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    Forum
    LiPo batteries
    Please can I get some advice on LiPo batteries. I intend to buy a 3300-5000mAh battery to run an offshore power boat model. I will be taking the battery with me to Hungary to use on my local river which I have found is ok as hand luggage properly protected from short circuit. My problem is that at present, I only go there three time a year so the battery would remain unused for 4 months at a time. If I leave the battery with a safety charge, will it last for four months unused or will it fall below the critical voltage. If it is felt that it will not hold the charge, I will have to carry it with me forward and back. Thanks.😊
    1 year ago by MouldBuilder
    Forum
    Slightly confused newbie
    Hi just a thought the VIPER 25 AMP has a BEC (Battery Elimination Circuit ) built into it and if you connect a power supply to your receiver as well to power from the motor battery all manner of thing can go wrong John
    5 months ago by JOHN
    Forum
    Billing’s Boat J-502-Progress
    Small boats have less access below the deck. I might use a flat battery pack instead of the quad shown here. The model tested well in the laundry tub under power. Much left to do yet, glad the electronics work. A mini rudder servo is being added.
    5 months ago by Ron
    Blog
    PS Iona - paddles
    I decided to build the paddles on my 3D printer, working off the plan rather than building in brass as this should be much quicker... should be! Feeling confident I designed ver 1 & printed it out... and scratched my head a lot to see how this was going to fit together. So ver 2 was much better and almost looked like it would work. Ver 3... same etc. Ver 4 πŸ‘ This would assemble looking like paddles. I decided against feathering paddles having talked to a few paddle steamer builders - it seemed more complicated, used slightly more
    battery power
    and in 1:36 scale would make little difference to performance. Having built one now I would probably make a few changes but it looks and performs ok. The assembled paddle is attached to a 4mm stainless steel drive shaft with brass bushes. I have recently added some pins to ensure they don't come loose on the lake.πŸ€“
    5 months ago by Harvey Kitten
    Blog
    6 Volts of Course of Course!
    Captain's Log: The right battery for the job! I found a battery that volts and amp's are just right! The most important thing the right weight! The battery weigh's in at 3 lbs. 1 ounce. Which is just right for the Brooklyn! Give or take a once or two.... But, can be adjusted to trim the water line! The battery is a 6 volt 8.5 amp battery. Which will power Brooklyn for 2.5 hours. Or 1.6 hours with her smoking unit on! Brooklyn will run on 5.2 amps with the smoker. Or 4.0 amps with out the smoker! Unfortunately you live and learn. I tried using the batteries from. Serenity, she's 12 volts 2.5 amps! This was no good, not enough power! Also the 12 batteries weigh too much! So, A 6 volt battery was the way to go! Next is replacing the motor and smoker! Am expecting the motor this morning! Will soon order the smoker! And again she will be completed. For a spring launching!πŸ‘
    6 months ago by figtree7nts
    Blog
    New Batteries!
    Captain's Log: Well, I order new batteries for the Tug Brooklyn. I placed the order about a week ago. I received them last night! Before I continue let me say this. I was using the Batteries from Tug Serenity AKA Jersey City! Those Batteries are 6 Volts at 2.5 Amps! For a total of two! I saw what I thought were the same battery. Only at 6 Volts at 8 Amps. For a total of 12 Volts at 8 Amps! Well the batteries are huge! I had to take all of the Forward ballast out of Tug Brooklyn! Even then she's a bit bow heavy. But, I really want the extra Power! Because Tug Brooklyn is a 12 Volt Tugboat! Take a look at the Batteries side by side. It's a good thing there's enough room in her forecastle! I'm putting the Batteries end to end and they fit! Oh, the Batteries weigh 6.5 LBS!😱
    6 months ago by figtree7nts
    Forum
    All hooked up, nowt happens...
    Hi All I use the Hobbyking car ESC's HK-45A, HK-60A SL and HK-100A which all use the same program card(HK PROG-CARD). I use the same setup for all my boat, only changing the battery setting for the 2s, 3S and 4S Lipo. 1 Cutoff Voltage for 3S=10.2 and 4S=13.6 2 Start Power Percent=5% 3 Advance Timing=4 4 Run Mode=2 5 Brake Force=1 6 Drag Brake Force=1 7 Neutral Range=1 8 initial Brake Force=1 9 Reverse Force=1 It works for me. Canabus
    7 months ago by canabus
    Forum
    Brushless motor(s)
    Hi, I have recently purchased a Precedent KD Perkasa kit 37" and would like to power it with a brushless motor, but being an Old F**t I know nothing at all about Brushless Motors or their relevant speed controllers or
    battery power
    . So I would like your input on what exactly I need, obviously I would like the model to have a fair turn of speed. Thanking you in anticipation of your much needed assistance. Little Charlie
    9 months ago by Little-Charlie
    Forum
    Proximity (Hall effect) sensor wiring
    switching off and on via the ESC switch does NOT disconnect the battery from the ESC just stops the ESC passing current. Power is still being used. The only way to end all current flow is to disconnect the batter by either opening the pos or neg lead from the battery. Mounting the magnet on the end of a screw and having that fit into a threaded hole should deal with the problem of keeping it in place while running.
    7 months ago by Haverlock
    Response
    HMS BRAVE BORDERER
    Doug, you are probably correct and good thought regarding the polarised caps , but I was just thinking that if the battery input was going through a fuse system as it appears in Rowens photos (difficult to see) it may have caused a slight problem. I have seen mentions of up to 12" between batt and ESC being no problem at lower Amps. You might notice that one of the inputs was from a guy from Castle Creations (USA) which I thought would give a bit of weight to the information. I have always gone with the ESC manufacturers suggestions regarding wire length and have never had a problem in boats or planes (mainly in planes,-18 most 'converted' to electric from IC -3 capable of pulling 1200W) it's great to be able to chuck ideas and info around, as we can all pick something out of it all which will solve a problem, or perhaps stop us from toasting an electronic component or whatever. BTW, I saw somewhere that extending the wires could cause stuttering and that was one other reason for mentioning the info, as I know Rowen's had a problem with that. I'm sure it will be ok as is,- if its working fine, and it's not going to be run flat out every day it will probably last for years. Probably me thinking on the cautious side as my personal approach to building is to use the K.I.S.S method (may not be the flashest but usually keeps me out of trouble) Regarding the quality of ESCs, you will find that many have the same internal bits just with different cases and colours, (same with chargers) HK is bad for this. Many I have seen use an Atmega chip and you can tell differences by the programming method (some you have to do 1 step and disconnect power before the next step, others just with stick forward center back center etc. Most boards are made in China (Castle Creations and a few others being exceptions) and what you get depends on the quality of assembly/soldering etc in the plant they are made in (if you want to see how many of these items are made in China check out Made in China.com and search ESCs for example. I have cheap ESCs I've used in my planes for years with no probs which look like the HK Red Brick ESCs (except blue) and they are better than the TGY branded ones at 3x the price, and really let the power through !. Even CC have apparently made boards for HK with different cases as have Hobbywing. it's really a case of "you pays ya money and ya takes ya chances". in saying that you are pretty safe with Hobbywing, Tamya, SkyRc, or Castle Creations (USA) but there are other better non China ones around but a a much bigger price. Hope we aren't overloading you Rowen, you might have to get into the 'anti-freeze' to soothe the brain in that cold weather. Another site for you to check out which I have found to be very good, with prices to match HK is RCEcho.com (Hong Kong) Have bought most of my aircraft ESCs from them (around 28 from 30A-120A with no probs)
    8 months ago by jbkiwi
    Forum
    Voltage increasing via regulator
    A somewhat confused question if I may say so Eric!😲 You can't 'regulate up' only down. The regulator's job is to produce a constant lower voltage from a range of higher voltages. I often use one to produce 5V for the RX and servos from a 12V SLA drive battery. A little 3 legged device (type LM7805) which looks just like the power FETs in a high current ESC. My version of a UBEC! πŸ˜‰ What is this 'regulator' you have? Type number? Manufacturer? Photo? To get 12V from 7.2V you would need to use a Voltage converter (also known as an inverter). This works by converting the DC input from the battery to an AC voltage which can then be increased using a transformer. More elegant (and expensive!) versions use a transistor oscillator and amplifier. This uses hi-power transistors instead of the transformer. The AC output of the transformer (or amplifier) is then rectified back to DC. All this is very inefficient which is why it is normally only used for very light currents, where the losses are not so significant, and when there is no other alternative, not often the case! You can't beat the physics and you will never get the same power out that you put in. This leads to a basic design question:- What is the total current consumption of the load? I.e. the motors. A simple example:- Let's say that at 7.2V the motors draw 10Amps total, i.e. 72W (or VAmps). Assuming a utopian 100% efficiency at 12V this would equate to 6A. Due to the three stages of conversion; DC to AC, transformation / amplification of AC to 12V, AC back to DC, you'll probably be lucky to get an efficiency of around 60% to 70%. Thus if you stick 720W in you'll get around 430 to 504W out. Not much of a gain is it!πŸ€” Your battery would be exhausted in about 2/3 the time it is now 😑 If your motors draw more than 10A the problem just gets worse. So what is it you really want to do? If you just want to up the volts to your motors stick a 12V SLA or an 11.1V LiPo (3S) in and hope that you don't cook your motors! Frankly I don't really know why you're bothering, tugs aren't sprinters! If you want more pulling power with the existing setup try experimenting with prop sizes and pitch. Will probably achieve much more than fiddlin' about with voltage converters. BTW: All this assumes that the RX has it's own separate 5V battery supply or from a BEC in the ESC. Some clarification needed from your side. Cheers, Doug 😎
    9 months ago by RNinMunich
    Place
    Sunset sailing
    Our club recently held a sunset sailing session, its surprising how a cheap set of
    battery power
    ed lights from a pound shop can add yet another world to r/c boat sailing, so why not have a go at your club too, great fun cheap to do and once finished, you can remove the lights ready for regular sailing.
    9 months ago by Gregg
    Blog
    Revell 1/72 Flower Class Corvett
    Revell model at stern you see a small servo with micro switch for the Ram whooper sound module. Pic with upper deck on side shows speaker and electronics with 9volt
    battery power
    . Moving forward Harbor Models small 6 volt smoker, 3000 nimh 6 volt battery with 2 connectors powers smoker fan and main motor from ESC.
    9 months ago by Mikep
    Forum
    Mtronics and Lipo's
    Basically ads is correct, but that's only half the story! The clue is to look for 'LiPo Safe' when buying ESCs. That tells you it has a programmable Cut Off voltage setting to prevent damage to your battery. Default is usually 3.2V per cell. Absolute minimum is 3.0V. Below that you risk irreversible damage to the battery due to chemical changes that can't be reversed. The alternative is to fit a battery monitor which can trigger an audio and/or visual alarm to warn you to 'make nearest port best speed' before your battery is deep discharged, from which it will not recover! Some ESCs have a programmable function which allows to preset a reduction of the max power to the motor (instead of a total shut down) to give you the chance to get home before disaster. PLEASE don't ask me which ones. Check the specs carefully before you buy. Many current TX/RX sets will tell you on the TX display when the battery volts are low. Cheers, Doug 😎
    9 months ago by RNinMunich
    Forum
    motor sizeing
    Hi Jim I used a Hobbyking D3548/4 1100kv , a car ESC (hk60A-SL)(electric fan on top for cooling), program card(HK PROG-CARD) and a 40mm 2blade prop(test out the one on the boat first). Battery a 3s 5800mah 30C Lipo. This is in my Sea Commander and gives a good turn of speed with a long run time. ESC set up:- 1 Cutoff Voltage for 3S=10.2 and 4S=13.6 2 Start Power Percent=5% 3 Advance Timing=4 4 Run Mode=2 5 Brake Force=1 6 Drag Brake Force=1 7 Neutral Range=1 8 initial Brake Force=1 9 Reverse Force=1 Canabus
    10 months ago by canabus
    Forum
    Nomenclature...
    Hi John, think somehow you've got the wrong end of the stick!πŸ€” All BECs are Battery Eliminator Circuits of one sort or another. The objective is to eliminate the separate receiver battery, sometimes necessary purely to save weight and/or space in small models. If you do that then the RX power must come from the main drive battery, which then has to supply all RX functions; servos, switched lights etc etc. Personally, if the boat / ship can carry it, I prefer to use drive batteries for just that and use separate battery for the RX and special functions. Some of which, like smokers for instance can be current gobblers. Cheers, Doug 😎 PS if you ever find a way of eliminating all batteries and still get the RX to work and the boat to move PATENT IT QUICK!! 😁 Cheers, Doug 😎 Hmmm! Maybe a raft towed behind with an array of hi-current solar panels!? 😁😁 Years ago in my work in NAVAL COMMS systems I once suggested to a shipbuilder, who was complaining about the number of antennas needed, to put some of them on a raft behind the ship πŸ˜‰ Now they are doing just that with antenna buoys from submerged submarines! No credits πŸ€” ... SIGH πŸ˜‰
    10 months ago by RNinMunich
    Forum
    Nomenclature...
    Hi Martin, 'Linear' in this context just means more or less a passive analogue device, and when it's on it's ON full stop. Decades ago I made my own with a simple one chip circuit using a 3 legged voltage regulator L7805 5V 1A and they're still going strong😊 The SBEC uses a fast switching type of power circuit, similar to the pulsed DC outputs of the ESCs. The switched type is an active device and is more efficient, less
    battery power
    wasted as heat, but can cause interference with older 27 / 40Meg RC receivers. Shouldn't affect 2.4Gig sets though. Cheers, Doug. PS even in a blackout I think I would find my way to the wine cooler or my malt whisky! πŸ˜πŸ˜‹
    10 months ago by RNinMunich
    Forum
    Nomenclature...
    I think WQ means if a BEC eliminates a battery and a UBEC and SBEC provide power where does the relevant /required power come from in each case. Also why eliminate a battery and if you do where does the power come from then? I think I've guessed right. if not I apologise Westquay. And what's a linear BEC etc. Regards JohnπŸ‘
    10 months ago by onetenor
    Forum
    Nomenclature...
    Thanks, Doug. Not sure what you mean by linear device. Sorry to be late answering, but at 7-30 this evening our power went off and it's just come back on! Boy was I after a cuppa! Sat and listened to
    battery power
    ed DAB radio eating peanuts in the dark and drinking pineapple juice! Martin
    10 months ago by Westquay
    Forum
    Nomenclature...
    Hi Martin, BEC is the Battery Eliminator Circuit built into an Electronic Speed Controller. UBEC is a Universal BEC which takes power from the main (drive) battery and supplies 5V or 6v to the receiver. it can be a linear device. SBEC does the same job as a UBEC but is a so called Switched device which is more efficient than a linear. So functionally for our purposes there is no difference. Alles klar Herr Kommissar!? πŸ˜‰ Cheers, Doug 😎
    10 months ago by RNinMunich
    Response
    BRAVE BORDERER
    Starting a bit backwards here as have posted more recently with some ideas. if you are going to have a twin brushless system using 1 REC, you probably should have twin 2200Mah 2s lipos, a power lead (I use a JST plug set) taken from the input leads of ONE ESC (not the batt leads) (I break into them and solder the JST leads on ) run those to a UBEC and then to your REC switch then to your receiver. if your ESCs have a built in BEC, withdraw the red power wires from the BEC receiver plugs and tape them back as you now don't need the power from these. if your TX is 2 stick 4/6ch etc and is capable of being changed to 2 throttle sticks (provision for ratchet strip - copy if necessary - on opposite gimbal - ie using set up as mode 1&2 throttle) you can use the existing throttle and elevator stick to give full independent control with either rudder or aileron Ch for rudder. The Chinese ESCs I use have a power switch as well as BECs which is handy. I would keep the brushed system separate from the brushless altogether with its own battery (or try power from the other batt as described above) otherwise you may be trying to mix 3 phase and single phase at some point. if you are using 2.4 you could use another paired 3ch receiver (does work, as mentioned in my later post) to only run the brushless throttle from a rotary sw on your TX (if you have that )
    10 months ago by jbkiwi
    Forum
    EarlyVosper M.T.B by Simplas
    "Maybe but ballast ,is ballast,is ballast. However it's achieved." Sure John, but at least a heavy battery is useful load and not 'just' ballast.πŸ˜‰ Have no idea what shaft power the Fuji produces (only know their excellent 35mm filmπŸ˜‰) but the Taycol Supermarine is rated at 22.5mHP (22.5/1000HP) at 3.5A, 4000rpm. Efficiency 52% πŸ€” so you have to stick twice as much electrical power in to achieve that! Sooo, given that 1HP = 745.7 Watts - And electrically P=IxV (Current x Volts) 22.5/1000HP = (745.7*22.5)/1000 = 16.778W so ~33.55W in. Thus if I = 3.5A they must have done that test / measurement at about 9.6V. The Supermarine also runs great at 12V but maybe not with max efficiency!? With a spec weight of 2&1/2 lb i don't even want to get into Power to Weight Ratio, although I measured Colin's motor at 947gm = 2.0877776229lb πŸ˜‰ But then, some of the motor had corroded away As I'm currently renovating a Supermarine for Colin H. This makes me start thinking about rigging up a test jig so I can see what it actually produces!!! Always up for a challenge 😁 Got nowt else to do 😁😁 Would be useful for other motors as well if I can get it figured outπŸ˜‰ Happy fiddlin' folks, cheers, Doug 😎
    10 months ago by RNinMunich
    Response
    lastest progress
    Hi TJ, that instruction is quite correctπŸ‘ It indicates that the ESCs have Battery eliminator Circuits (BEC) which means that there is an internal circuit which 'syphons' off 5V from the main drive battery to supply the receiver via the red wire in the ESC to RX cable. The ESC itself takes it's power from the drive battery. If all three red wires are left connected this will cross couple all three BEC circuits and may well damage the ESCs. The RX only needs one power supply! πŸ˜‰ In my multiple shaft boats I usually disconnect all the red leads from ESC to RX and fit a separate RX battery. Cheers, Doug 😎
    10 months ago by RNinMunich
    Blog
    Italeri P.T 109
    I bought an italeri PT109 kit in 2011. it took 4 months to build as I had other projects on at the time. I notices the high quality of the parts, especially the hull and the actual paint finish was very easy due to it being plastic and got the nearest colour match by using Humbrol spray acrylic of Grass Green with Regency Red acrylic for the waterline and below. Difficult decision was as to build as a triple screw to maintain scale or go for the single screw. I eventually went for the latter with just one rudder. Power was by a 480 brushed flight motor with a 30 amp esc which was a bit over the top as power was by a 2200mAh 2S Lipo but the esc was the only one they had in the shop. Getting the motor installed was very straight forward as it was done before the deck was fitted but I had to make the aft cabin detachable for access to taking the battery in and out and also lubricating the propshaft .The boat performed well at scale speed but got slightly out of shape when full power was applied, appearing more as a fast electric. Overall the boat was ideal for smaller ponds (providing it was not running flat out). The outcome was a well detailed model that appeared like the real thing on the water but I would not recommend sailing it in rough conditions.. Boaty😁
    10 months ago by boaty
    Blog
    Boaty P.T 109
    Three years ago I built an Italeri Kit of P.T. 109 and fitted it with a 480 motor and ran it off a 7.4 Li Po. I left the aft cabin detachable in order to change battery etc and the performance was very good with a speed of 8 knots on full power. Though in general, the boat was more suited to calmer conditions, it look so realistic on the water. Due to it being a plastic kit, I felt a bit guilty having built a model close to show standards without the time and effort of other model makers who had worked so hard with other materials to achieve the same outcome. I would like to hear from other boat enthusiasts who had completed similar projects especially around power units and how they overcame difficulties in converting what is basically a static model into a working one. Regards Boaty 😊
    4 years ago by boaty
    Forum
    54'' long Cervia tug.
    I have the same hull I made it as Ten Cents the cartoon character from the children's programme Tugs a friend gave me a hand to make the prop on his lathe was going to power it with a car radiator motor but lent it to a friend to try in his boat and never saw it again and use a car battery for power as well as ballast I now have spine problems so can't see it getting on the water any time soon
    10 months ago by scout13
    Forum
    1/16th scale Tamar
    Like many people, I originally built a Model Slipway 1:16 Tamar with the recommended brushed motors. Most of us switched to brushless motors for a number of reasons... 1. short battery duration using NiMHs, or an SLA with brushed. 2. These ALBs have an on-Service speed of 25+ knots and for scale speed, only brushless motors and LiPos can sensibly provide the power and duration. Model Slipway converted their demonstrator to brushless.
    10 months ago by kinmel
    Blog
    BRAVE BORDERER
    Decided to separate the two power systems; one to the port ESC and motor and the other the starboard. Hope this will reduce interference between the motor systems. Have also reverted to a remote
    battery power
    ed Rx rather than the BECC system, again to reduce possible interference. The modifications did not resolve the problems. The squeal and stutter are still present, but much reduced. Sounds rather like a slipping coupling, but as these have been checked many times they can be eliminated. Apart from the squeal and the stutter, everything works well. The squeal /stutter occurs at start up, when it happens the control is returned to neutral, if the motor is immediately reselected, usually the problem goes away and the motor runs up cleanly. it only occurs when both motors are selected at the same time. Either runs up cleanly when selected individually. Interestingly enough, did some research on various Model Boats site and found some references to RF interference, no specific solutions though. Also examined some Aero modeling sites as they use powerful brushless motors with ESCs. There is some history of the problem there. Evidently when the mosfets (?) of the ESCs convert DC to AC, RF interference is generated. it can often be addressed by using ferrite rings on the ESC control leads. My latest ESCs actually have ferrite rings, so the problem must have been anticipated. This might account for the latest reduction in squeal and stutter levels. Am at a loss to think of any other modifications, so decided to conduct a water test. Maybe it is a characteristic of brushless motors, but their control response seems β€œragged”, not smooth as with a brushed. Anyway, the squeal and stutter seemed reduced yet again, perhaps the water load damped them down. Was able to start exploring both the performance envelope and the viability of the brushed centre shaft motor. First impressions are that on a 2S battery the performance is fine, but it sparkles on 3S. On 3S the stutter and squeal are more pronounced though. intend to do further trials but, unless something unexpected occurs, now plan to use 2S power. The centre brushed motor idea works well, this layout seems a good compromise. Will design a simple switching circuit to ensure the brushless motors can selected separately. This will avoid the inadvertent operation of both brushed and brushless unintentionally as they are on the same control stick. The brushed can then be used for low speed operation. Returning to the problem of squeal and stutter – has anybody else experienced this and how was it resolved?
    11 months ago by RHBaker
    Forum
    1.5v AA Li-Fe/Li-ion/Li-po batteries
    OK, found some! https://www.ebay.com/itm/8pcs-JUGEE-3000mWh-1-5V-rechargeable-Lithium-li-ion-AA-battery-li-polymer/153101323059?hash=item23a58ccb33:g:hRwAAOSw44BYZ9Lo Interesting that they all quote mWh instead of mAh! I.e. energy instead of capacity! Power being V x I (Amps) divide the mWh rating by the nominal voltage to get an approximation of the capacity in mAh. Saves integrating across the varying voltage during a discharge cycle, i.e.'On Load' πŸ˜‰ Thus these 3000mWh cells seem to have a capacity of around 1800mAh. Which is considerably less than the typical 2500mAh of an alkaline or NiMh AA cell. Also, to produce the output voltage of 1.5V from 3.7V Lithium chemistry the cells have an internal voltage regulator, which also must consume some power, albeit miniscule. Something else which can go wrongπŸ€” Summary; yer pays yer money and takes yer choice! Seem rather expensive to me for what they deliver. Depends what you want to use them for. Might be useful in my Sony camera but I wouldn't use them for any high current load in a model. OK perhaps for LED lighting circuits which only need a few tens of mA. Here a list of battery types, sizes and chemistries for reference. https://www.wikiwand.com/en/List_of_battery_sizes#/overview Cheers, Doug 😎
    11 months ago by RNinMunich
    Forum
    1.5v AA Li-Fe/Li-ion/Li-po batteries
    Yes, I'd like to know that too! Please post links where you found them. I'm intrigued by batteries which seem to contradict the chemistry used in them😲 LiFe (LiFePo4) cells have a nominal voltage of 3.2V. Li-Ion have a nominal voltage of 3.6 to 3.85 V, They are a derivative of LiFe, which simply defines the metals used in the positive terminal; lithium + a Ferrous compound and carbon. Used in electric cars, military and aerospace. LiPo (Lithium Polymer) have a nominal cell voltage of 3.7V. They are also a variant of LiFe. The 'polymer' part simply refers to the material of the separator used to prevent electrode particles passing from from one to the other. it only allows Ion exchange, i.e. current flow. Hence in effect you can regard all of these rechargeable Lithium types as 'Li-Ion' batteries. Used in Laptops, notebooks, mobile phones / tablets etc, and of course RC modelsπŸ˜‰ There ARE 1.5V Lithium batteries, Li-FeS2, BUT they use Lithium metal as the anode and are NOT rechargeable!! Nominal voltage 1.4 -1.6V. Used as a high current, long storage life substitute for alkaline AA and AAA cells providing about two and a half times the energy of the alkaline. Similar not rechargeable chemistry, using other compounds of manganese (most common), copper, iron to name but a few, is also used in typical 3V Lithium button cells. 1.5V rechargeable suggests to me an alkaline battery, produced by RAYOVAC some years ago. I still have a few of their C size cells kicking about. Don't have a very good 'power to weight ratio' compared to modern LiPos though.πŸ€” Cheers, Doug 😎
    11 months ago by RNinMunich
    Response
    BRAVE BORDERER
    Hi Rowen, Interesting snag! Can you send me a wiring diagram please. Sounds like you might be getting some cross coupling of control pulse ripple through the battery wiring. Reminds me of similar problems on naval COMMS systems where we had to fit filters to all the power supplies to prevent cross coupling of sensitive info from 'Secure' to 'Plain' systems via the power leads! BTW: All brushless squeal and scream until the the pitch gets beyond human hearing frequency range πŸ˜‰ Alternative: if you use two 3S LiPos, each of half the capacity of the original, you should get the same endurance with only a small weight penalty. This ain't curing the real problem though πŸ˜‰ Cheers, Doug 😎
    11 months ago by RNinMunich
    Blog
    BRAVE BORDERER
    Blog 4 update – Adjustable transom flap using metallic tape did not work. Think the vibration caused flexing and fatigue, so it finally split. Fortunately had established the correct angle, so reproduced the flap arrangement with a fixed thin alloy plate. Much more robust. Have installed the new brushless motors and ESCs. The current layout is brushless motors on the outer propellers and brushed on the centre, all powered by a single 3S Li-Po battery and Rx. Am hoping to commence water trails this week, but have found an issue which was also present with the original brushless motors. When either brushless motor is powered up it operates nicely, however, as soon as the second motor is started either motor β€œstutters” and a pronounced β€œsqueal” can be heard. The brushed motor is unaffected. Have now tried several ESCs but to no avail, the issue remains. It can be cured though by powering each brushless motor with it's own battery. When this is done everything powers up cleanly and quietly. The obvious solution is to use two Li-Po batteries and abandon the single battery approach. Am reluctant to do this as the model weight will increase yet again. Has anybody experienced this when using twin brushless motors and, if so, how was it resolved?
    11 months ago by RHBaker
    Forum
    Graupner Jumbo 540 motors
    Help required please, I have two Graupner Jumbo 540 6volt motors in an eboat circa 1978, I had fitted an Mtroniks speed controller replacing the Bob's board only to find that when the voltage dropped below 6 volts down to 5.6 volts I was experiencing intermittent operation of the esc. I have been informed by Mtroniks that the minimum voltage for operation of the esc is 6volts. Graupner have also confirmed that the maximum voltage for the Jumbo 540 motors is 6 volts. Do I have any alternatives other than refitting the Bob's board?
    11 months ago by Will-I-Am
    Response
    SA Valour Class Frigate
    Wish I had caught up with you earlier Doug as your input re the MEKO 200 SAN would have been of great help. Fortunately (also late in the build) I found a long lost 2nd cousin (twice removed!) who served onboard the Spioenkop on her delivery voyage in 2005 and got some good stuff from him. Also found a clip on Facebook that provided detail that I had missed. Watch the interest of the bridge officers as they notice the drone filming them! https://www.facebook.com/andre.oosthuizen.9615/videos/vb.100001251523644/1649460131772355/?type=2&video_source=user_video_tab Currently the hangar door and chopper movement is not connected to anything...just demonstrated by putting then in contact with a battery individually. I have a spare channel on the stick and also the on/off switch used for model aircraft engine/power cut that I use on my Corvette model for the smoke generator. The sequence I would like to achieve is 1. Activate (power on) door opens. 2. Door reaches stop ...microswitch/ (stays fully open) 3. Chopper movement switch on 4. Chopper clears hangar and reaches stop on helipad. 5. if pos, close sequence in reverse of above. Reilly4 I can let you have a short video but I need some help as to how I place a video on the website. Some more pics taken during the build process attached just FYI.
    11 months ago by Joburg-sailor
    Forum
    Old Futaba servo wiring...
    Hi Martin, would have thought the name was self explanatory! πŸ˜‰ In the attached pic you can see my Robbe Servo Tester at the top. I used it to simulate the proportional signal from a receiver while testing your Taycol converter boards, not to power the motor.😲 Motor power came from the mains PSU in pic two, the battery eliminator circuit (BEC) in the ESC provided power to the tester. The tester provides the signal to drive servos, or in this case an ESC, and saves the faff of setting up TX and RX and fiddling with batteries when I want to test a circuit or function before building it into a boat. Cheers, Doug 😎 Oh, and by the way; when you get into lighting for your boats don't forget to buy an LED Tester as well 😁😁 You could also think about a simple RF Detector / Meter to check if your TX is actually transmitting 😁 Like I did with your TX using a home brew device - OR you could wait til I get around to publishing a Build Blog for the refined version I am making using a couple of RF diodes and a sensitive 300microamp meter 😊
    11 months ago by RNinMunich
    Blog
    BRAVE BORDERER
    This hobby gives countless opportunities for changing ideas! After some thought, have decided to try another approach. Whilst brushless motors give fantastic performance; so far have had poor experience of system reliability. As more information and advice from other modelers is gathered, suspect have been using undersized ESCs, accounting for many of the problems. However, whilst still waiting for the new brushless motors an idea developed. To instal a brushed motor on the centre shaft, whilst retaining brushless on the outers. My thinking is this could provide several advantages such as; a better slow speed performance more suitable for manoeuvring, lower current draw, improved fuse life and a reliable BECC output. it will also operate at below the Li-Po cut-off voltage, giving a β€œget home” facility in the event the brushless ESCs cut-offs operate. However, there is a slight weight penalty as brushed motors and ESCs are heavier than brushless. Fitted a brushed motor of the same O/D and mounting arrangement as the previous brushless to minimize installation issues. With a reliable Mtroniks ESC from my stock and suitable fuses, fitted these items along with the ballast and battery used earlier. Now, back to the pool. The system worked well. The vessel speed is much less than with a brushless motor on the centre shaft, but control-ability greatly improved. With the triple rudders she steers nicely. The thought of using a brushed motor on the centre shaft, with a brushless motor on each of the outers is attractive. it is hoped the additional operation of the outers in conjunction with with the centre shaft, will provide the expected performance. The centre shaft would then also provide manoeuvring and reliability with the outers shut down. If this works, think this power-train combination could be ideal. Once the new brushless motors and ESCs arrive will instal and report. On the attached pictures, the first shows the ballasted model sitting with the brushed centre shaft motor, the second with a brushless. The difference in draft is imperceptible, the bow sits slightly high in both cases. The third shows the model with the brushed centre shaft operating only at β€œfull” speed.
    12 months ago by RHBaker
    Blog
    push tug..
    Well.. sea trial's have taken place, a little to heavy so a smaller lighter battery to try next time, wrong propeller's to powerfull but they was one's i allready had so ordering new ones, and a minor pin hole leak.. otherwise, works well, pushed my big 4ft boat about ok... and forgot to take my *@#& phone so no photo's ....
    12 months ago by Steve-Teresa
    Forum
    Which motor
    Could someone advise on which motor to use in a smit amsterdam tug of approx 40 ins long with a 4 blade 3 ins dia. Prop and 4 mm. shaft, I want to run on 12v sealed lead acid battery. I am not going to tow anything but would still like a bit of power. Cheers. Neil.
    12 months ago by Helineil
    Blog
    BRAVE BORDERER
    Whilst waiting for the new motors and ESCs, reviewed videos of the vessel under power and noted that as the speed increases, the bow lifts towards a plane. However, as she gathers speed the transom flaps become effective, forcing the bow down in a cloud of spray. At this point the plane has been lost and the model becomes almost uncontrollable. Decided to temporarily ballast the hull to simulate the new motors and ESCs, then try to establish the optimum flap angle using just the centre propeller and shaft. This is the original 2838 brushless motor installation with a 30 mm propeller. With this simulated drivetrain it would also be an opportunity to determine the best battery locations for both 2 and 3S Li-Po batteries. Made up an angle template with a spirit level to get the correct deck inclination with the vessel floating at rest. From this located each type of battery statically - somewhere close to the mid-point of the hull. Which also seemed as good a place to start as any! Somewhere in the research for this model found a reference to the transom flap angle. This was at a 2 degree -ve (pointing downwards) angle. installed the 2S battery and tried the model. The bow dug in at speed. Adjusted the flap to a straight and level position and tried again. The bow still wanted to dig in, but to a reduced extent. Readjusted the angle to 2 + ve and repeated. The bow now lifted so the forefoot just cleared the water and then remained in that position. Replaced the 2S battery with the 3S. The extra power obviously increased speed and the bow lifted slightly further. The spray was deflected by the chine rails and a level plane established. The conclusion is that the transom flap angle is critical to the correct planing of this model and that it should not be negative. Until the new motors and ESCs are fitted will leave the transom flap and battery locations as is. Once these components are installed, intend to repeat the test. Am confident that with some fine tuning the model can be now made to plane properly at a scale speed. Interesting to note that the model will just about plane with only one propeller operating – wonder what it will be like with all three?
    1 year ago by RHBaker
    Forum
    Charging NiMhs, one for Doug?...
    Hi Doug, the battery in the new FlySky Tx is a 1s LiPo, so 3.7volts. it's 800 Mah and the set comes with a charge lead from a USB port. But they're 5 Volts, aren't they? So wouldn't that damage it? And they don't cut off when charged do they? Chris's efags are done that way as is her phone and I had a 4 port USB thingy in the glove compartment of me Reliant Fox for Chris's fags and phones. Now I have a neat tower of 6 mains sockets and 4 USB ports and they are down as 5 volts too. I have it to use shorter leads on all my small power tools and to charge stuff. As long as I'm not risking frying a LiPo, I'll be happy! Cheers, Martin
    1 year ago by Westquay
    Forum
    Spektrum, new, useless...
    Hi Don't know wether you solved this yet. I recently tried to bond my Dx8 to a receiver and failed. Reason my receiver battery too low. When charged bound first time. Clearly rx power is critical Regards Kevin
    1 year ago by kevinsharpe
    Forum
    Spektrum, new, useless...
    Doug, if you have an Orange Rx. like mine, the bit where the plugs go is on the end face, so when you tip the battery wire on its side to plug in, the red wire is indeed uppermost, the black wire, bottommost. The Spektrum Rx. has the plug bit in the top face, so the uppermost, red lead goes through a right angle and goes downwards, but yes, in the middle. I made sure of the polarity first, but that bit you mentioned meant nothing to me, just symbols. I didn't want to trust them if I didn't understand them. The bind plug did indeed go in the slot marked bind. On the Orange Rx. it says BIND/BATT. I didn't plug any servos in as it isn't necessary and I didn't have them to hand without fishing them out of the restricted space in my Vanity model. I have now watched so many you-tubes and read so many instructions that I can assure you I got the order right. Bind plug has never been out of the Orange Rx, except to assure myself of good contact. Battery pack plugged into AUX> socket, flashing yellow light, Tx. tother side of workshop, pull on trainer switch and turn on power. Beedlyboop noise, light on right hand side of array, but NO flashing on Tx. Hold trainer switch till will to live starts to ebb, give up. The Spektrum you show, Doug is the same, albeit with different aerials, but the guy assures me it bound to his DX5e before he sent it to me for the trial. Your Orange however is very different from mine. Mine, as I said, has the pins poking out the end and the writing where your pins are. Yes, it has an S in the case, which I read meant signal, not that I knew what that was. it is a much smaller box than yours. Now you can see why I spoke of uppermost as my battery cable has to go on its side to plug into my Orange and in that position the red wire is indeed, uppermost. if you see the normal position for the Rx. to be flat on it's back with the pretty stuff on top. So, what else can it be? I will try what you suggested about the metal free garden, tomorrow and after that we will have to wait till the Fly Sky arrives, estimated E.T.A., early next month. Your PTB looks very bare. Had you always intended to strip the tubes and rudders too? Now, you have to paint the insides a nice neutral colour, like Spitfire Cockpit green, which is also Jaguar cockpit green, but Maseratis were silvery grey. Don't ask how I know...long story Cheers, Martin
    1 year ago by Westquay
    Response
    H.M.S. BRAVE BORDERER
    If its of any help I run a all wood Perkasa with one motor (came from a old
    battery power
    tool) powered with a lead acid 12 volt, so as you can imagine its heavy. But she will plane as per any photo you can find on the NET. 😊 You state that you are waiting for parts from HK, is your BB a Hooben model ?. I purchased one of these and found the moulding of the transom to be atrocious and the company's customer service to be non existent.
    1 year ago by bikerjohn57
    Forum
    Charging NiMhs, one for Doug?...
    Evenin' Martin, Just back from 'nosh' with Gisela, my camera girl in the vid! She's mean like that too, keeps me hoppin' about like the proverbial cat on the proverbial hot stuff 😑 Can't wait to see the rotating teddyπŸ‘ Put a couple of mini Cam lenses in his eyeballs and you'll get a terrific 360Β° First Person View from the driving seat😁 Re Sea Scout, I took your advice and did the hull in Royal Blue (no navy knickers!πŸ˜†) or what passes for that here. Anyway I'm pleased how she turned out. OK, I admit I accidentally turned her into a Sport Fishing Boat😁 She's 24" what scale do you think that makes her? I'm looking for crew figures and stuff to fit out the cockpit but I'm not sure what size to look for. I thought maybe 1/20 i.e. a 40 footer? Waddya think? Re Kako; while recently trying (fruitlesslyπŸ€”) to make space in the workshop (got two renovations on the go in parallel - saves getting the same tools, rattle cans an' stuff out twice!😁) I ran across the original Kakos and Mabuchis I used in my scratch 53" H class destroyer Hotspur in 1966. She ran off a 4.5V EverReady flat (form not volts😁) battery until Granny took pity and bought me some 6V Lantern batteries! I ran 'em up on a power supply and they turned but now sound like mini football rattles! Think they need new big end shells 😁 Jeez, how many guys under pension age have ever been down to the bitza bazaar looking for 50 thou oversize bearing shells and compression and oil control rings?? Pics show her Sea trials in Radnor Park pond, Folkestone, Kent, summer 1966. Sorry about the quality, only had a Box Brownie 127 in those days and could only afford Gratispool free B/W filmsπŸ€” Pentax? Canon? Sony? Not to mention Digital? HD? Wassat? 50 years on I got all threeπŸ˜‰ I like Lupins too, preferably the blue and purple ones. BTW, for your steering guy's arms you don't need a separate RC function or channel! You just need a coupling from the rudder control to turn a pulley and cord which turns a suitably scaled pulley attached to the wheel axis. The arms are fixed to the wheel and go with it! Dead simple (to write anyway😁) and no lecktrickery! 😊 OR you could just put one of his hands on the wheel and the other on the throttle. Then use a 'Y' cable to split the ESC cable into two. Connect the second output to a servo which moves the throttle lever via a push-me-pull-you-rod, pulleys and cord or gears or whatever. Sure you can figure out the mechanics better than I. Whatever, have fun and don't electrocute yourself, keep your socks dryπŸ˜‰ Cheers, Doug 😎
    1 year ago by RNinMunich
    Forum
    Charging NiMhs, one for Doug?...
    as a rule of thumb charge your battery pack the night before you intend to take your model out to play ( that includes your transmitter). As to binding step 1 with binding plug in power up the receiver look for a rapid flashing light step 2 power up the transmitter with the bind switch held ON. rapid flashing light should change to solid power everything down remove bind plug and keep it safe. Since I have never used the spectrum that's the best I can do. an afterthought you say you have never removed the bind plug are you sure its actually plugged in where it should be not just " parked" for transit?
    1 year ago by Haverlock
    Forum
    Charging NiMhs, one for Doug?...
    Hi Martin, 1. What the blue blazes is a wall wart? πŸ€” 2. You can't do any harm to the RC gear with an under charged batteryπŸ‘ But if you use it before charging it you may drive it below it's damage threshold of 1.1V per cell if you use it too much in that state. A word of warning: some RXs and ESCs don't like more than 6.0V (e.g. Action electronics/Component Shop) and a fully charged NiMh can be more than that so check the specs of your RX and ESC first! 3. Get yourself a simple battery capacity checker, see attached pics of the two I have. As you can see, they all look the same except for plastic colour and brand name. They only cost few quid and save a lot of ruined batteries and cost/heartacheπŸ˜‰ Available from HobbyKing etc etc. They can check voltage and capacity. For LiPos they check individual cells. For NiCad or NiMh it just checks total voltage and capacity as most NiMh don't have external connections to individual cells like the LiPos do for balancing the cells. As I still have some hi power NiMh drive batteries, for ESCs that are not LiPo safe, I made a simple JR/Tamiya adaptor to connect to the monitor. In my pics you can see the % charge / capacity display. Some show only around 46% cos they are 'as delivered' with a storage charge only. Before use they need fully charging. 4. Re Charger: Just downloaded the manual - I'll get back to you on that when I've read it. Now it's 'Eat'n time' 😁 Cheers, Doug 😎
    1 year ago by RNinMunich
    Forum
    drum sail winch questions...
    Hmmm, seems whatever I do I need to tie more knots to use either a ring (as per Havelock's video) or a bowsie. The knots are tied in the string on the winch drum and that was a pain to get the tension right, so I'm thinking just a piece of slit tube to get over the string, then crimp up with electrical contact pliers for a good crimp. Still waiting for the battery pack to arrive for the RC and servos. Then I have to bind the Orange Rx. to the Spektrum Tx....ugh! I got a biddliboop from the Tx. when I put the batteries in and turned it on and a light came on in a line of lights. Fancy, this modern stuff, innit? First time the Tx. has ever been right out of the box in about 5 years since I bought it, ostensibly for a model aircraft. But aircraft are too expensive to insure, join clubs, etc., hence my switch to yachts. Just as involving as aircraft (wind strength, direction, sail trim and all that jazz), but more interesting than watching a power boat trolling round endlessly. At least, that's the plan Martin
    1 year ago by Westquay
    Forum
    Brushless motor selection
    Hi robhenry What volt battery are you running at present ?? 12 or 24 volts. If 24 volts those motors spec at 24,000rpm. Power is 511 Watts on 24 volts. 24,000 divide by 14.8(4S Lipo batteries) equal 1612 kv. So the closest motor would be 1700kv, eg water cooled 3660SL-1700kv which has a 5mm shaft and 44mm diameter with a length of 60mm( from Hobbyking). Power rated at 1800 Watts on 6S, so it would be lower than that. But if you are running 12 volts on the Graupner motor it would be about half the rpms. These brushless motors are far more powerful so check out the specs on the motors you are looking at !!! Canabus
    1 year ago by canabus
    Forum
    Smoker / Light Contoller
    Afternoon All, Really please as finished off the smoker/light controller i've been working on. it works with any smoker that has a fan. theres three version avaible, but all versions have the same light functions, one switch - on /off (can change to a proportional to work with a water pump) Three position Swich, controlls two light circuts or anything. Oil heater, will turn the fan and heater on only when required. saves on Battery and to replicate a diessel engine. Water vapor system, able to turn off/on the power to the system remotely, Diesel engine, will power the fan 100% and the start and the slow the fan down till model is just about to move off. Steam Engine - Fan at idle is about 20% so always push the smoke up but then it will encrease with throttle input. the best thing i think is that any thing can be changed via the arduino. Will be make a few so if any one interest in one, please PM me. this is one i've just made for a friend that use the Oil heater https://www.youtube.com/watch?v=JDLp5bACejc&feature=youtu.be and mine using the water vapor systemhttps://www.youtube.com/watch?v=pj2pICSLHcE Thanks
    1 year ago by timgarrod
    Forum
    LED Tug Mast Navigation Lights
    Hi Pete, Go easy with the prying!! You're right. The spring loaded button is the way in. But it can be very stiff and underneath the hatch is a dense foam rubber gasket which makes the hatch catch (πŸ˜†) difficult to release. Press the button firmly down while trying to ease the hatch forward with your blade. In my basic version there ain't much underneath except the rudder servo. But that's where I intend to put a decent battery. Re electronic speed controller (AKA ESC); it MAY be on the cct board but I doubt it cos I don't see the FET power transistors for the outputs to the motors! Unless that's them in the bottom left corner in the second pic? In mine it's a separate square block with the heat-sink tabs of the transistors clearly visible. Trace the wires back from the motors to find yoursπŸ˜‰ Everything else, RX and switched outputs, is on the cct board. Check out the blog with the link above and you will find all the secrets about removing the deck without busting anythingπŸ‘ More later, ciao, Doug 😎
    1 year ago by RNinMunich


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