|||
Current Website Support
87
Contributors
28
Subscribers
You are Not Registered
Subscribe for your gold medal ๐Ÿ…
Less Ads
Ad Free
Until Cancelled
ยฃ1
ยฃ2
ยฃ3
ยฃ5
Donate for your silver medal ๐Ÿ…
Less Ads
Ad Free
12 Months
ยฃ10
ยฃ15
ยฃ25
ยฃ50
You Will Be Helping Towards:

  • Domain Fees
  • Security Certificates
  • iOS & Android App Fees
  • Website Hosting
  • Fast Servers
  • Data Backups
  • Upkeep & Maintenance
  • Administration Costs

    Without your support the website wouldn't be what it is today.

    Please consider donating towards these fees to help keep us afloat.

    Read more

    All donations are securely managed through PayPal. Amounts donated are not published online.

    Many thanks for your kind support
  • Join Us On Social Media!
    Download The App!

    Login to Remove Ads
    Model Boats Website
    Model Boats Website
    Home
    Forum
    Build Blogs
    Media Gallery
    Boat Clubs & Lakes
    Events
    Boat Harbour
    How-To Articles
    Plans & Docs
    Useful Links
    Search
    Search
    Forum
    Anteo 2 Tug
    You can power a brushless from lead acid batteries electric is electric. Lipo batteries are often used because of their ability to provide power with a relatively low weight and can dump LOTS of amps. As Colin pointed out 2 6volt batteries in parallel will provide 6 volts and cannot be tapped for 12v to obtain 12v the batteries need to be in series and 6 volts can be tapped off but will only provide the
    energy
    from one of the two batteries.
    3 years ago by Haverlock
    Response
    HMS BRAVE BORDERER
    Hi Rowen, Re Relays. The so called 'back emf' (reverse voltage) is caused when you switch off the relay. The magnetic field collapses and the
    energy
    is releases as a voltage spike with opposite polarity to the 'pull in' voltage. Since you are using an electronic switch this spike could damage the output transistor of the switch.๐Ÿ˜ก The diode is connected across the relay coil as a blocking diode, i.e. back to front wrt the operating voltage, and absorbs the spike. Each and any relay coil needs one! This is a manifestation of the induction effect which makes E-motors and generators work ๐Ÿ˜‰ Capacitors: Parallel!! An idea with the Y lead๐Ÿ‘ You'll lose the 'tank' steering assistance function though.๐Ÿ˜ฒ Happy experimenting, cheers, Doug ๐Ÿ˜Ž PS I use the same alarms, also good for testing batteries on the bench, and ESCs from the same Quicrun range (in my Sea Scout for example), reliable and simple to set up. Even simpler if you buy the little programming card for them. Only a few bucks and well worth it. I've been wondering if it's the response of your ESCs which causes your 'modulation' problem! Remind me; which ESCs are you using? PPS have a look here for an explanation of the suppression (flyback) diode and how to connect it ๐Ÿ˜Š https://www.wikiwand.com/en/Flyback_diode
    4 years ago by RNinMunich
    Forum
    All hooked up, nowt happens...
    You're as BAD as me Boaty ๐Ÿ˜‰ but I had a Rover 2000 with fully reclining seats back then - no problem ๐Ÿ˜ Re 3 wires on a brushless. Simply put, this is analogous to a 3 phase AC motor (such as used in bathroom extractor fans etc). If you apply a single phase AC voltage to an AC motor it just twitches backwards and forwards in the same place as the voltage crosses from the positive to the negative half cycle. Thus 3 phases are applied giving 3 'shoves' in sequence to keep things moving. A starter capacitor is also needed to give the motor a 'belt' to shove it off. Similarly with a brushless: the ESC senses where the motor armature is in relation to the magnet poles and applies a DC pulse to the next armature coil in sequence. When you shove the throttle up the pulse width lengthens applying a longer shove and thus more
    energy
    and speed. Pulling the throttle back with a reversible ESC just turns the pulse train upside down so that negative DC pulses are applied to the motor, reversing the magnetic field created in the armature and thus the rotation. Simple really. It's the sensing and timing done inside the ESC that's the tricky bit, which is why we had to wait about a hundred years from the invention of the AC motor (Nikolai Tesla) until we could use them in models - thanks to micro-electronics. Here endeth today's seminar ๐Ÿ˜๐Ÿ˜ Happy brushlessing Folks, cheers, Doug ๐Ÿ˜Ž Hmmm, perhaps that's why electric toothbrushes use brushed motors! ๐Ÿ˜๐Ÿ˜œ
    4 years ago by RNinMunich
    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' ๐Ÿ˜‰ 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 wrong๐Ÿค” 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 ๐Ÿ˜Ž
    4 years 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 them๐Ÿ˜ฒ 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 models๐Ÿ˜‰ 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.๐Ÿค” Cheers, Doug ๐Ÿ˜Ž
    4 years ago by RNinMunich
    Forum
    Spektrum, new, useless...
    Do you NEED insurance to fly a model airplane no. Should you have it YES. its not very long ago a teenager was killed in Dartford. https://www.telegraph.co.uk/news/uknews/1447013/Girl-14-killed-by-model-plane-after-near-misses.html You may take the position that this was a large(ish) model yours will be smaller. While I cannot locate a reff. I have a memory of a story relating to a child killed by a .049 powered model. This was many years ago. Your idea of a foamy probably being to light to do much harm sounds good until you consider how much mass it holds in ballast. Remember the
    energy
    of a moving object is given by 1/2 MV^2. if you have a flying site which is remote from other people and privately owned so there are no members of the public around then again your probably good to go. if however there are chances of other members of the public around then its foolish to take a risk which is not needed.
    4 years ago by Haverlock
    Forum
    1960S Taycol electric motor
    Hi CB, Re 'Faraday Cage: I see what you're getting at, of course you are correct that a sealed and grounded metal box would shield the surroundings from spark generated RFI. The 'box' would need to be 'hermetically and electrically sealed', not easy with prop shaft an' all. One hole is enough and Whoops, all those nasty waves have escaped๐Ÿ˜ก. But actually a Faraday Cage works the other way round! It's purpose is to protect people and 'things' inside the cage from outside influences such as high voltage discharge (e.g. lightning) or unwanted radio or other high
    energy
    waves by conducting them around the outer skin of the cage to ground. I sat in one during my years of development of mobile radio systems to try to make sure that my test measurements weren't being falsified by external influences. I also didn't want to ruin the tests and alignments my 'bods' were doing on the current production equipment just outside๐Ÿ˜‰ I also had the pleasure ๐Ÿค” about 30 years ago of standing inside one at the Deutsches Museum while about a million volts was fired at it! Hair raising๐Ÿ˜ฒ but I'm still here to tell the tale๐Ÿ˜Š and bore the pants off you all๐Ÿ˜ Happy suppressing all, cheers Doug ๐Ÿ˜Ž
    4 years ago by RNinMunich
    Forum
    1960S Taycol electric motor
    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 ๐Ÿ˜‰ 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 expected๐Ÿ˜Š 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 ๐Ÿ˜‰ most sets only use 16 or 32 of the 85 frequencies available in the band! ๐Ÿ˜ฒ 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 0.1ยตF across the terminals and 0.047ยตF 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 it๐Ÿค” 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 sources๐Ÿ˜ก Never mind wasting precious battery power as heat๐Ÿ˜ฒ 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 SPARKS๐Ÿ˜Š and no capacitors๐Ÿ˜Š Trick is in the bridge rectifier used to connect the motor to a standard brushed ESC. The diodes in the rectifier suppress the sparks๐Ÿ˜Š 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 sparks๐Ÿ˜ก Sorry Dave_M, I can't upload the ozone smell๐Ÿค” 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 ๐Ÿ˜ญ 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 ๐Ÿ˜Ž
    4 years ago by RNinMunich
    Forum
    lipo storage charge
    Hi Dave, I'm sorry too cos I didn't say you recommended anything! But you did state that 'something is wrong', which it clearly wasn't operating the unit in Storage Charge mode. Also 3.7V is only the nominal cell voltage. The recommended Storage voltage is 3.85V, as stated in the charger manual, and which is what the charger did. The objective is to limit the amount of stored
    energy
    which can cause havoc if anything unforeseen happens in storage, as well as to prolong the life of the battery. See also attached LiPo storage tips. http://uterc.org/files/LipoStorageTips.pdf http://www.bigrcmodels.com/RC-Helicopter-LiPo-Battery-Storage.asp https://www.propwashed.com/lipo-storage-voltage/ Just three samples of several which all state the storage voltage (SV) as 3.8 or 3.85V. The safety leaflets which came with my LiPos also said the same. Cheers Doug ๐Ÿ˜Ž
    5 years ago by RNinMunich
    Forum
    General sailing
    Hi Dave, after some 'electronic digging' I'm pretty sure you are right and the Conrad
    energy
    range of batts are probably made in Shenzen China by 'Better Power'. What isn't Made in China these days ๐Ÿ˜ฒ ๐Ÿ˜Ž
    5 years ago by RNinMunich
    Forum
    battery charging
    Hi Roy I can understand your conundrum. My work at one time involved gathering and presenting statistics. The difficult part was knowing what answer was expected. There are statistics and dammed lies and at the end of the day they are at best an indication, but should be taken with a pinch of salt. To try and shed some light: What charger were you using and was it calibrated and if so who by? Same goes for the recorder. Did you measure the temperature when charging and discharging. Looking at your chart I not sure I quite agree with your consumption calculation as the 2.55 amps was at best for no more than 40 mins. Batteries will waste
    energy
    in the form of heat and this explains why more
    energy
    is required to charge to the retained capacity. We did discuss the battery internal resistance earlier and this can have a real effect on the capacity and the batteries ability to deliver. Assuming your measuring equipment is correct then I believe the differences are likely to be due to temperature variations caused by the internal resistance. If when you charge your pack one cell is noticeably warmer than the rest of the pack it has a higher internal resistance. At one time you used to be able to buy race packs which had been formed from individual cells that had been matched. Cost a lot more but if you were racing with the pack they gave you the edge. Cheers Dave
    5 years ago by Dave M
    Forum
    What type of wire?
    Hmmm! Didn't think it was necessary to get into this as PTFE is practically the industry standard, except for special cables used in aerospace and naval shipbuilding (my direct background experience). All the recommended types most probably have PTFE insulation and all used stranded copper wire to improve current carrying capacity and reduce losses. I never had any sweat stripping PTFE, been using the tool in the photo for donkey's years with ease. Adjustable for all sizes we are likely to need; grip, twist and pull and you're done! In emergency I have also 'carefully' used small (sharp!) side cutters or the ubiquitous Swiss Army Knife - no problem. Can't recommend using varnished CW like that, not what it's meant for. As you say solenoids, transformers, not to mention inductances for various circuits (including the all pervading solar garden lights, ever wondered how they make a 2V LED work on a 1.2V NiMH? Oscillation and inductance!) and of course E Motors! I On the electrical side: A single wire like this will have less current carrying capacity and warm up more than a stranded wire of the same diameter. Skin effects and so on! the warmth is wasting
    energy
    you want in the motor. On the practical side: A messy and time consuming business, and what happens when you want / need to mod something? Tear the ship apart? Not surprised you have never done it! Don't even want to think about what happens if the wire gets hot inside an epoxy jacket ๐Ÿ˜ก Also, before your can solder it you have to burn off the varnish, which produces toxic smoke so you have to work outside (!) or in front of an extractor / filter, as I do. 'Every home should have one' ๐Ÿ˜‰ But I only use TCW or varnished CW for fixed links on circuit breadboards and test jigs. Or sometimes for detailing on models; railings, ladders, masts, scale antennas etc. Very good for the Yagi antennas of the first generation naval radars etc. ๐Ÿ‘ Hope this clarifies and helps the novices to cut the wheat from the chaff. Happy modelling ๐Ÿ˜Ž
    5 years ago by RNinMunich
    Response
    Aerokit Sea Scout 'Jessica' Renovation
    Evening Dave, many thanks for the response ๐Ÿ˜ŠI wasn't sure how my 'style' would come over! Martin thinks you created a monster ๐Ÿ˜ฒ monster fun for all I hope, maybe a breath of fresh air ?? "Tune in next week!" Many German forums are very stiff also nehm ich nicht teil (so I don't take part!). But my brand of humour always stood me in good stead during contract negotiations over the years. Often not so easy to convince the Admiral to spend his hard won millions on my system design, not to mention the yards who want to maximise their own margin. British humour went a long way to breaking the ice with navies and yards around the world. The Koreans and Chinese were the most difficult to bring round, after that Algeria, Oman and UAE were child's play. The navies of Chile, Ecuador and especially Brazil were; very professional (and good dinner parties)๐Ÿ‘, interesting! ๐Ÿค”, and a barrel of laughs ๐Ÿ‘๐Ÿ˜‰ in that order! Canada was good, but bl...y cold! ๐Ÿ˜ก French & italian yards had great lunches ๐Ÿ‘but small budgets (thumb down!)! But seriously though folks; you're right of course, the ancient caps are now useless and I have much better ones now, plus ferrite rings and inductors to choose from. Re voltage; the Taycol specs also give values for 12V running! I can use the Spektrum TX programming to limit the max volts to 12, also, when the Target is fully renovated I will first test it using my regulated PSU to find our where the limits are. Non-destructive I hope. Theoretically the motor will only take what it wants, never mind what the LiPo can provide if asked. I will also use my new Watt-meter; a tip I got here from you guys. ๐Ÿ‘ Many thanks for that. Re sparks; thought I might try to see the
    energy
    spectrum on my 1G/S digital scope, most
    energy
    should be in the VLF-HF band and tail off considerably above VHF so an indication may be possible. Might be able to rig up some sort of rev counter using it's frequency meter?? Worth a try ๐Ÿ˜‰ After several years concentrating on gallivanting round the world I have some catching up to do! You guys have sure accelerated that. Muchas gracias y muito obrigado! I've learned a lot the last 3 months and I think I can give a lot back. Looking forward to it ๐Ÿ˜Ž Haven't used the 35Meg set for years, found it this week while looking for something else, as usual. Maybe I'll resurrect it for the flying boat?? It was replaced long ago with the Graupner MC-10. Latest set is the Spektrum DX6. Still learning how to modify or cancel all the fixed-wing and heli pre-programming I don't need. ๐Ÿค” @ John; thanks for the friendly response ๐Ÿ‘ There was an ESC in her with the Decaperm while Jessie was using her, massive alu box thing with a big ol' 2055 sitting in a heat sink on top! Did several years good service in HMS Hotspur and still works, I think! Glad to revive some hopefully happy memories. idea for a new topic perhaps- "Against the stream - Recycling the hard earned technologies of our youth!" ๐Ÿ˜‰ Happy modelling, or better "Sailing" ๐Ÿ˜Ž Gute nacht aus Mรผnchen ๐Ÿ˜‰ PPS @ Dave (and / or other administrators): WE NEED MORE EMOTICONS OR EMOJIS AS YOU CALL THEM! Check your dumb-phones!
    5 years ago by RNinMunich
    Forum
    Soldering suppressors to motor
    Hi Dave, sensible answer ๐Ÿ‘ A Footnote ? Sparks are essentially broadband but most of the
    energy
    is in the HF & VHF bands and tails off significantly above the UHF band >500MHz. However, since the
    energy
    is proportional to the arc current(spark) and this rises with the applied voltage causing it your comments re fast electrics using higher voltages is entirely relevant. Also any close neighbours still using 27, 35 or 40 Megs will not be too chuffed, especially the fliers ๐Ÿค” Cheers Doug ๐Ÿ˜Ž
    5 years ago by RNinMunich
    Forum
    Li-Poly batteries
    pmdevlin Sorry to confuse and you are right in what you say. What I was trying to point out was the relationship between
    energy
    storage and power availability. A big battery will usually have a greater
    energy
    storage capacity and depending on its design a greater power output but this is not always the case. As I would imagine the construction and manufacture of LiPo's is a bit of a " Black Art " as was the manufacture of many lead acid batteries and the likes of Boeing and Samsung have found out at great cost to themselves, if anyone has done any controlled tests on batteries used by the likes of our members it would be useful.
    5 years ago by nasraf
    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?
    5 years ago by nasraf
    Forum
    Website upgrade coming soon!
    Having dabbled with building websites, many many moons ago, I can appreciate the work that goes into projects like this. We're blessed to have someone with the talents and
    energy
    you have Stephen looking after us. Excellent work, well done and thank you.
    6 years ago by smiggy
    Forum
    Puffy lipos
    HI All I agree with all the advice given. The web link is to a useful article. The only issue I have is his thoughts on charging unattended, especially as it is in his house. All the warning devices he has will not prevent the event only tell him after it has happened. The destruction is of a chain reaction type in that once started all the
    energy
    in the battery is dissipated almost instantly. Fires are usually caused by the red hot bits of metal ejected causing nearby flamable items to ignite, so the charging bags are very useful in preventing this happening. The other by product is a copious amount of white/grey smoke that you really don't want in your house. If you are doing other jobs then stay close and charge on a fireproof surface with any easy and quick access to a door or window. Even if you follow the basics regarding max charge voltage and min discharge voltage the cells can become puffy. it would appear that the technology is very stable at 3.7v per cell, which is why 3 cells are sold as 11.1v, but become less stable and prone to internal chemical changes at higher or lower voltages. I used to charge my batteries ready for next use so they were often stored in a charged state. As a result over time some became puffy and were discarded. The advice given in the article is correct but it perhaps needs emphasizing as it is an important parameter to keep batteries safe. Fully discharged batteries are safe to dispose locally and contain no harmful chemicals. Do check that it is permitted to use your local disposal point. Dave
    7 years ago by Dave M
    Forum
    Wiring query
    going with the dpdt switch makes most sense what current are you intending to run? You need to get a switch rated at the intended current x2 giving 100% over current capability as a minimum. I know this seems excessive BUT some is good more is better. Your switch contacts themselves will act as a resistor and heat up. To low a current rating on the switch will result in
    energy
    being wasted in the switch and ultimately a failure. When not in use throw the switch to charging position that way the ESC is disconnected while not in use.
    7 years ago by Haverlock
    Forum
    Midhurst Modellers Exhibition
    Hey Thanks for such a quick reply, I haven't a clue if anybody from Basingstoke are coming, I am not a member, but hopefully myself & a friend will be coming. At the moment I am building a German e Boat: S1 At present I am busy looking for parts to go on the boat & same time my friend is building a Battle class Destroyer & I think he's looking for parts too, is there going to be anyone selling parts for boats? Thank you so much for your time, patience &
    energy
    used Damon ๐Ÿ˜€
    8 years ago by Damon
    Forum
    Dangers of charging LIPOS
    HI Olly Sorry to hear this tale of woe. LiPo's are very high
    energy
    batteries and any misuse can and does lead to dramatic failure as you have found to your cost. I totally agree with your last sentence and offer this advice to all model boat members There are dedicated chargers and cell balancers that allow safe charging but you should always be present for the whole of the charge time to stop the charge should the battery overheat or start to swell. Disconnect the battery once the charge has completed. Battery bags also provide a safe charging medium should you experience any problems. It is a good idea to charge near to an easy exit and away from any flammable material, so the battery can be removed to an outside safe area.. Any batteries that swell have suffered some internal damage and personally I never re-use such batteries as they may fail in a model and I value my models. It is Important to balance the individual cells in a pack between charges. Many chargers give a balanced charge so will protect your battery, but standalone balancers are available. Heat can alter the charge rate so charging should only be commenced when the battery has reached room temperature. Thankfully no one was hurt in this instance, but we all need to be aware and take care.
    8 years ago by Dave M
    Forum
    Smoke Generator
    Cheapest way and one ofthe most efficient is to use a 'Mist Generator' rather than smoke. Uses far less
    energy
    to power as you are not heating an electric element. I have made one recently for my trawler and it works a treat. The only setback is they need 24 volts , I have used 2 lipos in series. The Mist Generators are very cheap, I bought 4 from Hongkong for about ยฃ12 incl.p&p. They need about 12mm of water above them, too much and they will not work, if the water gets too low they have a clever cut off. Use distilled water not tap. I made mine using a CLEAR plastic container with a full plastic screw lid about 4" diam and 4" deep, make it deeper if you have the space reasons coming up! Use a tube for ducting the mist up the funnel, I used a 22mm piece of overflow plumbing pipe. Make a hole in the lid to accept the pipe, a tightish fit allows for easy adjustment up and down. Also in the lid you need to fit a small fan to encourage the mist up the pipe so keep the hole for the mist pipe to one edge of the lid and the fan hole opposite. I used a fan from a defunct 320 amp speed controller and powered is from 3 x aa batteries. You need to fit a plate just under the hole for the fan to prevent any water spitting up into the fan electronics, obviously the deeper the container the lest chance of this happening. Before going any further you need to calculate the length of 22mm pipe needed so site the unit in position in the hull so pipe lines up under the funnel, now measure distance between the bottom of the container and just short of the top of the funnel. From this dimension deduct the height of the Mist Generator (MG) as this will be mounted on the base of the pipe. Measure the inside height of the container and deduct the height of the MG less about 5mm, mark this distance up the pipe and another about 5mm from the bottom of the pipe where the MG will fit. Between these 2 marks cut 2 slots, top to bottom as wide as possible leaving just 2 small strips of plastic again about 5mm wide each. The 2 slots allow the air flow from the fan to go up the pipe and allow water onto the top of the MG that now needs to be attached to the bottom of the pipe, I used a couple of elastic bands through the slots. A further hole needs to be made in the lid to take a grommet to accept the electric wires from the MG unit. Screw the lid assembly into the container and push the pipe down so the MG is just shy of the container base. Fit the whole unit back into the hull, use a funnel to pour some water into the unit covering the MG by about 12mm, connect the power, switch on the fan and away you go. Hope this helps.
    8 years ago by HoweGY177
    Forum
    Voltage Reduction
    HI John I must admit I have bought motors designed for power tools but only used in Tugs and slow moving craft. They are quite torky but some are also rather heavy on current. If you are getting heat problems it is because the motor is overloaded and not running at peak efficiency. Your ESC is getting hot because of the high current drawn. Using lower voltage motors with a higher supply voltage is not advisable for any length of time and will more than likely burn out the brushes or even the motor coils. I know the racing fraternity favour high voltages but they water cool everything and use special motors. With your Perkassa I assume you wish to sail with a nice plane and to achieve that will you need a good high rev motor. The position of your battery and ballast will have a marked effect on the sailing performance - too far forward and you waste
    energy
    lifting the boat out of the water to achieve a plane. The other Important bits are the shaft drive and prop. The shaft should turn freely with no high spots and be dead straight. Couplings and motor need to be correctly aligned so they are dead in line. Finally the prop must be of a suitable size and pitch for the motor. Adding a larger prop or increasing the pitch will increase the current drawn. A smaller lesser pitched prop will allow the motor to run faster (and cooler) and your model will also go faster. I'm guessing you are using a racing type prop on your model and this may be the cause of your overheating. A good 3 blade brass prop will work much better but you still have to pick a size and pitch to suit the motor. Hope this helps ๐Ÿ˜€
    9 years ago by Dave M
    Forum
    Confused about motors? Thats me then.
    HI Crowie, Welcome to the website ๐Ÿ˜Š There is a small section on the website that gives you the basics. You can find it here: http://model-boats.com/rc/motors In general: - Power can be determined in two ways, speed and torque. Speed is simply the RPM (Rotations Per Minute) and torque is like the strength of those rotations. in boat terms, does it need to turn a big propellor or a small one. - Watts is the amount of
    energy
    it requires. and is a calculation based on the voltage and the amps. Voltage and Amps I usually like to give my water tank example on: Voltage you can think of as being the height of the water in a tank, the higher the water the more pressure at the bottom. Amps is the width of the tank, so how long that pressure will last for before it runs out. - Brushless & Brushed are types of motors explained in the example link above. Any other specific questions and I'll do my best to answer! ๐Ÿ˜Ž Stephen
    9 years ago by Fireboat
    Response
    Lesro Rapier
    HI Ian Glad to hear you have solved your noise at speed problem. Any misalignment in the drive system wastes
    energy
    and can lead to premature failure of the system. At least you have now checked everything so I hope you are more than satisfied with the result. ๐Ÿ˜€
    10 years ago by Dave M
    Response
    Lesro Rapier
    I thought Dave and Alan might be interested to know I have just installed a ModelBoatsBits coupling on my Sportsman and the difference on the bench is remarkable. The current draw is also less- I suppose the noise being made by the Huco coupling has to represent an unwanted expenditure of
    energy
    . Anyway- good result,thanks! By the way Dave I checked the shaft- straight as a die, so it was just the coupling. Ian
    10 years ago by ianed57
    Response
    Plating of hull commences
    HI Dave it was a bit of a glib comment and on more considered thought, you will have no problems with
    energy
    capacity from a battery of the size you are fitting, which I think would be about 60 AH at 12 volts. Your idea on lighting port holes, I think I will incorporate in the Coromandel as I expect it to spend virtually all its time on the wall and not in water. The Coromandel must have been lit with oil lamps ( due to its age ) so it may be better to use filament lamps on a low voltage to get a more realistic colour. With kind regards nasraf
    11 years ago by nasraf
    Forum
    Brush-Less Motor ESC/Data-logger
    HI John Do you have any details to use these motors in a model boat? The data sheet is aimed at model planes. I see that the max efficiency current is variable between 30 - 60 amps and wonder if you have used the amp/wattmeter to take any measurements. is it possible that at lower speeds the wattage may exceed the esc/battery capacity with much wasted
    energy
    converted to heat. I have just ordered a wattmeter from GiantCod here in the UK and intend to check my brushless set up following an incident (thankfully not serious) with a LiPo. Hence my interest in any data you may be able to share. Dave
    12 years ago by Dave M
    Forum
    Need Advice On Robbe Dusseldorf Fireboat
    battery capacity all depends on what cruising speeds you get up to on the water. I have a single 12v 10 amp/hr battery on mine and with a 50/50 split between steady cruising and some full throttle high speed emergency calls, my battery lasts about 1.5 hrs. I split this in to 3 seperate on water jobs, purely to let the motors cool off between spells on the water, especially on high speed stuff, the motors do get a little warm, even with cooling fans switched on! I did not want to get involved with cooling coils, having 1 water pipe feed coming in through the hull is more than enough, let alone installing more for coils too. I do have a pair of 6v batteries I use as backup if I want to stay at the pool longer, but find they dont have as much capacity, even though they are 6v 10 amp/hr units themselves, they dont last as long on the water. When you do get to the stage of ballasting your boat, make sure all the electrics AND drive servos are in and working, then just try with moving the batteries around first, as you may not need anything "other" than the batteries. I only use the batteries as ballast in mine, as why not use the ballast as an
    energy
    source, rather than dead weight by lumps of inaminate zinc [or worst case - lead].
    12 years ago by Gregg
    Forum
    Brushless Motors
    The whole point of using Hall Effect sensor is to control low-speed scale speeds.This is why they are used for rock crawlers.They operate from zero speed on without stumbling or cogging.ALSO brushless inrunner motors stay cool while running because the windings are next to the motor housing.I'm using a 6.6 volt LiFePo battery pack and get hours of usage.To generalise brushless motors in one group is like saying that all motor designs are the same.A low kv outrunner motor will work perfectly with a correct non Halls Effect ecs ( Castle Creations) , providing the kv and torque rating matches the prop size.This is the most Important match that is seldom considered when using brushless motors.I like inrunners for their durability,cool running,powerful torque,direct drive capability and
    energy
    efficiency. Some of the newer generation brushless motors/esc combos have pc connectivity for precisicely programming the low/high speed adjustments,instant braking and reverse adjustments. I'm using an 8.5KW brushless motor used in full-scale boat propulsion drives.It uses a Halls Effect sensor esc and it has excellent low speed control.I use this motor on my custom built drill press that requires precise control for a combination drill/tap bit. There are many rc boat builders using brushless motors for low-speed scale use all over the world and will eventually become the norm,especially when the prices are dropping substantually as we speak.I have no investment in these BL motors other than my own use. Regards, John Regards, John
    12 years ago by sunworksco
    Forum
    Gannet 15cc engine
    Hello from the colony. Well sparkie engines were my delight 1. The sparkie donks , need good cooling and very much so as they are hotter fueled petrol, but you need to have good large water pipes to enable a high rate of 'heat transfer ' in the water rate flow from the head or a large sized water cooling pipe diameter (say 1/4 inch to 3/8 inch pipe dia) from the pick up and through the model to exit . The principle is actually not to cool off the combustion running temperature of the cylinder but rather to allow for the departure of 'excess heat' from the combustion temperature. So many 'over cool' the engines rather than allow for normal operating temperature ' to continue. Hence engines are fiddled with in the Winter cold having so called poor performance when if allowed to operate at normal temperature they are then so reliable. Similar when in warmer water they need the excess above operating temperature heat to be dispelled. As best Illustrated in air cooled motor mower engines which rely upon the effective excess heat dissipation above that of normal combustion operation. 2. A good quality motor oil is essential and we used basic 'standard '/ 'neat' petrol in those days , probably low octane car unleaded is the equivalent today, however do not go for the ethanol additive fuel sold these days for motor cars as I think it is not suitable as it is a cocktail blend when the old motor pump fuels were more straight petrols without the chemical additives of todays engined fuels.3.Using nicads or nickel hydrides (?) not sure on actual chemical name for Ignition is great these days as they have more kick and do use a auxillairy pair of batteries for booster when starting as to not drain onboard battery supply to the coil. 4. Keep spark plug very clean and try to have a small paper type pad to insert between the points to 'dry" away excess oil to help spark jump across points. As it is the spark which is the only excuse for not too ready starts. 5.Sparkies should be easy to start these days with transistorised Ignition circuits and better current/ oomphah batteries and are easy on fuel gulping as very economical.6. But sometimes they can be a bit noisy but generally a good big 2''/3" daimeter muffler box/pipe say 3 to 4 inches long helps with noise dissipation. The exhaust
    energy
    is best dissipated with large rates of expansion in a large chamber then the following contraction into the exhaust pipe say 1/2 inch outlet to air and noise
    energy
    is thus lessened, good for all stable running boats but not too much approved by the high speed types who want Mach 1 performance horses and tuned exhausts etc. 7. Also the large capacity Sparkies ( not sure about the smaller capacity sparkies) can throw a heavy flywheel as low down power / grunt on less revs , hence can take a very large daI prop with a big pitch as steam boat props tend to do. 8. Remember it is not a high revving glo at 14,000 to 23,000 and more revs, but a nice high power for its day of latter day design and machining tollerances and mettalurgy. See ya from the colony. Lyle.
    13 years ago by Lyle
    Forum
    Wiring Issues
    There is a good site that gives information on battery performance in a relatively simple form. This is " mpoweruk.com " under Electrical
    energy
    Storage/Battery Performance, it is worth looking at.
    13 years ago by nasraf
    Directory
    Fire Boat
    My Model is some 20 to 25 or more years young & wore out two .35 glo motors over the years & only has a 1/8 inch only steel, drive shaft which I recently replaced & always used a leather washer (no metal noise) between the drive plates as modelled from the old 'Taplin Twin' type (never torn) & I updated to a SC .40 Glo motor not for speed but just as a plodder, hand starts with chord are easy & if you use electric starter loosen the glow plug in the thread when starting and it WILL fire & run at idle & disconnect glo lead and screw in plug and take to water etc. MY model actually weighs some 20 to 22 pounds.(I could not delete the 176 ounces in the table above) & exhausts from the factory muffler into a tin can resonator & is super quiet out the stern & no nitro & water pipe is wrapped around muffler which in cooling takes away noise
    energy
    . Lyle (Motor: Sc .40 r/c & I/C motor (quiet)) (ESC: Sanwa) (10/10)
    14 years ago by Lyle
    Media
    More Crash boating In OZ and OFFICIAL TRANSPORTER
    Of all the data files on the Crash Boat I have not ever seen any details/ drwgs for the vehicle specifically used to transport the Crash Boat types ( Ie the British Power Boat co ) had transporters for their craft. Anyway I enclose a picture of the OFFICIAL English designed TRANSPORTER vehicle for the Crash Boat and a photo of verification as modelled by Peter Dimberline. I have kept my model stock standard, still have the original plastic red Graupener prop of old I think it is a 30 with a nick or two. Soft copper brake tubing pipe (1/8 I/d) is only around the head and one of the inline exhaust resonators has a water tube outer casing to cool the exhaust piping and inner tube gas temperature which takes out the
    energy
    /heat of the exhaust gas and dramatically reduces noise. Hope my hints help .All the best Lyle.
    14 years ago by Lyle


    About This Website
    Terms of Service
    Privacy Policy
    Cookies used in this website are gluten free, wheat free and dairy free. By using this website you agree to our use of cookies. More Info