TWIN Power stick mount system w/ gearbox EPS100

 Ninjatech 3650 points

As i stated on my review , i'm currently using 2 X 25-30A ESC's , tried to use a single 50A ESC but unfortunately the motors denied to cooperate ...

 nibnobsam 63 points

Yes, a gear will lose 10% efficiency. One shaft is more efficient, but you need to make sure the motors coils are aligned. I don't know why you would just use a bigger, lower kv motor at this scale though. P.S. See this thread for www.link

 sorenlaf 92 points

Note to mumanair: Two motors might allow better balance and more important allows you to use a higher kv motor and a large prop. Running two motors on the same shaft seems a lot like using one longer motor, though I could see some advantages with a nose heavy airplane, hmmm... Higher kv motors generally allow more current than a lower kv motor of the same size, but force you into a small prop, which are generally less efficient. The reduction is 5.33:1, so it makes a 2400kv motor act like a 450kv motor.

 Emad H. 6 points

I think you are mistaken cause the winding inside the motor is identical and also the magnets what really controls it is frequency and the voltage so if they are the same the error that could occure you would not even be able to calculate it and it may result only in one motor doing only half a turn more over a 1000 rpm...

 funflying 81 points

At this price you would hope so =)

 Andreas 68 points

Yes, the motors are inlcuded, but no instruction sheet.

cheers

 Sloperdude 1309 points

And one ESC?

 byrne1157 77 points

The theory is that the torque generated by the two smaller,lighter motors would result in a greater power to weight ratio than you would get from one larger motor. Also the heat generated in each of the smaller motors would be less than in a single, larger motor. Thus, you could swing a larger, or higher pitch prop. I'm going to try one on my slo-stick soon...

 sparkie 325 points

Sloperdude. No, would have to be 2 ESC's Reason being is that the speed sense would not work correctly for the timing. For Brushed Motors, One ESC will run multi motors, Brushless Motors require seperate ESC's

 Sloperdude 1309 points

sparkle, I meant that if you used one larger motor instead of two, you would only need one ESC, for less weight and expense. I'm aware that each motor needs a separate ESC.

 sparkie 325 points

OK... There are quite a few people out there who do no know that. I saw one person try that. The ***r ESC Caught on fire.... Literally.

 trucheek62 381 points

because motors are tied together with gear, one esc will work fine* just make sure the esc is large enough for both motors. hope this helps.

 byrne1157 77 points

1 ESC for both motors can be used, but ONLY if you get the timing set lined up correctly.

 boingk 257 points

If you want to go all experimental and risky for the sake of a few dollars, use only one 40 to 50A ESC. If you want something that will work very well, reliably, then use two 20 to 25A ESC's. Easy as that.

 thochisa 7 points

attention si vous avez un probl�**me avec hobby ne comptez pas sur la guarantie, j'ai re�**u un swift avec un servo d�**fectueux cela fait 3 mois que je les contacte pour qu'il me le remplace !!! ne pas achetez chez eux a fuir careful if you have a problem with hobby do not count on the warranty, I received a swift with a faulty servo that's three months that I contact them to replace it myself! not to buy a home escape

 Mazafaka 655 points

1x 45-50A ESC. I suggest it will be enough, because off: Prop: GWS 1147, Voltage: 12.6V, Current: 39.5A, Watts: 497.7W for example. If you will use prop not larger than 11x4.7.
How 2 commutate 2 motors and 1 ESC - you can read my post below.
Good luck

 Mark 601 points

you can't commutate 2 brushless motors with one esc. The brushless esc is timed for the load and position of the stators and magnets of the motor. If you have 2 motors on one gearbox, they will both be turning at the same speed, and theoretically the positions of the motors will remain constantly in synch with one another. but you have to have two identical (completely identical) motors with the exact same windings and wire gauge, and line up the motors so that they are both at the same timing as each other before you set them in the gearbox. Many of the brushless motors have ***r quality control. Other manufacturers experiment with different configurations or use different manufacturing facilities for the same motors. Some of The motors get an extra winding, or they use a slightly different gauge wire in one batch or use copper in one shop and nickle in the other... if there is any binding, or one is operating more efficiently than the other a Single ESC has no way of regulating the current and voltage properly to the two motors. Any time you have two brushless motors it is a good idea to have two seperate ESC's. Here you have 400-500 watts of power going through the system you don't want any balancing problems.

 Sloperdude 1309 points

Great answer, Mark.

 Goose 222 points

I was unsure about useing 2 motors and 1 ESC but thanks to Mark it all makes sense.
Cheers Mark

 Mark 601 points

all that typing and I didn't answer Florian's question! You need to have ESC's that are designed for the motors you are running. This gearbox doesn't come with motors. If you buy 2 motors that each need a 25 amp ESC then buy 2 of the 25 amp esc's to go with them.

 loren 53 points

I THINK U R WRONG I THINK IT DOES COME WITH MOTORS CAN ANY BODY TELL 4 SHURE

 Mark 601 points

I think you're right Loren. I was looking at the weight at the bottom of the spec sheet. It's listed at 25 grams. I think that must be the weight without the motors. When I was reading the description the other day, I did not notice the other weight at the top of the spec sheet of 65 grams. That seems a lot more likely to be the weight of the unit with two motors. IT doesn't give enough information on the motors to give a solid recommendation on esc, but just going on the test data, two 15amp esc's should be more than enough for a 1047 prop. The 1147 prop is going to need a couple 20amp escs. I wouldn't use anything larger without knowing what motors they were and what load handling they were capable of.

 Mazafaka 655 points

Mark... generally and especially for delta windings, it will be as you said. But if you use "star" windings and the same (model\type, kV, power output, manufacturer) motors, and THE MAIN(!): - both motors will turn THE SAME (one) SHAFT by 2 motor pinions and 1 (shaft) spur gear - you can use 1 ESC and operation will be so smooth as in case of 1 motor\ 1 ESC. Why that? -Motors will be MECHANICALLY syncronized by one shaft.
It is not very difficult to try & check - you can see it by your own eyes :-)))
Good luck!

 Mark 601 points

With a nylon spur gear and brass pinion gears it wouldn't be hard to jump a tooth on one of the gears. $10-15 bucks for an esc makes a lot more sense than cooking your electronics because your prop took a hit when you nosed over on a landing.

 Mazafaka 655 points

I've flew GWS formosa(I) with the formosa(II) gearbox "armed" with 2 outrunners w\o some serious crash by a few month - there was no "hard jumps tooth" at all. Generally, my props took NO HIT during landings and other cases, but sometimes - it happends. :-)
Mark, may be some training for more safe landing (and not for me only) will be much better, then giving each other advances what to do with 10-15 bucks?

 Mazafaka 655 points

Mark, how can you explain that: www.link is no mechanical or other kind of syncronizing in this case, except of ESC and outrunners are TOTALLY different by type\size. They're working smooth, isn't it???
I'm forced to repeat: If you can load 2 exactly the same type/model/kV/manufacturer motors by 1 shaft - there will be no synchro-problem at all. But, I beleive, you're against the gears, as such :-)))
May be all heli-pilots and track&buggy racers will try to operate with "no gears" out of respect for you, but I don't think so :-D

 Mazafaka 655 points

the link is: www.link

 Mazafaka 655 points

:-( can not attach youtube video there - will try to uload it in video section

 Mazafaka 655 points

pls find 2_outrunners-1_ESC.flv in this product's videos section
Good luck!

 Mark 601 points

You can run two non identical motors off of one esc in series if they are not delta windings. Even if they get moved out of synch, they should be able to reposition themselves if they are free to do so. If they are locked into a gearbox and one of them jumps a tooth, it forces that motor out of time with the other motor, and thats where the problem lies. I'm not saying you shouldn't use a gearbox with an outrunner, I'm saying you shouldn't use a dual motor gearbox with only one esc. ESC's are cheap and don't take up a lot of room.. (at this scale)
Also, Thanks for posting that video. It definitely illustrates the capability of running two completely different motors off of one esc. I like how you stalled the one motor and showed how the second motor stops in sync with the other.

 Mazafaka 655 points

Ok Mark. Let we each other stay on own. Its a pity - I have no video with 2x160 Watt outrunners in 1(!) gearbox running almost 1 Kg weight formosa(I) with approx 1.5 Kg thrust on 1(!) 35A ESC and 1x2200 3S1P 25C LiPo. May be if had I recorded flights that time - you could "see the base" to trust its practically possible and useful for that time. That was 2007 and there wasn't cheap ESCs and over 300 Watt brushless motors - so 2 smaller motors on 1 ESC - was not the worst solution up to date.
Good luck!

 Mazafaka 655 points

P.S. IT IS PRACTICALLY PROVED: that it doesn't matter on how many teeth one motor jumps respect to other. You can imagine that: I installed pinions and spurs w/o any tooth syncronization in a mind at all. But normally in that gearboxes, which I've used, this "jump" was totally IMPOSSIBLE (except of case of gearbox destruction in crash). During installation of 2 motors you must connect its "phases" correctly - it means motor wires only. I construct 2 such motorsets, use 4 pinions, 2 spur gears - and havenot even heard about the "problem of 1 tooth jump" - all works perfectly.

 Mazafaka 655 points

P.P.S. motors will synchronize to each other every time when you switch the power "on"
That's all, folks...

 Mark 601 points

thats my point though. On a single esc with dual motors, When you slow one motor, the other motor will slow to stay in synch with it. If you have both of those motors locked into the same gearbox, and one of them jumps a tooth, it won't be able to slow or speed up to re synchronize with the other motor. The two motors are locked together and if the are at different timings on the position of the stator in the bell, the single esc won't be able to send the correct impulses to drive both motors effectively. One or both motors will be recieving a signal that is out of time with the position of the stators and the motors won't be able to differentiate their positions to realign themselves. The only situation where this would not be an issue is if the pinion had the same number of teeth as the motor had magnets and the teeth and magnets were identically aligned on both motors. Then if you jumped a tooth the two motors would still be in synch.

 Mazafaka 655 points

Mark, may be I don't know quite right but... firstly in whole my life I heard about "tooth jump" from you and up to date - from you only. Why during normal use in well constructed, correctly assembled gearbox teeth will jump??? Are they crazy? Or you just noticed that the possibility of tooth jump exists..? From other hand, you see - there is the possibility of End Of Days just tomorrow - what is the probability of this case? May be it is better to discuss something more probable then jumping teeth... Over 5 years I use different gearbox types/countries of origin and had NO CASE of tooth jump, had you?
One more question Mark, are you theorist? If so - I have no more questions to man, who do not bother himself to test the theory, which advocates. Its not difficult way - simply repeate many times about "tooth jumps","you can't commutate 2 brushless motors with one esc", "a Single ESC has no way of regulating the current and voltage properly to the two motors" and etc (citating you).
I prove to all: 2 motors/1ESC works normally and what you have done to disprove this ???

 Mark 601 points

wow.. please keep the discussion on topic and don't make personal attacks against me. I've never stripped an all metal gear box before. I HAVE jumped teeth and broken teeth on nylon and composite gears that were in mixed media gear boxes. (one material harder than the other between pinion and spur gears) they are designed to do that so you don't rip the whole nose off of your plane and rip the wires out of the sockets if you slap your prop against something solid. (I've done that on a scratch build using all brass gears) It's a lot easier to replace a spur gear with stripped teeth than it is to reconstruct half of your fuselage. Not a theory... Done it lots of times. Ever notice how they sell replacement gears? It's because people wear theirs out or break them. Most of the time when you jump a tooth or two, you'll never know you did it. If The tooth on the spur gear is soft enough it will flex without breaking off, and after a few revolutions, any burr that would have been there from the slip will wear off. Do it enough times and the gears will start to chatter. Use too hard a compound in the spur gear and you'll chip and break teeth. Not theory... I've been flying and building micro planes and park flyers for about 10 years now. I've also wound my own motors and actuators, built my own gear boxes, and used to put micro recievers together out of bitchar-g cars before anyone was making micro flying gear. I did test my theory on a gearbox with the motors set out of time. A C05XL and an ADH30S. From what you say it shouldn't matter that they are both different size motors. I now have an ADH30S that doesn't work. I can't guarantee that it was because of the motors being out of synch with each other, but there is no other reason for the motor to have fried. Both were new motors running no load at half throttle. I kida had plans for that motor on a plane I'm building but I still have lots of time before I'm done building to order another motor for it. thank you very much.

 Mark 601 points

update: BTW, when both motors were in synch, they seemed to be working fine. When I set them out of synch, they didn't turn at all. I only gave it half throttle for about 2 seconds, then I turned the gear box a little and tried again for a couple seconds. After the second attempt failed, I tested the motors individually on a different esc and only one of them was working. I didn't check the esc they were hooked up to untill later. Uppon checking the esc I found that the esc is fried too.

 Mazafaka 655 points

Okay Mark - again and again all your arguments are only words and nothing more :-)
Thank you for paying so much attention to my modest person.
Let it be as you said: 2 fully identical and mechanically syncsonized (1 shaft) outrunners with "star" windings CANNOT NORMALLY RUN with 1 ESC. I'm too lazy to find the new twin frame/spur/pinions and assemble one more motorset for proving you're not right - I don't care :-D
P.S. My experience indicates quite the opposite, but in it there was no tooth jump, for me that time - it does not matter, it works perfectly as I want it to do and it was good thing.
Good luck!

 Michlll 63 points

Thanks Mazafaka for assuring that this works. As I'm a pragmatic person myself, I prefer the experience of a practician when making decisions.

 Mark 601 points

****

 drflogalot 46 points

after reading the same stuff over and over and over im left wondering why you would hook up your motors like that when according to you and your knowlege or what you believe you know... you had it comming to you the second you connected the battery.. as for mazafaka goading you.. wtf i think you just started to confuse yourself and were maybe a unsure .. if i told you the fire was hot and you will burn yourself if you touch it ... im guessing you would have a feel just to make sure ... now back to being nice and no need for anyone to get worked up over $30.00

 Mark 601 points

Now if you posted video of you sticking your hand in the fire and saying, "this particular fire doesn't burn" It would make me question whether or not it was possible. Of course I was unsure and starting to doubt myself... I wouldn't have stuck my hand in the fire otherwise. 30 bucks to be sure, and to take one for the team in order to disprove some misinformation... not a total loss. its all good.

 Boaterguy 68 points

Two motors can be run on one ESC, it has been done with three and even four motors. I have seen videos of two motors running off of 1 ESC, 1 loaded and 1 unloaded, it ran perfectly fine, of course if there were MAJOR manufacturing differences than there would be a problem

 Mark 601 points

I've seen it work as well boaterguy, Mazafaka posted videos of it. There are even some aircraft that have been marketed with dual motors and single ESC. Of course the warranty for those aircraft specifically excludes the motor and esc.

 JohnMcG 21 points

Will you guys give up theorising and upload some evidence. Boaterguy Where specificly have you seen it done ? provide the link don't just follow the "I can P*** further that you can" type of exchange that's going on hear. Happy New Year ("Kun Hay Fat Choy")

 dubaudio 12 points

Any measurements ? :D

 drflogalot 46 points

and of co**** it comes with motors .. thought the twin motor specialist would have realised gearboxes alone dont have max currents or produce watts ... hmmmm it could be time to focus a bit more on the actual product and details .. not half the crazy posts that are put up ..

 vfrjohn 27 points

Right on, drflogalot! I wonder why so often we feel compelled to persuade others to our personal point of view, when it would be more productive to simply state our experience and leave it at that... (Oops, there I go, still off topic.) This really looks like a spiffy idea - different - whether it is most cost/weight/esc efficient or not! John :)

 H-KING_SCOTT 5161 points

GWS 1047 to 1147.

 Florian 7 points

What esc I need to run bouth motors at 7,4V did i neeed 2 ESC with 25A each oder 12,5A each esc??

 denny0AUW 48 points

I too agree that only one ESC is needed when the motors are physically slaved, but you left out an important info...you may have to remove one motor and turn it until the rotor is exactly in the same position with respect to its windings as the other motor. Then the ESC will "see" the pair wired in parallel as one motor. This will also double the current draw than just one motor. This is similar to the technique I use to slave 3 motors so I can connect them in series (and don't tell me it can't be done)for much higher efficiency than can be achieved with a lot bigger motor/direct drive. It doubles the voltage needed but the current is way less than a single motor/direct drive and way more torque!Remember the watts wasted in heat is directly proportional to the square of the current. Also, a lot less heat from the battery. Invest in high voltage ESC.

 Sloperdude 1309 points

And what happens when the motor pinion gear on one motor was glued in a slightly different position from the one on the other motor? You won't be able to align both motors without removing one of the pinions, realigning it and gluing it back on the shaft. Personally, I'd just get two separate ESC's and be safe.

 denny0AUW 48 points

Safe choice, but the actual method I use doesn't require gears, but something I'm working on for a patent. However I can relate to your trouble with a glued pinion.It would present a problem with respect to my method using gears because there is no tolerance for a slipped tooth. Anyway parallel wired motors isn't my thing either. Doubling the current makes four times the heat dissipated in the battery. Doubling the number of ESCs also doubles the watts wasted there. As for power to weight advantages, three smaller motors wired in series for high voltage low current are the only way to go otherwise. You also have to select much lower Kv motors, and use multiple batteries with lower capacities. Just opposite to the trend. The important thing is to have fun, and don't spend all your money on one crash! Mark has already pointed out many problems that must be considered, and that was just the motors part. Engineering a great drive isn't something one can cover in a single post...I should have said:" you're right, what was I thinking!"

 norbique 457 points

yes, you'll need 2 ESCs to operate the two motors...

 Mazafaka 655 points

It is not absolutely necessary to use 2 ESCs. Take 2 motors of the same model, type, kV rating and manufacturer. Simply connect them in syncro rotation direction(also you have to make 3 connection adaptors for comutating 2 motors to 1 ESC), plug it to 1 ESC and you're almost done.
Sometimes you'll be needed 2 reverse "phases" on motors for more smooth operation, because of the possibility of slightly different Ohms in their windings, but with the correct rotation direction in a mind.
All above is true for "star" type winding, but not 4 "delta".
Good luck!