast. That really simplifies the approach (also allows for use of same sized drum diameters for each of the yards if that approach is used)
For the more prototypical approach, start with the minimum number of servos. On Syren, under no wind load (which is pretty balanced across the sail anyway), the maximum current I measured on rotation with a spring loaded sled for slack take-up was only 280mA. I think the servo is rated at 2A (need to check). Net, I think the servo can put out a lot more.
Kind of meandering above.
E looks good, I think. Allows for testing with one servo and then adding second if necessary. With complexity of slide servo and spring tension and multiple yard setup, maybe a separate slide for each mast would allow easier tuning of the individual mast operation, But then again, tying the yards of two masts together is easier still.
One thing I found - the "cocking" force on the sled requires low friction slides. I don't see space for, or indiction of, details of the slide approach in your drawing.
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Old Dec 29, 2012, 12:27 PM
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los angeles
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Thanks Dan.
For some reason, rotating masts does not seem to be an option for me. I do want some measure of prototypical control. I think I will start, as you suggest with a simpler setup. One servo for the foremast squares (maybe I will use a cheaper smaller Chinese sailwinch), second servo (definitely hitec) for main and mizzen squares, third servo (probably another small Chinese) for jigger mast fore and aft sails and geared motor shuttle for the head sails. Each square sail servo will have two different diameter drums to control two yards per mast. I will connect the corresponding yards on the main and mizzen, so they would move together. Should this prove insufficient, I will start adding complexity. I think I can relatively easily connect additional braces to the "active" ones using bungee or your trolley system to compensate for quirks of geometry. Thankfuly, the length of the yards on the Kruzenshtern variesless than on earlier vessels. I can, as you suggest, attach my secondary braces same distance from the mast.
If it is necessary, I can add a mizzen square servo, and slave it to the main. I can use a Y-harness if I simply need more power, or, more likely I can slave its channel on Tx and have an ability to do some adjustments on the transmitter.

On my rev. E I do have sufficient space for servo attachment. I am still in the process of designing that. I am considering using various L shapes, probably alluminum or brass and brass rod for sliders. I think I need to experiment.

I would also really like to hear your opinion on the shuttle system to control the head sails. I think it works well, but I have only used it once, and I have not used any other setup. Also, what about using a geared motor instead of servo? Am I trying to complicate my life too much?
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Old Dec 29, 2012, 12:58 PM
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crossover headsails

yalex - I have no experience with shuttles, but have seen them. Seem to take a ot of room and seem complex.
For headsails, there is no triangular geometry problem as with yards. And they can be rigged so there is never any large amount of slack. Attached is a drawing from a very old post somewhere that shows the Syren system. Uses a $39 HiTec winch servo. Also a vid clip showing it in action.
Works for me, so that's what I recommend.

http://www.youtube.com/watch?feature...&v=21I3Uur1yls
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Old Dec 30, 2012, 10:40 AM
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Questions that may assist you in choosing a control method:

1. What is my Primary goal, Sailing or Viewing?
2. How long do I want to spend setting up and taking down at the pond?
3. Do I accept that all engineering and design decisions involve trade-offs?
4. Do I derive more pleasure from invention & debugging, or from operation? When I look back on my hobbies, when did I have the most fun?
5. What is my intended audience: sailors or non-sailors? Will I be bothered if someone disparages my model because it is not identical to their concept of what a model should be?

What ever method you choose, you will be able to make it work. Some methods will require more time to achieve your personally-defined standard of success.

My take on 3 methods of controlling braces. I've only experience with manual adjustment of braces (on my free-sailers) and servo arm/parallelogram (my RC boats). Rest of my opinions are based on my interpretation of what I've read:

Winch: Great running rigging realism for close-up viewing. Intellectually satisfying since in mimics real ships. Requires maintenance to avoid snarls. Longer time required to setup and takedown if you need to alter ship size for transport (due to the long lines of the braces, which tend to catch on yards). The more braces installed, the longer the setup time (true for servo arm method also).

Servo arm/parallelogram: Does not look realistic close-up;non-sailors won't notice, but sailors will. Easy to install, compared to winch. Standard airplane servos, relatively cheap. Maintenance easy (tighten slack in braces). Less prone to snarl compared to winch. Setup possibly less time-consuming than winch due to shorter brace lines. The more braces installed, the longer the setup time. If the arms are longer than the winch drum diameter, will require more space down below decks. I've used 1.5" arms and 4" arms (total length). CD's are a little over 4.5" in diameter.

Mast rotation: No realism whatsoever; however, viewed from 100 feet, probably not a concern. Conceptually, simple to install. Servo cost unknown, probably somewhere between winches and standard airplane servos. Maintenance minimal (lube the bearings, good to go). Replacement of worn bearings more expensive than replacement of worn lines. Setup minimal, plug in masts and good to go. Minimal space required below decks.

Only your clone would make the same decisions as you :-) Whatever modeling and operation problems you choose to concentrate on is fine, it's your hobby.

My preferences are: sailing, quick setup,operation. I've only ever had one guy disparage my model at the pond; it bothered me, then I decided it was just due to jealousy. I've had truckers stop to watch while I've been sailing, very gratifying :-). All squareriggers are so beautiful at sea, and so unusual, that the overwhelming response the past 5 years has been "Wow, that's beautiful, did you make it?"

Hope this helps.
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Old Jan 01, 2013, 12:36 AM
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los angeles
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Happy New Year, everyone! May it bring health, piece, prosperity, and new and successful
models.
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Old Feb 26, 2013, 02:51 PM
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los angeles
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While I was working on the design of a new servo deck, I continued slowly and not always steadily to work on the hull. I made the decks. I used a different laser setting to burn a deck planking pattern. Because of the size limitations of the cutter, the main deck is cut in three pieces, including a piece that covers the access hatch to the servo deck. I glued the two main deck parts as presicely as I could. Than the deck got two layers of thinned epoxy on both sides. The outside surface will be sanded and covered with one more coat of epoxy. It has to be glued to the hull before puttying and sanding is finished. Two aft openings are the access for the rudder horn and rudder servo. All the rudder components will have to be installed before the deck is glued to the hull.

The work is going slowly, but the progress is being made.
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Old Feb 26, 2013, 03:47 PM
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los angeles
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As I was working on the control deck, I realized that pretty soon I will need to start on masts and controlled yards. I want to measure the actual distance the brace moves in order to get accurate a diameter for the winch drum as possible. Of course, I will be doing the final adjustments on my Tx, but I think it will help to get the drum size right from the beginning.

I planned to use a 1/2" dowel for the lower masts. It's a bit thicker than scale, but I would rather have sturdy masts capable of taking a lot of abuse. To make my tops and cross-trees I laser cut components from 1mm aircraft plywood and glue them together. This way I have a top that has some nice detail, looks scale and has 9 ply layers and thickness of less than 4mm. The parts are very stiff and solid, and feel like they can withstand a lot of force. I forgot to mention that I used the patterns from the paper kit with only slight modifications, so they should be reasonably correct in appearance.
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Old Feb 26, 2013, 05:11 PM
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yalex,
I've just made new drums for Syren, as part of the new spring loaded system.
As you say - make the drums after rigging masts and yards.
You can then rig with marker lines that follow the route you intend for your braces. Then move the yards through their range of travel and mark the lines to determine actual pull distances. Then you will have a really close number to calculate your drum diameters. Add about 10% for stretch, slop.
For headsail crossover, the Syren system has worked flawlessly. Not sure of the sail design/number of your headsails, so can't absolutely recommend it.

Re-reading this thread, I think the main reasons to go with separate drum servos on each mast are these: In an old thread (in Ray C's original brig thread), when I looked into blowing fuses and servo burnout in the early model, I compared max current readings with the drum vs arm servos. Drum max current is a fraction of what an arm servo needs to pull. Also, gearing in drum servo adds a lot of resistance to wind-forced rotation, so servo holds position with little current draw. Arm servo current ramps up when arm needs to force back against wind force. Also, as you mentioned, you can 'Y-connect" the signal lines of the separate servos if desired (and keep individually fused power feed wires separate for each servo, directly from a power distribution panel) Or use the TX slave programming to link desired servos if enough channels available.
I installed new precision 320 degree rotation pots on my TX to replace the 120 degree cheapos. Much smoother and more precise control of the yard rotation servos. (Posted in the Syren thread somewhere)
I think you can get away with having functional braces only on the two lower yards. But if you rig masts and yards before servo/drum design, you can experiment manually to see what works best.
I've changed Syren setup and details so many times - best to experiment before final design/build.
You need a smoky signal cannon!
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Old Feb 27, 2013, 01:28 AM
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Quote:
Originally Posted by DanL View Post
...You can then rig with marker lines that follow the route you intend for your braces. Then move the yards through their range of travel and mark the lines to determine actual pull distances.
I just did that a day ago. My bigger drum came to 1.5" in diameter. Will figure out the smaller one shortly.

Quote:
Originally Posted by DanL View Post
For headsail crossover, the Syren system has worked flawlessly. Not sure of the sail design/number of your headsails, so can't absolutely recommend it.
I will do a loop that runs from a geared motor I took off of the old printer. It's just an experiment of mine. I know the drum servo would, probably, be more reliable, not to mention simpler to design and control. I will include a diagram and photos when I get to the headsails. In principle it's very close to what you have.

Quote:
Originally Posted by DanL View Post
Re-reading this thread, I think the main reasons to go with separate drum servos on each mast are these: In an old thread (in Ray C's original brig thread), when I looked into blowing fuses and servo burnout in the early model, I compared max current readings with the drum vs arm servos. Drum max current is a fraction of what an arm servo needs to pull. Also, gearing in drum servo adds a lot of resistance to wind-forced rotation, so servo holds position with little current draw. Arm servo current ramps up when arm needs to force back against wind force. Also, as you mentioned, you can 'Y-connect" the signal lines of the separate servos if desired (and keep individually fused power feed wires separate for each servo, directly from a power distribution panel) Or use the TX slave programming to link desired servos if enough channels available.
For now I will do only one servo for main and mizzen sails (or first and second main, as they are called in Kruzenshtern's original Rusian and in paper kit's Polish). I hope that the winches are strong enough and square sails do not require that much force to move. I do have a space for an extra servo on my control deck, so that if I need more power I can easily add it. Another thought occurred to me: I can connect the lower sails of the aft masts to one winch, and the extra servo can be used for upper sails.

Quote:
Originally Posted by DanL View Post
I think you can get away with having functional braces only on the two lower yards. But if you rig masts and yards before servo/drum design, you can experiment manually to see what works best.
I am planning to space out my controlled yards. I am thinking of controlling the lower topsail yard and lower topgallant yard. I hope this will distribute the control more evenly

Quote:
Originally Posted by DanL View Post
You need a smoky signal cannon!
Yes, I do.
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Old Feb 28, 2013, 01:31 PM
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As I said, I designed a new control deck. It is a forth major redesign, and a second remake of this part. I am not surprised, actually, because it is literally the heart of the boat. It has all the sail controls built in with all the support mechanisms. I already posted the photos of the old version. In the new one I got rid of all the shuttles and replaced the square sail controls with Dan's new sliding winches. I did keep my geared motor for headsails control. As I said before, I know it's overcomplicated, but I wanted to check if such control would be practical (no, doable). If it proves to be to convoluted to work, I have already designed another (fifth!) configuration with regular servo winch.

For the new deck I have reduced the drum size on the geared motor in order to reduce speed and increase torque. I am satisfied with speed now, but because of the multiple layers of thread on the drum, the thread tension changes as the drum turns. In order to compensate for this, I made a bungee loaded tensioner.

I like this new deck a lot more than the first. It is simpler, more compact and easier to insert through the hatch.
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Old Mar 03, 2013, 12:23 PM
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Hi Alex

Amazing work and piece of engineering.

kind regards
Tim
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Old Mar 03, 2013, 02:06 PM
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I see from your threads that you are an experienced RC sailor, with a gaff rig sloop and a large schooner. So, I hope my comments are not too basic, that I'm not carrying coals to Newcastle :-)

1. Complication below decks: The more complication, the more time spent in maintenance and the less time on the water. As long as you are happy with this situation, no problem. I prefer simplicity since I prefer to sail, but it's your hobby so you should please yourself. In the steam boat world, I see some builders shooting for maximum complication in the engine/boiler room, which has an attraction of it's own, of course. My experience with squareriggers has shown that simple systems will perform just fine at sea.

2. Headsails: If your tension arm results in the headsail sheets being too tight, your sails will be too flat to make effective airfoils. The problem is that that poorly setting sails won't allow you to achieve "balance", a necessity for a multimasted vessel. A sailing vessel balances the lift off the keel with the lift off the sails. If balance isn't achieved, then the ship will constantly try to head up into the wind (weather helm) or fall off (lee helm). The jibs are vital to balance. The balance force generated by airfoils (eg. properly setting jibs) is much greater than the balance force generated by flat, drag devices (flat, tightly sheeted jibs).

I see a variation of this problem whenever my Pamir jibs' clews don't cross-over on a tack. When the sails are "flat" due to the jib clew remaining to windward, the Pamir acquires a very strong weather helm; when coupled with excess heeling and a strong leebow wave, the ship will drive into the wind, setting sails aback. My rudder is quite big (4-5x scale size), but will be unable to prevent this aback condition developing in a gust.

With a multimaster, it's possible to reduce sail aft (jiggermast) to help with the problem. But better to design the jibs to fly with a good airfoil in the first place. On Aldebaran, I achieved this by alterning jib shape to make overlap minimal, reducing the occasions when the jibs don't cross-over. A positive cross-over RC system of sheeting is another way to achieve this. As long as the system does not end up making the same "flat jib" problem, then all is well.

3. Rather than tensioning your sheets to keep them on the winch drum, have you checked out JayDee's (John Doud) winch boxes? He's used them to successfully handle slack on his big Bluenose model. He posts on the Model Boat Mayhem site.

4, I'm not clear how many braces you are planning for each mast. One will do the job, but 2 will do better if you are a fanatic about microseamanship (like me). I run my 2nd off the same servo arm. I imagine you can figure how to do the same with a winch setup. More than 2 brace sets (2 yards controlled/mast) is needless overkill for a model, in my experience. If you want to duplicate the spiral set of yards used in the Pamir heyday, then mechanical devices (my jaw-jammers, for instance) will work in lieu of more braces. I find that a servo for the foremast, and a servo for the main+mizzen+jigger, works for Pamir. Main and mizzen are slaved. The jigger uses an alternate reeving of it's sheet off the same m+m servo arm. See my Pamir threads for details.

5. I find it imperative to be able to strike and set sail to match the wind conditions. Too much sail will give too much leebow wave, leading to heading up. Too little will make tacks more iffy since you can't generate enough speed & momentum to complete a tack reliably. So, give some thought to how you will deal with changing the suite of sails while at the pond. This itself would argue for fewer braces per mast :-)

As you change the sails, you have to keep track of balance, of course. Not all sails are equal, since all but the outermost jib works in dirty air (downwash off the upwind wing, ie mast). This downwash is one of the reasons sails on after masts (and staysails) are sheeted more tightly than you might expect. It's an interesting problem, and one that makes sailing squareriggers so much more satisfying than sailing sloops, I think.

Hope this helps :-)
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Old Mar 03, 2013, 10:20 PM
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Brooks:

All your comments are a treasure of information and, therefore, helpful, even if I do not follow your advise. As far as the tension arm goes, it will not tension the sheets. It will tension the loop to which the sheets are attached. This way I will be able to control the sheets pretty well and not worry about them slipping off the drum.

The schematics I am posting are not to scale and not to correct proportions. They are just a crude representation. But notice that the loop that is run by a servo (or a geared motor) is always taught and is never in danger of tangling or slipping off the drum
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Old Mar 03, 2013, 10:42 PM
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Brooks assures me that one set of braces per mast should be enough. I trust his experience. As I said before, I planned to brace two yards: lower topsail yard and lower topgallant yard. My thinking was to space the controlled yards along the mast. Now, her's what I am going to do now. I will make the double drums a la DanL for two yards per mast, just like I planned. But in the beginning I will only control the lower topsail yards. If I need more control to sail the ship, I will connect braces for the other sails. Likewise, if ever I reach the lofty stage in my seamanship where I will feel more control makes a subtle but important difference, again, I will connect the other sails. But for the beginning I will fo with "Keep It Simple, Stupid".
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Old Mar 04, 2013, 01:09 AM
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With one set of braces, the yards will spiral (rather than remain perfectly parallel to one another). The spiral will be in the opposite manner as the real ships' spiral (I'll call it a model's reverse spiral).

For the single brace setup: The lowest braced yard will be where you set it. The upper yards will brace a little sharper due to slack in their sheets (and stretching of the sail fabric). Each will naturally brace sharper than it's lower neighbor. By the time you get to the uppermost yard, it will likely end up almost parallel to the hull. Thus, the upper-most sail, the smallest, will contribute more to heeling than to forward motion.

This "reverse spiral" does not prove a problem for "normal" sailing. The ship will sail fine on a beat. Even w/o the thrust/lift of the uppermost sails, models don't falter because our models sail faster than scale speeds anyway. The spiral set actually looks very pretty since each sail will throw a different shadow since it's at a different angle to the sun.

By the time of the Grain Racers, top skippers deliberately spiraled their yards, with the the lowest (course yard) sharpest braced, and the highest yard the least braced (most square to the hull) . This spiral increased sail efficiency since the wind is "fairer aloft." It's an apparent wind thing: as you get higher, the wind speed increases since there is less friction from waves. The change in windspeed reduces the effect of the ship's own speed. Thus the apparent wind, which is what the sails see, is fairer aloft. You can prove this with vectors if you wish, or just trust in the fact that the skippers were pretty sharp witted.

Where I found model trouble was when I wanted to perfect my maneuvers. When heading up to tack, the upper sails, because of their not-entirely-constrained yards, would sometimes catch a swirl of wind (probably off the mast to windward), and go aback before the lower, braced yard. This might be a momentary aback, with the yards slatting back and forth. In challenging conditions, this slatting acts as a brake to ship speed, impeding the tack. Also, it looks wrong, and the sound will have you wondering "will something break?"

Adding the 2nd set of braces constrains some of the unwanted yard swing. There will still be some reverse spiral, but it'll be greatly reduced. This makes tacking easier, and reaching less of a challenge, too.

I'd follow your plan, namely starting with a single brace set. Then if the reverse spiral gives you difficulty, add the 2nd set of braces. It sort of depends on how fanatical you wish to be in your sailing. I sailed for many weeks with just single braces, and had lots of fun. For Pamir, I set the 1st brace on the course yard. The 2nd brace went to the upper topsail yard (ie, 2 yards farther up the mast). When striking sail, I just remove the yard and it's attached sail. Can't easily do that when there's a brace attached, so some thought to your sail reduction sequence is in order. Heavy weather sails were the topsails on squareriggers of the 1930's. Thus my braces can be left in place in the fiercest of scale gales. I strike the course by leaving it's yard and removing the sail itself; the topgallants and royals are struck yard and all.

It might be possible to design a 2nd set to work off the initial brace, ie tied directly to it, not needing a 2nd spool on your winch. Making use of the geometry of angles in the braces, you might be able to figure out how to reduce the throw of the 1st brace enough to get your 2nd brace swing geometry right. This would save you having to work under deck to reeve the new brace set on the 2nd spool.

One of the interesting things I discovered with my free-sailing squareriggers was that the yards Want to swing to a sharply braced position (ie the beat). They just have to be given a start, to get them past the back-winded postion. After that,they will swing on their own the rest of the way. The purpose of braces is thus to limit their swing, not force them to swing sharper.

This is true of the real ships also, although I did not understand it at the time. When tacking HMBark Endeavor, we hauled the lowest yard (course) around by pulling it's leeward brace, and let the rest of them swing w/o anyone needing to tug on their leeward braces. The windward braces were tended by a crewman, who fed out brace line from the belaying pins. He was mainly there just to keep the yards from slamming to a stop when their hanger's jammed. It's also possible to break a yard if it hits the shrouds with a slam, I was told.

The automatic swing is due to the center of lift being at the 1/4 chord point (out on the windward portion of the yard), not at the 1/2 chord pt (which would be at the yard hanger). Just another example of how sails behave like wings :-)
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