Can you run this BLDC motor backwards?

[skyeg3]

I am interested in using the hub motors from the Segway Ninebot G30 scooter to make this cart pictured below. Motor link:

Hub Motor & Rear Wheel Assembly for the Ninebot MAX G30x Scooter

Hub Motor & Rear Wheel Assembly for the Ninebot MAX G30x Scooter

www.monsterscooterparts.com

Could anyone speculate as to whether these motors could be run in reverse? Just wondering if all BLDC motors can be run in reverse or if it is likely that they have some kind of timing that is optimized for forward travel. Ideally the motors would have the same power and speed profiles whether in reverse or forward.

 

[Botvink]

Yes it can be reversible, from images it looks like basic hall sensored motor. Timing can be optimised at coding or maybe modifying motor inner structure (repositinoning hall sensors little).

 

[chuyskywalker]

all BLDC motors can be run in reverse

Yes.

 

[lnanek]

Generally, you have to search for a teardown video/web page. If the motor is direct drive, you are good. If it is geared, you generally have to weld the clutch to run it backwards.

Often you can tell by rolling it backwards with the power off. If there's resistance to rolling backwards, it can usually be run backwards too.

 

[amberwolf]

Could anyone speculate as to whether these motors could be run in reverse? Just wondering if all BLDC motors can be run in reverse or if it is likely that they have some kind of timing that is optimized for forward travel.

Yes.

Meaning, all of those could be true, but it is likely they are neutrally timed for any hall sensors they have installed, so would behave the same forward and reverse.

If a motor has non-neutrally-timed position sensors, then you could use it sensorless and sensor timing/placement then would not matter.

Or you can install your own neutrally-timed sensors inside it. (there are some threads about adding hall sensors to outrunners that apply to most motor configurations).

 

[skyeg3]

Ah I knew I'd find great help here! Good old Endless Sphere... @Inanek, Found a teardown video. The motor looks to be direct drive. Is anyone able to tell if these are neutrally timed from this crappy screenshot? Video link:

Next question... If I wanted to find a controller for this that I could send signals to from a rasberry pi or similar. What controller would you guys recommend? I would want regen and reverse. I would think the Ninebot g30 controller might not be easily hacked so looking for something made for hobbyists if possible and something that integrates well with the pi. Also would the controller be able to tell me how fast the motor was turning? Would it be able to do so if I used a sensorless motor? I'm going to want this information to know how aggressively the steering can turn.

Thanks everyone for the help.

 

[amberwolf]

Neutrally timed halls are usually in the center of coils or directly between them, non nuetural are usually offset from centerlines.

VESC is probably your best bet for a customizable controller with potential for communication with an external MCU, since you can customize it's software yourself if necessary to suit your needs, so fi ti doesn't already talk over a serial bus or whateve ryou can write something to do that and add it to the VESC code.

 

[stancecoke]

I would think the Ninebot g30 controller might not be easily hacked

There is an open source firmware for the original g30 controller, that supports the VESC Tool and there's a community that will help you implementing your backwards function for sure.

GitHub - Koxx3/SmartESC_STM32_v2: M365_MC_WB

M365_MC_WB. Contribute to Koxx3/SmartESC_STM32_v2 development by creating an account on GitHub.

github.com

The developers have a telegram group: SmartESC FW - devs - Opensource firmware for M365/G30 controllers

I've developed a branch of the EBiCS firmware (for Lishui FOC controllers) for a wheelchair puller just a few weeks ago. It uses this bidirectional Wuxing throttle for accelerating/regenerating in both directions. I've built a fun vehicle for testing

regards
stancecoke

 

[skyeg3]

Sounds like there are a few options. That's great there is a community modifying them. What are most guys doing exactly? That is great to know the controller can send variable regen signals to the motor. Question - with 4 motors and strong regen, do you think I will be ok not having mechanical brakes?

Haha nice rig! but I don't understand - is that a hub motor? It looks like the front wheel which is just the drum brake right?

Tonight's modeling of the swerve drive yielded this: This is the front load version.

 

[stancecoke]

is that a hub motor?

yes, this is a geared hub motor with a blocked freewheel, so it can work in both directions and can do regen. Why do you want to use four additional wheels? You have two big wheels already?!

regards
stancecoke

Photo of a commercial offer.

 

[skyeg3]

@stancecoke Kind of a long answer with multiple pieces but one piece of it is that I don't have very much function compared to a paraplegic. I lack hand and full arm function so attaching a bike like this is not something I could imagine doing myself at this point. I am a c5/6 quadriplegic. I have enough function to basically move a manual wheelchair on flat ground with my palms but I cant grab anything. This is why the joystick is attractive. But the other piece of it is I seem to be obsessed with the idea of a rideable swerve drive. I can't really explain this project logically. Like, I don't need it. I have a van already. I just want it and I don't know how to make the itch go away except by scratching it. I'm going to go to empty parking lots to ride this thing and let my friends ride it through cones and stuff. Who knows I may not ever even build it. That would probably be the smart thing to do!

 

[stancecoke]

I'm going to go to empty parking lots to ride this thing

Please consider some kind of suspension, otherwise one wheel will have no or at least poor contact to the street....

 

[skyeg3]

@stancecoke Definitely taking this into consideration.

 

[A-DamW]

Are 3 wheels possible for your design?

 

[skyeg3]

@A-DamW Yes and I think a low platform trike I'd roll in the back of would be a pretty simple easy way to go. And I'd just forgo all the stepper motor steering in favor of a handle bar. It would be a little top heavy and also the better thing about rolling in from the front for me is I can mount a shoulder support and seatbelts to the rollbar and just back into it. If I roll in from the back the shoulder support would need to swing away and back in after I'm in.