I guess I'm mostly disappointed with the turning motor because the prototype ship was said to have excellent turning ability by reversing one of the props. I know water doesn't scale, but still... I was expecting something. A water detection circuit isn't a bad idea, but it is just something else physical that can fail. At least with software, I know that it won't stop working in the middle of a fight. That feels strange to write since engineering-risk-analysis always says the exact opposite. At some point in the future, I may augment it with a water sensor; but only to increase the frequency of pumping. I like the idea of having the timer as a failsafe. Right now the pump is on a triple position switch {off, delay, full}. I think I will add an audible alert for the off position, so I won't forget. -- Cognitive load - I've been thinking about what it "feels like" for some time now. My impression is that the complexity comes from having two points of reference. - Where I stand - I use this to drive the ship. - The ship orientation - I use this to aim the cannons. The second issue is there are two systems happening at the same time. - The ship is relational. E.g. - Whatever orientation the ship is in, if I move the rudder left, the ship will turn left. - The turret stick is positional. E.g. - I point the stick to where ever the target is, and the cannons point at it. Mentally, I'm having trouble with keeping all of that straight at the same time, and I have three ideas on how to deal with it: - Practice - I simply need to learn to be a better ship jockey. Practicing with the ship in my pool doesn't work because the ship doesn't really get up to speed before it runs out of space. - Add a GPS, and make both driving the ship and aiming the cannon relational to me. Definitely the most tech-heavy solution, so I'd rather not try this unless I have to. - Convert the turret stick to relational. The math isn't hard, but I'm not sure I fully understand if this will make things better or worse. Anyway, I'm going to start with practice and see if I can overcome on my own.
Did you try slowing down the prop opposite the turn? Say you're turning to port, slow down or stop the starboard prop? In my experience this has produced the best handling. With fast gun I can't actively take advantage of this but there's been enough times where a motor or esc dies and I'm running a boat on one shaft and it's always turns amazing towards the powered prop.
These are the tests I've run so far, which sucked, but I am very open to trying other ideas: - Test 1: Slow down the outside prop, proportionally to the rudder. EG - When turning to port, the starboard prop will slow down. When turning hard to port, the starboard prop will stop completely. - Test 2: Slow down the outside prop, reduced proportional to the rudder. EG - When turning to port, the starboard prop will slow down. When turning hard to port, the starboard prop will be {1/4 and 1/2} speed. - Test 3: Reverse the outside prop, proportional to the rudder. EG - When turning to port, the starboard prop spin in reverse. When turning hard to port, the starboard prop will be in full reverse. - Test 4: Reverse the outside prop, reduced proportional to the rudder. EG - When turning to port, the starboard prop spin in reverse. When turning hard to port, the starboard prop will be {1/4 and 1/2} speed in reverse. I never ran any tests adjusting the inside prop with the rudder. -- Maybe it's the big gun rudder? Empirically, I learned that turning the prop 90-degrees does not turn the ship as fast as about 45-degrees. So this is approximately what the ship's rudder looks like when 'hard over', in the above tests.
I'd suggest re-evaluating a water detection circuit if you're forgetting to turn your pump on and wanting to reduce your mental workload/free it up for other tasks. Saying a physical circuit can fail but something with software won't doesn't make a lot of sense, what is the software running on after all ... a physical circuit. A simple water detection circuit can be built out of a handful of jellybean passives and the whole thing works because physics works, other than connections failing or not setting it up correctly there isn't much that can go wrong, and those are pretty easy to do correctly. (if physics stops working...I'd say there may be other more pressing issues requiring your immediate attention ;-) ) I wouldn't even have it control the pump if you don't want it to, all it has to do is light up an LED in your superstructure to alert/remind you to turn on the pump, no moving parts or software needed. In a lot of ways the end result is the same as a audible alert on your radio but based on water in the hull instead of time. Worst case if it does fail you're in the same situation you are now where it is up to you to remember to turn the pump on. For turning (say to port) with propellers you'd want to stop/reverse the inside propeller (port propeller in this example) and possibly even over-drive the outer propeller (starboard propeller in this example). But like Kotori pointed out doing that robs the rudder of flow which is really how these boats turn so in general the downside is probably greater than the upside for trying to turn with your propellers on a two shafted ship. The impact of propeller steering on two shafted ships is going to be smaller than similar 3 or 4 shaft ships simply because the propellers are closer to the centerline so the torque is less. (yet again two shafted ships get hosed in this hobby) These ships don't really behave, or get used, like the prototypes did, it's a whole different ballgame with the similarities tending to stop once you get visually within about 10 ft of them. In terms of how far to turn your rudder it can really depend on your rudder how it is setup/aligned with your propellers during a turn also what type of performance you're after. Max speed through a turn and minimum turning radius are likely not achieved with the same rudder throw. Is one of those more important than the other? Also turning the rudder a full 90° can help you stop sometimes too, it kicks you to one side or the other but that can still be better than ramming someone or driving into someplace you'd rather not be. It does add more mental load if you're trying to only throw the rudder a bit in the middle of battle to get an "optimal" turn instead of just slamming the stick all the way left or right, more tradeoffs. If you want to improve your turning, can you move the location of your rudder post, or props? Or a different rudder shape? Is any of that allowed in Big Gun? Have you been testing it fully loaded at speed?
As complicated as I've made this build so far, it's probably silly for me to say I'm trying to KISS by using software. ahaha. My logic is that the software is in the radio transmitter, which isn't getting wet or moving around. So if that goes wrong, I have big issues which I'll notice immediately. I might add a water-detection circuit at some point, but only after I have a few dozen other problems behind me... like having a float! New question... what is a jellybean passive? I hear you. Especially since I moved the props (in red color above) so close to the centerline; they are basically acting like a single prop at this point. Oh well, I'll keep the dual ESC on the alpha-test ship, but at least I'll be able to re-use that radio channel for the third firing circuit. Interesting ideas here. I'll try programming the rudder to turn to 90-degrees whenever I go from full forward to full reverse; might give me better stopping power. Honestly, while I'm at it, I might as well try keeping the rudder at 90-degrees whenever the ship is in reverse. It's not like the rudder is doing anything for me when I drive backwards. I do wish sometimes that the computer knew what speed the ship was going. I could adjust the rudder performance, like you are saying. It would also give me enough info to auto-turn my turrets to track a target as I pass by it. But again, I'm over complicating things, and it's better to KISS. Applicable Rudder & Prop rules: - Rudders may be made of any material and may be up to 25% larger in area than on the prototype ship. - Rudders must be the same shape and installed in the same position as on the prototype ship. - Ships may have up to the same number of propellers as the prototype ship. - Propellers that are installed must be in the same position as on the prototype ship and have the same number of blades. - Propellers may be up to 50% larger in circular area than on the prototype ship. There's no rules about rudder shafts, so I already moved it around a bit to get me the prop wash:rudder overlap that (I think) I wanted. - In the photo above, the red are the props and the gold is the rudder. - Please recommend any changes you'd make for the next revision of the ship? Rudder shape, practically speaking, the Big Gun are simply looking for 'classic rudder' shape. They don't care if it's exactly the wedge shape that the original ship had, but I can't use the fast-gun hour-glass style rudders. She's much heavier than the early videos, so I think she's arguably at weight. My pool isn't big enough for me to realistically measure her speed. I'm guessing she's too fast through.
Update - well, magically pneumatics for all 6 cannons fit. However, I'm definitely seeing an upgrade is needed for the next revision. My goal of saving space by not having accumulators has failed. I do like the idea of having single shot cannons & I'm happy I get to try it out. However, can admit I was fixated on one design element & didn't see past it. For the next hull revision; I need to seriously consider: 1) Reducing to 1x battery total. 2) Reducing to 2x valves and 2x accumulators. 3) Cutting out a dedicated spot for the valves, so it's not so tedious to take the bottle in/out. Probably in the bow, since there isn't much up there.
Jellybean parts are common parts you can get from multiple manufacturers with effectively identical specs, resistors, capacitors, diodes, basic transistors, LEDs, inductors, basic ICs, stuff like that. Passives are basically just wires or conductors, resistors, capacitors, inductors, stuff like that. Actives can source or amplify a signal, like a transistor, voltage regulator, op amps, etc. Not sure where diodes and LEDs fall, doesn't really matter for our use. Im wrong about passives only, the transistor is an active component, don't know what I was thinking. Still it's controlled by physics and not software so I would argue my point still stands. Not sure on Big Gun rules but I know a small paddle wheel under the boat was used in the fast gun world to get current speed...before it was outlawed. Regular old GPS isn't great for our boats unless you want a really rough reading. It might be better for big gun with the slower speeds but maybe not. A full RTK GPS setup would be better but those aren't really cheap. Wonder if you could use some sort of pitot static tube in the superstructure or ?underwater? To get a useable velocity measurement... No idea on what the acceptable wiggle room is for big gun. I'd put the rudders shaft at the 1/4 chord and then move the props rearward to get them as close to the rudders as possible. If you can try a thicker rudders to, I haven't messed with that much but some people have seen some improvement from it. Might be a little late but any shot of adding a little "toe in" to the shafts instead of them being parallel?? More flow over the rudders for better turning. Or just move them closer together, if they clang against each other a little 80-grit will take care of that.
WRT prop/rudder locations, you're pretty well set up already. The props are in their scale locations, the rudder is scale size and shape. There isn't much more you can do to play with it per the rules as written. Maybe a thicker, more hydrofoil cross-section. That said, talk with your local club to see what they are comfortable with, if you can shift your props closer to the rudder or add some toe-in. After all, even Fast Gun has rules about props and rudders in scale locations that have been blatantly ignored for so long that most people don't even remember that it exists. As for mixing throttle/rudder to improve turning, I don't believe it is possible for a two-shaft boat within the rules. With that in mind, how is the turning performance? is it noticeably worse than other ships you're competing against? From a Big Gun perspective, you out-gun all of the small boats that can turn with you. Your only fear should be the big fast battleships like Iowa, Roma, Scharnhorst, etc. that can catch up with you. If you can out-turn them, you'll do fine. From a Fast Gun perspective, just make your stern gun pivot the way my predread sterns do, and you'll give 'em just enough hope to keep chasing as you rip open their bows. A paddle wheel is an interesting idea for measuring speed. Based on it getting outlawed, I'm guessing what you described was installed on each ship so they could accelerate at full throttle until hitting their allowed speed. If it was just used for speed trials, you could have a small box that you place on the deck amidships. Use a paddle wheel on each side to calculate speed, average the two results together to compensate for any waves or turns, and display results on a LED screen. OTOH for that level of effort and technological skill, you could use a few sets of IR emitters and detectors to build a speed trap for ships to drive through, which would work for more boats and be more accurate. OK never mind, I talked myself out of it. Those solenoids look like a mess. Are you going to have a single solenoid supply three cannons? I am very curious how well that works. I've got a pair of Viribus Unitis and I'm just dreaming of arming all main guns with rotating/depressing turrets. They're about the same barbette size as pocket boats, too
Thanks for the recommendations! RE:JellyBeans - OK, I'm interested. How do you put all those parts together? Wouldn't you be looking to step-up the transistor with a relay so as to not burn it out? It's been a while, but I remember that FETs were a lot less fidgety with this sort of thing. Either way, what are you using for the circuit board? Do you have a diagram? RE:Toe-in - I didn't see anything in the rules against a toe-in. So, I gave her a reasonable amount already, but I guess I didn't really capture it very well in earlier photos: - Green are the motors. - Blue is the drive shafts & the props. Any recommendations to get them cleaned up? Today's boat has 6x solenoids, with independent firing channels for each. The firing boards are wired so I can fire all cannons from a single turret at the same time. I do want to know if I can fire all three simultaneously without needing an accumulator. I had remembered back in the day being able to run two cannons from a single solenoid, am I remembering that wrong? I guess I must be remembering that wrong... now that I sit down and think about it, once one cannon fires it'll depressurize the other cannons. DARN. This set up will work well enough for alpha test, but I'll need to find a better home for all 6x solenoids. _
I believe only one person did it, or had a system setup to do it, before it got outlawed but yeah using it to accelerate faster was the idea. This was 20+ years ago. As for speed traps, I've built a few...it's really not that hard. 1. The Sun can be really freakin bright which can cause problems and washout your signal if you dont account for it. 2. People's INABILITY to drive in a straight line and/or through a "narrow" (3-4 ft across) gap a few feet from shore is....?impressive? Otherwise it works pretty darn well. Something like this: The two probes (Probe 1 and Probe 2) can be pretty much anything that conducts well, i'd stick with brass/bronze/copper soldered to the wire. One of the probes goes in the water channel the other is set the the height that you want the circuit to activate when water reaches. The rest of the parts could all easily be found at Radio Shack if that was still a thing or you have someplace like that. (Micro Center or a local Mom&Pop type spot) For the NPN transistor, pretty much any old NPN transistor will work, if you're just lighting up an LED you dont need much current even. I use these: https://www.mouser.com/ProductDetail/863-MMBT3904LT1G But this would work fine and easier to connect: https://www.mouser.com/ProductDetail/onsemi-Fairchild/BC33725BU?qs=LU5rZWrBGo0gUheVwmNJVQ== The resistor (R1) and LED (LED1) can be a million different combinations, it's no different than hooking up an LED anywhere else. The resistor limits the current so you don't burn up the LED or Transistor; for a 5v supply voltage and run of the mill LED I'd grab for a resistor in the 470Ω to 1kΩ range, the exact value isn't too critical. You're just using the NPN Transistor as a switch to turn on the LED and letting the water in the ship flick the switch for you. Put the LED somewhere you can see it and Bob's your uncle.
Doh, I wasn't paying attention last night when I drew that up, here is the right circuit. I also added another resistor (R2) to this one, it isn't required, but it helps protect the transistor if the two probes touch or are conducting through something other than water. (value isn't super critical, something around 1k Ω should be fine) If you wanted to control a pump with this there are a few ways to go about that and it can depend on the pump motor you want to control, here are a couple that I've used. 1. Brushed Motor - Replace the NPN with an some sort of FET (like a MOSFET or IGBT) that can handle high power loads, may need to use the NPN to trigger the FET. The Motor would go in parallel with the Resistor/LED or between the V+ and FET (Assuming an N-Channel FET which are better suited for this than P-Channel FETs) if using the NPN to trigger it) Unless there is a specific reason why you need to use a FET I personally don't think its worth the hassle. 2. Brushed Motor - Replace (or run in parallel) R1&LED with a Relay (Mechanical, sure you could use a solid state but you dont really get much for the money and at the power loads typical of pumps mechanical just does better). Tons of different relays to choose from. My personal favorite is the American Zettler AZ2100-1A-5DE, it works on a 5V control signal, can handle up to 40Amps, and is Epoxy Sealed from the factory so water doesn't get inside and corrode the working bits. they have a long history of use in the hobby and perform great. They come in other control voltages as well if needed. 3. Brushless OR Brushed Motor - A bit more involved. Brushless motors need a fancier control scheme than Brushed motors so they are a little harder to use, but this can really work for either. Pull out a microcontroller, modify the above circuit just a tad to feed a micro-controller: Then use the micro-controller to generate a control signal for the brushless pump esc. (This is what my auto-pump boards do, they allow for manual control for both OFF and ON as well as a setting to allow the watersensor/microcontroller to control the pump(AUTO), your radio needs a 3 position switch or some fancy mixing but gives the best of both automatic and manual control.) The control signal could go to a brushed ESC or relay type board for a brushed pump or integrate the relay on with the microcontroller for a brushed pump. Lots of ways to skin the cat. Probably a few other ways, like using a 555-timer to create a control signal for an ESC or whatever else you can think of but I've done it using all three of these methods. Generally speaking I don't think the first one is worthwhile, maybe if you were super constrained on space or something but it just seems like extra hassle when a sealed relay is so easy, cheaper, and IMO more reliable.
I’ve been trying. I wish I could. I didn’t realize how steep the ledge was on that lake. At this point, I think it’s gone for good.
This reminds me of the RC Sub Guy losing a sub under a rock outcropping. You either need a diver, or one of those FiFish rov subs with a claw.
Update! Diver comes tomorrow! I’m surprisingly happy about seeing her again tomorrow. I know I can reprint most of her, but I have to be honest her lost was very disheartening. Keep your fingers crossed!
