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>> Home > Tags > volts

Too Powerful Brushless ? by Traiderman Sub-Lieutenant   Posted: 7 days ago
Hi all, what do we all think of the Graupner 500 ECO? it only does 7500 rpm but high torque, about 1500 watts, 14.8 volts. The say it is especially built for boats. I would like to know your thoughts on the small outrunner motor? Regards Graham

Too Powerful Brushless ? by RNinMunich Fleet Admiral!   Posted: 12 days ago
"The max current is the Max Watts divided by the Battery Voltage." Hmmm! Dave, I=P/V works fine for DC and static resistances but it gets much more complex in a dynamic system like an AC motor, which is all a Brushless is. Don't want to get into rms and power factor and co here so I agree the wattmeter is the way to go to find out what's really happening. Normally (at least here, not so sure with China!!) the max power output is quoted at nominal voltage and max efficiency. If you (can!) trace the motors back to the original manufacturer they publish performance graphs showing efficiency, power vs current and volts. But who does that? Except nuts like me😉 According to the DC formula the ECO 600 would draw 131A at 11 Volts or 97A at nominal 14.8V. The real 'Black art' is then to work out what power you want/need for how much thrust, acceleration and top speed for a given boat and hull type🤔 Best way is to ask those who've 'Been there, done that'. That's why I appreciated very much Canabus' advice when I was looking for a brushless for my Sea Scout upgrade👍 Happy sailing all - Whatever pushes your boat! Doug

Too Powerful Brushless ? by canabus Admiral   Posted: 12 days ago
Hi I found this PDF on Graupner motors. Also the Hobbyking site shows the specs on a large number of their brushless motors. I am looking at replacements for two Graupner speed 600 7.2 volts for a mate. I found a D3530/8 1700kv on Banggood with the same 5mm shaft and more grunt, less weight(74 grams against 192 grams)and about a third the price!!! I am going to install one in a Sea Commander(34") with a smaller 2 blade 32mm CNC prop on 3S Lipo 3300mah to test it out. Canabus

Too Powerful Brushless ? by RNinMunich Fleet Admiral!   Posted: 12 days ago
Mon plaisir Haig, that's what we're all here for - ain' it? 😉 Happy sailing, Doug 😎 BTW: that's one thing I really like about the German suppliers, most of them give much more info in their on-line specs. Funny; for years at work here I used to moan that our marketing dept. worried more about dB's and microvolts than about what the customer could actually do with the bl..dy box! 🤔 I used to rewrite the system specs My Way (thanks Frank!!😉) so the Admiral knew why he was spending his hard fought for budget!

Too Powerful Brushless ? by rmwall107 Lieutenant   Posted: 15 days ago
Hi traiderman I am no expert. dont forget, as pmdent highlights, you you multiply the KV by the volts of the supply to get the RPM of the prop. so you can play with the volts supplied or the Kv of the motor or both. regarding the vibration, have you supported the outer end of the shaft? if the shaft leaves the hull and has a good amount of unsupported shaft the end of the shaft effectively will scribe a circle. At the speed the shaft is turning and with the pressure on the prop this may cause your vibration. Richard

LiPo Battery Monitor by Dave M Fleet Admiral!   Posted: 16 days ago
Hi Bill Doug has shown a battery checker and alarm. You can get battery checkers see If you are going down the LiPo route I suggest you make sure the ESC you buy has a built in circuit which reduces the current should the battery volts drop below the set voltage (3.3v is common). In my experience the alarms although they work well are not loud enough to be heard, if your model is not near, and they do not cut or reduce the current, leaving your battery at risk of over discharging. Good luck with your model

M Sonic microprocessor ESC. by Colin H. Fleet Admiral!   Posted: 29 days ago
Thanks Dave, will probably be using 6 volts, as the boat its for only has a motor rated at 1.5 to 6.0 volts which is from the late 1950's and is the original motor that my granddad fitted when it was built. It was originally a free sailed but I hope to add rc. Its the small one in the picture.

M Sonic microprocessor ESC. by Dave M Fleet Admiral!   Posted: 29 days ago
I have just seen an Msonic advertised on Ebay. Its a tempo11 version and designed for model cars. It is an early Mtronik and possibly has a max voltage of 7.2 to 8.4 volts and probably 10 amps (my guess). As its maybe for a car the reverse may just be a brake. If you plug it into a 7.2 battery or less, connect a motor and plug the ESC into a rx you should be able to test. Check that the rx plug is wired neg (black) pos (red) signal (white) incase it was being used with a differently wired rx ie the red then black then white. If so you will need to swop over the red and black wires. The small button is used to set up the ESC once you get it going.

MV TEAKWOOD by RHBaker Fleet Admiral!   Posted: 1 month ago
Before the funnel could be installed wanted to fit a working radar scanner, navigation lights and the batteries. Decided to use sub C NIMH batteries in plastic holders, they should have the target endurance and provide some ballast. Fitted two sets of 4 cells, one at the forward end of the superstructure and the other at the rear, both at keel level. These were inserted into wooden battery trays to hold them in place. A dry test run showed a full speed motor run time well exceeding the hour target, so will try on water. Also took the opportunity to fit the Rx and then adjust the rudder before finishing off the wiring. Both the navigation lights (LEDs) and the radar scanner work. The radar is driven by a servo with the potentiometer removed and a magnetic drive shaft run up through the superstructure from below the deck. The motor requires about 9 volts to run at what would seem to be something approximating to scale speed; fitted a voltage reducer to allow the lights and the radar to work on less than 6 volts. The mast lights are to be installed in a separate circuit after the masts are added. As I get more into the detail it is evident the GA drawing and the photographs of the vessel in service differ. Fortunately the component locations seem consistent, although the equipment is not. This most apparent in the hold ventilators. The GA shows the standard cowl vents, but the photographs show a mixture between an vertically squeezed oval vent (which am advised is more typically German) and ventilator columns with cylindrical caps. The column style vents with cylindrical caps were easily made from two different sizes of styrene tube with the cap tops made from styrene offcuts. The squeezed oval style vents were more difficult. Broke them down into the major parts of the cylindrical vertical tube and, from a larger tube cut a small ring and filed one end to straddle the tube once it had been squeezed oval. Glued it into place whilst restrained in a small hand vice. Once set, removed and sanded the the two to give a smooth transition, closing the rear aperture off with styrene offcuts. Then resorted to wood filler, filed down to give a smooth, oval vent.

Steam sound unit (variable speed) by ads90 Commander   Posted: 1 month ago
Thanks Dave for letting us know - I only checked yesterday and had a good look at the Forge Electronics website. I only have a 50mm dia speaker in my large tug running at 6 volts and that is loud enough and I can hear it on t'other side of the pond, your set-up must be deafening 👍 Alan

850 Brushless by canabus Admiral   Posted: 2 months ago
Hi Andy Slightly more power with a brushless motor is a no go!!! Brushless motors the same size are far more powerful !!! But, the about same RPM a Turnigy L5055-700kv(500 rpm more on a 4S(14.8 volts) Lipo battery would be a good replacement. Mind you at 1600 watts( about 2 and 1/4 HP) these will used in a large boat like a 46" Vosper Crash Tender or a 46" Sea Queen!!! My move into brushless motors I have found that they are 7 to 10 times more powerful and equal to, if not better than the old IC motors!!! My Sea Hornet, Sea Commander and Huntsman run brushless motors . My Crash Tender is getting the 5055 motor, so it will be interesting to see what it will go like!!

Happy Hunter by jarvo Fleet Admiral!   Posted: 3 months ago
No worries mate, have the esc's got a max and min voltage??? they may not work at 6volts, if not then a set of 7.2v NimH packs will be brilliant x2 or possibly 4 packs with a Y lead for each pair, 3300mah packs are going for a good price on ebay at the moment, also have a look at component shop and hobbyking, be sure you are on the uk site to keep the postage down!!!! Wouldn't bother with lipo batteries, SLA or NimH are more user friendly. If you want the H/H superstructure try contacting Krick they now make the kit, took over from Robbe when the went bust. Are the propshafts ok??? withdraw the shafts and lightly oil them get the oil into the inner bearing as well. Mark

Happy hunter by jarvo Fleet Admiral!   Posted: 3 months ago
The motor units are Robbe EF76 with fitted gearboxes, rated at 6 - 8volts, superb units and very reliable, did you strip and clean the gearboxes as well???? were the photos taken before you cleaned the motors??? The battery space looks to have been fitted with 4 x 6v 4ah batteries, probably giving 6v drive power, might have been 12v. Is there an ESC fitted?? that would give us the final key, apart from the red and black wire in the 4th photo is there any other wiring??? Mark

46" Firefloat What Motor/Battery by jarvo Fleet Admiral!   Posted: 3 months ago
HI JJ. Your question about a safety bag, Damaged / overcharged lipo's can catch fire, think of the Boeing scandal that grounded the fleet last year. Charging in a safety bag is advised the bag is fire retardant material, which will contain any problem. Your remarks about the boat not coming onto the plane is down to the weight of the battery, my fireboat started with 7.2v NimH packs 1 for each motor, Graupner 700bb's, good cruise but not quick, but short run time, 10mins. I have re-wired to allow 3s lipo's, but not had chance to test it yet, but should go like stink. With a fast hull, weight is important, 4 x lipo packs, 1kg, half the weight and possibly 6 times the power delivery. In your first post you mention 600 motors on 6volts, they are probably rated at 8.4volts, same as my 700's hence the lack of performance, also the battery, at 12ah it should last about 30mins, was it fully charged??? and is it showing at least 6volts, ie not got a duff cell??? Canabus, in his post described an ideal set up with brushless motors, 1600 watts is just over 2 hp, 750 per horsepower so you can see the difference in performance with different motors and battery set up's

Electronics Down Below (5) by NPJ Captain   Posted: 3 months ago
RN - Thanks for the confidence boost it does help! I have picked up the gizmo that provides 5 volts off the mixer. It is very small and will tuck away. Re rudders, I have been reading that larger ones can help steering when in reverse, also that small rudders the other side of the props are good........ All up for consideration at the moment. Image here from 'Andy' on, but other shapes are around. All the best. NPJ