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>> Home > Tags > volts

The wheelhouse navigation light. by mturpin013 Fleet Admiral!   Posted: 3 days ago
This is a small item but very visible on the wheelhouse and since the standard for this item has been set I have to follow suit. So first of all get some 3mm blue LEDs ordered and then it’s on with preparing the white metal body. I used by hand as suggested a series of drills increasing in diameter until 3.1 dia was reached but only 2/3 down the length from the front the smaller hole (1.5mm) was bored right through for the wires to exit. Arrival of the LEDs, first check the LED using my power supply, just over 3 volts seems to illuminate to the correct level. Next was to remove the shoulder on its plastic casing so the whole body does not exceed 3mm over its length and lightly abrade the outside to give a diffused light. Next cut the LED legs to 2mm from the plastic casing noting which is positive, next prepare the wires. I used Futaba servo wire cable 22awg which is very flexible and with the white signal wire stripped off leaving a red and black wire. These were tinned and cropped to 2mm and then quickly soldered to the appropriate terminal. Next check the LED still works! first hurdle over, I now needed to check the that when the LED goes into the body it doesn’t short out so checking the diameter over the widest part which is over the soldered terminals this was 0.1 below 3mm. I decided that shrink sleeve was too thick so I mixed some epoxy resin and coated all around the terminals, this proved to be satisfactory in both non-conductivity and dimensionally. Now the final test, using some aliphatic wood glue I slid the LED into the body whilst it was illuminated as it was a tight push fit, bingo it’s still lit – leave to set. I used aliphatic glue, as it would be easier to remove should I ever have to change the LED. The body still needs painting white but this will be done with all the other fittings at a later stage.

Equipment wire by b111yboy71 Seaman   Posted: 13 days ago
Hello, try looking for old 25way data cables at your local car boot sale. The cores are multi-coloured and very thin. Most LEDs only use a breath of current to drive them so you won't start a fire! Here's a tip about dropper resistors for LEDs: put them at the power supply end where you can tie them down securely. Also, the formula for finding the resistance you need is: R equals Volts(supply) minus Volts needed by LED (Vf) divided by the required LED current (If). So, say 12V supply, 2V LED wanting 15mA = 12-2=10/.015 = 666.667, so you'd use the nearest value above, which would be 680ohms. Easy! The size of the resistor in watts/milliwatts is found by I(current) times E(volts), so 10X.015=.15W, or 150mW. Hope I'm not teaching an old sea dog new tricks! Starting a new Firefloat - oh boy.😲

Brushless motors (again) by Haverlock Fleet Admiral!   Posted: 18 days ago
depending upon the type of motor cooling it can be a problem. Most brushless motors are out runners so the case rotates! In runners are usually for higher speed applications (or driving a gearbox). If you have an idea as to the size of IC engine the boat was intended to have then this list may be a help .049 or .051 = 100 watts 0.10 = 200 watts 0.15 = 300 watts 0.25 = 500 watts 0.32 = 640 watts 0.40 = 800 watts 0.45 = 900 watts 0.51 = 1020 watts 0.61 = 1220 watts 0.75 = 1500 watts 0.91 = 1820 watts Since Watts are Volts * Amps ( I know this is not accurate for a reactive load like an electric motor but its a rule of thumb) This gives you a ball park next point is the KV ( revs per volt) of a motor. The higher the KV the smaller the prop. Finally buy a Watt meter they are not expensive and give you a chance to " fine tune" a setup. Car ESCs ( usually) have a reverse function while the airplane versions do not. They are generally cheaper than boat specific ESCs.

Voltage increasing via regulator by RNinMunich Fleet Admiral!   Posted: 27 days ago
OK, Understood, I think! If you just want to boost the bow thruster why don't you just fit a small 12V (or 11.1V LiPo) just for that? Frankly I might start with an 9.6V batt before I jump from 7.2 to 12V. I assume it's just either On or OFF, i.e. no ESC. As you can see from the specs of your Booster, as the output volts increase the deliverable current (for a given input volts) decreases inversely, as I predicted! Ya don't get summat for nuttin! Soooo, you need to carefully check the specs of the thruster motor; max voltage, current at maximum efficiency versus volts applied! That will tell you the max volts battery that you can safely and most efficiently use, and you can check if your booster can deliver the required current at the voltage needed. I'd just use a separate battery and a servo operated micro switch, but then I'm just a dumb engineer!😲 Bon chance mon ami👍 Cheers, Doug 😎

Voltage increasing via regulator by RNinMunich Fleet Admiral!   Posted: 27 days ago
A somewhat confused question if I may say so Eric!😲 You can't 'regulate up' only down. The regulator's job is to produce a constant lower voltage from a range of higher voltages. I often use one to produce 5V for the RX and servos from a 12V SLA drive battery. A little 3 legged device (type LM7805) which looks just like the power FETs in a high current ESC. My version of a UBEC! 😉 What is this 'regulator' you have? Type number? Manufacturer? Photo? To get 12V from 7.2V you would need to use a Voltage converter (also known as an inverter). This works by converting the DC input from the battery to an AC voltage which can then be increased using a transformer. More elegant (and expensive!) versions use a transistor oscillator and amplifier. This uses hi-power transistors instead of the transformer. The AC output of the transformer (or amplifier) is then rectified back to DC. All this is very inefficient which is why it is normally only used for very light currents, where the losses are not so significant, and when there is no other alternative, not often the case! You can't beat the physics and you will never get the same power out that you put in. This leads to a basic design question:- What is the total current consumption of the load? I.e. the motors. A simple example:- Let's say that at 7.2V the motors draw 10Amps total, i.e. 72W (or VAmps). Assuming a utopian 100% efficiency at 12V this would equate to 6A. Due to the three stages of conversion; DC to AC, transformation / amplification of AC to 12V, AC back to DC, you'll probably be lucky to get an efficiency of around 60% to 70%. Thus if you stick 720W in you'll get around 430 to 504W out. Not much of a gain is it!🤔 Your battery would be exhausted in about 2/3 the time it is now 😡 If your motors draw more than 10A the problem just gets worse. So what is it you really want to do? If you just want to up the volts to your motors stick a 12V SLA or an 11.1V LiPo (3S) in and hope that you don't cook your motors! Frankly I don't really know why you're bothering, tugs aren't sprinters! If you want more pulling power with the existing setup try experimenting with prop sizes and pitch. Will probably achieve much more than fiddlin' about with voltage converters. BTW: All this assumes that the RX has it's own separate 5V battery supply or from a BEC in the ESC. Some clarification needed from your side. Cheers, Doug 😎

Margaret's health by onetenor Fleet Admiral!   Posted: 30 days ago
Thanks Doug but can't see a current rating. Just volts in and out. I thought about 10 Ohms but your numbers are right . Is 5 amps a bit high. It's only for up to 4 Nimh AA cells after all or are you playing safe? Sorry I don't know how I missed previous answers. A similar one shows 400 Mah. |But thinking back I think the original was 7.2 v @w250 Mah. I only think though.

Old outboard motor... by Westquay Fleet Admiral!   Posted: 1 month ago
Hi Doug, I do have a Hobbyking CNC ally one and now have a brushless inrunner for it. I got it when they were very cheap a while back. Wouldn't pay what they now want for them and Graupner are always way overpriced. I could be tempted with 7 quid for a Hobbies one though, just to see how it goes together. The K&O are gorgeous but collector money and the Alterscale are dummies, albeit nice dummies and also bloody expensive. I sliced the little vintage jobby I bought down the joint line with a fine saw blade in the minidrill today and all is well. It just needs new wires and some grease when I can find some good styrene/nylon grease. The motor is a two magnet Kako, many examples of which I have in store. Even has a nice little built in switch. I reckon 3 volts is probably all the transmission can take. The gears are not, as I assumed bevels, but 2 spur gears! I now have to find a way of making the prop shaft stay on the motor shaft! I'm loving this restoration stuff. Painted the red on my Star yacht today with my best chisel headed sable and got a special 1/4 litre of the emerald green mixed in HMG enamel (the very best there is). Tried to win a lovely Starlet off ebay, but some sod beat me to it last minute. I hope it leaks Martin

Mtronics and Lipo's by RNinMunich Fleet Admiral!   Posted: 1 month ago
Basically ads is correct, but that's only half the story! The clue is to look for 'LiPo Safe' when buying ESCs. That tells you it has a programmable Cut Off voltage setting to prevent damage to your battery. Default is usually 3.2V per cell. Absolute minimum is 3.0V. Below that you risk irreversible damage to the battery due to chemical changes that can't be reversed. The alternative is to fit a battery monitor which can trigger an audio and/or visual alarm to warn you to 'make nearest port best speed' before your battery is deep discharged, from which it will not recover! Some ESCs have a programmable function which allows to preset a reduction of the max power to the motor (instead of a total shut down) to give you the chance to get home before disaster. PLEASE don't ask me which ones. Check the specs carefully before you buy. Many current TX/RX sets will tell you on the TX display when the battery volts are low. Cheers, Doug 😎

Cygnus GM32 by canabus Fleet Admiral!   Posted: 1 month ago
Hi Cygnus GM32 I am using these Hobbyking ones Links to setup the ESC on Lipo and Niamh. I have used them on 12 volts , but, they will not work on 6 volts. You can crash straight from forward into reverse !!! Running a 70mm 3blade on one Hellen fishing boat (weight 14 pounds) and a 60mm brass 3 blade on the other Hellen.

solar by lesliebreame Admiral   Posted: 2 months ago
Members might like to view my experimental solar powered "BOAT " More like an aircraft carrier !! No batteries carried even for the radio. Brushless motor running from 24 cells giving 12volts. Slightest shadow will stop it.The panel i made myself by buying individual solar cells from Ebay and soldering them up.The cells are sandwiched between glass which makes it quite heavy and next project will have no glass but the cells are VERY fragile.

EarlyVosper M.T.B by Simplas by RNinMunich Fleet Admiral!   Posted: 2 months ago
"Maybe but ballast ,is ballast,is ballast. However it's achieved." Sure John, but at least a heavy battery is useful load and not 'just' ballast.😉 Have no idea what shaft power the Fuji produces (only know their excellent 35mm film😉) but the Taycol Supermarine is rated at 22.5mHP (22.5/1000HP) at 3.5A, 4000rpm. Efficiency 52% 🤔 so you have to stick twice as much electrical power in to achieve that! Sooo, given that 1HP = 745.7 Watts - And electrically P=IxV (Current x Volts) 22.5/1000HP = (745.7*22.5)/1000 = 16.778W so ~33.55W in. Thus if I = 3.5A they must have done that test / measurement at about 9.6V. The Supermarine also runs great at 12V but maybe not with max efficiency!? With a spec weight of 2&1/2 lb i don't even want to get into Power to Weight Ratio, although I measured Colin's motor at 947gm = 2.0877776229lb 😉 But then, some of the motor had corroded away As I'm currently renovating a Supermarine for Colin H. This makes me start thinking about rigging up a test jig so I can see what it actually produces!!! Always up for a challenge 😁 Got nowt else to do 😁😁 Would be useful for other motors as well if I can get it figured out😉 Happy fiddlin' folks, cheers, Doug 😎

S.H.Grainger Formula Powerboat by vortex Sub-Lieutenant   Posted: 2 months ago
Hi Steve im not sure now regarding motors as they have water cooling cans on but Surfury runs from memory a 1075kva motor Turnigy 160 A speedo watercooled on 2x2s 5200 lipo`s in series ie 14.4volts with 52mm mocom Alum prop approx 3hp. I think the Tornado has approx 2045kva motor same speedo + lipo`s x 50mm nylon prop both do scale speed to as fast as 40/61 IC and look great on our choppy water with just prop and rudder in the water. Both motors will take 6s if you like ballistic? All gear from Hobby king. Try the IC first, post some pics please

Robbe Paloma by chippy Sub-Lieutenant   Posted: 2 months ago
Just wondering if anyone's got any experience of building one of these boats. I've managed to get one brand new in the box. Wondering if 2 x 555 motors will be enough for it running on 11.4 Volts. Any information gratefully received. Regards Mike.

LiPo batteries by MouldBuilder Captain   Posted: 3 months ago
Hi Doug and all. Delay in answering your post as for some reason, my phone was useless on the internet. I did not see your post about checking the capacity percentage until I returned home, so that is why in April my checks were not complete. On my return to Hungary a couple of weeks ago, I checked the batteries and they were both at 3.85 volts per cell and at 51% capacity. When they were new, they were at 31% capacity. My new smaller batteries were also at 30% capacity and when I left on a storage charge, they are also at around 50%. The new, lighter 4S batteries are 1800mAh. On the first full charge they only gave me 89% capacity. I used them both, unfortunately they lasted about 6 minutes each, and recharged. This time they charged to 99% and lasted 10 minutes. Hopefully they get a little better after a few uses. I am now back in England and when I left, all of the batteries were at around 3.86 volts per cell an 50% capacity. I will check again at Christmas but I will have to see if the Danube freezes to see if I can use the boats then or not.😉

Graupner Jumbo 540 motors by Will-I-Am Sub-Lieutenant   Posted: 3 months ago
Doug, The 6volt battery is currently an NiMh battery not an SLA. The problem was that according to Mtroniks the minimum voltage to the ESC to adequately run the BEC connection is 6volts. That is why I was getting erratic control when the battery voltage was 5.6 volts. The action speed controller will work 2-12 volts and I am going to use a separate receiver battery as suggested by Dave Milbourn just to make sure. Regards Will