Thank you from the bottom of my heart you guys, I consider myself well and truly bolloked!!, love you're engines. I feel better now with your support, your correct, why should we just accept it, I'm keeping 95% of my IC boats and engines now, in fact I've just ordered a 6volt battery to fire up the 15cc coil ignition gannet in the huntsman and intend giving it an outing. This is just my opinion I do not wish to offend, however I believe as we with IC boats in clubs became the minority then most members who just like pootling around looked upon the fast loud smelly ICs as a nuisance so let's ban them. Thanks again guys "power to the people"✌️.
I have a 47" classic Fireboat which I would like to use my G-60 500kv electric motor with a 6s Lipo battery and a 120 amp watercooled esc. I wondered if anyone could give me anyone idea of what prop size to start with experimenting to give best power anyone and endurance ? I am told the G-60 is the electric equivalent of a 10cc glow engine, so what size would go on that might be a start. Thanks in anticipation, Dave W 😊
Thanks all for the responses. Donnieboy - have thought out the plumbing, which is simplified by using a cooling pump. See future episodes! Doug - appreciate the concern regarding the red ESC wires. Have been trying to understand the rationale behind that theory. If all ESCs share a common input voltage, i.e. from one battery, what would the connection of multiple red wires do? Can understand if there were several unique power sources, but that is not the case here. Perhaps with your electronics background you can explain. Colmar - Used the angle on the scale drawing. If it were good enough for Vosper, should be good enough for me! Think it close to 7 degrees anyway. Think short shafts with oilers should help. Have heard of bushings running dry and seizing with these high speed motors. The initial props are scale versions of the originals. Rather suspect they will not prove to be ideal. Have purchased some 2 blade racing style props for a future test. They have a much coarser pitch and are designed for high speed motors. Intend to use plastic props initially as they are cheap enough to experiment with. Perhaps others have a comments on the cavitation question?. Incidentally, this is my first high speed boat too, but there is much of information on both this web site and Model Boat Mayhem for guidance. Posting questions always generates useful information. Look widely though at all types of fast models, MTBs, RAF launches, E Boats etc. - it has all been done before!
Just to clarify. Shipping was only 7 days to Canada, manufacture slightly longer. Examined the hull closely and was pleased. It is dimensionally accurate and robust, but light. It had also been reinforced in strategic areas and trimmed to the correct deck line. My many questions to Christian Sheppard – Capurro of MTBHulls were quickly and knowledgeably answered. A company I would recommend others. Reviewing the build blogs and U Tube videos of the both the Brave and Perkasa models, shows most use either single or twin screws. The original vessel had a triple screw contra - rotating layout. Experience from others suggests the third screw just adds weight and complexity, but little to the performance. Nevertheless, it was how the Braves were built, so that was how it would be. Christian gave several suggestions for other modelers who have built this vessel. Contacted them and was readily provided with information and advice. The finished weight of this model is important and a target of around 6 lbs recommended for a 1:32 scale version. This is to achieve the potential performance. Plans for drivetrain are 3 x 2835 4500kVa brushless motors, direct driving 3 x scale 3 blade 30mm screws. Decided use a single Li-Po battery for the best performance with minimum weight. It was suggested three batteries, each powering a single motor would be the best layout. After some research, concluded this would introduce a weight penalty and was discounted. There are various ideas for the best drivetrain. Unfortunately none for triple screws. Decided the best approach would be to fit the bare hull out as planned, then try it. Leaving all the finishing features for later. A contact in Australia had already done this using a single screw layout and kindly sent pictures of his hull layout and then under test. Very informative. The positions of the rudders, propellers and shafts are established by the scale dimensions and were permanently installed. Everything else was to be temporarily fitted, so it could be moved or replaced if necessary.
hi Richard this is a hump back battery (pic 1) or you could use a compact battery (pic 2) both can be found at https://www.componentshop.co.uk/batteries/radio-control/larg... You could change the motor for the smaller 400 type if you could find use for the 500 for something else but you have altered the framing to fit the 500 now so it would mean having to undo what you have done and at this stage do you think its worth the hassle only you can decide that. Ron
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.😊
I have an Aerokits Fast Patrol Boat, what scale 20mm deck gun did you buy is it 1/24? Also I was thinking of powering mine with a Graupner 700BB Turbo motor and Nicad battery packs or Lipo batteries. My hull doesn't have spray rails, should I fit some? Sorry for all the questions but I'm returning to powered model boats after a long absence! Thank you for any help received.
Hi All. all good advice for the normal brushed motors in cans with carbon brushes. But the Taycol is a totally different animal! It has no carbon brushes. They are simply stamped thin copper or phosphor bronze sheet. Contrary to carbon brushes they need OILING to reduce the wear and sparking! Attached are some pics from my Taycol Target renovation and modification to graphically illustrate the point. Pic one 'Before', pic 2 the new phosphor bronze brushes I made. BTW: don't EVER put oil on your carbon brushes! Try it if you're curious, but then buy a new motor or try to find some replacement brushes 😉 If you run the Taycols dry they wear the brushes through until they have a hole in the middle and spark like crazy Pic 1. You can put what capacitors you like on, you'll still get interference especially at 27MHz. Pic 3 shows the effect this has on the commutator. Pic 4 shows the renovated commutator, there was more 'meat' left on it than I expected😊 Pic 2 shows the new brushes I made from phosphor bronze sheet. The spark energy density spectrum peaks in the HF band (e.g. 27MHz!) and falls off rapidly in the VHF band (30MHz upwards) to virtually nothing in the UHF and Gigahertz bands. That (and the frequency hopping process the 2.4Gig sets use) is why they don't suffer such interference. BTW: as a matter of probably no interest 😉 most sets only use 16 or 32 of the 85 frequencies available in the band! 😲 The capacitor values given above are unusual and will only work with a 'canned' motor, which the Taycol ain't! The norm for a standard canned motor with carbon brushes would be 0.1µF across the terminals and 0.047µF from each terminal to the can, which with a Taycol you ain't got! Earthing to the prop shaft is also a problem. Where do you connect the wire? There's no 'can'. Frame? That's paxolin! try soldering to laminated iron core if you want. Good luck. Won't achieve much even if you manage it🤔 Once again I ask which Taycol you have, as the construction varies and hence the suppression methods / connections. Imperative is the condition of the brushes and commutator to minimise the intensity of the spark generation in the first place! Also important is how you are controlling the speed: also 'Period' with a Bob's Board or resistor coil and servo driven wiper?? These can also be spark sources😡 Never mind wasting precious battery power as heat😲 If you want to convert to using an ESC with proportional forwards and reverse, which Taycol field motors can not do without reversing the polarity of EITHER the field coil or the rotor coil but not both, I can show you how. I did it with Dad's old Taycol Target, see my Build Blog 'Sea Scout Jessica'. Pic 5 shows my Taycol target dismantled, before the renovation. Pics 6 & 7 the reassembled motor after renovation. Pic 8 shows the motor voltage across the terminals before the conversion, complete with gigantic sparks of amplitude 100% of supply voltage. Pics 9 & 10 show the waveform on the terminals of the modified motor at slow and fast speeds, hence different pulse width; broad pulse more speed, narrow less speed. BUT: virtually NO SPARKS😊 and no capacitors😊 Trick is in the bridge rectifier used to connect the motor to a standard brushed ESC. The diodes in the rectifier suppress the sparks😊 Pic 11 shows the wiring 'lash-up' I made to test the motor before mods. Pic 12 the PSU used for the tests. ESC is a 30A Graupner Navy. Instead of TX and RX I used a simple servo tester to drive the ESC. Scope used speaks for itself! As expected speed control was possible but no reverse. Media File 1 Vid shows the renovated motor running but unmodified, complete with sparks😡 Sorry Dave_M, I can't upload the ozone smell🤔 Media File 2 shows the scope display of the unmodified motor test, complete with the sparks that cause the kind of interference you are suffering from. Wanted to add the final vid showing the clean waveform after the mods but it's too big for the site: 30MB max and the vid is 47MB 😭 Penultimate pic shows the circuit used to connect to a standard ESC (Brushed!) for full remote control proportional forward and reverse. Final pic shows the test set up for the fully modified motor. Note 4 connections: 2 to field coil, 2 to brushes (i.e. rotor coil) as per circuit diagram of the interface board. Have fun, cheers Doug 😎
Traditionally, when powering a Rx from more than one source, such as using a BEC circuit and a separate Rx supply battery, the positive power feed from the ESC is disconnected. This avoids the double power feed. I am embarking on a triple hand screw model with 3 x ESCs so each screw can then be controlled individually from the Rx. In this situation, where all the Rx power will come from ESCs running off the same main battery (using the BECC), with no separate Rx battery supply, is it necessary to cut all the positive ESC supply leads except 1? Appreciate any advice. Thanks Rowen
Hi MouldBuilder As for motor upgrade a 35mm brushless motor with an ESC and lipo battery would be a far better choice. These motors are far more powerful and the Lipo batteries, less weight and delivery the power the brushless motors require. As for a prop a 2 blade 40mm or 3 blade 35/37mm. Canabus
Problem solved for the moment with insertion of correct battery. Battery arrived this morning, ordered yesterday... great service! Power Sonic PS 630 ST 6v 3.4Ah £7.75. Readings (average) 6.05V, less than 1.7 amps, less than 10 watts. Will update after maiden voyage. Thanks again for all your help. ps site does not appear to support less than symbol.
Hi Doug I was referring to watts produced by the battery in the model and the quoted amps of 40. I made no mention of the motor's power rating. The battery looks ok to me and would struggle to give 40 amps with a duff cell. I agree the best course is to suck it and see as is. May sail fine and the motor not overheat.
I think you might need pointing in a direction, so I had a quick look on Hobbyking, and this motor is the sort of thing you can use, although this particular one would need you to swop the shaft around, this is just a guide, other s will no doubt add comment, its the right size, 5mm shaft, right kv and watts. https://hobbyking.com/en_us/turnigy-g15-brushless-outrunner-... brushless esc https://hobbyking.com/en_us/hobbyking-90a-boat-esc-4a-sbec.h... you don't need the high amp capability, but its reversing, programmable, water cooled, and has an sbec, so the main battery power this 5 mm shaft, move your motor to the centre section meaning weight distribution is more central, and you can now use a shorter shaft, and get a couple off plastic "x" props, I would say 40 to 45mm will be the one. This will give a good speed, and you can power on 3 cells or 4 cells lipo, get higher c rating (40c or more) and higher mah so you have fuel in the tank available https://hobbyking.com/en_us/turnigy-battery-3000mah-4s-40c-l... This is just a guide, a starting point, as I feel you are unsure where to start, others with more knowledge will come in regarding this, having experience with lipo, brushless, 3 foot ply boats, and esc's, depending on budget, this would be the sort of thing I would be getting.