There is a lot of mystery surrounding motors & motor technology… There is not much info online and hardly anyone has done any testing for the motors we like to use for our electric skateboards… When I first started building electric skateboards for people I figured all motors must be fairly much the same, so I figured I will just get the cheapest ones with the correct KV and Shaft Size, Because just like everyone else I don’t want to be ripped off and pay more for something that is just as good as the cheaper option…
Well… it would appear that motors are one of those things that “you get what you pay for” So I went searching for the best, I thought I found it several times… Until you blow it up or it falls apart, then the search continues for another motor…
The current version of the R-SPEC (R-SPEC 2.0) is rock solid… never gets hot!, sounds like an F1 car! its very impressive… I tried bartering my motor factory down to get a better price, but they would not budge! So then I started to wonder how can other factories offer basically the same thing (they all look very similar, lots of copy cats!) for much less… So I started investigating!
And it would appear there is a a lot of things that can be done to make motors cost less to manufacture… pretty much all these “money saving” things reduce the quality of the the motor… cheap motors are CRAP!
Anyway here is the video I made to help educate people about the differences between crap motors & good ones.
The R-SPEC looks very solid !
What is the difference (a part from the KV) with the tacon bigfoot ?
It share the same external structure at least, right ?
YES, they look very similar, I asked my motor factory if they made the Tacon BigFoot, But they said it is not from their factory. I have not purchased a BigFoot to do a comparison.
I think some factories buy the same “End Cap” Parts from CNC suppliers. That is why so many motors look similar on the outside.
i was beginning to get suspicious about that when I was comparing motors online a while back. It makes sense that the supplier would also have suppliers and that there’s probably only a couple shops out there making these end caps.
Locking ring is also on the Tacon Bigfoot.
Most motors wiring are all machined and not handwound unless you purchase 20 custom motors only.
The balance goop is also on the Tacon Bigfoot.
The 50mm SK3 motors have a locking ring.
I’m pretty sure the 63mm SK3 motors also have a locking ring.
Those are all standard features Crack me up
The rear end of a motor that clamps onto the motor shaft should always be checked preferably replaced with an M3 or M4 bolt than a set screw which can provide more torque or force. A bit of medium threadlock helps too to help prevent the bolts from backing out due to vibration and rotations.
My video was getting rather lengthy so couldnt go into full details, So lets talk specifics of my findings over the last 18 months of testing motors.
SAITE: Who have confirmed to be manufacture of the Alien Power System motors hand wind their motors, they mostly outsource machining of parts to different factories, they basically just do final assembly. But they do have a Magnet locking ring. From testing their motors I get inconsistent results, some are good some burn up very quickly. Overall assembly seems fine, however some quality issues like epoxy everywhere (inside tapped holes etc) I think there are big inconsistencies with KV rating. Biggest Problem is overheating and shorting out.
NTM PROP DRIVE: Supplier HobbyKing.com, Manufacturer unknown, look to be machine wound, don’t have locking ring - epoxy only for holding magnets. Some are good some are not so good, they don’t seem to handle high temps well and eventually seem to fall apart. But some last really well… The shaft commonly comes loose & Insulation melts on phase wires.
SK3: Supplier HobbyKing.com, Manufacturer unknown, Appear to be machine wound, most appear to have locking ring, From testing these overall seem fairly good. But suffer from the same problem of the NTM they eventually seem to fall apart. It must be due to the epoxy quality used to hold everything together, probably not rated for higher temps. Phase Wire Insulation melts. Motors can get very hot. If you must get a hobby grade motor probably get these.
EMP: Huge China Motor Factory, there motors are everywhere & are very cheap… but build quality seems poor from samples. Overall the biggest let down is assembly & precision. Loose shafts, loose magnets, Epoxy Everywhere (or not anywhere) Some samples fell apart in my hand, barrel not glued securely to end cap. No magnet locking ring. They don’t seem to be balanced. In some of the 63mm motors tested the actual size of stator was really short. So lots of “empty” space inside motor, this appears to be a money saving strategy. During testing had motors completely seize.
I made some mistakes in my video.
I said the windings can handle 180 degrees temperature. In my mind I was thinking about the MAX temp your motor should ever go to before it is destroyed. The winding used can go much higher to around 300C however at that temperature the magnets start to permanently lose their magnetic properties.
The magnets are safe to about 120C any higher and they start to loose some magnetic properties 5-10%… keep pushing pass this temperature for extended time and they will permanently de-magnetise.
The Sator & Windings of R-SPEC are dipped in a special chemical bath for 24 hours to make the motor stator & windings water resistant. However you should not ride through water.
I may have gotten lucky with my prop drives. I keep hearing things about them but i keep getting amazing performance out of them. Even in the Florida rain and heat.
I’ve still got my first ever Ntm prop drives… one of them even went hurtling down the road at 45km/h and smashed into the gutter when my alien motor mount snapped… but it still works.
I had to disassemble one once to put extra glue onto set screws.
Unbelievable really…
I have a feeling they switch factorys about 12 months ago and the reliability dropped.
The other option is to grind a flat spot on the shaft for your grub screw. That’s what I’m doing at the moment and I’m having zero problems. A keyway is definitely a better option though. Just make sure those grubs are tightened and thread locked because I have lost keys on the trail before.
Crack me up