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Bedford

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Everything posted by Bedford

  1. Twister, thanks heaps! The RMG sailwinch site explains it perfectly and as I hypothesised. I wish I had known about these guys ages ago and they are an Aussie outfit too!
  2. Mark, I am looking into various options but there is no point powering up the radio after the ESC as it isn't the drain, it is the limiting factor for the power to the radio and every digital servo adds to the power drain so it doesn't matter if I power them up one by one they will still over tax the system. The extra battery pack idea is apparently what the fly boys do with their big 1/4 scale planes with high power servos, they hook up a battery pack for every servo and since it all connects in parallel they provide built in redundancy because each battery pack powers the entire system. I don't want to go down that path for a few reasons :- First, every time I touch her she puts on weight and I doubt I will be able to put more than 1.5Kg of ballast in the sailing keel. Second, I have already invested quite a few $ in this and doing the extra batt pack idea will add quite a few to the tally. The battery pack I have fitted will be capable of supplying more than enough power to run everything but I need to find a separate way to supply a regulated 6V to the rx. I have considered ditching the current ESC which has two motor outputs and replacing it with two that have single motor outputs. This should double the power available to the rx but has the down side that the ESC's can't be guaranteed to be 100% balanced which could result in the schooner doing an imitation of the Bismark when she was beaten. There is a device called a UBEC which apparently does the job of the BEC (radio power supply) in the ESC and if I get one or two of these I can use them as well as the ESC power supply to feed the rx and they are much cheaper than batt packs. Does that make sense?
  3. Ok boys and girls, tech talk time ! I have had more severe radio issues in that when I was setting up the winch servo for raising/lowering the stays'ls and I plugged it in to the receiver the whole on board system went berserk! The motors were going forward and reverse, the servos were going crazy ( the tops'l lazy jack master line broke again ) and the receiver was beeping and flashing. I asked the guys who have been following this build and know radio control what they thought and thank you all for your replies. Cap n Bob mentioned voltage among other things which got me thinking and from googling speed controllers I started to form a hypothesis. The power for the radio comes from a 7.2volt 2400mah battery pack via the electronic speed controller which controls the voltage to 6V for the radio. The problem is that the speed controller or ESC is designed for cars which may have two servos to run as well as the ESC so the output from the ESC to the radio just isn't putting enough power into the radio especially when I am running high torque digital servos which require constant power. The result is the same as any electrical circuit where you have too much load on the circuit, you end up with excessive voltage drop and nothing working properly. The cure, which I am yet to invest in is to add 6Volt battery packs to the servos, you can get "Y" leads which are normally used to run two servos on one channel but you can run one side to a servo and the other to a 6V battery pack. The power will feed into the receiver as well as the feed from the ESC thus boosting the power available to the servos. You can add a batt pack to one or all of the servo leads but I don't think I will need to add many. Feedback from Cap n Bobs old rc sailing club, although not saying this in so many words because they are not used to powering via an ESC, seems to confirm this hypothesis. For now I will disconnect all servos except the one I am setting up at the time. I realise that most of us who make rc sail boats won't fit auxilliary motors an therefore won't have the issues that arise from powering the system via an ESC but I thought it worth posting for posterity. Bob, you might wish to forward this on to your Indy buddies for their future reference along with my thanks.
  4. I have replaced the broken master lazy jack with one of larger diameter to ensure it can't run off the spool on the servo. The original was thinner and could fit in the gap between the spool and the guide drum. By very gingerly turning it on and paying close attention to what happens I learned that the tops'l winch pulls on the lazy jack when the radio is turned on. It doesn't matter if the servo is all the way to it's preset stop in that direction it will still pull about 1/2 a turn more. Solution :- remember to always leave the tops'ls drawn out when turning the radio off, this way all it will do is pull the sail in a bit then return to the correct position without harming anything.
  5. Michael, you wouldn't believe the strain the servos pull against to achieve all that. When I first tried raising the gaffs by pulling the halyards at the servo end I thought it would never work but was amazed at the torque of the servos. I have however encountered a small disaster. Last night I left her with tops'ls nicely pulled in but when I got up this morning I realised this could crease the sails so I switched on the radio and when I switched on the receiver the servos I have set travel limits on via the transmitter ran, searching for their limits and there was an almighty thump as the lazy jack final line from the connection of the three individual lines to the servo snapped under huge tension. I had feared this and am considering my options now. If I can find suitable switches I may switch off the servos individually and once the receiver has stabilised I will turn them on one by one, other wise I don't know how to overcome this problem. Any ideas........anyone???? Steve
  6. Well Omega, it's like this. The lazy jacks which haul the gaffs down are attached to the sail at several points as in the real thing, kind of like a draw string. This keeps the sail nicely contained and controlled back to a bit past half way and while the balance of the sail can spill out it can't go far. So yes, I intend to at least motor out from the shore into open water before setting sails and I can choose how much sail to raise. If the wind comes up or my sailing skills let me down I can drop sails and power her home. If I were to sail on a windy day I would probably tie the tops'ls and stays'ls down to better control them.
  7. Update, at last. As stated before the pipe work below deck is a pain but I have now completed all of it to the aft deck house. That includes raising and lowering the sails, tops'ls and controlling the sails. Next step is to raise, lower and control the stays'ls, this will be done from the fore deck house. Here is a little clip.
  8. My two bobs worth.... It won't be very tall if you make it so the mast can be dropped which would be much easier than dislocating 40 oars. Build a shallow crate, like a big flat suit case, out of ply. Make it so you can secure the ship inside by keel mounting screws or clamps. Put it in, close the crate and you can tip it any way you need to and nothing can get to it. As for sweeping the oars further back than normal, I'm not sure how your set up will work but perhaps mounting the drive system on a sliding seat like that in a rowing boat would allow you to lock the drive mechanism in either of two positions, one for working and display and one where the oars are swept in for transit. Whatever you do I am keen to see her in action!
  9. Michael, I just found this and read through it and I guess I can just refer you to almost every comment I have made on your 1/8th cutter. A few things that may be worth considering, I used to wind electric motors in another life and if you use a varnish coated wire of that small size you can very easily remove the varnish by running the wire slowly through a cigarette lighter flame, anything hotter will break the wire. Also I once made a very crude miniature of the "Schooner for Port Jackson" which I bottled, don't know where it got to, but I planked the deck by taking a very thin cut from soft radiata pine with a plane. It curls but if the blade is sharp and the cut is short it doesn't curl much, you can then use good sharp scissors to cut it into planks.
  10. A true craftsman in every aspect of the build.
  11. Thanks guys! Yeah John, I just started on the pipe work for the tops'ls and have walked away from it. Just can't get the fore to sit right.
  12. She dwarfs the motors, It sounds like you should have very nice speed control on the oars, I'm looking forward to action videos
  13. I have been slack lately, not looking forward to the lazy jacks. I have sorted them now and I can now lower the sails properly. The video is a little bit dodgey as the camera kept trying to auto focus but it's ok. Once all the running rigging for the tops'ls is done I think it will be smoother and more controlled too.
  14. She is looking great already, love this one.
  15. Halliards are one thing but it appears I may have a problem tacking. I put her outside in a breeze yesterday and the sails wouldn't reliably pull the line out of the tubes in a light breeze. If I let line out and the sails don't draw it through the tubes then it can foul around the winch drum. I may have to completely re-think them, possibly running them above deck through blocks and attach to the booms from either side but I see problems there too in that because the point of attachment to the boom will move in an arc the pulls will exponential rather than linear. Just another challenge for me.
  16. We have reached a truly momentous occasion........... http://youtu.be/oVoMhYSnHvA I am so pleased with how the sails raise, it takes a fair bit of effort but the servo handles the task with ease. I can't lower them properly yet because I have yet to run the lazy jacks to the servo, when they are connected the gaffs will pull down easily and the bulk of the sail will be controlled rather than spilling out all over the deck.
  17. More plumbing done, I am getting better at bending the pipes without needing to cut and adjust, the joint in this run is to make the distance, the pipes are only 30cm long.
  18. First a pic of the flared tube fresh off the lathe. These are for the joined ropes from two or three masts to easily pull into the final tube back to the servo. More plumbing done, that's tacking of the courses and raising of the gafs taken care of. I have found that epoxy putty is excellent for fitting the tubes in place, easy and it allows time to adjust the position properly while getting a good hold on it fairly quickly.
  19. There is an old electricians trick for getting a draw string through a long conduit run, it's called a vacuum cleaner. I will look into making some type of adapter to fit my cordless vac to the tubes by way of a clear pvc tube so I can draw the lines through.
  20. 27.5 degrees, that's about 1.5 too hot to be comfortable for me, you can keep it ! Back to ship building. The epoxy has set, the control room is re-fitted and I have done more "plumbing" I hope the pics make sense. This shows two tubes running to the winch drum, just held together with wire for now. I was going to solder them together but I am worried about the heat so I think I will use epoxy and epoxy putty to secure it all. In the following pics you can make out the two tubes from the fore and main masts coming together and aiming towards the stern. There is another tube with a flared end facing forward towards the other two. The idea being that a line off each boom will join to a single line that runs back to the winch drum. The gap between the tubes that allows for joining of the lines is located in the area of a large cargo hatch to allow repeat access should it be required. Nothing is permanently aligned yet. I flared the receiving tube to allow the join in the ropes to pass into the tube easily, I did this in the lathe. Anneal the tube then mount it in the chuck, place a centre drill in the tail stock and run the lathe in reverse while easing the centre drill into the tube. The cutting edge of the drill does not bite into the brass because the lathe is going backwards so the angled step on the drill acts as a gentle flaring tool.
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