Since there aren't any hall effect sensors (typically 3), your motor controller is using back EMF to determine when to commutate the motor as well as calculating your speed. Speed controllers drive 2 of the 3 phase wires in 6 different states with MosFETs, one driven with battery voltage and the other ground. The phase wire not driven goes into some electronics on the motor controller (resistors, caps, and op-amps) and it senses the back-emf. The designers use this info not only to know when to commutate the next phase of the motor, but uses the MCUs timer to calculate wheel speed. It measures the time in between the EMF pulses and based on the diameter of the hub and tire calculates your speed - 2*PI*R * time for one rotation ( 3 EMF pulses). Google back EMF for more detailed information on the topic. Same as Ale's comment below....
Thank you for that detailed explanation, very helpful. A lot of stuff going on there to get inaccurate speed most of the time. Lol. Either way thank very much you for your time.
Great video, thanks for sharing. I found some time to take my wheels off today and installed the tube liners, I took my time because I wanted a clean fit, with no over or underlap, got it back together, and took it for a couple spins around the neighborhood, all good bro. Yea thanks for the heads up on making sure it was cut to the right length to avoid speed wobble in the tire. I feel better running on puncture proof or at least puncture resistant tires. Cheers man!!
@@wattsinyours Thanks, hey for sure I love my scooter. In hind sight I should have replaced the inner tubes as long as I had them out of the tire, I remember you said you got some off Amazon, I should have done that, but at least I have the liners in the tires so it will be a good experiment. I will keep you posted on any developments.
Great content as usual. Subscribed. I built esk8 for a while and was curious to see these escooters open up. I am also going to modify mainly the electronics of these scooters. You can get more out of them. Since you asked, her efew clarications. I hope useful for everyone. The brushless motors used in escooter and skate for instance are not DC, that's one of the reason why there is a speed ccntroller to talk with them. They are powered by a battery (DC) but they are 3 phases motors. Regarding the hall sensors they are, as you said, telling the speed controller (ESC) the position of the sensors in angle related to the stator and are used to smooth out the take off when starting from stand still. Then they have no use anymore. Sometime there is also a temp sensor on it to read motor temp to prevent overheating (you can implement that, sensors cost like 5$). Concerning your correct question how the speed is calculated then the speed is based on RPM or to better say Engine RPM (ERPM). The ESC reads the back-emf and count it as 1 rotation (you can read here from an open project for advacne ESC that we used in esk8 vedder.se/tag/esc/). Since is ERPM then the size of the motor matters so you have to know the number of poles of the stator. The conversion of these values plus the size of the wheels combined with the 3.14 constant (circonference) will tell you the speed. That's why on your dashboard you can set the wheels diameter, but actually to be correct it should have the number of poles as well in order to adjust them and get the right speed. I hope it can help and thanks for your content!
Damn that was a learning experience! Thankyou for taking the time to explain this in depth. I learned more with this video than I learned in all my HS science classes combined
Hello again. Been a while. I finally had my first flat tire on my D5+2.0. It was the rear. I live in NYC. I ride every day to and from work, in the rain, and recently in the snow. Well on my way home today I had to cross the 59th street bridge ( using the bike lane ) and there was some kind of nail or bolt, spiky thing ( no point on it ) sticking out and I didn't see it. All I heard was the explosion of my rear tire. Luckily I was not going too fast. The piece of metal snapped off and stayed inside the tire. When I replaced the tire and tube it fell out. Anywho, I was hoping to also change out my rotor which is bent, but after taking the real wheel apart I realized the rotor sits on the cable side of the wheel. Do you have any idea how to take it off without having to cut the cables? If so any chance of you making a video on that process? As always thank you so much for you educational videos. I've learned so much from your efforts and I truly appreciate what you do!
Yes its the same process as the d4+. I have a video on it. Pretty easy with a little patience. Go to my videos and look for d4+ flat tire repair. Thank you for watching.
My rear motor is on the fritz. It engages for about one second and then it quits and it feels like it’s rubbing on something like the magnets are in the right place just a little off I don’t know I haven’t gotten into it yet but there’s a warning indicator light that I can’t seem to find with the indicators I don’t know where they’re at in their instruction so I’ll keep looking. thank you
@@guillermoguzman250 make sure all original screws are being used & when reinstalling the screws do all of them together like a star pattern evenly. 12 o’clock, 6 o’clock, 10 o’clock, 4 o’clock…..
Well since the rim is a split ring and i looked closely at that, i didn't see anything that looked like a sensor and also it wouldn't be in the tire itself bc that wouldn't be practical bc of flats and tire changes. But either way i will look again just to make sure. You never know i could of definitely missed something. My best guess as of right now is that it sends something like a pulse width signal back to the controller through the motor wires during rotation and is calibrated to read those pulses at a predetermined rpm or rotational force. Thats a pretty cheap and easy way to read speed but not as accurate as hall sensors.Thanks for your input and eventually together we will find out exactly what is reading the speed.
love ur videos man...does nanrobot even have a legit american tech guy for troubleshooting cause I've sent him my issue with video evidence and he said he would jus look into it and that was a month ago...my issue is jus odd like the motor is overvolting at hard throttle from start and makes a plastic grinding noise...any thoughts?
Lol no they don't. That's why we got to try and do it ourselves. So as far as your issue there are only 3 things it could be. Speed controller, throttle controller or motor going bad. Either item is not to expensive to replace but im ruling out your throttle so it's between your speed controller or motor. I would replace the speed controller first bc it's the cheapest and the easiest but mostly bc that's usually the issue. But before u go through all that go through the scooter and make sure all your connections are tight. Once verified and it doesn't get better then replace the speed controller.
This is fantastic information. Other than the bearings these motors should last a long long time right? So theoretically how long could it last with a quality set of bearings? I didn't get to finish the video. Just saw the first 10 minutes so forgive me for a lack of information.
A good quality set of bearings will last a super long time. The one's that came with it are fine just not as good. Japanese or german bearings are usually top shelf.
@@wattsinyours Any speciality tools needed to change out the bearings? It would be fantastic to not have to depend on the manufacturer to repair the scooters. So much money saved and of course the pride you get doing it yourself. Thanks again for this video.
@@mtbse789 possible need a bearing puller and something to press the new bearing on, but if you get creative and be carefull with the bearing you can probably do it with some basic tools.
It wouldn't be in the other motor because when you have the switch on the dash panel to only single motor then it would only be reading back motor speed and not front motor speed. The speed is read through a voltage signal, so if the front motor isn't powered it will not read any speed on the front motor. Only the back.
@@wattsinyours Well I made a really simple test with my D4 and it's the rear motor that senses speed. Just make only Front wheel then only Rear wheel spin and look at the speedometer... Don't mess with the P2 adjustment.
@@-12382 there might be a loose connection at your on and off switch so i would check that first, but if that is good then you will have to take off the deck and look inside the scooter. I did a video on that and i go through the wires, so maybe that will help you out after you watch it.
hello good I want to ask you a question I have a D6 because the air chamber deflates every so often, I check it and it has a minimum hole on one side, I mean, it drills it then I put a new air chamber and it continues the same I roll like 20 min and then deflated a little hole you will know what the problem is, thank you very much
I have been having problems with my scooter. It is not even 1 year old, and when I ride it, it makes this vibration from the rear wheel, and it overheats causing a puncture in the inner tube. Over 1 month I replaced the inner tube 3 times. Is there something I can do
@@wattsinyours set p0 to 10 and p2 to 18. Speed accuracy is way better per my garmin GPS speedo. I know you explained it in your video but can you summarize why setting p2 to 18 did the trick?
@@MinhvuLy because its not reading hall sensors. P3 is reading pulse width modulation. Basically it corresponds with voltage. Thats why p3 is default at 1 and not 0 like the manual says.
For me i don't think it would be hard at all..15min job at most once you have the motor apart. I cant really speak for others though. There is a little skill and technique involved but it is not a complicated job.
Very helpful! What is the p2 setting you found to get accurate speed? mine seems to be 17 18 or 19 but I'm not certain because I can't look at my phone while I'm riding, I don't have a mount set up
I haven't had a chance to retest for accuracy before i post it. I dont want to give the wrong info, but i think it was 18 if i remember correctly. Also remember when going at higher speeds (over 25mph) don't get discouraged bc the voltage increase and decrease bc of "pwm" is going to fluctuate until your going at a consistent speed.
Hi, I also set up my P0 to 6 and the speed is quite accurate ; Did you finally changed your settings (P0, P2 and P3) in order to be as accurate as possible ? I missed the point Thanks
That is what i had it set orginally P0 to 6, but now that i know it does not have hall sensors i will make that adjustment. I haven't had a chance to make the adjustments and test yet, but i will soon and let you know the results. Thank you for your comments and watching my videos.
You said in th-cam.com/video/9Pzyjyexfjc/w-d-xo.html 12:12 those black thingys are 6 sensors I guess that was before you opened up the motor. What do you have P2 set now to?
Since there aren't any hall effect sensors (typically 3), your motor controller is using back EMF to determine when to commutate the motor as well as calculating your speed. Speed controllers drive 2 of the 3 phase wires in 6 different states with MosFETs, one driven with battery voltage and the other ground. The phase wire not driven goes into some electronics on the motor controller (resistors, caps, and op-amps) and it senses the back-emf. The designers use this info not only to know when to commutate the next phase of the motor, but uses the MCUs timer to calculate wheel speed. It measures the time in between the EMF pulses and based on the diameter of the hub and tire calculates your speed - 2*PI*R * time for one rotation ( 3 EMF pulses). Google back EMF for more detailed information on the topic.
Same as Ale's comment below....
Thank you for that detailed explanation, very helpful. A lot of stuff going on there to get inaccurate speed most of the time. Lol. Either way thank very much you for your time.
Great video, thanks for sharing. I found some time to take my wheels off today and installed the tube liners, I took my time because I wanted a clean fit, with no over or underlap, got it back together, and took it for a couple spins around the neighborhood, all good bro. Yea thanks for the heads up on making sure it was cut to the right length to avoid speed wobble in the tire. I feel better running on puncture proof or at least puncture resistant tires. Cheers man!!
Good job man! Glad to hear that worked out for you. Keep us updated later on with any issues or success. Ride safe.
@@wattsinyours Thanks, hey for sure I love my scooter. In hind sight I should have replaced the inner tubes as long as I had them out of the tire, I remember you said you got some off Amazon, I should have done that, but at least I have the liners in the tires so it will be a good experiment. I will keep you posted on any developments.
Great content as usual. Subscribed. I built esk8 for a while and was curious to see these escooters open up. I am also going to modify mainly the electronics of these scooters. You can get more out of them. Since you asked, her efew clarications. I hope useful for everyone. The brushless motors used in escooter and skate for instance are not DC, that's one of the reason why there is a speed ccntroller to talk with them. They are powered by a battery (DC) but they are 3 phases motors.
Regarding the hall sensors they are, as you said, telling the speed controller (ESC) the position of the sensors in angle related to the stator and are used to smooth out the take off when starting from stand still. Then they have no use anymore. Sometime there is also a temp sensor on it to read motor temp to prevent overheating (you can implement that, sensors cost like 5$).
Concerning your correct question how the speed is calculated then the speed is based on RPM or to better say Engine RPM (ERPM). The ESC reads the back-emf and count it as 1 rotation (you can read here from an open project for advacne ESC that we used in esk8 vedder.se/tag/esc/). Since is ERPM then the size of the motor matters so you have to know the number of poles of the stator. The conversion of these values plus the size of the wheels combined with the 3.14 constant (circonference) will tell you the speed. That's why on your dashboard you can set the wheels diameter, but actually to be correct it should have the number of poles as well in order to adjust them and get the right speed.
I hope it can help and thanks for your content!
Nice input man. Thanks for sharing
Hmm. Do you think the D4+2.0 motor is the same (no hall sensor)? Changing the hall sensor reading seems much more logical. SUCH a good call, man.
I just looking back at my video for the d4+ and yep no hall sensors.
Damn that was a learning experience! Thankyou for taking the time to explain this in depth. I learned more with this video than I learned in all my HS science classes combined
'This is my scooter, there are many like it but this one is mine' ~
Slogan of the Future Marine Stealth Invasion Vehicle poster.
Lmao! Good one.
Hello again. Been a while. I finally had my first flat tire on my D5+2.0. It was the rear. I live in NYC. I ride every day to and from work, in the rain, and recently in the snow. Well on my way home today I had to cross the 59th street bridge ( using the bike lane ) and there was some kind of nail or bolt, spiky thing ( no point on it ) sticking out and I didn't see it. All I heard was the explosion of my rear tire. Luckily I was not going too fast. The piece of metal snapped off and stayed inside the tire. When I replaced the tire and tube it fell out. Anywho, I was hoping to also change out my rotor which is bent, but after taking the real wheel apart I realized the rotor sits on the cable side of the wheel. Do you have any idea how to take it off without having to cut the cables? If so any chance of you making a video on that process?
As always thank you so much for you educational videos. I've learned so much from your efforts and I truly appreciate what you do!
Yes its the same process as the d4+. I have a video on it. Pretty easy with a little patience. Go to my videos and look for d4+ flat tire repair. Thank you for watching.
My rear motor is on the fritz. It engages for about one second and then it quits and it feels like it’s rubbing on something like the magnets are in the right place just a little off I don’t know I haven’t gotten into it yet but there’s a warning indicator light that I can’t seem to find with the indicators I don’t know where they’re at in their instruction so I’ll keep looking. thank you
My motor is rubing also what do I do
@@guillermoguzman250 make sure all original screws are being used & when reinstalling the screws do all of them together like a star pattern evenly. 12 o’clock, 6 o’clock, 10 o’clock, 4 o’clock…..
Speed sensor could be in the back wheel? Since single motor mode is just the back wheel. Just and idea
Well since the rim is a split ring and i looked closely at that, i didn't see anything that looked like a sensor and also it wouldn't be in the tire itself bc that wouldn't be practical bc of flats and tire changes. But either way i will look again just to make sure. You never know i could of definitely missed something. My best guess as of right now is that it sends something like a pulse width signal back to the controller through the motor wires during rotation and is calibrated to read those pulses at a predetermined rpm or rotational force. Thats a pretty cheap and easy way to read speed but not as accurate as hall sensors.Thanks for your input and eventually together we will find out exactly what is reading the speed.
love ur videos man...does nanrobot even have a legit american tech guy for troubleshooting cause I've sent him my issue with video evidence and he said he would jus look into it and that was a month ago...my issue is jus odd like the motor is overvolting at hard throttle from start and makes a plastic grinding noise...any thoughts?
Lol no they don't. That's why we got to try and do it ourselves. So as far as your issue there are only 3 things it could be. Speed controller, throttle controller or motor going bad. Either item is not to expensive to replace but im ruling out your throttle so it's between your speed controller or motor. I would replace the speed controller first bc it's the cheapest and the easiest but mostly bc that's usually the issue. But before u go through all that go through the scooter and make sure all your connections are tight. Once verified and it doesn't get better then replace the speed controller.
This is fantastic information. Other than the bearings these motors should last a long long time right? So theoretically how long could it last with a quality set of bearings? I didn't get to finish the video. Just saw the first 10 minutes so forgive me for a lack of information.
A good quality set of bearings will last a super long time. The one's that came with it are fine just not as good. Japanese or german bearings are usually top shelf.
Good to know.
@@wattsinyours Any speciality tools needed to change out the bearings? It would be fantastic to not have to depend on the manufacturer to repair the scooters. So much money saved and of course the pride you get doing it yourself. Thanks again for this video.
@@mtbse789 possible need a bearing puller and something to press the new bearing on, but if you get creative and be carefull with the bearing you can probably do it with some basic tools.
@@wattsinyours Thanks. I will look it up.
It may be on the other motor....
It wouldn't be in the other motor because when you have the switch on the dash panel to only single motor then it would only be reading back motor speed and not front motor speed. The speed is read through a voltage signal, so if the front motor isn't powered it will not read any speed on the front motor. Only the back.
wattsinyours just a thought. Thanks for the reply
@@123motd Thank you for watching. It's feed back like yours that help us have fun and keep our scooters running smooth.
@@wattsinyours Well I made a really simple test with my D4 and it's the rear motor that senses speed.
Just make only Front wheel then only Rear wheel spin and look at the speedometer...
Don't mess with the P2 adjustment.
Great videos, thank you. Btw. please, make a video about what is inside of Nanrobot lower tube.
What lower tube are you referring to?
@@wattsinyours I mean vertical stem. I have an electric problem with front -and rear lights and I wonder how cables are inside of the vertical stem.
@@-12382 there might be a loose connection at your on and off switch so i would check that first, but if that is good then you will have to take off the deck and look inside the scooter. I did a video on that and i go through the wires, so maybe that will help you out after you watch it.
Have you delt with a rear tire on a e scooter not having any rotation when you manually turn it and when you try to use the throttle?
hello good I want to ask you a question I have a D6 because the air chamber deflates every so often, I check it and it has a minimum hole on one side, I mean, it drills it then I put a new air chamber and it continues the same I roll like 20 min and then deflated a little hole you will know what the problem is, thank you very much
I have been having problems with my scooter. It is not even 1 year old, and when I ride it, it makes this vibration from the rear wheel, and it overheats causing a puncture in the inner tube. Over 1 month I replaced the inner tube 3 times. Is there something I can do
can you provide summary? set P0 back to 10 then P2 to?
P2 will be 18
@@wattsinyours I'll try it after work. Thanks a bunch bro!
@@wattsinyours set p0 to 10 and p2 to 18. Speed accuracy is way better per my garmin GPS speedo. I know you explained it in your video but can you summarize why setting p2 to 18 did the trick?
@@MinhvuLy because its not reading hall sensors. P3 is reading pulse width modulation. Basically it corresponds with voltage. Thats why p3 is default at 1 and not 0 like the manual says.
Thanks fellas I set mine back to 10 and adjust the p2 to 18 works nice
How hard would be be to replace the bearings on this model?
For me i don't think it would be hard at all..15min job at most once you have the motor apart. I cant really speak for others though. There is a little skill and technique involved but it is not a complicated job.
Can u do one how to change a motor on nanrobot
Very helpful! What is the p2 setting you found to get accurate speed? mine seems to be 17 18 or 19 but I'm not certain because I can't look at my phone while I'm riding, I don't have a mount set up
I haven't had a chance to retest for accuracy before i post it. I dont want to give the wrong info, but i think it was 18 if i remember correctly. Also remember when going at higher speeds (over 25mph) don't get discouraged bc the voltage increase and decrease bc of "pwm" is going to fluctuate until your going at a consistent speed.
Just checked its 18
Hi,
I also set up my P0 to 6 and the speed is quite accurate ;
Did you finally changed your settings (P0, P2 and P3) in order to be as accurate as possible ? I missed the point
Thanks
That is what i had it set orginally P0 to 6, but now that i know it does not have hall sensors i will make that adjustment. I haven't had a chance to make the adjustments and test yet, but i will soon and let you know the results. Thank you for your comments and watching my videos.
Dang maybe I should lube or grease those wheel bearings
Are you a electrical engineer? Just wondering
No mechanical but both kinda go hand in hand. Thanks for watching.
You said in th-cam.com/video/9Pzyjyexfjc/w-d-xo.html 12:12 those black thingys are 6 sensors I guess that was before you opened up the motor. What do you have P2 set now to?
Stop scraping the cap against the insulation on the wires!