Response

Internal wiring & bottom skins

Hi Rob, the Police Launch is coming along nicely. I see that you have long leads from the battery to the ESC. The general rule is that these leads should be kept as short as possible to minimize voltage spikes caused by the fast switching currents and the inductance of the leads. Brushless ESC's have large capacitors, often visible at the end to absorb the transients. You may well get away with it but the life of the ESC could be reduced. Hope your Xmas goes well, Alan

5 years ago by ukengineman

Forum

Voltage increasing via regulator

Evening all, I have a voltage regulator I’d like to fit to my Southport tug (currently running on 7.2v Ni-MHs) in order to get it up to 12v. I’m after more speed/power and would particularly like the bow thruster running a bit faster than it does on 7.2v. So, the questions are, where to fit it in the wiring loom, and what will the effect be on the ? Advice please! Thank you in advance...

6 years ago by EricMB

Blog

54 year old Crash Tender

I would like first to say that this is NOT a restoration. It has always been mine and followed me around all those years, been used extensively on Oyster beds on the Essex coast and Valentine's Park in Ilford, Essex...even the great Victoria Park, of which my Granddad was a founder member. It has eaten its way through lantern batteries out of number which my Dad, who was in the business could magic from thin air. There was always a nook in the boot of the Triumph Town and Country saloon and then the Austin Westminster for another new lantern battery, which the Taycol would destroy in about 20 intermittent minutes of left, centre, right, centre from the REP single channel gear. How I wish I still had that, but it was stolen. The REP, that is, the Taycol remains, restored and cleaned and like new again waiting to go back in the boat. I finally decided I should finish it. My wife bought me a set of white metal fittings by Yeoman out of IP Engineering, so I have no excuse. Not that I need one. It has suffered a bit over that half a century, losing odd panels, but they are easily remade and replaced. First, I had to clean out the insides of the detritus and loft life of decades. Vacuuming, scraping with a pointy thing and brushing with a stiff brush, followed by more vacuuming using a clever attachment that my dear wife thought might be useful and it was, being at least a dozen stiff, but small diameter tubes poking out of the end of a nozzle. It both pokes and nudges the old dirt and dust and sucks it away. After that the old thin mahogany deck planks, my friend thought to add in the late 60s were removed and saved where salvageable as I quite like them for trim on other boats. The deck was rather brutalised with a coarse rasp and any loose nails punched back in flush or slightly below. Then some way too old, but still good, epoxy (WEST) was used to slar all over the decks and most of the insides, even some of the cabin sides. That will be finished before dark today. I can hardly believe the epoxy still works, but it does, perfectly and so is pressed into use. In this warm weather it set very quickly. I did my usual trick of squeegeeing it on into the grain with an old credit card or Gummi, which is a sample block of silicon. Styrene will also do. I use some spare 2mm stuff I was given (that guy at IP Engineering again). The roofs had already been corrected the other evening and heavily cellulose sanding sealed. The forward cabin removeable roof was unwarped by having a tight fitting diagonal piece of pear pressed in under the top skin and glued. The new hatch on that roof was made and the shape of the roof and hatch runners changed slightly, as per drawings from this site. Here are pics. of the work today. The above resinning, the remade cabin panels a new wheelhouse bulkhead and the tow hook base panel, finally a new aft cockpit rear coaming which it never had but should have. Cheers, Martin

6 years ago by Westquay

Blog

M.V. TEAKWOOD

Water trials have been delayed by trying to resolve the challenges with my HMS Brave Borderer project drivetrain. As those efforts have been halted, waiting for new components, decided to complete the Teakwood water trails. First battery trails used 8 x 1.2 Ni-Mh cells is series, giving 9.6 volts. This was unsuccessful as the was only minutes. Lesson from this is not to buy cheap Ni-Mh cells from an Oriental source. Tried 2 x 7.4 Ni-Mh packs is series giving 14.8 volts. Vessel was far too fast and throttle control poorly modulated. Was thinking of fitting a voltage reducer with this battery layout so could adjust the top speed. Have done this before and it works well. When searching in my box of bits found a voltage step up increaser. Never used this before so rewired the Ni-Mh packs to parallel and adjusted the output voltage to 10 volts to see how it worked. Result is a nicely performing model with an usable top speed potential for emergency, Duration of the first run comfortable exceeded 1 ½ hours, which am satisfied with. The cells are positioned around mid hull to supplement the fitted ballast. From the pictures the model has all the grace and style of the original vessel and sails well. In conclusion, a successful project that justifies the many hours spent in building and refining the model

6 years ago by Rowen

Forum

Charging NiMhs, one for Doug?...

Evenin' Martin, Oh dear oh dear oh dear! 😲 There is some good advice above, but maybe not optimally expressed for use by a Luddite! Sorry guys but this might be a relatively long post to separate the wheat from the chaff, explode a few myths and resolve this little conundrum of Martin's! One thing at a time! NUMBER1. THE RADIO- Dear Martin: Whatever possessed a self confessed Luddite and Scrooge like you to spring a large chunk of your hard earned pension on one of the most expensive and complex RC sets on the market in the first place???? I bought a Spektrum DX6 on impulse a few years ago while strolling around Conrad here in Munich. I've regretted it ever since. in retrospect it was way too expensive >600€, and complex. it is intended for the Fly Boys, as unfortunately most sets are these days. I have still not successfully programmed it to do what I want to do, instead of what it is pre-programmed to do for helis and fixed wing aircraft. Not even with it's own Spektrum RX, let alone a 'foreign' RX like Orange. So I have not yet risked it in a model. Definitely NOT my Catalina. Since then I have bought a Turnigy I6. Which does the same as the Spektrum, works fine with my Orange RX with giro for the Catalina😉, cost only 69€ (is now available for around 33 quid😡) and within a few hours I had it programmed and tested to do all I want in my destroyer and Sea Scout.👍 In short: the Spektrum is way way way Overkill for your yacht or Fire Float or similar, where you will only ever want rudder and sail servo / winch or rudder and speed control. So flog the Spektrum and get a nice simple (and cheap😉) 2 or 4 channel set. I can't imagine you ever wanting to start building special effects into your models so 2 (max 4) channels is all you will probably ever need. Stick your Spektrum on eBay, maybe you'll get at least a 100 quid for it. If you still want to go 2.4Gig get yourself a Turnigy i6 set with RX, 6 ch but cheap enough and I can help you directly with binding and programming from experience - I have a good English manual with no Chenglish gobbledygook. If not and you still have a working 27 or 40MHz FM set (40 would be better) use that. Where you sail, all alone, who's going to bother you or be bothered? BTW: Yes the Spektrum TX IS DSM2 and DSX compatible BUT you have to tell it what you want to use!!! Frankly I think trying that with a non-Spektrum RX is risky - especially first time out and for a novice Luddite😉 NUMBER 2. THE NiMh BATTERY- Voltage is not a reliable indication of battery charge / remaining capacity. After use a battery will recover slightly when at rest and the open terminal (off load) voltage will rise, often to the nominal voltage or slightly above. This is NO indicator of remaining charge as when a load is applied the voltage will drop again rapidly, the higher the current drawn the faster the voltage drops. if it goes below 1.0V per cell the battery will be permanently damaged and never regain it's original capacity. Haverlock is dead right about batteries losing charge when not used or regularly recharged. An NiMh batt loses charge at the rate of about 1% per day so after 3 months or so you can send it to the great recycling depot in the sky and buy a new one. Periodic cycling, discharge / charge prevents / minimises this - see care hints I posted above. And yes, NiMh do have that irritating Memory effect🤔 albeit not so pronounced as with NiCads. Lipos apparently not, but I ain't seen any evidence yet - the jury is still out! Sooo - ignore the 6.37V and run the batt through a discharge and full charge cycle. if your new NiMh batt has not yet been cycled and charged I would bet that it's present capacity is about 45%. See example below (and in attached pic) of one of my new 4.8V (nom) NiMh RX batts. NUMBER 3. THE CAPACITY CHECKER - "Glorified voltmeter" ? Where did the 6.37V reading come from if not from your 'new toy'? If it is showing volts it should also be showing capacity in %age. If you received the wrong thing it's not the "bloody electrics" but the bloody nit who packed and sent it that's at fault. Before you send it back check the below😉 Send me a photo of the Checker you have and with your battery plugged in so I can see what's happening on the display. Otherwise we are all poking about in the dark (Are we back to Jules and his friend Sandy😉😲) The link I sent you was for a checker exactly the same as mine except for the labelling! As you can see in my photo, properly connected it shows the terminal voltage and the remaining capacity (charge level) of the battery pack. Forget the Nixx (=2 Ni possibilities) display, that just means 'It ain't a LiXX' (3 Li- pissibolities). Attached photo shows a brand new 4 cell NiMh RX pack 4.8V (Nominal) connected to one of my Checkers. As you can see the voltage shown is 5.19V, according to the popular 'folklore' that would seem to indicate FULL charge. Unfortunately not🤔 Capacity indication is 45% which is normal for brand new batteries in storage and transit. Explanation thereof - see above! RE: " if it can do LiPos, why not the relatively simpler NiMhs?" a) the LiPo pack has a different chemistry and construction which requires different input circuitry on the checker, b) LiPos need balancing and are fitted with Balancer Plugs which connect to the multipin connectors on the checker. Each pin connects to one cell of the LiPo so that they can be monitored individually. LiPo chargers use this to balance the cells to within 0.01V (100mV) or less by adjusting the charge / discharge currents to each cell. The checkers use this to show you the individual cell voltages and charge states. A big difference, i.e.lower V and capacity, indicates cells with faults, e.g. higher internal resistance, or a discharged pack which needs charging and balancing. NiMh packs don't usually have this facility to measure individual cells. They are thus connected to a separate input on the checker which can then only show total pack terminal voltage and capacity. BTW: if you can get it passed 'THE Management' store your battery packs in the fridge😲 The 'coolth' slows down the rate of self discharge, which is a function of the battery internal resistance, which reduces slightly with reduced temperature😉 Enough for now, back to stripping my PTB for it's Midlife Refit! Cheers, Doug 😎 PS Martin: Just saw your post about another RX. Why the hell not buy a Spektrum designed Rx guaranteed to work with their TX? Or better still; flog the Spektrum and get a nice simple Turnigy set as above, also recommended by Ron, albeit the 9 ch version. All this frigging about with 'claimed compatible' bits and pieces just wastes money and time, fogs the issue and don't prove nutt'n!

6 years ago by RNinMunich

Forum

Help Needed new Builder Billings St Canute

Hi Richard, if the charger was good for the original battery and both are NiMH it will be good for the new one as well. One thing bothers me slightly: what does 'Sprint' charger mean? Just a name or does it only do fast charging at high current? Which is not recommended as it shortens the . 😆 Which charger is it? All the best, Doug 😎

6 years ago by RNinMunich

Forum

Sea Queen Prop Shaft

Hi Andy What size is your Sea Queen? is it from a kit or a published plan? What particular motor, ESC, battery and prop size are you intending to fit? If the supplied prop shaft is true it should be OK. I suggest you test it by removing the inner shaft and rolling it on a piece of glass. Any bend will easily show and that shaft will be unusable for your purpose. As Jarvo says you can perhaps shorten the length. I have just looked on the Cornwall Model Boats site and they have 5mm prop shafts which may be a better quality than those you have and are supplied with the common prop threads. Modern prop shafts are much better than were available a few years ago and yes I still have (unfitted) the original aluminium and mild steel prop shafts for my Aeorkits Solent 48" lifeboat and they were both bent!

6 years ago by Dave M

Forum

Motor problem

before you fit a water cooling system try a smaller prop. You need to think of the gearbox in a car. Too big a prop can be looked at as being like trying to drive off in top gear! A smaller prop will allow any given motor to spin faster and strange as it may seem use LESS not more current. if you keep the drawn current down to the limits set by the motor constructor then its probable you will need no extra cooling. if the boat moves faster than you want use the throttle its what its for. Throttling down also extends . The air intakes on boats like this were intended for IC engines and they NEED air to work.

7 years ago by Haverlock

Forum

MFA TORPEDO 500 / BATTERY INFO

Hi al, jarvo's answer is more or less correct but not the whole story! Here is a reprint from my attempt to clarify various misunderstandings and misuse of terms related to batteries - usage and maintenance - posted to a thread "battery charging" you can find under 'General Sailing'. "Hi Both (and all other non-technical guys here!) (Dave_M please jump to the next post or topic!😉) To avoid further confusion amongst the non-technical members can we perhaps straighten out the technical terms involved in battery charging and use (strictly speaking the dimensions or quantities involved). mAh (milli-amphour) is a measure of the capacity of a battery: how many 1/1000 of an ampere (A) it can theoretically deliver in one hour, if in perfect fully charged condition and under perfect environmental conditions. (What you ain't never gonna get!) When the outside temperature drops so does the usable capacity 🤔 Charge and discharge rates are measured in ampere (A). under 1A the milliamp (1A/1000, unit mA) is usually used for convenience. Quality battery packs are marked on the case with maximum charge and discharge rates in A. Sometimes marked as xC/yC. xC is the MAX charge rate and means x times the nominal capacity/1000. yC is the MAX discharge rate (i.e. what your motors take) and often means y times the nominal capacity/1000. Sometimes the max discharge rate is given as a multiple of the max charge rate. See example in my photo. These are MAXIMUM warnings and NOT to be taken as the norm! See example in pic. Capacity 4000mAh = 4Ah, MAX charging current is 8A =2C, (4000/1000)x2. Half an hour charging gives then 8/2=4Ah. I would never ever charge at anywhere near this rate! Charging at 500mA (0.5A) for 8 hours (0.5Ax8h=4Ah) is perfectly adequate and much more gentle on the cells i.e. longer life 😉 MAX discharge current is given as 240A = 30 times max charge current or 60 times capacity in Ah.(4). if I used it at this rate it would probably be irreparably damaged (toasted) in just under a minute (0.9999r) 😡 If any Lixx pack gets HOT while charging or in use take it to recycling pronto, before it sets fire to your boat or workshop/house😡 ALWAYS MAKE CERTAIN THAT YOUR CHARGER IS SET FOR THE TYPE OF PACK YOU ARE USING, NicAD, NiMh, LiPo OR LiION etc (don't forget the balancer connection!). Sorry for teaching some 'grandmas' to suck eggs but having seen so many questions about battery charging and much misuse of the parameter units for batteries in the responses (as above) I felt it was time to clarify things for the non-technical among us, for their own safety and the health of their wallets!" Cheers Doug 😎

7 years ago by RNinMunich

Forum

MFA TORPEDO 500 / BATTERY INFO

The basic of C rating is charge and discharge. ie 2200 mah X 25 max discharge, dont charge above 1amp as it will shorten the and if you are getting close to the 50amp discharge the cells wont last long. The watt meter is fitted in line from the batteries to check what power you are drawing when sailing so giving you an idea about run time. The voltage beepers are needed to protect the cells from being discharged to far, below 3.3 volts and the cells can die. They are fitted into the dallance lead of each battery. There is a deal on ebay for Flurion 3s 2200 lipos £12-99 each i have 4 in use in my RAF Fire Tender with twin 700BB turbo motors, get about 15 mins at full throttle Mark

7 years ago by jarvo

Blog

Hobby Engine 'Richardson' Tug Upgrade

This is the beginning of a ‘diary’ of events. it involves a small Tug, the Hobby Engine Richardson and my attempts to improve its performance. This is my first attempt at such a project and would not have been possible without the assistance of certain members of this site. For those not familiar with this model here are the basic details......... Pic1&2 At 1/32 scale ( 1 metre = 31.25mm; 1 inch = 2 feet 8 inches), it has a Length of 54cm (21.25 inches) beam 17cm (6.75inches) height to radio aerial top 37cm (14.5inches) and weight at 1924grams (4.5 lbs) with standard battery and fittings. It comes with 2.4 digital radio, 7.2v 800mAh rechargeable battery and charger. Features include:- Twin 280 motors, functioning internal lights, external lights, smoke and horn. So some (such as Rallyst) have quite rightly said “Why change it”? My answer is that I can never ‘leave well alone’ , that I found the transmitter controls rather ‘rough’, the too short, the horn sound very weak and the smoke almost non existent. Plus the fact that it has been reported elsewhere that the steering when going astern was very hit and miss. So I started to take it apart! Pic3 It is easy to remove the Wheelhouse by sliding the dark grey locker at the front of the wheelhouse/bridge and the stairway. Once the unit is released, the white electrics connector underneath can be difficult and needs very gentle prising with a small screw driver. The other two plugs come easily. This is where members ‘Jarvo’ and ‘RNinMunich’ came to my aid............. However, some of the screws are obvious but others have been well hidden. They are to be found under some of the fittings on the deck. Pic4,5,6,7. The next move will be to remove the deck, but that is for next week. What am I hoping to achieve.....well from zero knowledge I would like to have engine sound connected to the throttle control, good horn sound, better control of steering when going astern and a six channel receiver with new transmitter that feels good to use!

7 years ago by NPJ

Forum

FRESH BATTERY RUNNING TIME

Hi Les I see from an earlier post you were considering a Dragon Flight 95 yacht. This looks like the larger version of the RG65 yacht I have. Regarding the battery I suggest you remove after every sail and open up the hull covering to allow any moisture to evaporate. Leaving the battery connected with or without a switch when there is moisture present will over time result in catalytic action on the black wire from the battery to the rx connection. The whole wire will turn black and need replacing Far better to store your battery in an inside environment where there is no condensation. Lixx I store in a metal box in case of any problem. As Doug says the capacity of the battery and the equipment it is supplying determine how long the battery lasts. When you set up the yacht do make sure your winch and rudder servo are not driving up to the end stops as servos can and do draw large currents if stalled. My RG 65 sails happily for 2-3 hours on a fully charges LiFe 6v battery, but I had to add a 5v UBEC to protect the minature rudder servo. Hope this helps Dave

7 years ago by Dave M

Forum

General sailing

Hi Both (and all other non-technical guys here!) (Dave_M please jump to the next post or topic!😉) To avoid further confusion amongst the non-technical members can we perhaps straighten out the technical terms involved in battery charging and use (strictly speaking the dimensions or quantities involved). mAh (milli-amphour) is a measure of the capacity of a battery: how many 1/1000 of an ampere (A) it can theoretically deliver in one hour, if in perfect fully charged condition and under perfect environmental conditions. (What you ain't never gonna get!) When the outside temperature drops so does the usable capacity 🤔 Charge and discharge rates are measured in ampere (A). under 1A the milliamp (1A/1000, unit mA) is usually used for convenience. Quality battery packs are marked on the case with maximum charge and discharge rates in A. Sometimes marked as xC/yC. xC is the MAX charge rate and means x times the nominal capacity/1000. yC is the MAX discharge rate (i.e. what your motors want) and often means y times the nominal capacity/1000. Sometimes the max discharge rate is given as a multiple of the max charge rate. See example in my photo. These are MAXIMUM warnings and NOT to be taken as the norm! See example in pic. Capacity 4000mAh = 4Ah, MAX charging current is 8A =2C, (4000/1000)x2. Half an hour gives then 8/2=4Ah. I would never ever charge at anywhere near this rate! Charging at 500mA (0.5A) for 8 hours (0.5Ax8h=4Ah) overnight is perfectly adequate and much more gentle on the cells i.e. longer life 😉 MAX discharge current is 240A = 30 times max charge current or 60 times capacity in Ah.(4). If I used it at this rate it would probably be irreparably damaged (toasted) in just under a minute (0.9999r) 😡 If any Lixx pack gets HOT while charging or in use take it to recycling pronto, before it sets fire to your boat or workshop/house😡 ALWAYS MAKE CERTAIN THAT YOUR CHARGER IS SET FOR THE TYPE OF PACK YOU ARE USING, NicAD, NiMh, LiPo OR LiION etc (don't forget the balancer connection!). Sorry for teaching some 'grandmas' to suck eggs but having seen so many questions about battery charging and much misuse of the parameter units for batteries in the responses (as above) I felt it was time to clarify things for the non-technical among us, for their own safety and the health of their wallets! Cheers Doug 😎

7 years ago by RNinMunich

Forum

Hi there, I still can't upload photos or reply to PM's.

Aha! interesting clue about freezing photos! Missed that 🤔 You can free up a lot of operating memory by stopping or deleting loads of Apps which otherwise run in the background, whether you need or want them or not! Go to the Applications Manager via Settings. Doing this on my Samsung (and previous Nokia E7) solved a similar problem with photos by MMS and prolonged the enormously 😊 Many Apps regularly 'log in' and check for updates, or report where you are etc., without you noticing. This wastes lots of power 😲 Cheers Doug 😎

7 years ago by RNinMunich

Forum

3 blades v 2 blades on air boat

if your using electric power its a case of matching rpm to watts. it is quite normal to use 3 bladed prop of the same diameter and pitch as a 2 bladed prop on the same model. The increase of blade area results in increased thrust with an obvious increase in current used. So for any given system its a case of matching motor revs/current/ to the motor parameters.

7 years ago by Haverlock

Blog

The electrics, drive & radio

The switch panel and wiring loom was made, tested and dry fitted a while ago and so it only needs securing to the bulkhead with four fixing screws, the two NiMh batteries were strapped down to the bearers with cable ties as close to the chines as possible and the XT60 connectors mated. I have read that placing the heavy batteries as far away from the keel as possible improves the handling, all other heavy items are centered along the keel for symmetry and should help the boat to sit evenly in the water. I’m not sure if I will need to do any ballasting, hopefully the maiden voyages should give me an indication. The prop shaft was greased and fitted, and with the prop, thrust washers and lock nuts in place, the clearance was adjusted and locked with some Loctite so the motor could then be installed. The initial motor alignment was made with a solid coupler which was then replaced with the universal joint, I took the precaution to grind a flat on the motor shaft so that the locking grub screw has better grip on the shaft. The grease tube was then fitted to the shaft clamp and secured to the side of the switch panel. The ESC was fixed to the back of the bulkhead with another couple of cable ties and the input cables, again XT60 types, and the three pole XT60 motor connectors mated. I have also fitted a Turnigy in-line volt, amp and watt meter in the circuit before the ESC so that I can log readings in case of spurious fuse blowing issues or unexpected problems. The water cooling tubes were then run from the water pickup, through the ESC and then back to the transom ‘exhaust’ outlet, all water connections are fitted with spring clips to ensure water tight connections. I have used quite a large bore silicone tubing to ensure maximum water flow and made sure that all bends are kink and compression free. The R/C receiver is fixed to the rear cabin wall with some Velcro pads for easy removal, the two aerials were fitted in some plastic tubing at 90 degrees to each other as recommended for 2.4 gig systems and as high above the waterline as possible. The receiver is connected to a separate 4.8 volt NiMh battery via a changeover switch that also has a charging connection and LED power indicator, and I have also fitted a battery voltage indicator, just because they are cheap and convenient although the R/C system that I have has telemetry that reports RX voltage as standard. The battery charger I have chosen can handle the 16 cell series configuration of the drive batteries and so they can be charged in-situ when the main power switch is toggled over to the charge position. The RX and lighting batteries are charged separately. All of the servo and lighting switch cables are routed through the hull to the receiver through pre drilled holes in the bulkheads at high level for neatness and to retain the integrity of each compartment just in case 😲!!. The servo and cables and the water cooling tubes are strapped to a supporting bar between the bulkheads for neatness and security. With the TX switched on first, the RX is then powered up and the main power switch toggled to the ‘operate’ position, the ESC then gives a reassuring series of bleeps that confirm that all is well. The ESC was set up using a Turnigy programming card specifically for that model of controller and if required I can tweak the settings once the boat has had a few sailings. The last things to do now are to fit some strong magnets to hold the hatches and roofs down securely and then finally raise the RAF ensigns 😁

7 years ago by robbob

Forum

No power

Hi Nick I am fairly certain your problems are mainly battery related. Do you use the Tamiya (white plug and socket) type battery connector? if so these can make a bad contact which then causes all kinds of unusual problems. We did get a good connection with the ESC working correctly. Subsequently the same set up had no power. This could be a flat battery or a bad connector not making contact. if you push and pull the connector and the set comes to life you have found the problem. Charging the flat battery should get you up and running again. Getting late now so perhaps we can have another attempt tomorrow Cheers dave

7 years ago by Dave M

Response

Gentlemans Cruiser

Hello, The keel was cut on the 13th of May 2017. Power tools are the secret, i would not like to be without the Proxxon table saw, and or the B&D jigsaw plus a Battery drill, makes life a lot easier. The longest job so far has been the Deck planking, it's more like anger management..lol... Hope this helps, regards Muddy....

7 years ago by muddy

Blog

Gentlemans Cruiser

Running gear or furniture.. Once the skeleton or frame was completed it's a good idea to dry fit all the running gear, Drive motors shaft's and prop's, plus the radio gear and battery boxes/trays, and even sound unit locations. Then start the skinning. This hull has very curvy bottom skins, in that they turn from the transom to the bow 90 degrees sharply. Tried some test pieces of vertical grain ply, ( 1.5mm ) but it was the same as horizontal grain.. Skins were placed in as large as pieces as possible at about 45 degrees to the keel, or planking in ply.. Not a pretty sight, but makes life a lot easier. The skins were dry fitted with brass pins first, mainly to assist in the cutting of the skin shape. When the bottom skins were completed and rough trimmed the side skins were applied and these were vertically grained, again makes life a lot easier and they fall onto the stringers, means less brass pins and elastic bands. Not forgetting to drill some 1" holes in the breast-hook and No; 1 former, as i always pour in a little Fibre glass resin to help seal the bow section and add some strength. Regards Muddy....

7 years ago by muddy

Forum

Battery problems

Hi Patto, Sounds like you aught to be running on a decent lipo. The motor is probably taking more amps out of the battery than it can maintain. Lipos are much much lighter than lead acid and can give a higher discharge rate. The dicharge rate is the 'C' rating of the lipo, the higher the number the greater the discharge capacity. if the 'C' rating is too low the battery will start swelling up and its life expectancy greatly reduced. Go for the highest you can afford with the greatest capacity and always use an alarm with the battery, it plugs into the little white plug and can be set so when the battery gets to a set voltage an alarm sounds indicating to stop using it until it is recharged. A 3 cell will give you the required 12volts. The 'C' rating now goes up to 130 in the more expensive lipos but an 80 will probably suffice. The higher the amperage of the lipo the longer running you will get. A 2500 may only give you 8-10 minutes whilst a 4500 (cost just under £50) will give you up to 20 mins. You will have to check your speed controller to make sure it is compatable with lipos, a few are not. Remember you will need a balanced Lipo charger, I only spend about £20 or less but they only charge lipos, quite often the more expensive ones will charge a variety of battery types. I'm not an expert on electronics my knowledge comes through personel experience. With the lipo you will get better performance as the lead acid weighs the boat down. Good luck.

7 years ago by HoweGY177

Forum

Li-Poly batteries

The link to rchelicopters.com that pmdevlin has indicated I found very informative and I think should be read by all those using lipo's. in addition if they follow its recommendations is likely to save them a lot of money as to the life they will get out of their batteries. One thing I discovered was the meaning of the two "c" values shown on the batteries which from what previous contributors have said looks a bit confused. From the web site article the lower of the two numbers is the maximum charge rate that can be applied to the battery without causing its immediate destruction i.e. assuming a capacity of 1000 ma.hrs and a "c" of 5, 5 amps would be the absolute maximum charging current. However if this rate is used the number of charging cycles that can be done before the battery is seriously damaged would be greatly reduced. The author of the article recommends that the rate should never exceed 1 c if you want to get a good life. The higher "c" rating is in general better understood and is an indication of the maximum short term discharge rate that can be drawn. Going back to an example of a 1000 ma.hr battery a "c" of 25 would give a discharge current of of 25 amps but not for long and the internal battery heating would not do much for the .

7 years ago by nasraf

Forum

Battery problems

A quick check on the specs of your motor /esc combo states its good up to 5s LiPo. So step 1 get a watt meter ( cheaper than burned out motors ) Step 2 check with your bank manager ( or wife) for available funds Step 3 buy the biggest 4s or 5s LiPo you can fit in the available space. you will also need a LiPo charger do not attempt to skimp on that step LiPo batteries need special handling and can be spectacular if you do it wrong. You have not mentioned the prop your using if you use the watt meter you can play around with different props so the current used by your setup heads towards the point you pick twixt performance / running time. if you do go LiPo you will also need a battery monitor part of the careful handing includes not discharging them below around 3.3 Volts per cell. 3s =3cells 4s=4cells etc. So if you go 4s then you should not discharge below 13.2V. http://www.rchelicopterfun.com/rc-lipo-batteries.html http://www.4-max.co.uk/pdf/prolong-life-lipo.pdf some text on the care and feeding of LiPo batteries. The reason for your problem is a simple case of battery chemistry a lead acid accumulator cannot deliver a high current for extended periods gasses on the plates prevent the electrolyte coming in contact so the battery loses power. After a while the gasses are re dissolved and the battery can then go on providing power. Nothing wrong with the battery its just a case of wrong tool for the job.

7 years ago by Haverlock

Forum

Li-Poly batteries

I do not know much about the detail design of Li Po batteries but in the past have spent quite a lot of time and tax payers money looking at the performance of lead acid and nickle cad batteries when starting petrol engines over a large ambient temperature range and have the following observations, my interest in model boats is restricted to modest speed versions and I have enough trouble there with Li Po's. It is a pity that to impress those who have a limited knowledge that the capacity of these batteries is quoted in ma. hours rather than amp hours, I know it is easy to convert if you have a bit of a mathmatical background but not eveyone does. it took me many years before I understood the difference between energy and power and I think a lot of people still do. Basically the ma. hr. rating is the amount of "energy" that the battery can store but how much of it that you can get out is very much dependant on the rate of discharge ( i.e. the "c" value with its multiplier ) in general the higher the rate of discharge ( i.e. the "power" ) the less of it you can get out. in addition batteries have an internal resistance so the higher the " amperage " the lower the " voltage " applied to the motor terminals, so as "Watts" ( Power ) equals volts times amps the actual power available to drive the boat is reduced. Also the loss due to the battery internal resistance ends up as heat in the battery which does not improve its life. It must be almost impossible with the information available to be able to select the best battery available for the high rate discharge uses, I wonder if ayone has done any comparative tests?

7 years ago by nasraf

Forum

For sale ww2 corvette class

This is a beautifully made large model it has been made with the very best loving skills, the detail is second to none done to the very best , the boat is ready to sail all that is needed is a compatible receiver , it comes compete with battery. Genuine reason for sale this was taken in part exchange for a lifeboat i had , but iam not into war ships i prefer tugs, fishing boats. First to see will buy it is a top spec boat in fantastic condition. Dimensions are - Length 63ins Beam 11ins Height 25 to top of mast Any viewing welcome ! DUE TO THE SIZE THIS IS CASH ON COLLECTION ONLY ! £350 ono Any questions please contact me thankyou ! OPEN TO DECENT OFFERS PLEASE CONTACT ME THANKYOU

7 years ago by Nev01

Directory

(Tug Boat) CANNING

good sailor,,long (Motor: mm t12) (ESC: electronize) (8/10)

7 years ago by thepirate

Forum

Thankyou very much. I will obtain a propeller as per your suggestion. Regards Keith

7 years ago by Keith

Forum

When I charge my battery to 7.5 v I only get about 10 minutes running time. When I go to recharge the battery the charger tells me that it is sitting on 6.2 v. My question is is the time of 10 minutes usual,if not what if anything I am doing is wrong. Thankyou in advance

7 years ago by Keith

Forum

Keith I have just seen your post re the Phoenix. if this is the model then I suspect the prop is perhaps too large for the brushless motor which will be struggling to reach max revs. Net result will be high current and short run times. if you can get or borrow a watt meter this will tell you the current draw and watts whilst holding and running the boat in water. Trying different size props will identify the best match. Personally I dont use s type 2 blade racing props on my models with brushless as they tend to be too coarse pitch. A good 3 blade brass prop will give realistic speed and long running times. My Sea Queen has a similar motor to yours and gives me about 45 mins if I run at full throttle. Pic attached of the model and setup. I also have a 34" Crash tender with a similar setup so some pics attached Dave

7 years ago by Dave M

Forum

Dave Thank you for your reply and information Regards Keith

7 years ago by Keith

Forum

Hi Keith I see you have a 2 cell Lipo battery of 5100Ma. The charger shows Li 2S charging at 1amp with the overall voltage of 7.43volts on the charge so far. Your charger need to be set to the correct battery type if your battery is to be fully charged safely. You have a balance lead connected so the charger will take care of the process if correctly set up for the battery. There are several flavours of Li batteries so your charger need to be set for LiPo which appears to be the 2nd setting. I can't quite read the writing but suspect it is Lion, LiPo and LiFe. Your charger supports charging up the 5amp and I suggest you use this for your battery which is 5.1amp. As the charge proceeds your charger will reduce the current as full capacity is reached. My charger then flashes a message to say charge end and stops any current flow. Your may have a similar message or indication. When fully charged your battery will have a voltage of about 8.4v. You should not discharge below 6.3v which is probably where your ESC shut down power to your model. LiPos should not be stored fully charged. The safe storage voltage is 3.7v per cell or 7.4v in your case. There may be a setting on your charger that allows you to charge to this level. If you are still unsure please ask. A copy of the charger manual would help. Hope this helps.😁

7 years ago by Dave M

Response

Bullet

very nice, and good 😀

7 years ago by ron1956

Response

Fitting the side skins.

Hi Paul. Thanks for your encouraging comments. The motor is a Turnigy SK3-4250-500kv brushless outrunner, batteries are 2 x 9.6v NiMh 5000mA, a combination recommended for this boat by VMW. You are not the only one to express a concern on it's potential performance but I'll go with what I have and if indeed it does under perform I can easily up-rate the motor and battery combination. The ESC I have is more that capable apparently. I'm too far down the road to reconfigure to a two motor setup and really I'm building this as a test of my re-awakened model making skills and for the satisfaction of it all rather than terrifying the pond life and myself to boot, assuming I can find a 'pond' that is. The spray rails are indeed a nice square profile as you suggest and will hopefully help with the cornering. I'm trying to find out more about the mysterious stern navigation light that appears in a couple 'photos I have seen, I might like to incorporate this in my boat if it's a significant detail...anyone know? This is the sort of constructive criticism that I was hoping to get from other members to my blog so please do chip in if I'm getting it wrong, albeit too late for me but for others building similar boats. By the way, my comments about the fire boat content of the plans and docs section is not intended to offend anyone, but I can't understand why 'copyright issues' means that 'photos and drawings have to be deliberately blurred to render them next to useless, it's like giving someone a book to read and then poking then in the eyes! Rob

8 years ago by robbob

Forum

ESC problem

Hi Ashley Welcome to the site. With such high currents it would be advisable to fit a fuse in the wiring to the battery. I would reiterate Haverlock's advice, LiPos need correct handling in both the charge and discharge. The lowest recommended charge (should be with the paperwork received with the battery) for your battery should be observed and should be set in your ESC. Don't store them charged, the safe voltage is 3.7volts per cell and most decent chargers have a facility to discharge to this voltage. A Wattmeter would be useful the check the actual current under load. Exceeding the motor or battery rating will cause damage and for about £20 a Wattmeter will save you time and money. The Graupner Jet Drive is interesting to me as I am awaiting two jet propulsion units from KMB for my Shannon lifeboat. There is a max rev limit of 20000 revs on these units so it is important to match the brushless revs or risk damaging the bearings. I can't find specs for the Graupner but I suggest you check your documentation. Good luck and please keep us posted. Dave

8 years ago by Dave M

Forum

Poor run time

You don't say what mAh your 12 volt battery is, a 12v 4mAh lead acid battery will give a lot less run time than a 12v 7mAh one. Lead acid is probably the least favourable power supply for a 46 inch Sea Queen with a brushless motor, brushless motors tend to want to draw their power faster than a lead acid battery can give it which could account for the slow speed whilst the battery is still showing a high % of its capacity left. The Sea Queen at 46 inches is a big model and its all wood construction makes it a relatively heavy boat to move through the water, the prop size can also have an effect on the run time. I have the Aerokits Solent Lifeboat which is similar in size at 49 inches and weight, I run two MFA 800 brushed motors with three bladed 50mm brass props on 2 x 8.4volt NiMH and can achieve run times in excess of an hour, admittedly speed wise it isn't as fast as the Sea Queen would be. it would be worth looking at changing the Lead Acid to NiMH, say 12V 5000mAh (35 Amp discharge capability) which would improve things substantially, if you are a member of a club maybe someone with such a battery would allow you to try it out before outlaying the £40 it would cost for such a battery. Afraid I have never been a fan of LiPos but I'm sure that somebody on the site, maybe Dave M would be able to advise on their use.

8 years ago by Flack

Forum

72'' 6S Brushless Power

25c batteries will I suspect be a limiting factor. if you run at a full 25c you can only pull 130A and that will lead to a much shorter . http://www.rchelicopterfun.com/rc-lipo-batteries.html That's a pretty full treatise of the factors involved. To daw 130A you would in practice need 50c batteries. if you intend to run the batteries for more that one or two times. You WILL need a watt meter so you have some idea as to the actual current being used. Using a watt meter you can then find out what a prop/motor combo draws static and thus have some idea of the way to go. Sharpened balanced props are a MUST. Really if you just want speed have a look at the outriggers. They seem to run at insane speeds and since they are raced they have to be fettled to do it time after time. https://www.youtube.com/watch?v=EHC_0wS7P9M one example ( single shaft 60A ESC). https://www.youtube.com/watch?v=p6ban1MMgUY actual race footage. The simple facts are the less of a boat in the water the faster it CAN go, this is independent of how much power you have. So hydroplanes are the faster hull type. if your intending to design your own I doubt you can better them for speed. Hull design is paramount when it comes to speed, no amount of power will make a badly designed hull go blisteringly fast. Sorry if I seem to be negative but I hate the idea of a lot of money and enthusiasm being thrown at a probable failure.

9 years ago by Haverlock

Forum

Wiring query

You will need to disconnect the battery from the ESC when the model is not in use. This is because there is some current flow even when the ESC is switched off, and you would risk the long term life of the battery pack if it is allowed to fully discharge ( even if its not a LIPO ). http://www.maplin.co.uk/p/dpdt-toggle-switch-fh39n can you not find room for that?

9 years ago by Haverlock

Response

VOSPER PERKASA 49 INCH KIT PART 2

Really motoring. The battery can be mounted anyway just make sure the leads are clear of the motor and remote from your radio wires. I suspect you will not be happy with the NiMh batteries. I am assuming they are NiMh as NiCads have not been available for some time. if they are NiCad then they must be nearing the end of their useful Life so another excuse to switch to LiPo. Glad to see you project successfully on the pond. if you invest in a Wattmeter you will be able to tune your motor to the prop and achieve max speed and time on the water. Happy sailing Dave

9 years ago by Dave M

Forum

Brushless Speed Controllers

HI Mark My experience is with both brushed and brushless setups where a micro controller is installed in both the ESC and receiver. Older equipment is not affected but most modern kit use these controllers. Some 2.4Ghz receivers seem to take quite some time before they actually lock into the binding on switch-on. Result is if the ESC is also setting up it can decide there is no receiver signal present and goes into a fail safe condition that requires a power down and restart to reset. if a BEC on the ESC is being used the above process repeats. Some systems seem OK but my Futaba can be a particular problem. Using a separate battery or stand alone BEC seems to avoid this problem especially if you power up the receiver before switching on the ESC Servo judder on switch on is not uncommon but any judder thereafter suggests some form of interference or weak signal. I always make sure my high power wires are well away from any servo or receiver wires and that the receiver aerial is positioned well clear of any motors and power wires. 2.4Ghz require a clear line of sight from the TX to Rx so make sure your rx aerial is above the waterline preferably at or above deck level. My Trent lifeboat suffered from this when I decided the rx aerial would be OK pointing down into the hull - at about 10 yards I started to lose control but it was OK at nearer distances. Reversing the rx with the aerial pointing up cured the problem. Dave

9 years ago by Dave M

Forum

Lighting

Thom As Mark has indicated grain of wheat bulbs are heavy on current plus they generate a lot of heat and have a nasty habit of blowing and can be difficult to get at to replace. However it seems like you have already installed the lights so we need to find you a suitable power source. You have mentioned small so I guess space may be at a premium. If you have room and they will not be too heavy you could use AA or even AAA Alkaline batteries in battery boxes. A four box would give you 6v and if you add another two box this would give you the 9v plus the 3v. Rechargeable batteries will give slightly less volts but would still work and may help prolong the life of your bulbs. Wiring Would be: Negative A (Black wire) 4 box Positive B (red wire) 6v Negative C (Black wire) 2 box Positive D (red wire) 3v If you connect a black wire to the 4 box Positive B and the 2 box Negative C then the Negative A from the 4 box plus the Positive D from the 2 box will give you 9v. If you are using a 6v main battery and space/weight is a problem then you could use it in place of the 4 battery box. Battery boxes should be available locally. Hope this makes sense and gives you some ideas 😀

9 years ago by Dave M

Forum

Battery Choice

Shaun, You are right to be cautious about LiFe batteries. I bought a couple because I needed to keep weight down. I had only run them a few times and then after one run I found one battery was swollen. I had to replace it and, as you say, they are not cheap. You are right to go with NiMH unless you have a pressing reason to use LiFe or LiPo. Roy

9 years ago by Trillium

Forum

Too many questions

HI Steve Welcome to the site. Sounds more like a commercial enterprise than a modelling topic. Must be great fun to actually use a model to collect firewood. I am not familiar with your particular motor and can't find any specs on the web, but with your set up it sounds good for the task you have in mind. As you can use plenty of battery power and weight is not a problem a good heavy duty SLA or two should give ample power. Not sure of the voltage for the motor but you can put batteries in series to achieve higher volts. The higher the AmpHr rating the better. If you already have a speed controller I see no need to change. However more modern ESCs are likely to be more efficient and give you better low speed control. The amp rating need to be at least 50% greater than the motor stall current. Sorry but without knowing the motor stats its difficult to give more detailed info. If your setup is using lots of watts (amps x volts) then you may need to water cool the motor if it is getting too hot to touch after say a couple of minutes hard use. Brushless motors have masses of power and as you possible realise do not require maintenance of brushes. However low revving high power motors and controllers are not that cheap and can be difficult (at times) to reverse, so may not be that good in a tug. I personally would stick with your existing set-up and see how it performs. Moving to brushless with that size prop will be an interesting exercise to get the prop speed down to a reasonable level. I have tried running brushless at lower volts. The problem is the current increases at lower volts so you have a shorter and a big heat problem. I solved my problem by adjusting the control to the ESC on my Futaba 6EX transmitter but this was on a fast Fireboat and may not work as well on a slow tug. Wishing you the Seasons greetings and good luck with your project 😀

9 years ago by Dave M

Forum

Speed controller

Glad to here you got some, plus agree I have always found suppliers on Ebay will bend over backwards to ensure they get good feed back. I got a battery packs (9.6v?) did not charge at first, sent a email to supplier who sent me some replacements no quibble, didn't need me to return faulty battery, felt a little guilty as suddenly it sprang to life and started to excepted a charge, and is still going, no idea why. I am still awaiting stuff order outside of ebay, despite many emails and telephone conversations (W.....urne Models), placed in early may Grr....:-(. I am waiting for another supplier to deliver a 320 amp controller, this time that are designed to run single motors and have no fan, at a cost of around a £5-6, worth a punt, seen them even cheaper since, will report when received and tested.

10 years ago by Peter47

Response

Aerokits 46'' Fireboat twin screw brushless conversion

HI alan yes I could but it would mean sacrificing motor to run it or lugging around another power source so unessary weight. The cooling works fine its just the visual effects I lost unfortunately when the boat did its first test runs I tried shorter lengths of tube and draped it over the side in the middle of the Hull. The pressure was greater so I think it's down to how far the water is travelling maybe it's worth revisiting at a later date 👍

11 years ago by pmdevlin

Forum

Voltage Reduction

HI John Using motors out of power tools may be a bit risky as they may only be rated for short running periods and may be arranged with the field windings in series with the rotor to give max torque like a car starter motor. if they have permanent magnets for the field they will be ok as far as the winding arrangements are concerned, but may be short period rated as far as heating is concerned. Series connected motors are not much good in model applications as it is very difficult to control the speed. Shunt wound I.e. with the field connected in parallel with the rotor or permanent magnet motors,due to the back emf they generate run at a speed proportional to the applied voltage with the current changing as the load varies. If you do not mind replacing motors if they burn out or only run your boat for a short period the use of ex power tool shunt motor may be OK. A good solution would be as you suggest is to run a motor rated at a higher voltage than the battery e.g.your 18 v motor/12 v battery combination thus derating the motor, but you will get considerably less power. Unless you are running a very power hungry motor the battery should not heat very much and discharging at these high rates will not do much for the . Your battery has a capacity rating of 3.4 Ah, this means that in a fully charged state is should be capable of supplying 3.4 amps at 12 volts for 1 hour. At a rate 10 times that I.e. 34 amps, the time of discharge mathematically is 6 minutes, but due to the loss of efficiency in the chemical reaction in the battery the actual time of discharge will be considerably shorter, and heating in the battery may damage its construction. I would have thought that with a 3.4 ah lead/acid battery it would be advisable not to exceed a max current of 15 amps and for normal running 10 amps. nasraf

11 years ago by nasraf

Media

Tabletop Waterway - literally!

Built out of house guttering to a scale equivalent to model railways HO the layout is approx. 4 x 3 ft. Mounted in a wooden frame and provided with a protective see through cover it fits into the car and can go anywhere. it has been an on-going project to build RC boats to suit. Those used at present are commercial products (loa 5" (125mm)) with simple two channel two prop drives - not proportional but with forward and reverse and by operating one or both props plus reverse steering is OK. limited to 6-8 minutes with similar recharge time. Built largely from scrap and odds and ends the project cost well under £80. The idea is/was to have several units and link them together to make a large layout!

11 years ago by CapnJim

Media

Magic Vee (Joysway)

RTR minI electric speed boat with proportional 2CH RC. 280mm loa (11") Good boat and fast. Watercooled brushed motor. Normal problem with commercial mini-boats is lack of proportional RC but this is fine. about ten minutes - low freeboard and takes on water but electrics/RC have proven resistant to regular swamping!

11 years ago by CapnJim

Response

Vosper MTB ( perkasa type )

Hi. I have just posted asking about the Precedent Perkasa kit. is that what you have built here? What did you think of the kit? Do you think smaller motors might still give planing performance and give longer ? I am about to opt for a kit to build and would be grateful for any info to help me choose the right one. You have certainly done a nice job of the build and it tempts me to choose this one

12 years ago by lesfac

Blog

Ebay quick refurb.

I noticed this nice looking speedboat on Ebay, I thought to myself that it had some potential, especially with its sleek shape. The item description may of put some people/bidders off, because it had no electrics and the motor was described as "not working", but at least the original gearbox drive was still in, along with the original style rudder and "Z" drive uj coupling to the prop. First job was to remove the motor, only to find it was a "Le mans " sport motor. The bearings were a little tight, but after removing the brushes, the commutator was badly oxidised, giving the reason why it would not power up. So I carefully cleaned it up with some fine abrhasive paper, I also cleaned the drive faces of the brushes before refitting. I also lubricated the motor bearings before going any further. I put the motor in my vice, connected up a couple of power leads to a 6v battery, not wanting to go full voltage straight away and he presto, the motor sprang in to life!

12 years ago by Gregg

Response

veron fast patrol boat

HI Ian, thanks. As regards LIPOs I use Turnigy 2200 $40-40c Discharge. I have doubled them up in the boat 4400 11.1v. So good capacity, no more power. No problems with the brushed engines. On my Veron Huntsman, 52" again, with a brushless no problems, but I have used 20-25c discharge and they puffed up, I can still use them on low powered aircraft, flying time is just down a tad. So get the biggest mAh battery you can afford, with the biggest discharge available you shouldn't have any problems, just don't get salt water near them. As far as costs a re concerned go for reputable supplier, I only use Turnigy, in the early days I used various suppliers but I was Ignorant and did most of the damage myself!! so I can't blame the battery, but I do know that Turnigy are pretty bullet proof, but if you want a recommendation I would go for A123's but make sure you can charge them from your existing charger, (LIFE4 is how I charge mine), good luck Brian

12 years ago by sharpy1071

Response

Propshaft Coupling arrived - Construction Full Speed Ahead!

I was merely giving advise and warning you about the coupling, and Dave m agrees, you have to watch the flexI coupling. I would not really recommend using Nimh batteries with a brushless motor, they do no give out sufficient amperage that a brushless motor requires and damage to a nimh battery might reduce its usual service life, its much better to use a lipo battery of 7.4v, but get a higher "C" rating, so 20, 25 or 30c would be much better, the power output of a Nimh battery allows a lower current output, but on a longer length of time, whereas a lipo will cover any loading. I personally now use Lipo battery sticks on the majority of my boats, they are lighter, give better output, even with standard brushed motors, you can tell the difference. best of luck with your build, its looking good !

12 years ago by Gregg