HI JJ. Your question about a safety bag, Damaged / overcharged lipo's can catch fire, think of the Boeing scandal that grounded the fleet last year. Charging in a safety bag is advised the bag is fire retardant material, which will contain any problem. Your remarks about the boat not coming onto the plane is down to the weight of the battery, my fireboat started with 7.2v NimH packs 1 for each motor, Graupner 700bb's, good cruise but not quick, but short run time, 10mins. I have re-wired to allow 3s lipo's, but not had chance to test it yet, but should go like stink. With a fast hull, weight is important, 4 x lipo packs, 1kg, half the weight and possibly 6 times the power delivery. In your first post you mention 600 motors on 6volts, they are probably rated at 8.4volts, same as my 700's hence the lack of performance, also the battery, at 12ah it should last about 30mins, was it fully charged??? and is it showing at least 6volts, ie not got a duff cell??? Canabus, in his post described an ideal set up with brushless motors, 1600 watts is just over 2 hp, 750 per horsepower so you can see the difference in performance with different motors and battery set up's
Hi What type of props are you using(size and number of blades). I see your basic problem is under powered motors and a very heavy battery. I made the big switch over three years ago from brush to brushless motors and to Lipo batteries. With the help on the forum and club members it was a learning curve, but, I would not go back. A 5800mah Lipo battery is in the weight of 450 to 570 grams and would give you a good 1/2 hour run time. A good balance charger and safety bag are the main requirements, also maximum charging for the 5800mah battery is 5.8 Amps(same as the old Nicads). Also a low voltage battery alarm. Your 600 motors can draw up to12Amps !!! Replacement same size motors for your mounts would be 35mm brushless motors, but, you will require two ESCs with a Y connector to run on the same throttle channel. Replacement brushless motors are far more powerful e.g. a Hobbyking 3639-1100kv with a 60Amp ESC on a 4S 5800mah Lipo Battery is 800watts and with two in your boat is 1600 watts!!! Your old motor would in the 100 watt each mark !! I have the same size crash tender, but, with a single brushless motor. I have all the order numbers for the motors etc. and a setup the ESCs if your require. Canabus
Hello chaps. I'm very new to this but have just finished scratch building a 46" Vosper Firefloat in the old Aerokits fashion (ie all wood) to the point where I've primered it, fitted a radio and couple of motors (Graupner 600 chosen at random cos they looked adequate!) and a Lead Acid 6v 12Ahr battery. Tried it on the local canal today and two problems. 1: its underpowered...nearly gets on the plane with a fresh battery but not quite. 2: The battery only lasts about five minutes. I'm an old git and don't understand "Lipids" or the benefits of "Brushless Motors" etc and would appreciate any help or advice any of you experienced guys could offer me please on motor/battery choices to get the thing planing and running for more than five minutes. Many thanks in anticipation Cheers John
Only a short one, as I have realised that dealing with Battery Mounting means I need to deal with changing the Rudder Servo first! (Pic 1) So to remove the servo was easy as was replacing with the better unit. It is by the way much easier to remove the Servo Bracket and then the Servo than leaving it in. Same naturally applies when fitting (Pic 2/3) I had to remember to have the lead coming out on the correct side though! (Pic 4) I had been thinking about whether I should be using proper metal linkages to the rudder mechanism and issues about ‘slop’, but now it looks like there will not be a choice, but let us leave that until later as this is going to be a short session. (Pic 5) In fitting the battery I was conscious that it has to pass in and out of that rear hatch, stay on the centre line and avoid fouling the Rudder Servo...................... So I cut a base plate of Balsa to stick in the bottom of the Hull so making it reasonably flat for the Battery and a Balsa Plank to stop the Battery accidentally moving towards the gear boxes. Before gluing them in place I attached Velcro/ hook and eye patches to hold the Battery in place. (Pic 6 ) There appears to be at least two thicknesses of this stuff, very rigid and strong and the other softer, more flexible and slightly less ‘grab power’ (Pic 7 ). I opted for the lighter stuff as it could be a struggle getting in and out of the Hatch! (Pic 8) I may need to put a loop of something around the battery to assist in removal, but that is for later. I just glued the Balsa in with ‘Gorilla’ glue and laid the battery in to add weight whilst drying (Pic 9/10/11) Next time I hope to concentrate on getting the forward platform loaded and the power linked up. NPJ
This time I will try to remember to put in the ‘source’ information on the bits and pieces I use........... In the most recent piece I should have included exciters/transducers are Dayton Audio DAEX 25VT -4, 4 Ohms – 20 Watt pair, obtained from Sound Imports Netherlands and very quickly as well. The sound unit is a Mtroniks Digisound 5M diesel sound, available all over the place. Now to look at where I am at. Exciters are in place as high up the Hull as possible, but remembering the Deck level. Used the adhesive pads as supplied after wiping that part of the Hull with Meths and Silicone adhesive to keep in place as well as using the wiring tidies from Modelsport Ltd., for the cabling. (Pic 1+2) Before I start the motor and controller wiring I changed the platform ‘up front’ (pic3) with a piece of thin ply which I have given a couple of coats of varnish to waterproof. Then I thought to myself “why am I waterproofing this when, if it gets that wet, it will have gone to the bottom and be useless anyway”! (Pics 4) However, the platform gives a little more choice in terms of layout of other components and my plan for them is not really settled yet. I am concerned about the stern and possible swamping, but it currently seems the best place for the upgraded battery. (Pic5 ) Whilst talking batteries, I have gone for a separate battery supply for the receiver and hope to use the Bec supply for running other less critical items. Also the fitting of the battery in the stern bay drew my attention to the rudder servo for a couple of reasons. First is I am still considering increasing the size of the rudders and I am assuming that will increase the strain on the servo. The servo supplied is a standard issue and not water resistant so I have gone for an upgrade as shown(Pic6) That gives torque increase of 17Kg/cm over the Hobby Engine S1040C and has metal gears, metal control arm and waterproof for 20grams extra weight. Second is the closeness to the new battery position. So I was going to alter the servo arm setup anyway and the new metal arm suits this well. Maybe my ‘tutors’ will consider all this to be a little ‘over the top’ but I do so enjoy messing......................... New Servo DS 3218 by AYANI from Amazon. (Pics 6/7 ) Following that distraction, back to the front end and the Motor/Mixer placing and wiring. Now a little time ago I drew a plan to see what could go where and it came out that most of the ‘bits’ would go in the front bay with motors to be wired once power was brought forward, followed by the Esc/Mixer. (Pic 8) At that time I bought a P94 dual esc/mixer from Action Electronics and got the 20 amp version to be on the safe side................. My ‘guardians’ did point out this was ‘over-kill’ but I had already got it. Now, when placing the unit on the mounting board I found that the heatsinks made it too high to fit in the Hull! So being a spoilt brat only child I ordered the 10 amp version and as usual it came very quickly from up here in Bangor. ( Will keep the other one for the next project............Happy Hunter??) Unboxed it and it looked just the same, heatsinks and all. (Pic 9/10 ) So at that moment there was a bit of a set-back so I rang Component Shop at Bangor, they said “take the heat sinks off and you have a P94 lite”! Such a simple answer and such a nice chap. (Pic 11 ) Now a quick 'measure up' before I have a glass of wine (Pic 12) and does it all fit...? Well it appears to at the moment! (Pic 13) Next time really going to screw down the components under the forward hatch and wire it up. NPJ
Motor fitted to platform and luckily there was enough depth to screw the motor platform to the stringers, I have moved the reciever forward to where it was and resecured the powerbox in a better position, just the leads with the bullet connectors from the motor to fit, although I have fitted the sealed lead acid 12 volt battery instead of the lead ballast (same weight) I have left the7.2v in situ as I trimmed the boat with them in and will see how it goes, it may have too much power on 12 volt and at least if my finger on the stick lacks control on the speed, I can slow things down by swapping over to the 7.2v batteries. If and when the sailing side is sorted, after seeing the pictures of members boats and ships, I think I will give it a good rub down and respray and smarten the inside up as well. Eventually I will get on with the Lloydsman
Dave, mtroinks have switches, so maybe when it had the pair of vipers, they where for the esc's? I would disconnect the red signal wire from the receiver end on the "y" harness, and use a separate 6v receiver supply, I have a number of twin screw setups, with a cheap battery monitor, if the esc fails, you still at least have rudder control, if the feed esc goes down, power is lost to the receiver, ensure you have a failsafe set at zero throttle. With spectrum, its usually automatic, unless...... you have reversed the throttle! that means you throttle will go wide open in event of esc failure. Easy test, on the bench, all set up to go, make sure all the props etc are clear, just turn your transmitter off, see what happens, nothing should! Have you done the range test? you might have been lucky having it go in reverse, Also, the gunner that is holding the esc wire, is he wearing a Teflon glove? His hand might get hot
Hi John Thanks for the pics. I see you are using Tamiya connectors. My experience is that they are unreliable and not suitable for currents above about 5amps. You appear to have the battery wired to both ESCs though one socket. As your problem occurs when both ESCs are connected I suspect the connectors are the culprits as they work then fail fairly quickly. Easily checked by using two separate batteries. If this is the problem I would hard wire the two ESCs to a chocolate screw block with just one socket for the battery. You might also want to consider a fuse in the positive wire to the battery. There are two switches, what are they switching and what type of switch? I can see the Y lead has one red wire taped up so assume power is from one of the ESCs? Where do you put the rx when the top is on? Hope you manage to move forward tomorrow. Dave
I looked at the Cornwall model site and saw that, what i have decided to do is to leave the two Ni cad batteries in situ and I have weighed the rear/mid section lead weight and it is just 56 grams heavier than the 12 volt 7 amp/h lead acid alarm battery so I will use the 12 volt battery and ditch the lead, the weight of the boat will be the same, I also trimmed the lead at the front end so the bow will come up a fraction more. I have taken the prop of and measured it to be a 55mm, so I am going to fit the water intake, hopefully with some advice from the forum "techys"as to the position, in the photos this is where I can fit it so it is out of the way of the rudder and prop.what do you reckon, I can then get a suitable motor with a water jacket which will be happy to run on 12 volt with enough power not to get hot turning a 45 to 50 mm two blade "x" prop, as suggested by pmdevlin, I may get the Lloydsman up and running as all that needs is dusting of and batteries charging up, (two 12 volt 7amp/h in parallel) and the receiver from the commander fitted although I have not floated it I bought it as a complete working model in 2015, so it is about time it came out of dry dock, also I can look to repairing the rigging and finishing the Odessy Yacht I bought at the same time as the Llyodsman also in dry dock.
I had a quick look around and discovered this hull matched 12V 750 Speed electric motor, hull matched 40mm 2 bladed prop this from http://www.cornwallmodelboats.co.uk/acatalog/aerokits-sea-co... However if you want performance http://www.kingslynnmodelshop.co.uk/Motors_and_Speed_Control... That should give the equivalent power output to a .40 IC engine and make the hull come to life the way it was intended to. Couple that to a LIPO battery and a suitable ESC. Remember when the kit was originally made IC was the norm The Sea Commander was introduced by Aerokits at Gorleston Norfolk in the early 1950s. Designed by L J Rowell the Sea Commander is a smaller version of the Sea Queen. The length is 34 1/4 inches by 10 3/4 inches and is almost identical except there is no mast. Intended for the ED Marine Racer and Hunter power plants
Hi Richard, as an extra to Dave M. the battery packs are different sizes, 5000mah and 3300mah, if both batteries are connected together they will cause problems with power balance, as said the cooling slots are covered. You said the motor was cooking, have you tried it since? maybe it was the ESC that cut out through the overloading with the prop to big. PS what size prop is fitted? The 540 in the 4th pic may not be big enough, a 600 size or even an 850 would give a lot more torque and probably more speed, you can back off the throttle but a small motor will always struggle, and will probably be run at near full power a lot of the time. Hope this helps Mark
Hi Les Thank you. There are three LEDS which change from red to green when fully charged. I can see no mention of setting a half charge. Haverlock was right in thinking each cell was charged by the balance lead so you will be protected from overcharging. The solution is to buy a battery checker theirs is DYN4071 and I have one in my collection. Using the checker involves plugging the battery via the balance lead into the balancer and each cell voltage is displayed sequentially. So you charge for half your normal length of time and check the voltage of each cell is about 3.7 to 3.8v. Bit clunky but would work. A better solution would be to invest in a balancer charger which will automatically charge to full voltage or the storage charge. There are several available some with mains power supplies and others needing a DC power source. Have a look at https://www.componentshop.co.uk/catalogsearch/result/?q=bala... I have a Giant Power G6AC but they all work just as well. Please ask if you need more info
Hi Tony You have not said if the model performs normally as soon as you are back on the surface, but if it doesn't I have the following suggestions. I like Mtronic and have used them in many of my models but they can (as do several other manufacturers), in the event of a power wipe out, go into reset mode and this can result in you losing the fwd/rev function. The ESC has reset to minimum throttle stick down and only one direction as a result. I guess its pot luck whether this is fwd or rev but rev seems to be the most common. If you replace the BEC with a battery to power the rx this may help. You do need to disconnect the red lead from the ESC to the rx and still need to switch on the esc after the rx. If it has reset you need to reset the controls whilst the two lights are flashing by pressing the ESC button and moving the sticks to their full extreems. You will need to have capacitors across the motor terminals and also between each motor terminal and the case. Your rx connecting wires and aerial should be as far away as possible from the high current battery wires and the wires from the motor to the ESC. Doug has already suggested re rerouting the aerial and as you have this suggests a weak signal. Have you done a range check with the Tx aerial down? You should be able to have control from at least 20' without any interference? Please let us know how you progress.
Great post fantastic project - most of use Li-Po batteries without any issues allbeit in portable or laptop computers, some cell phones, portable chargers and elsewhere. Heck, a standard alkaline 1.5 or 9 volt battery can cause issues if not properly used or placed under stress. But - I’ve made mistakes myself and come close to bad issues using power sources improperly or without heading instructions such as using them full out without allowing them to cool. It’s all about using caution and precautions, understandably accidents do happen though
John As you are using 2.4Ghz radios there is quite a long delay in the binding between Tx and Rx. The ESCs also perform a set up and I have noticed that this is often quicker than the radio. As a result the ESCs have no signal and can revert to a failsafe state. If you have correctly set up the ESC with the tx then it should retain this setting unless you press the set up button whilst the lights are flashing. I suspect this is at the root of the problem. To restore the settings to your set I suggest you use a separate rx battery, centre the throttle stick and trim and get the Tx/rx working together. Then switch on the ESC and whilst the lights are flashing press the set up button and move the throttle stick full forward (solid green) then full reverse (solid red) return to neutral solid red/green. If you now switch off the esc and rx battery and switch back on the ESC should have solid red/green light showing. Repeat with the other ESC and test. Switch off and connect both escs via the Y lead. You can use one ESC to provide the rx power but do disconnect one red lead. Centre the tx throttle and trim and make sure you switch on the ESC with the BEC connected first. Hopefully both ESCs will now have solid red/green leds. I use three Mtronic ESCs with my RMS Olympic and had a very similar problem. I suspect the change from bench to water is more to do with stick/trim alignment and longer binding time due to other 2.4 Tx working in close proximity at the sailing site. I look forward to hearing your efforts next wednesday - hopefully the next hurricane will have passed by then.