QS205 50H V3 and Sabvoton SVMC 96120 Throttle and Motor Noise...

Putting my new build together but so far I've encountered 2 problems...

𝗠𝗬 𝗦𝗘𝗧𝗨𝗣:
𝗠𝗼𝘁𝗼𝗿: QS205 50H V3
𝗖𝗼𝗻𝘁𝗿𝗼𝗹𝗹𝗲𝗿: Sabvoton SVMC 96120
𝗕𝗮𝘁𝘁𝗲𝗿𝘆 has a top charge of 97.7v and a low cut off of 70v, capable of 80 amps continuous output.


𝟭. 𝗶𝗳 𝗜 𝗲𝘃𝗲𝗻 𝘁𝘂𝗿𝗻 𝘁𝗵𝗲 𝘁𝗵𝗿𝗼𝘁𝘁𝗹𝗲 𝗲𝘃𝗲𝗻 ~𝟭/𝟭𝟬𝘁𝗵 𝗼𝗳 𝘁𝗵𝗲 𝘄𝗮𝘆, 𝗶𝘁 𝗷𝘂𝘀𝘁 𝗴𝗼𝗲𝘀 𝗳𝘂𝗹𝗹 𝗯𝗹𝗮𝘀𝘁... it's like it's 0 or 100 and nothing in between. My throttle shows the voltage range is from 1.17v to 5v as I twist it to 100% but the motor just goes full blast as soon as the throttle is even 0.1v above the low voltage - 1.17v (it seems). Currently have mid voltage set to 2.5v. I tried setting my throttle mid current to 50 (phase amps) for testing but... for some reason it resets to 0.02 A every time I twist the throttle or go to a different tab and then back...? Anyone know what I'm doing wrong here?

𝟮. 𝗠𝘆 𝗤𝗦𝟮𝟬𝟱 𝗶𝘀 𝗹𝗶𝗸𝗲... 𝗦𝗨𝗣𝗘𝗥 𝗹𝗼𝘂𝗱 compared to every other motor I've had (on a sinewave controller). The noise level is about equivalent to a table or circular saw (see video in link below). When I spin the motor by hand, it's very clunky and almost sounds like something is scraping. Something I've never heard in any of my other hub motors. Is it normal for the QS205 to be this loud?

Link to video and settings photos:

https://drive.google.com/drive/folders/1okClsmJCk3Mo6cDQU19e-KE_a6_rYn5w?usp=sharing

DotScott said:

𝟭. 𝗶𝗳 𝗜 𝗲𝘃𝗲𝗻 𝘁𝘂𝗿𝗻 𝘁𝗵𝗲 𝘁𝗵𝗿𝗼𝘁𝘁𝗹𝗲 𝗲𝘃𝗲𝗻 ~𝟭/𝟭𝟬𝘁𝗵 𝗼𝗳 𝘁𝗵𝗲 𝘄𝗮𝘆, 𝗶𝘁 𝗷𝘂𝘀𝘁 𝗴𝗼𝗲𝘀 𝗳𝘂𝗹𝗹 𝗯𝗹𝗮𝘀𝘁...

Click to expand...

if you're testing offground, no load, and the throttle control type in the controller is "torque throttle" or "current throttle", then that is normal. you'd have to test while riding, or with a significant load on the tire, to see it's normal operation mode.

can't help with the "settings not staying" problem.

𝟮. 𝗠𝘆 𝗤𝗦𝟮𝟬𝟱 𝗶𝘀 𝗹𝗶𝗸𝗲... 𝗦𝗨𝗣𝗘𝗥 𝗹𝗼𝘂𝗱 compared to every other motor I've had (on a sinewave controller). The noise level is about equivalent to a table or circular saw (see video in link below). When I spin the motor by hand, it's very clunky and almost sounds like something is scraping. Something I've never heard in any of my other hub motors. Is it normal for the QS205 to be this loud?

Click to expand...

can't access the pics/etc., but if you're hearing actual noises inside it while hand-spinning it, there's a problem somewhere. you'd ahve to open it to find out what that is. but if it's brand new, you should first ask qs about that, because if it has a warranty, it might not after you open it up.

it could be a cable not tied down, or a magnet that has come loose, or a bit of debris left from manufacturing, etc.



if you need to post pics the best way is to attach htem directly to the post, because then anyone that can see the post can see the pics.

for video, youtube seems to work (be visible, play) for a majority of people around the world.

if you're testing offground, no load, and the throttle control type in the controller is "torque throttle" or "current throttle", then that is normal. you'd have to test while riding, or with a significant load on the tire, to see it's normal operation mode.

can't help with the "settings not staying" problem.

Click to expand...

Good call on the throttle - I figured that soon after posting this. Forgot to update.

can't access the pics/etc., but if you're hearing actual noises inside it while hand-spinning it, there's a problem somewhere. you'd ahve to open it to find out what that is. but if it's brand new, you should first ask qs about that, because if it has a warranty, it might not after you open it up.

it could be a cable not tied down, or a magnet that has come loose, or a bit of debris left from manufacturing, etc.



if you need to post pics the best way is to attach htem directly to the post, because then anyone that can see the post can see the pics.

for video, youtube seems to work (be visible, play) for a majority of people around the world.

Click to expand...

Added the photos to the original post. Working on uploading the video to youtube :thumb: in terms of the motor: It's a good idea but at the same time... I have had TERRIBLE luck with QS customer support. They basically just tell me whatever I want to hear or whatever will get me to stop bothering them (just in my experience). Getting them to correct my order was like pulling teeth (and took several months) but... I'll give it a shot :thumb:

There's not that much noise when hand spinning it. In fact, if I shut the controller off while the motor is spinning, the whining/whistling noise goes away. I've been trying various hall tests seeing if that changes anything but so far, nothing. It still sounds like a table saw or circular saw. Just very noisy like a power tool. It IS the largest motor I've put to use but... it's weird that this one is making so much noise when my Crystalyte was dead silent at the same amount of power...

Thanks for taking the time to make suggestions and help! Greatly appreciated!

if the noise isn't present *at the same rpm* when handspinning the motor, vs when controller-spinning it, then the problem is in the way the controller is driving it. that could be any of a bunch of things, so the simplest way to test first is to try a different controller if you have one (even if it is not powerful enough to do what you want, if it will drive it at all, it's better than no test).

if the hand test is not at the same rpm as the controller test, then the noises could be completely different, and incomparable.

but, you did say that when you spin the motor by hand there is a mechanical noise inside. to find and fix that, you would *have* to open it up (or send it to qsmotor under warranty, if there is one).

if this mechanical noise is caused by the right kind of things, then it could be even worse when under power, and some of the problems (wires or windings rubbing on covers, etc) could actually cause electrical issues, even controller failure, once the insulation wears off.


the qs205 i have here isn't yet able to be tested with a controller (i got it used with the axles sheared off), or rotated by hand properly, but i don't recall any noise in the tiny rotational by-hand test i did before opening it up.


as a side note, i think someone has said that this particular motor must be driven by a sinewave controller in sine mode (some have a fallback trapezoidal mode if something doesn't work, like hall errors, etc). if true, it would likely be noisier in trap mode than other motors in the same situation.