Brushless Motor Prices vs Quality

[wintersdawn 176]

I need to purchase a new 4 pole sensorless/brushless motor soon with around 4000kv.

I have found 3 possible choices that vary a lot in price and wonder if the cheapest one will do a similar job to the more expensive ones or if not what the difference is?  Cheers.

3650 3900KV RC Brushless Motor £18.55 delivered:

 

Robitronic Razer ten Brushless Motor 3652 4000kV for 1/10 RC Cars £35.89 delivered:

 

HPI Flux Mmh-4000kv Brushless Motor £71.49 delivered.

 

[Jonathon Gillham 4607]

My experience in this is based around sensored motors but I suspect that since sensorless are even simpler then it will still be relevant.  I have never had a motor fail unless I did something stupid, like overheated it.  Otherwise, I've got motors which I've replaced after a few seasons racing and they still work well.

More expensive motors are usually faster as they are the latest designs to meet the rules, and they are always pushing the boundaries on whats allowed.  A couple of years ago a new generation of motors came out and they were noticeably faster than the previous generation.  However, since that happened I haven't seen another step change like that.  In saying that, a Surpass Hobby motor for US60 is just as good as a Orion/Maclan/Muchmore/Hobbywing which costs US100, and that is in performance, reliability, quality control etc.  So the issue wasn't the more expensive motor was faster, it was that a whole generation of motors was faster.   So now if you buy an older motor which is cheaper because its an old model, it may be slower than a more expensive motor which is new.

There are also only a few manufacturers, with many companies contracting others to make their motors for them.  So there is a good chance that the cheap brand is actually the manufacturer of the fast motor, and the cheap one is just as good (the Surpass Rocket V4S looked a lot like the R1 Wurks V21 and had very similar performance for example).

It also depends on what you want it for.  A cheap old Trackstar motor for US35 will be plenty good enough for a backyard racer or an upgrade from a kit motor.  It won't win a world championship, but will do the job nicely.

Looking at the 3 you have posted, I would get the cheap one.  To me the top and bottom look like they could easily be the same motor with different coloured wires.  If it doesn't work out, you're not that far out of pocket but it will probably be fine and you'll save quite a decent chunk of money.

[Mrowka 496]

Jonathan makes several good points here.

One of which is that, especially at the lower end of the scale, a lot of motors, servos, ESCs, etc. all come from the same factories and are otherwise identical but for the brand name and maybe some cosmetics.

Doesn't mean that they won't work just fine for what you or I need or want.

[Unknown Driver 262]

I'll 2nd Jonathan's comments. For "fun" driving you can get away with a less expensive motor. If it makes less power than a top-tier equivalent, who cares? Drop a point or two (13.5 --> 10.5 for example) and as long as your electronics can handle it, you're good to go. As much as I despise HobbyKing, I've run the TrackStar motors before and they're actually pretty good, even compared to high-end motors. Keep them oiled and running reasonable temps and you saved some money.

In a racing situation: totally different story. When you're limited to a 17.5, or 13.5, or WHATEVER - you need the motor to be as stout as the rules, regulations, and engineering can permit. That's why you'll see "super-elite-premium-hand-picked-unobtanium" edition motors. Because SOMEONE, SOMEWHERE, will pay to have a motor that's 2% better than average.

Half the time though, those people also can't drive. So...godbless. LOL

[wintersdawn 176]

Thanks all for the info and advice, much appreciated.

My other concern is, if a motor burns up or fails in some other way, can it damage the ESC?  Cheers.

[Jonathon Gillham 4607]

56 minutes ago, wintersdawn said:

Thanks all for the info and advice, much appreciated.

My other concern is, if a motor burns up or fails in some other way, can it damage the ESC?  Cheers.

I would say its possible but don't know for sure. I've had a servo cause an ESC to fail (TBLE 02S BEC went), and another servo cause a different ESC (Surpass version of a 1060) to go crazy, so anything is possible.

I've had ESC fail after a couple of years of racing dirt offroad, and the price didn't determine the longevity. The quickest to fail was the most expensive, an Orca B32 stock spec after 6 months. A SkyRC TS160 failed after a couple of meets but was replaced under warranty (I don't count this as failure, I think it was bad from the factory as it lasted such a short time, same as the Orca, first one didn't work out of the box but the warranty replacement one only lasted 6 months). Trackstar 80a Turbo gave 2 years of service before dying. I've now switched to SkyRC TS120 or TS160 as my go to as they are at the cheap end, perform well and seem to last as long as anything else.

So that doesn't really help. I wouldn't expect a cheap motor to kill an ESC because its cheap, and wouldn't expect a motor to come faulty as they are pretty basic things

[wintersdawn 176]

Thanks for sharing your experiences. The reason for my concern is my last ESC and motor died at the same time and I thought one might have caused the other.

[Wooders28 4723]

In the 'top' tier motors ,as Jonathon says, they are pushing the envelope with designs and innovation, but this costs cash, so need to charge a bit more.

They also use things like rare earth 'permanent' magnets which are much stronger (giving more torque), than 'induction' magnets , which use powerful electronic magnets, to magnetise them (think, wiping a screw driver over a magnet, then using the screwdriver as a magnet) 

Better quality wire ,with finer tolerances etc, and with better quality control (how many of the cheap Goolrc motors or escs where going pop at one point).

With going for sensorless, I'm guessing you're not racing,  so a second quicker over a lap isn't a major factor? My experience, is that there is a fairly big difference between motors, but only as I've a few different ones. The Goolrc 4300kv motor I have is slow and underpowered compared to my Castle 3800kv motor, but if you only had the Goolrc, you'd think it was fine.

 

The 4300kv Goolrc combo on 3s -

 

The 3800kv Castle combo on 3s (although a different beach) -

 

Ideally, I'd like to test the different motors using the same stretch of beach, on the same day.

[wintersdawn 176]

Thanks for the info and videos 😊

I am mostly bashing, occasional speed runs, no racing.

If a motor with a lower kv is faster than one with a higher kv, is that down to poor quality manufacturing/parts? Cheers.

 

[Wooders28 4723]

7 hours ago, wintersdawn said:

If a motor with a lower kv is faster than one with a higher kv, is that down to poor quality manufacturing/parts?

Plus a few other reasons imo.

I'm not sure how ,accurate, manufactures need to be with their KV numbers,  some may add few to make them more appealing.

Also, some of the cheaper (not sure about that Goolrc, more the Finned motors you can get) motors are a 380 sized motor, in a big 540 can, so maybe decent KV on paper, but as soon as they're asked to work, the RPM drops like a stone.

[wintersdawn 176]

Cheers, I think someone said the brushless 380's were the ones in the blue can. Sounds like low torque problems.

There's so many goolrc and hobbywing rip-offs on Ebay where they say it's that brand and look identical but there's no branding on them. Maybe they're the same quality, don't know.

Out of the motors above I went for the HPI as it's the matching motor for the HPI ESC I have. Maybe didn't need to spend that much but have more confidence in it.

[rwordenjr 1890]

I’ve been using these and they’re awesome !

https://usa-m.banggood.com/Surpass-Hobby-Waterproof-F540-V2-Sensorless-Brushless-Motor-with-60A-ESC-for-1-or-10-RC-Vehicles-p-1548050.html?rmmds=search&act_poa=POA5459014&cur_warehouse=CN

[Wooders28 4723]

23 hours ago, wintersdawn said:

Out of the motors above I went for the HPI

Probably would have done the same, or kept an eye out for a nice 2nd hand Castle (or both...🙄) 

 

23 hours ago, wintersdawn said:

I think someone said the brushless 380's were the ones in the blue can. Sounds like low torque problems.

I think it's all the finned ones, no matter what the colour, not too bad in a lightweight 2wd, but struggle in 4wd, still a cheap introduction to brushless!

 

 

[Big Jon 684]

I've never been happy with the super low priced electronics of any sort, while I've been very satisfied with some lower cost motors and ESCs. The Turnigy Trackstar stuff is very OK, I like the Hobbywing EZ Run and Quicrun stuff quite a bit, the Hobbywing XE Run Justock combos are a favorite of mine, and the SkyRC racing speedos and motors are excellent. The very cheap stuff has poor throttle feel and cogging issues.

For my applications, high end racing electronics are overkill, so the cost isn't worth it, but I really enjoy a properly driving car, so I splurge a little by using second tier motors and ESCs with nicer servos. Good servos make everything drive better, making them money well spent. Sensored brushless systems drive so much better than sensorless systems, which is why I use them in most builds. My more budget-minded builds use Hobbywing 1080s and a suitable brushed motor, while light runners and shelf units get whatever silvercan I have laying around and a modified Tamiya ESC. 

My "standard" servo is the Pro-Tek 100T or 100SS, which have been absolutely reliable and better than adequate in the applications, while touring cars and modern buggies get Savox 1251 low profile servos as standard to free up a little room. The race cars, and the primary rock and trail rigs, get much nicer servos and power systems, naturally.

I really enjoy building my junk to work the way that I think that the designers imagined, and speccing electronics that won't detract from the driving experience is a part of that pleasure. These things are endlessly fascinating.

 

[Mad Zero 316]

Rebranding can confuse motor/esc selection.. similar lists for motors 

(not my work)

• Traxxas MXL-6s= Castle MM2 (F360C)
• Traxxas ET-3s= Castle MMP (WITH ONLY 3S LIPO CAPABILITY UNTIL HACKED, THEN YOU CAN USE 6S)
• HPI Blur=Castle MMM (WITH LIMITED PROGRAMMABILITY) (F310/F360C)
• HPI ELC-6s= Castle MM2 (LIMITED PROGRAMMING) (F360C)
• HPI Rage= Hobbywing 8BL-120
• HPI ELH-6s= Hobbywing 8BL-150
• HPI Q-Base= Castle MMP (LIMITED PROGRAMMING, RESTRICTED TO 4S, INTERNAL CAPICITORS MODIFIED,CANNOT TAKE 6S)
• Axial AE= Castle Sidewinder
• Axial AE-2= Castle Sidewinder 2
• Axial AE-3= Castle Sidewinder 3
• Axial AE-4= Castle Sidewinder 8th
• Arrma BLX-200= Hobbywing Max8 (LIMITED PROGRAMMING)
• Arrma BLX-185= Hobbywing 8BL-150 (LIMITED PROGRAMMING)
• Arrma BLX-120= Hobbywing Max10SCT(LIMITED PROGRAMMING)
• Arrma BLX-100= Hobbywing Max10 (LIMITED PROGRAMMING)
• Hexfly HEX 8= Hobbywing Max8 (LIMITED PROGRAMMING)
• Hexfly Hex6= Hobbywing Max6 (SOME LIMITED TO 6S MAX, BOTH VERSIONS LIMITED PROGRAMMING)
• Hexfly Hex10= Hobbywing Max10 SCT (LIMITED PROGRAMMING)
• Dynamite Fuze-150A= Hobbywing 8BL-150 (PROGRAM VIA DYNAMITE CARD)
• Dynamite Fuze 160A= Hobbywing Max6(PROGRAM LIMITED VIA DYNAMITE CARD, EXTREME HV BEC)
• Dynamite Fuze 130A= Hobbywing SC8 (PROGRAM VIA DYNAMITE CARD)
• Dynamite Fuze 90A= Castle Sidewinder 8th
• Thunder Tiger BLC-150C= Hobbywing EzRun 150a (LIMITED PROGRAMMING)
• Thunder Tiger BLC- 80C= Hobbywing EzRun 80a (LIMITED PROGRAMMING)
• Ace 150a= Hobbywing EzRun 150a (LIMITED PROGRAMMING)
• Reedy SC300-BL= Hobbywing Quicrun 16BL30. (LIMITED PROGRAMMING)
• Reedy SC600-BL= Hobbywing Quicrun 10BL60 (LIMITED PROGRAMMING)
• Reedy SC800-BL= Hobbywing Quicrun WPBL80 (LIMITED PROGRAMMING)
• Reedy SC1000-BL= Hobbywing SC8 (LIMITED PROGRAMMING)
• Leopard BL5= Hobbywing Max5 (LIMITEDPROGRAMMING)
• Leopard BL6= Hobbywing Max6 (Limited PROGRAMMING, ALL BL6 UNITS LIMITED TO 6S LIPO MAX)
• HoBao 89421= Hobbywing Quicrun 8BL-150 (LIMITED PROGRAMMING)
• HoBao 89341= Hobbywing Quicrun 8BL-100
• Spektrum Firma 80a = Hobbywing Max10 SCT with smart features(limited to 3s.)
• Spektrum Firma 100a = Hobbywing Max10 SCT with smart features(limited to 3s.)
• Spektrum Firma 120a = Hobbywing Max10 SCT with smart features.
• Spektrum Firma 130a = Hobbywing Max10 SCT with smart features. 
• Spektrum Firma 150a = Hobbywing Max8 with smart features.
• Spektrum Firma 160a = Hobbywing Max6 with smart features.
• Team Corally Torox 185 = Hobbywing Max8.
• WP-6BL160 = Hobbywing Max6(COMES IN 6S AND 8S VERSIONS. SIMILAR TO THE HEX6)