Brushless motor controller with reverse

I have been searching for a motor controller for a sensored brushless hub motor that includes reverse capability. The application for all intensive purposes during this discussion would be very similar to how a Segway reacts. There will be constant swapping between forward and reverse based on the demand from an Arduino. The motor i will be driving will be between 36v - 48v and between 350w to 500w. Is there a controller out there that anyone has seen that has this capability that won't break the bank?

Kelly controllers offer variable reverse but im not sure how it handles constant swapping but i would assume it ok as long as the throttle signal is momentarily cut between swaps. Check the manuals out on kellycontroller.com

Many controllers have a reverse function but in most of them the reverse speed is much lower than the forward speed. Some may have settings in software to change the reverse speed limit.

Kelly def has program option for 100% speed in reverse

Thanks for getting back so fast. I checked out Kelly controllers. The KLS4812S looks like it would do the job, though it's slightly pricy for my application at this point. I'm in the proof of concept stage of prototyping something and was hoping for a controller to play with at a more disposable price...considering a standard hub motor controller can be had for about $30 on eBay. Does anyone know of a method for achieving this for a little less money?

I'm more used to working with brushed DC motors and the controller would have a pwm speed input pin as well as 2 direction pins. So, simply pick which direction pin to pull up, and away you go.

Thanks

I've had a few generic ebike brushless controllers with reverse, but they all work a bit differently from each other.

Some will reverse at lower speed or power.

Some reverse full speed/power, but only if you completely stop the motor motion manually first.

Only one (an old Grinfineon thats not made anymore) will start reverse at full speed/power *and* while still moving forward.

So, I looked into the Grin Technologies controllers and actually found them still being sold at ebikes.ca. I read through the whole manual and couldn't find anywhere that it explicitly stated that you could reverse will in forward motion. They did look like nice controllers though. I have searched the web today for about 7 hours scouring every forum I could find and I'm very surprised to see that there isn't a brushless controller out there anywhere that could accomplish what I need. (Segway type function)

I really have to find one as it is essential to what I'm trying to achieve. Can anyone confirm that the Grinfineon controllers can deal with a reverse signal will rotating forward and apply appropriate reverse torque? Almost like braking that continues on to driving in the reverse direction.

If anyone has any leads on where to find a controller or how to accomplish this...PLEASE let me know.

Thanks!

shane0926 said:

So, I looked into the Grin Technologies controllers and actually found them still being sold at ebikes.ca.

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That's probably because ebikes.ca *is* Grin Tech.

Keep in mind that, as I said above, the one I have isn't made anymore; it's an old version.

Doesnt' mean the new ones won't do the same thing, but I haven't had one so I don't know.

Can anyone confirm that the Grinfineon controllers can deal with a reverse signal will rotating forward and apply appropriate reverse torque? Almost like braking that continues on to driving in the reverse direction.

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Have you asked Grin Tech if the model they currently sell can do that? (or any of their other controllers, like the Phaserunner, etc) They may have tested this specific scenario on one of their Unicycle builds.


I'm sure there's something out there that can do what you want.

Most controllers aren't going to allow reversing direction if the throttle is above zero. Your control circuit would need to ramp the throttle down to zero, then hit the reverse switch and ramp the throttle back up. This could all be done pretty quickly but the ramp up speed might be limited by the controller.

Perhaps controllers intended for unicycle use will have the appropriate rapid-reversing logic. Grin does work with unicycles so they should know which of their products would be appropriate. You might try corresponding with their customer support.

fechter said:

Your control circuit would need to ramp the throttle down to zero, then hit the reverse switch and ramp the throttle back up.

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Yes, this is it precisely. It seems that one of the only applications for this specifically is a Segway/Unicycle/Hoverboard. So, I guess the complanies behind these devices must have all designed their own proprietary controllers.

Alan B said:

Perhaps controllers intended for unicycle use will have the appropriate rapid-reversing logic. Grin does work with unicycles so they should know which of their products would be appropriate. You might try corresponding with their customer support.

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I have reached out to them, waiting on a response.

Thanks!

This guy has made a number of self-balancing projects that would need to have a motor controller with reverse. I haven't dug through the website thoroughly, but it may have the info you're looking for or he may be able to help out.

https://sites.google.com/site/onewheeledselfbalancing/

If you are using an Arduino or some other microprocessor to manage the gyro inputs etc., that could be programmed to do the throttle ramping and reverse switching so you can use a "normal" controller that has a reverse function. I don't think any controller is going to be happy with a direction change while the motor is being powered.

The problem with most of the "normal" controllers I have used that have a full-power/speed reverse function, is that this function cannot be engaged until the motor comes to a full and complete stop, whether it's being powered or not.

I don't know how representative mine are of the generally available ebike type controllers, but I suspect they're fairly typical of generic stuff.

amberwolf said:

The problem with most of the "normal" controllers I have used that have a full-power/speed reverse function, is that this function cannot be engaged until the motor comes to a full and complete stop, whether it's being powered or not.

I don't know how representative mine are of the generally available ebike type controllers, but I suspect they're fairly typical of generic stuff.

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Hi sorry to jump in this post so abrupt but I am actually trying to achieve this function myself. I just want my utility cart to go forward and reverse to but I don't need speed of zero Mega fast back and forth. Just simple.. come to a stop... then reverse nice and gently, with a thumb throttle and continue. I'm in the business of moving lots of weight at work, so I motorized a rubbermaid cart, reg. Controller, 36v 350watt brushless hub motor wheels, and battery. Just need to fig. Out how to engage the reverse function. Please send thoughts thank you

Are your controllers capable of reverse? What does it say on the website they were bought from? If there is no reverse function listed it's possible (likely) they don't have one. If you're not sure, post the link here so we can check.

If you can afford new ones if these are damaged, then you can experiment by opening one up and taking good clear pics of both sides of the board inside, so that all of the existing wires and the pads they solder to are clearly visible and their markings readable.

The pics are both so you can have a reference of how it is wired now in case wires come loose in this testing, and so you can post them here to see if anyone happens to know your specific controller.

Sometimes there are unused pads with markings that indicate their function...but there is no clear set of standards used for these markings, so which function is which marking is guesswork.

That's where the experimentation would come in. Most of these types of functions are turned on by connecting them to ground.

amberwolf said:

Are your controllers capable of reverse? What does it say on the website they were bought from? If there is no reverse function listed it's possible (likely) they don't have one. If you're not sure, post the link here so we can check.

If you can afford new ones if these are damaged, then you can experiment by opening one up and taking good clear pics of both sides of the board inside, so that all of the existing wires and the pads they solder to are clearly visible and their markings readable.

The pics are both so you can have a reference of how it is wired now in case wires come loose in this testing, and so you can post them here to see if anyone happens to know your specific controller.

Sometimes there are unused pads with markings that indicate their function...but there is no clear set of standards used for these markings, so which function is which marking is guesswork.

That's where the experimentation would come in. Most of these types of functions are turned on by connecting them to ground.

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Nice. Got it thanks I'm looking for the link

amberwolf said:

Are your controllers capable of reverse? What does it say on the website they were bought from? If there is no reverse function listed it's possible (likely) they don't have one. If you're not sure, post the link here so we can check.

If you can afford new ones if these are damaged, then you can experiment by opening one up and taking good clear pics of both sides of the board inside, so that all of the existing wires and the pads they solder to are clearly visible and their markings readable.

The pics are both so you can have a reference of how it is wired now in case wires come loose in this testing, and so you can post them here to see if anyone happens to know your specific controller.

Sometimes there are unused pads with markings that indicate their function...but there is no clear set of standards used for these markings, so which function is which marking is guesswork.

That's where the experimentation would come in. Most of these types of functions are turned on by connecting them to ground.

Click to expand...

Hi again, so this is what I have and in the description it says this controller has directional change capability. Just don't know how to engage this function, or maybe put a switch and wire it? And I don't want to install a reverse polarity know that u twist... I'm trying to make this so I can reverse direction when need be and use a thumb throttle nice and gently. VGEBY Brushless Speed Motor Controller, Brushless Motor Sine Wave Controller with LED Display for Electric Bicycle Scooter(36V) Ebike Controller Electric Motor Fat Tires 19/7/8 https://a.co/d/6d4emKl. Also this is the DC brushless motor I'm using to pair with so it can move a heavy load. Alomejor 350W High Power Single Drive Scooter Hub Motor Kit DC Brushless Wheel Motor Remote Control for The Electric Skateboard https://a.co/d/cNKpu6B

Also if I have to use a toggle switch and controller that reverses polarity or "direction" by switch, I really don't like toggle throttle.. really uncomfortable and thumb throttle with sensitivity is what I'm aiming for. Please, thoughts

I don't see a reverse wire in the picture of the controller. Ones with reverse typically have a forward/reverse switch. The controller may be able to be set up in either direction, but I don't see a way to change it with a switch. Sometimes inside the controller you can find a spot on the board for the reverse switch but no wires are attached.

Theoretically, couldn't you add reverse to any controller just by having some huge switches/relays that swap the hall sensor order and phase wire order? Although, like stated, some might need to be stopped when you do that. I've never managed to get my Grin Baserunner controller to start correctly without rolling forward slightly first before adding throttle.

The controller linked doesn't appear to have any externally-available reverse function. It may have one in it's display setup menus, but it probably isn't accessible quickly and easily.

There could be a pad available on the board for the function...but it would require disassembly of the controller and experimentation to find, if it exists. (risking damage to the controller).

I am not sure how well the motor will do what you want, but I haven't tried something like this, so you'll have to try it out and see.

Presumably you are trying to only move the cart at walking speeds, so I would recommend picking parts that will result in the wheel(s) driven by the motor having a maximum speed that matches the fastest speed you want the cart to move at.

If you use a system that has a much higher speed than what you will use it at, and have to use full throttle to make it move the load, it will overheat the motor and possibly controller.

The closer to the speed you want the cart to go that the system actually runs at, the better and more efficiently it will operate, and the more controllable it will be.

BTW, a "trigger" type throttle might be easier to manipulate on a cart handle than a thumb type, and be harder to accidentally trigger by bumping into it with something. But that's something you'll have to decide based on your actual usage scenaro.


The sensitivity of the throttle usually depends more on the controller response and how well matched the system is to the intended usage and speed.

Most controllers, like the one you link to, control speed of the motor (not of the whole system), but there are controllers called FOC that control torque of the motor instead, and those are easier to control in situations like yours.

If you find it difficult to control with the setup you start with, and ti's already optimized for the speed range you need it to move at, then if you have to change controllers at any point, using one with FOC control (like any VESC, for instance) can make it easier to control with high loads at low speeds.

lnanek said:

Theoretically, couldn't you add reverse to any controller just by having some huge switches/relays that swap the hall sensor order and phase wire order?

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Yes, but you'd almost certainly have to power off the controller during the changeover so no damage could occur to the FETs due to controller trying to do something in reaction to the wiring change as it occurs. Not just come to a stop, but actually power off the controller (or at least it's LVPS / KSI wire disconnected), before switching directions this way.

Dam, this just leaves me with more questions... I appreciate and hear what everyone is saying but is. There any way Or if it's possible. Does this site or is there any way? I can do a live chat with someone here or one of you in a chat room. It would be much easier to ask and get feedback

It would just be much easier to interact

Like for instance, is there a setup you're supposed to have for pushing something with heavy weight at low speeds.. or i honestly thought that, what I did was, look up how many watts it took to = 1 hp, because 1 hp can move roughly 330 pounds.. therefore I bought 2, 36v 350 watt skateboard dbs2.0 wheel assembly sets, and both combined.. = about 700watts together. So with that wattage I should definitely be able to move all these hospital supplies I'm hauling. It's so heavy like 300 pounds of sterile water. Sorry off topic, but that's the type of goal hear. Please if I went about it all wrong and there's easier better way, I'm open to that too, but really want to use these hub wheels. THE other issue mentioned.. I understand now but not before. You are saying, if my wheels are meant to operate sufficient at high speeds.. then using it to push heavy Weight at low speed will damage? To add to that, I saw a video where a man bridged or "jumped" or "shorted" sorry if the wrong term, 2 other extraneous wires and this actually limited the speed.. and full use of throttle was fully functional but limited. Can this be an option for my situation? Also I was going to get the 36v 10s4 100ah , 100000mah blue battery from alibaba to match this setup. Hoping I can get at least 4 hrs of use out of it. ( sorry for this long comment question, wish there was live chat), thoughts please .