RC vs "other" non hub motors

[Desertprep]

At the risk of starting a feud or displaying my ignorance I would like to summarize some observations I have made from reading posts here about these 2 kinds of motors.

RC (outrunner) motors tend to be high rpms. Other non-hub motors (onhm) are lower rpm
RC motors need more gear reduction. ONHM need less
RC motors are lighter weight than ONHM and would be a better choice than ONHM if weight is a concern, as long as the gear reduction did not eliminate this advantage.
RC motors are more likely to need batteries with a higher C rating than ONHM's to take advantage of their power.
Lipo batteries are more well suited than Life batteries for RC motors.
RC motors require the owner to install hall sensors. ONHM come with them installed.
Because of the additional costs of gearing and the lipo batteries, when considering the total cost of purchasing, the rc motor may be more expensive than an ONHM

 

[TylerDurden]

This is generally true: "RC motors tend to be high rpms."
(That is how they can deliver high power while being low in weight and size.)


The other observations are generally dependent on configuration.

 

[gwhy!]

The only thing I would comment on this is the cost... I think a RC setup is so much cheaper but do involve a bit more man hours. The total cost of the setup on my bike not including battery comes to between 100-130 uk pounds and this includes the motor, reduction and speed controller plus all the other bits and pieces to bolt to my bike to make it work. As regards needing a higher C battery this will depend on what power levels you want to run at.

 

[AussieJester]

Yup agree with GWhy, any setup can be as cheap or as expensive as you wanna make it its up to you which it will be, I've seen very cheapily or frugile rc setups on here that run extremely well and also builds that run into the 1000's all depends what you want from it, if you want to run like a maniac at high speeds it will cost you, want to cruise at average speed not so much...I think what your seeing alot of with rc setups is more than not (some of the new outrunner new friction setups aside)are running rc motors are opting for higher speed setups, 99 bucks for a motor not much larger than a coke can or heavier and capable of 8kw is pretty tempting to many i guess even if it is ~7 times the legal power allowed on USofA streets. ...

KiM

 

[Desertprep]

man hours? I am in China - labor is cheap...I should be a good capitalist and take advantage of it Chinese mfgs sell a couple of models of ebikes that still have pedals - though they do not much resemble pedal bikes, other than having 2 wheels and a seat. The pedals are put there for legal purposes - to be considered an ebike - but also to help get the bike started and extend the range of the bike/battery. There is an empty space around the crank that would easily accommodate an rc motor and associated parts - it already has the chain going to the back wheel - so a lot of the tinkering would be taken care of. I go back and forth, though, as I ask more questions and get a deeper richness of info about the topic. The consensus on this panel seems to be that in order for rc motors to be more efficient they should be run near their upper limits, or beyond the limits that are used in model airplanes. Higher voltages means more power and more expensive batteries The secret to keeping the cost of a conversion down seems to be to find a way to keep the cost of the batteries down. I would like the rpms that rc motors can produce - at such a light weight - but I am not looking for seriously fast acceleration. The results of a post I made her suggest that a controller can be wisely chosen so that it will limit the characteristics in such a way that I can still get rpms from the motor but at a more regulated draw from the battery - I don't have to peel out in all gears..but I am looking to cruise at 30 mph Still, it seems that a ping battery pack is not likely to be a good candidate for a turnigy 80-100 B...unless I get a 60v 30 amp.... $$$$$$$$$$$$$$$$$$$ ...unless, I can go with a lesser motor than the 80-100 B The problem with the lighter, lower power motors that I have found is that the kv is sky high. I need to turn the wheel of my bike at about 550 rpm to make my day and make my 180 pound body and 80 pound bike hit a little over 30...i am open to suggestions for other motors. I now have a way to breach the firewall here so can do some serious reading/researching

 

[AussieJester]

Still, it seems that a ping battery pack is not likely to be a good candidate for a turnigy 80-100 B...unless I get a 60v 30 amp.... $$$$$$$$$$$$$$$$$$$

Nagh prolly not, how ever i do like to 'peel out' haha and would kill a ping not long after leaving my driveway with my Turnigy 80-100 LoL... Thankfully lipos are very cheap now ~400 bucks gets you a 44v 20ah 25c pack

KiM

 

[gwhy!]

..but I am looking to cruise at 30 mph Still, it seems that a ping battery pack is not likely to be a good candidate for a turnigy 80-100 B...unless I get a 60v 30 amp.... $$$$$$$$$$$$$$$$$$$ ...unless, I can go with a lesser motor than the 80-100 B The problem with the lighter, lower power motors that I have found is that the kv is sky high. I need to turn the wheel of my bike at about 550 rpm to make my day and make my 180 pound body and 80 pound bike hit a little over 30...i am open to suggestions for other motors. I now have a way to breach the firewall here so can do some serious reading/researching

If you only want to cruise at around 30 Look at the motor I pointed you to in the PM (3250w aerodriveXP 170kv) this will take you to 30 on the road and not get stressed about doing it and its a bit kinder on controllers

 

[recumpence]

You can use RC sensorless controllers and motor together in a very reliable system if the output is kept reasonable. I have nearly 600 miles on my trike without any problems, what-so-ever, not even a loose set screw! But, I have gotten very knowledgeable in these setups and know how to design and build them reliably.

I will say it this way, for someone with knowledge in RC and bikes, a RC setup can be very reliable and very efficient. But, for beginners, much advice is needed for success.

Matt

 

[scouser-nick:)]

sorry to post this guys but "RC" as in "radio controlled"?
i think im retarded :lol: :|
cheers nick

 

[gwhy!]

sorry to post this guys but "RC" as in "radio controlled"?
i think im retarded :lol: :|
cheers nick

Yes the motors referred to as a RC motor are what is used in RC model car,boats and planes and any other model that uses a electric motor.

 

[Thud]

RC....bah the moniker RC.
They are not "RC" motors unless they are being controled "remotely" or by "radio" :wink: I was flying an rc plane one day & some spectator commented that it was just like a "real airplan" I explaned that it is a "real" airplne, just a smaller one that is flown by radio. (DUH!)
We should come up with an apropriate ackronym for small & wonderfully powerful motors shackeld with the toy-associated mis nomer & be done with it....how about Small,Tourquey,Ultra,Petite,Ingenius,Drive? S.T.U.PI.D.(theres one for the hub crowd :lol: )

on topic: I have helped a buddy build an S_____D cyclone type reduction unit. powering his bike through the crank ring. here is an excert from an e-mail from him
Aaron said:

Pulled 28mph on a flat in top gear.

Picked up some chain lube too. That helps.

Low speed, hill climb in my back yard produced 105amps.

sensorless- massive reduction to the crank ring, bike has an excelent synergy....its fun to pedal along with with the motor, makes you feel rather cy-borgish.
P, are you getting enough info from your inquires? I am anxious to see what you decide on in the end. Good Luck. T

 

[Miles]

Yeah, I hate calling them RC motors, too.

How about "H.O." (High-speed Out-runner) or "H.I." (High-speed In-runner)?

 

[Desertprep]

Yes, I am getting lots of food for thought. What about calling them HOOM - High Output Outrunner Motors?

I am still struggling with the weight thing, though am almost resigned to believe that a 1.5 pound motor can do the trick Yes, the megalomaniancs have put fear in me. But there is always the "what-if" mentality. For example, when I looked at cylone motors i was thinking that 36v 650 watt motor would be adequate for my needs unless I rode with 2 people, when it seemed that 48v would be more suitable - especially for decent acceleration....and, like most guys, once we get something between our legs that has power we want to use it! :lol: ....so it becomes very easy to start building a scenario - and bike/motor combo- that will peel out in all gears, even a "reverse" if we have it.

I am setting up paypal to access my bank account in the u.s. and hopefully will make a purchase in a short while. Now I have to go through the pains of learning about controllers (ESC and otherwise) as well as Lipo batteries that can catch on fire when charging/recharging.

It would be nice if someone set up a blog entirely for people who have done conversions, including standardized pictures and statistics...hey, wait a minute, I have lots of webspace and blogging software....

 

[Hillhater]

Maybe i am missing something .(i certainly lack the extensive experience of these systems that come of you already have )...
... but my experience so far with these "RC" drives has been disappointing and frustrating.
It seem to be easy to assemble a system from "proven" commercial components that does not work as you would hope.
Specifically, low speed ( say the lower 50% of the operating range) can be very unreliable and prone to "sync" failure, on sensorless systems, and as pointed out , sensored motors and controllers seem to be a strictly DIY exercise currently.

I dont want to discourage anyone contemplating an "RC" based set up, but just make them aware of the issues and limitations of the commercially available kit.
I would not want my life, ( or even my next trip to the pub) ,.. to have to depend on an "RC" based drive ! :wink:

 

[Hillhater]

Yeah, I hate calling them RC motors, too.

How about "H.O." (High-speed Out-runner) or "H.I." (High-speed In-runner)?

Well , i wouldnt exactly call the motors we use "High speed" compared to other motors in the "RC" field. ( 40-50k rpm)
........In fact , i thought we were trying to get these motors developed into "low speed" versions (low kV ?)

Why not just "BLOR" (Brusless OutRunner) and... "BLIR" (Brushless InRunner)

 

[Miles]

Why not just "BLOR" (Brusless OutRunner) and... "BLIR" (Brushless InRunner)

That's defining them by what they are not

They are high speed in relation to most motors, that's the point. That's how they get the power density.

 

[Hillhater]

It just seems that Brusless outrunner or Inrunner , is the term commonly used to identify them currently.
If you go into an RC hobby store and ask for a "High Speed RC " motor, you are going to have a lot of explaining to do as to why you are calling one of the slowest motors in the shop... "High speed" ! :lol: :lol:

 

[Miles]

I thought we might consider what is useful to us.

Brushed motors are on the way out, so that distinction will be less and less significant.

What's important?

Outrunner;inrunner;axial flux;transverse flux

High speed/low torque; Low speed/high torque

 

[recumpence]

Maybe i am missing something .(i certainly lack the extensive experience of these systems that come of you already have )...
... but my experience so far with these "RC" drives has been disappointing and frustrating.
It seem to be easy to assemble a system from "proven" commercial components that does not work as you would hope.
Specifically, low speed ( say the lower 50% of the operating range) can be very unreliable and prone to "sync" failure, on sensorless systems, and as pointed out , sensored motors and controllers seem to be a strictly DIY exercise currently.

I dont want to discourage anyone contemplating an "RC" based set up, but just make them aware of the issues and limitations of the commercially available kit.
I would not want my life, ( or even my next trip to the pub) ,.. to have to depend on an "RC" based drive ! :wink:

This is almost 100% caused by using cheapo motors and (more importantly) cheapo controllers. I have no sync issues what-so-ever and never had with a Castle controller. I get annoyed when this is brought up because it is only a problem with cheap components. Also, reliability is not an issue if a good controller is used and the amperage rating is observed. No problems at all if these rules are followed.

I wouldn't trust cheapo RC components either. However, I have nearly 600 miles on my Catrike RC system without a single hickup. I trust that thing riding 10 miles from my house and back home.

It is all about quality. Now, the next gripe that will be brought up is cost. "Yes, but high-end components cost alot." Yes, all I can say to that is, welcome to reality. That is how the world works, the better the equipment, [generally] the more it costs. If you see an F1 car on a track and want to duplicate it, but on a budget, you will be disapointed.

This is not a rant, it is merely the truth. RC systems do have their downsides. However, saying they are unreliable and prone to sync issues is not true if decent components are used.

Matt

 

[AussieJester]

Maybe i am missing something .

Sure are... people like myself for example are having issues soley because we are attempting to run these motors way above their limits, i.e 6500watt motor pushed to 10000watt+ somethings gunna give, also some are using cheap rc escs that won't work simply because they are cheap but complain and jump up and down when they blow...on the other hand there are many on here that have trouble free setups using the "RC" motors in their bikes we dont hear alot from them because they aren't having problems, I know for a fact Recumpence alone has sold dozens and dozens of his reductions drives yet we have only ever seen but a handful on here using them. I could very easily (and am about to) set mine up to be extremely reliable by de-tuning it from my over ambitious setup to something lil tamer, soon as you start pumping more power than any motor and/or controller is designed for you will get unreliable setups, its exactly the same with a frock setup go confirm with DocBass how many Infineons he popped in a week just last month trying to break 100km/hr...it was 5 at last count IIRC... Quite simple the way i see it, want reliable use proven quality components and don't push them past their limits .

KiM

 

[Thud]

pengyou,
Here is a photo of the bike I mentioned. you see its not a conventional (oops almost typed RC LOL) HOBO (Hi Output Brushless Outrunner)build
bad photo taken at nearly sundown tonight.

My good friend cunsulted in great detail Listening to all my experiance & suggestions....Then as allways did exactly what he wanted against all advice & built this cyclone copy. I will say he did a fabulus Job. One thing I noticed tonight is he used a comercial chain lube on all the internal chains & the unit is the Quietest HOBO powerd bike I have experianced to date. A big factor is the running on 22 volts & not making the motor shriek.The bike consumes about 20amps at 25+ mph (he regularly hits 28 without pedaling in top gear. We downloaded the controller log to look at peaks & ripple voltages..the Caps are doing thier Job as ripple was .3v max. Max Amperage deliverd by the Ice100 was 118 amps the average was 22amps drawn. its a 10 mile round trip from his house to mine. I loand him a meanwell charger that tops off his 20ah battery in just less than an hour & he has been riding the wheels off this the last week or so....Ev grins all around.

 

[Hillhater]

RC systems do have their downsides. However, saying they are unreliable and prone to sync issues is not true if decent components are used.

Matt

Matt, I am sure that is true, and your experience has led you to those components (Astro , Castle etc) that give that reliability however,...
... you will notice that many (probably the majority) of people building these RC based systems are using "Turnigy" level components ..often with apparent trouble free results whilst others (myself included), using the same components end up with problems (sync)
Now , if the solution to trouble free RC set ups is to only use top spec components, thats fine, but i think we should make people aware of the risks and unpredictability with using "Turnigy" level of kit.
Personally i suspect there is a little more to it than "quality" of components. Throttleiser system and current control (ramp speed) have been identified by some as a part player in sync problems, so establishing the correct set up of those factors would be useful too.

 

[recumpence]

RC systems do have their downsides. However, saying they are unreliable and prone to sync issues is not true if decent components are used.

Matt

Matt, I am sure that is true, and your experience has led you to those components (Astro , Castle etc) that give that reliability however,...
... you will notice that many (probably the majority) of people building these RC based systems are using "Turnigy" level components ..often with apparent trouble free results whilst others (myself included), using the same components end up with problems (sync)
Now , if the solution to trouble free RC set ups is to only use top spec components, thats fine, but i think we should make people aware of the risks and unpredictability with using "Turnigy" level of kit.
Personally i suspect there is a little more to it than "quality" of components. Throttleiser system and current control (ramp speed) have been identified by some as a part player in sync problems, so establishing the correct set up of those factors would be useful too.

That is what I am already doing. I tell people directly that I do not recommend cheap motors and I am very firm about not running any controller except Castle controllers.

The big problem is the proliferation of the use of these cheapo motors. They are seen as the norm because there are so many out there, therefore, RC systems become branded by the traits of these popular motors.

Using my F1 car analogy, if a large number of people use cheap engines and chassis and try to race them in F1, the average Joe may begin thinking F1 cars are poor quality and unreliable, when, in reality, it is the mindset that you can race at that level with cheap components and the insistance of running those components by many people that leads to that conclusion.

I have steered many people away from RC setups if their budget is low and expectations are high. I always tell them this is the high-end of E-bikes and, as such, is costly. But, the costly side is rewarded by high efficiency and, yes, high reliability [if it is setup and used properly].

Matt

 

[Kepler]

I think that these lower end ESCs and motors have there place and I have found some combinations to be more then adequate in relation to reliability and sync ability when used on the right application.

Reality is that people who want to experiment with a cheap RC project are not going to spend $600 on a motor/ESC combo when they can enter the game with a $100 outlay.

It can be done and can be made to work reliably. This has been proven. Find a combo that works well, and tell us about it. If it doesn’t work, tell us too. I have repeated myself over and over again with what I have found to work.

If I was going to build a high powered RC drive, it would be CC 160A all the way. The Astro would be high on the list also. It’s a proven well tested combo and I trust Matt's judgment and experience.

However, we are talking about low to medium powered friction drives in this thread and most are looking to do it as economically as possible. Like it or not, cheap Hobby City gear is going to be used so lets make the most of it and select what we know works.

The key to using low cost RC gear is being conservative. My recommendation is to halve their advertised ratings and you will have a good chance of enjoying your purchase without being disappointed. Also, keep the voltage down. Even 6S is starting to push it in my opinion. 50A on 5S is still going to give you a 1000W. Plenty for most hills and a very tidy top speed.

Lastly, if using a servo tester throttle interface, be gentle under low speed/high load and hopefully you will avoid killing the ESC and keep sync under control.

 

[liveforphysics]

I personally think it's find to call them RC motors, because they were designed for use on RC machines, and normally used on RC machines, and we borrow them from this appliction to put them in ebikes. Obviously any motor is just a motor, you could use it to power the fan in your bathroom, a drill press in your garage, the sump-pump in your basement, or really any appliction that involves motion, but we don't have to call it a sump-pump motor if we take it off an RC plane to put it on our sump-pump. But that's just my $0.02



Any type of build can be as reliable or un-reliable as you choose to make it. Take a $30 rc motor, don't bother to put good bearing in it, don't bother to dimple where the set screws mount and loc-tite them, don't bother to re-glue the magnets, and pair it up with a Turnigy/HXT/etc controller, it's going to super-suck, and WILL fail after a while of it's sucky performance.

Same thing happens if you buy a crap hubmotor and just bolt it into an aluminum frame with no torque washers or torque arms, and wire it up with the garbage wire some of you guys manage to find, and little badly crimped push connectors going to some joke of a battery with a BMS that cuts out at 15amps and the BMS ends up shorting cells etc, and when you get it to run, you spin the axle wrecking the frame and tear the wires out of the hub which shorts the controller and blows it up etc etc.



An RC build done like crap make a very crappy bike.
A hubmotor build done like crap makes a very crappy bike.

If you do it crappy and use a bunch of crap parts, it's going to suck no matter what type of build you choose to do. The same is true visa-versa.