Hi Pugwash1 Thanks for your comments. I am no expert in motors but I think its a given that brushless motors out perform brushed motors and lipo batteries out perform lead acid and nimh batteries. Therefore if you want a model that can pick its skirts up ang go you put brushless motors with lipo batteries. If your model is not meant to rip around the pond then I dont know how to look at the pros and cons of brushed versus brushless or the merits of the different battery types. Les
Part 1. Ideal conditions; nearly 30°C, cool Bier at hand😜 Sea Scout built by Dad in the early sixties with a Taycol Target and 6V lead acid wet cells (very wet😡). Renovated and dragged into the 21st century over the last several months 😉 See Build Blog 'Sea Scout 'Jessica'' for details! Motor: Propdrive 2830, 1000kV, 30mm 3 blade Raboesch prop. Quicrun 16BL30 (30A) ESC with BEC. Tested with 3 battery types, all started with 99% measured capacity- 1. NiMh 4.2Ah 7.2V, nom. 408gm. Result: Speed sedate (OK 😉scale river cruising!) No planing. Max current: 3.6A End status V / capacity left: At end of short run ca 3 mins. 7.78V 99%. 2. 2S LiPo 4.0Ah 7.4V nom. 257gm. Result: Speed still sedate but due to lower batt weight at least the forefoot came out of the wet stuff! Max current: 4.1A End status V / capacity left: At end of short run ca 3 mins. 8.25V 93%. 3. 3S LiPo 4.0Ah 11.1V nom. 315gm. Result: Now we're getting somewhere!!😁 Good speed, manoeuvrability and planing 😊 Max current: 7.5A End status: 11.95V 74% after several long runs, ca 20 mins total. Estimated (extrapolated) endurance on a 4Ah LiPo around one hour - mostly 'full bore' - 'Pedal to the metal man' 😊 See also: https://youtu.be/oMUlSOaAREM The competition! https://youtu.be/zPgYicA0yGw Final run. (Beer was getting warm😁) Cap'ns log entry: Boat dead-weight w/o battery: 1.8kg. Spray rails to be added!😲 Slight list to port to be trimmed. Rudder servo to be reversed!!😲 Keel protection to be added: some scratches and flaking from stony sloping shore 🤔 Summary: much as expected👍 Forget anything less than 3S. Anyone want to buy a batch (4) of new 2S 4Ah 45C Lipos? 'One careful owner'! Happy boating people, Cheers Doug 😎 PS Many thanks to Camera girl Gisela 👍 Recorded in 1080p HD.
Most of this actually took place last August / July! Regular readers may have seen that when Dad built this boat in the 60s he put a Taycol Target field motor in it. About 25 years ago I put a Decaperm and 'modern' transistor ESC in her to provide forward and reverse. Performance was sedate to say the least. I have since modified the Taycol (see below) so it can be run forward and reverse and decided to put it in an ancient Billings Boats Danish fish cutter (Gina) that I inherited from an Aunt. The cutter is badly in need of renovation (see pic 1) and the Taycol will be more suited to her performance requirement! On advice from Canabus in Hobart I obtained a Propdrive 2830 1000kV brushless motor, appropriate ESC and a 35mm 3 blade prop from Raboesch. Pic 2 shows the old and new motors. Next step was to trial fit new motor mount, coupling and prop. Pics 3 &4. While doing this it became obvious that a new shaft was in order, as mentioned in last update. Soooo, - appropriate stainless steel rod, thrust washers and set ring were acquired and back to the workshop. After cutting to length to accommodate the new coupling type a 3mm thread was cut a the prop end. At the inboard end I milled recesses for the grub screws in the set ring and the coupling, pics 5 - 7. I don't like to just file(or even mill) flats for the screws cos they have a tendency to slip and work loose😡 Trial fitted the new shaft and found I'd boobed a bit with the measurements and need extra thrust washers to make up the difference. 😲 Pic 8. No sweat, they came in a pack of 50 anyway😊 You can also see in this pic that I decided to fit an oiler pipe while everything was in bits anyway.😉 To solder it on in a cramped space without setting the boat on fire 😡 I packed a wet rag underneath and used a gas Kitchen Torch! Known as a 'Gas Gourmet Burner'. Yep, those handy little gas torches like your Missus uses to melt the brown sugar on her Crème Brûlée!! So do I, delicious 😜😉 The torches are not expensive, small, very handy, refillable with lighter gas and can be adjusted to a very small hot flame. Ideal for this job. See pics 9 & 10. Pic 11 shows the new motor & mount, shaft and coupling all trial fitted after using a brass alignment tool I quickly made up on the lathe. Pic also shows the trial electrical installation after cleaning up the 'machinery compartment' a little and painting with silver Hammerite. A Quickrun BL ESC is sitting in the bottom in one of the trays my Dad originally fitted for the 2 wet cell (very wet!) 6V lead acid batteries. The home made board on the left carries the battery and ESC connectors, main ON/OFF switch with LED, blade fuse holder with a 20A fuse and a green LED which tells me if the fuse is blown! Stuck on the walls (OK Bulkheads!) with so called Servo Tape are a 6 ch Turnigy iA6 2.4Gig RX and the arming switch for the ESC. Battery compartment is sized to fit 2S and 3S hard case LiPos. For trials I can fit my Wattmeter forward of the switchboard and splice it into the battery supply using Tamiya connectors. Might change these to XT60s later if current drain is more than 12 to 15A. All for now, all this was pulled out again preparatory to cosmetics on the hull, decks, cabin roof and walls inside and out. But that's another chapter so, 'Tune in next week, same time same channel when once again it's time for 'WHAT DO YOU MEAN BUCK RODGERS IS APPROACHING!? 😁 Or 'The Saga of the Cabin Roof' 😉 Cheers Doug 😎 BTW: After drilling the shaft tube for the oiler pipe I flushed it out with light machine oil (pumped in from a big syringe) and shoved a few pipe cleaners through (rotating them on the way) to remove any remaining drill swarf!!
[Score: 8/10] 45"/9800g Amsterdam Capable of 4mph and a runtime of 120mins Single Propellor (4 Blade 50mm) Direct Drive to a graupner (4 Blade) Powered by Lead Acid (12v) 7Amp/h Batteries Controlled Through Artesania Latina (45Amps) ESC - Comments: Very strong tug , can tow 2 persons in a rowboat . Runs very long time with 2 lead acid 12 v 7 amp
Hi - I've got one of those and once I've progressed with some of my other builds I'm planning on replacing the old MFA 850 with a brushless. Being quite a heavy beast and wanting decent speed but not manic I'm looking at one of the Overlander 50 dia. brushless outrunners which will provide the torque required and use a 45 or 50mm 3 blade prop. Definitely LiPos for me. The 7.3v lead acid was fine in the boat weightwise on the water but too heavy and unwieldy for moving around and launching and with LiPos you can easily up the volts without much increase in weight. Chris
So here we go again! I have decided to give other projects a rest for a time in favour of this little gem. Pick up off eBay for less than £100 NIB posted, couldnt resist! Its the Dumas (kit no:1203) 44' Coast Guard Lifeboat. I dont know if this kit is still produced by Dumas and having looked at the Die cutting of the parts, certainly seems like an old kit? However, I love my building and the challenges, so I am sure it will turn out nice at the end. Finished length 33". I shall be converting this to a RNLI Waveney Class Lifeboat and will possibly go with 44-003 named "Khami" which was based in Great Yarmouth and Gorleston, which is local to me here in Suffolk. Sadly very little turns up on this boat via Google, but at some stage may pop out to the Great Yarmouth Lifeboat station and see if I can hunt anymore info on her. I shall not be using the recommended Dumas running gear for 2 reasons, 1st its a geared set-up (I am going with MFA540 brushed direct drive) and the cost of over £150! Photos show the box artwork, plans and the included wood. Last photo shows my electrics less propshafts and props that are on order. Note the Star Wars 3.75" figures that with poetic licence could be painted to represent crew. However, at this point the model is approx 1;16 scale and the figures would be 1:18 scale so maybe too small. There are 1:16 scale lifeboat figures available but pricey? My one issue at this point is going to battery choice? do I go with a small 6v lead acid or perhaps 2 Tamiya type 7.2v NIMH in series. anyone who has built anything like this may want to advise. LIPO not an option as the Mtroniks ESC do not support LIPO. Space inside the hull may also be an issue? Another issue is going to be fabricating some propshaft struts for the rear next to the props. There is quite a bit of prop shaft exposed outside the hull, so these would be integral to support and strength of the propshafts. Is there anything available off the shelf (they are included in the running gear set, but dont seem to be available on there own) of do I need to fabricate from brass tube and sheet/strip brass?
[Score: 8/10] 48" VALIANT Capable of 4mph and a runtime of 90mins Single Propellor (4 Blade 70mm) Geared to a 540 (4 Blade) Powered by Lead Acid (12v) 14Amp/h Batteries Controlled Through MTroniks Viper marine (25Amps) ESC - Comments: This tug was built by a modeler in Bristol during the early 1960's it was given to me at the Abergavenny Steam and vintage show in 2016 by the makers grandson who told me it had been on display in his mums house from 1970 when his grandad died till 1987 when she died then put in his parents attic till it was given to me. it had a couple of holes in the hull and the upper works had been broken so required fixing. not having any pictures I used all the original bits that came with it so I hope it looks as it should. It's made mostly from balsa with some wooden bits and replacement planking from coffee stirrers otherwise all original. It requires 2 x 12v 7ah lead acid batteries and about 5 kilograms of ballast. (Silver Sand in 500grm packs). On the only test run I've managed to tow a 16 foot fishing boat with three men on my local fishing lake.
Hi John, you might now be scratching your head, and wishing you have not asked the original question! This seems to be a common issue, as the boating community is light years behind the other disciplines, rc cars, planes helis and so on, its probably due to the facts general boating doesnt really need the later generation technology, the average boater age is probably higher than the other disciplines so budgeting might be an issue, and there is less younger blood in the clubs to explain the lipo/brushless etc. We see posts with a load of numbers, specs, warnings etc, its enough to put people off. Im a big fan of brushless/lipo/ 2.4 etc, been doing it for years, its cheaper and more efficient (once you have the basics) but for the average guy, who just wants to spend an easy afternoon at the local lake gently cruising around, brushed motors, nimhs batteries, even lead acid, will do the job👍 Your 4 foot ply boat, once painted, with fittings, will be heavy, I know, I own one. Those 600 motors are not big enough, they are better suited to the smaller 3 foot boat, then, pushing them with a 6v lead acid, just cant do it. The battery will be screaming HELP!! I started 15 years back exactly the same, 600 motor, 6v battery, massive 50mm prop, I knew no better and took advise from people who didnt know what they were talking about😡, remember those gold hi tech speed controllers!! I had one, it melted, literally melted on the first use😭 Get 700 size motors, they will need to be water cooled, as mentioned by jarvo, the nominal voltage or below isnt good enough, power them at the max voltage. Brushed means you can use one apropriate esc, look out for electronize (are they still in existance?) or mtroniks, preferably use nimhs batteries over lead acid with a high mah. If after all this you want to venture into lipos and brushless motors, go to a club, spot a boat that is similar in size to yours, if you like the performance talk to the owner and gain experience and knowledge that way, it will save money, lost time and a lot of disappointment, I have been there so feel your pain. I say I would never go back to brushed motors and none lipo batteries, but I always want silly speed, not runtime, after 15 minutes Ive had enough and am bored. Rambling over! My 4 foot boat is twin brushless and uses 4 lipo 5000mah cells per motor, it will do 25mph for 15 mins, then I go home😁 Message is, you can get a "reasonable" performance from brushed motors, with the correct batteries, right props, but weight is the enemy. Looks lie you are at Biddulph, get onto Dave M a moderator on here, and arrange to go over to see the crewe and district boys on one of their sailing days, take your boat with you, they will help👍
so following a plea for a cast off boat for a friend, Dave generously donated this hull, its very nice. We discussed a gun boat, in a stand off sort of scale, as he likes military, with perhaps a superstructure that can be removed, and a different one made to fit, so two boats In one. But the more I look at it, the more I think it would make a minesweeper etc sort of thing. I'm not that well up with this sort of craft, its 43 inches long, so quite narrow, It has to be pretty much "none fussy" as the owner and builder is relatively new to this, Ill help, but its his boat, and he has clumsy hands, 😊 so it wont be super detailed. Easy to use, so single screw, more than likely brushed motor running nimhs or even lead acid (ouch🤓 that goes against everything I do!)_ Ideas please!
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
further to my previous post, I have now fitted the two NiMH Batteries (not nicad as I kept saying)in the rear compartment, held in with Velcro, and tidied the wires up and fitted an inline fuse, yet to be wired, the boat is much lighter, however all the other Velcro is still in place so I can move them forward if needed and fit the lead or Lead acid battery, so one visit to a pond and hopefully I can get it sailing correctly, my problem is I would not know what is correct and what is not, at least I have Pauls video as a reference.
very interesting Paul, I watched the video, I have weighed the boat as best I can, using the kitchen scales, the boat without any batteries or lead is 6Ib 3 oz (2815 gms)the lead ballast is 2 Lb (915 gms)the lead acid battery is 5Ib 9oz (grams) and the two NiMH batteries are 1Ib 10oz (747 gms) the boat now has an 850 motor with a 55mm 3 bladed prop, I do not have the experience to know whether the boat is sitting correctly without the ballast but do know that if I have the lead acid 12volt battery fitted in the only place it will fit then I need the ballast in the forward compartment making the boat weigh 13 Ib (6252 gms). if you are saying that I should keep it light then I could move theNiMH batteries to the compartment rear of the motor thus moving the weight towards the back and ditch the LA battery and lead ballast, I have no idea which part of the country you reside in, is it too far for me to drive to? as your sailing pond looks a lot better than the postage stamp we have to use in Swindon.
Hi Richard, that lead acid is way too big and heavy. I Remember going on hols as a kid, car was loaded up, all family, roofrack, deck chairs, tent and so on, and Dads old Moggie Traveller would barely climb the Welsh hills! Same here, its just dead weight, ideal for a tug etc, no speed required, and ballast needed. This boat wasn't any slouch in its day, As Havelock says, it was originally built as a ic powered model so could stand being heavy. To achieve balance, its a matter of moving things around, not adding, so just move things forward, you will be surprised how the weight increases once you start adding Deck clutter, fittings and so on. Lightweight, is good. Your comment, stood up in the water at half throttle isn't going fast, its just bad weight displacement causing the bow tyo be too high. That setup would never have been that fast, the motor/battery combo will never cause a heavy ply boat to be going that fast its standing on end Couple of things to consider. Your nimhs, how many times have these been cycled, and what sort of charger are you using? A reasonable charger will give the information, if I know what you are using, Ill advise accordingly as you might not be getting the best from these batteries what prop are you on Think of an rc plane (if you fly them its easier) If the cog is too far back, the nose is pitching up, and its almost impossible to control, it almost porpoises in the air, and is very bad. COG is vital on a rc plane, nose heavy is better, only because its more controllable. COG is equally important with a boat, but harder to see the implications, the hull will give us false info, such as if the bow is up its on the plane, no, not necessarily, its not planing due to speed, its just out of balance. Shifting the weight radically will let you see this, sorry for the ramble, Wish you where closer to me I would love to help hands on👍 Ive tried to find a suitable video of my Huntman to display what I'm rambling on about. This video is poor quality, but it displays that boat moving very fast (25mph with on board data logger) but look how flat it is, its planning, as the forward 1/3 of the hull is out of the water, but its not standing on its tail, this is because its balanced. You boat is pretty similar in design to this so whilst you wont want to go this fast, the picture should look the same. This Huntsman weighs 6kg with batteries (lipos, you will NEVER get a nimh or lead acid to do this) and is 4 foot long, so quite a heavy old girl first constructed as an IC model in the early 70's. https://www.youtube.com/watch?v=e5-YmmElIfk&t=34s and here is a picture of my 3 foot aerokits fireboat, bow up, is it planing, no, its way out of balance, it wasnt actaully going that fast Hope that helps Paul