PSA: Why small hub motors overheat and fail

Hahaha @mccloed ?

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The community demands answers. I shall give them these answers.

I know about beer, not hub motors. :rolling_eyes:

What kind of question is thatā€¦ We all know the answer you need 12 Beer per person to build a 4wdrā€¦ because if you give 12 to 4 people they will argue over none sens for the next decade :stuck_out_tongue_winking_eye:

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4 beers each for four clones is 16 beers worth of piss. The original drinking all 16 beers is ā€¦256 beers of piss. Whoā€™s gunna prove me wrong. ? This would apply to pulley or hub beers

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Hold on. Iā€™m only on my second. Iā€™ll pm you when Iā€™m done

Ive built 4wd board with 4 different types of hub motors and three different 12S batteries from 3P to 6P. My experience with them is not inline with yours. On my 1st 2wd hub board was 12S3P with 130KV hubs, Low speed acceleration was rather poor but the board would still pull 38mph. I then added two more of the same hubs to make it 4wd and divided all battery max and regen settings in half but left the motor min and max the same per motor. Acceleration and braking (especially from low to moderate speeds) were drastically improved with the same 50A total battery Max and Min because the motor max and min total added up to double.

I did see a loss of range from about 12 to 10 miles on a 7.5Ah pack but I attribute this to the increased rolling reaistance of the front hubs compared to the clones that were on the front in the 2wd configuration.

I do agree that you need a larger battery to take FULL advantage of 4 motors but there are definite power advantages even with the same battery .The same would hold true for a belt drive.

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Motor amps are a true amount of amps circulating in the motor. U get increased low speed power and the same losses based on whatever amps, motor or, and, battery, in the motor. High motor amps since they occur at lowest speeds especially cause losses beyond the standard i2r

Not if your using zippy lipos! I can put out almost 300 amps con from them, so more than enough juice :stuck_out_tongue:

you can prob. half a zippy C ratingā€¦ just saying, itā€™s not a tattuā€¦

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The total amount of torque my 4wd board puts out would snap a single belt or bend pretty much any of the belt motor mounts Ive seen. I dont see this happening with a single FOC box, VESC 6 or other, but if anyone with a big single running a VESC wants to try there luck, performance day is only 1 month away :wink:

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@Cobber But as far as braking goes, lipos should still be charged at 1C so with out double battery high speed braking cant be doubled.

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Iā€™ve seen lipo and other chem that can be charged at a much higher rate. Also seen evidence the charge rate doesnā€™t effect cell cycles as much as max voltage charged

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Agreed, but if whatever battery you were using with the 2wd was already maxed out for batt max and regen (1C or higher if youā€™re comfortable with that) then youd need more battery to increase the limits and take full advantage of the extra hubs.

Extra total motor amps is a huge advantage for 4wd on vescs, but extra battery amps in addition to the motor amps would be taking full advantage imo.

soā€¦ your two hubs were weak at launch and you added two more and finally got up to what your pack could actually put out. YEah that makes sense. And it cost four times as much as a 38mph RWD belt system that would have just torn off the mark to begin with.

i get the math, and i get what happens on the street.

No matter how i look at it, i canā€™t justify 4wd in 99.9% of cases that donā€™t involve overcoming wind resistance on the top end.

Obviously my outlook is biased toward belt drives. I only just recently got to ride a raptor 2. I was pleasantly surprised that it almost kept up with my belt drives off the mark. I donā€™t hate hubs or 4wd, they just donā€™t deliver what i need yet. What i need is options and configurability. They have neither of those things, and the only pro is literally ease of build. The industry is driving hubs because theyā€™re cheaper to build boards with. I have never done things the easy way or the cheap way so benefits like that are easily dismissed by me. Up until about three months ago, i wasnā€™t even THINKING about hubs. Direct drives, sure. Gear drives, yeah. Even planetary geared hubs would be a vast improvement provided the ratios could be adjusted easily. But thane on a can?

iā€™m waiting for somebody to get it right (for me) still. So far, i see a lot of awesomeness but its still not right for me.

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Yes by my 280lb standards startup was weak with two 90mm wheel (6355) 130kv hubs. It had way more than enough for my 130lb friend though.

It cost me under 2k to build my 1st 4wd, which is comparable to the price you sell your builds for, but has double the motor amps a two vesc build can supply. You also said later in your post that hubs are cheaper to build with (obviously refering to 2wd hubs), which would imply that its not 4x the cost of a 2wd belt drive set up. The cost of wheels, bearings, trucks, pulleys and belts are also required for belt drive set ups but two pairs of hub motors have those parts included or are not required.

A dual belt drive with the same sized stators and a total of 50A battery and 260A motor is not going to tear off the line by my standards either unless its geared to much less than 38mph. The Raptor 2 I tested was impressive for a premade board but just moderate by my acceleration standards and was minor league compared to my 4wd hub boards acceleration from a dig all the way up, especially considering the raptor 2 tops out at 30 mph where as mine hits 40 mph.

Otherwise I agree with the rest of your post. I am also waiting for someone to get it right :crossed_fingers::wink:. And it doesnt make sense for most to go 4wd.

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Where s the info on this performance day? I need to come out, where ever it isā€¦

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YES! Maybe we should match settings on our 4wd boards to get some hub comparisons!

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Breaking news, Enertion might have something up their sleeve for performane day as well!

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Nha Unless @onloop joint the partyā€¦ Iā€™m only one guy with is Raptorā€¦ If I can bring it, because of plane and restriction and the pain in the ass of sending a battery.