Adding hall sensors to outrunners

[gwhy!]

OK guys, I guess I didn't make the question clear, how do I actually determine the degrees on the motor? Do you use a degree wheel mounted on the shaft, or do you just use a protractor and more or less guess at the correct alignment? It can be quite hard to figure degrees on a round object without a degree wheel or something...

Hi Whiplash,
How I done it was to draw a circle of the dia of the motor then divide the circle up Just like in the drawing in my previous post. There are no alignment issues because when the halls are mounted ( they are not fixed to the motor but to the mounting plate) they can be adjusted to give the correct alignment.

 

[gwhy!]

Jeremy - gwhy,

Is there some advantage with specific models of motors for different hall spacing, as in better performance, lower no load current, etc?

Just wondering if KISS still applies and putting sensors @ 120 degrees around the casing doesn't make more sense?

Sorry for being ignorant, I've actually modded a few outrunners now but I just counted off the slots and guesstimated 120 degree placement then tuned for lowest no load current....

Thanks in advance!

-Mike

Hi Mike,
I have only played with 3 makes ( models ) of motor with all sorts of spacing configs but they all performed the same so I cant really say for sure if there will be any advantage of using true 120 degree spacing on other motors but I wouldn't have thought It will make any difference, The only thing I would say is that if using 17.1 degrees and guesstimating the placement would need to be far more accurate than using 120 degrees spacing and guesstimating.

 

[mwkeefer]

I suppose this is easy enough to fab up a ring or semi ring to retain the halls at the electrical 120 degree on a single phase, can you see 23 pole hub motors with 120 physical mounted hall sensors? LOL

Thanks!

-Mike

 

[Whiplash]

OK guys, I guess I didn't make the question clear, how do I actually determine the degrees on the motor? Do you use a degree wheel mounted on the shaft, or do you just use a protractor and more or less guess at the correct alignment? It can be quite hard to figure degrees on a round object without a degree wheel or something...

Hi Whiplash,
How I done it was to draw a circle of the dia of the motor then divide the circle up Just like in the drawing in my previous post. There are no alignment issues because when the halls are mounted ( they are not fixed to the motor but to the mounting plate) they can be adjusted to give the correct alignment.

Ah, OK I see, so its not as detailed as say, degreeing in a camshaft in a ICE, that is what I think of when I hear the term degrees, like it must be within 1/2 a degree of accuracy or something..

 

[Jeremy Harris]

Jeremy - gwhy,

Is there some advantage with specific models of motors for different hall spacing, as in better performance, lower no load current, etc?

Just wondering if KISS still applies and putting sensors @ 120 degrees around the casing doesn't make more sense?

Sorry for being ignorant, I've actually modded a few outrunners now but I just counted off the slots and guesstimated 120 degree placement then tuned for lowest no load current....

Thanks in advance!

-Mike

I've only used 120 degree spacing, just because its easy to fit Halls internally like this (they just fit in between the stator slots at exactly 120 degrees). I can't see that there is any significant difference between using 120 degree or any other arrangement that gives either 60 degree or 120 degree electrical angle resolution (there are several different configurations of sensors that could give signals that work OK with 60/120 auto detect controllers, like the Infineons).

Jeremy

 

[liveforphysics]

If I'm not mistaken, the in-the-slots position only works out with correct timing if you are terminated in wye. Delta will always be 30eDeg advanced or retarded of the neutral wye timing.

 

[mwkeefer]

Luke,

I could be mistaken on this but... isn't the difference a matter of flipping the middle hall to take it 60 degrees out for delta?

I know that inverting the output of the B phase hall via will correct the issue for many controllers but I've never had timing issues flipping delta / wye with infineons and stock 120 degree spacing (experience only on DD hub motors).

-Mike

 

[liveforphysics]

Luke,

I could be mistaken on this but... isn't the difference a matter of flipping the middle hall to take it 60 degrees out for delta?

I know that inverting the output of the B phase hall via will correct the issue for many controllers but I've never had timing issues flipping delta / wye with infineons and stock 120 degree spacing (experience only on DD hub motors).

-Mike

I'm not certian, and I'm in no condition to rationalize it out at the moment. lol

 

[mwkeefer]

oh, ping back to my court... why do you think I hit it your way in the first place...

Well as I recall one individual mounted a pair of halls in the center position but inverted one of the sensors (he used a dremel to grind out a bit more area) so it was face up (down, can't remember) but when he flipped to Delta initially he switched to this odd middle hall...

Then quite by accident he discovered that on the infineon controller (EB812 I believe) the no load current was the same no matter if the middle (B phase) hall was inverted or not... apparently the controller adapts automatically...

Dont think it will apply to all controllers... but it should apply to most

-Mike

 

[Burtie]

Hi Mike,

Yes, I believe you are correct about the infineon controller being able to auto detect a 120 degree or 60 degree hall pattern and work with either.

There is a field in the Parameter Designer software labelled 'PhaseDegree£'. it has options of '120', '60' and 'Compatible' . The Compatible option if the one that enables the auto detect feature.

But, I don't think this feature helps us with the theoretical 30 degree timing shift that is desireable when changing from wye to delta.



In practise the RC outrunners seem to run ok in both delta or wye when we just place the sensors between the stator teeth. But there is of course some room for improvement if the timing can be optimised for each mode.

Edit: more detail ----- http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=15686&start=200#p358949

Burtie.

 

[dbaker]

Whip lash,

If you are placing the Halls on the outside of the motor you locate them by trial and error, getting the lowest no load current and good starting ability. If you are placing them inside the motor the easiest way is to place them on the winding slots at 120 degrees. Look at Gwhy's attachment for clarity outside placement and Burtie's photos for inside placement. Distance from one Hall to the next will depend on the diameter of the circle in which they are mounted.

 

[mwkeefer]

Burtie,

I was aware of the old 846 (EB8XX) series performing autodetect but it's not assignable it's always auto detect, the 116 based (EB2XX) infineons are settable to 120, 60 or compatible... but this is for spacing of the halls...

What I am referring to is:

1.) No load current and kV doesn't change regardless of middle hall orientation (same as others or flipped) in delta or wye modes when used with Infineon controllers mentioned above..

2.) This must mean they detect termination somehow or perhaps its really just the 60/120 auto adjust that lets this happen, I really don't quite understand it...

I also haven't tested the newest EB7XX series at 60 degrees - but they use the 846 so that should be a non issue.

-Mike

 

[JuicyBurger]

Hey guys, I've read through this entire thread but I'm having a few issues here....

I'm planning on using the following:

ESC
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10370

Motor
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7070

in a Mountain Board project (will be used for transportation around my University). I don't need one of the huge motors like you guys are using (I have to STAND on it while it's accelerating) so this will work for my application... The speed controller is the cheapest CAR ESC I could find (money is an issue here for now) even though I'm worried about running at only 16 volts (for efficiency's sake).

I noticed this speed controller has a sensor input and with a little googling I found this thread! I've read through and it doesn't seem too hard to make the actual bracket to hold the three hall effect sensors on the outside at 17.1 degrees (or so). The major issue I'm having is how to wire the three sensors up to this speed controller! I realize I'm a complete noob here but a little help would be very much appreciated.

 

[JuicyBurger]

Oh and another reason for the RC controller is weight, not just price. I'm hoping to keep combined weight under 20 lbs (which is hard considering the wheels alone weigh 8 lbs). I need to carry this around!

 

[AussieJester]

I noticed this speed controller has a sensor input and with a little googling I found this thread!

I doubt that 'sensor' input is for hall sensors mate, more likely temperature sensor, rpm etc?
these guys are using brushless motor ebike speed controllers to run the rc motors after
they have fitted hall sensors, for your skate board application the rc esc will
likely be fine, couple of kicks to get the board going then hit the throttle
i gather you will be using a transmitter handset or similar to control throttle?

KiM

 

[JuicyBurger]

Yes I will be using a transmitter in my hand, this ESC provides remote Braking if I somehow fall off = P.

I'm pretty sure this sensor input is for running hall effect sensors. It says compatible with sensored/sensorless motors, such as the Novak, which uses 120 degree spaced hall effect sensors (95% sure).

So if this is true, I just need to figure out how to wire in the halls to this port for the sensor ( which is what I need help with). Not sure how exactly all the pins get used in the hall effect sensor set up (I'm a ME not an EE = P )

 

[gwhy!]

Hey guys, I've read through this entire thread but I'm having a few issues here....

I'm planning on using the following:

ESC
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10370

Motor
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7070

in a Mountain Board project (will be used for transportation around my University). I don't need one of the huge motors like you guys are using (I have to STAND on it while it's accelerating) so this will work for my application... The speed controller is the cheapest CAR ESC I could find (money is an issue here for now) even though I'm worried about running at only 16 volts (for efficiency's sake).

I noticed this speed controller has a sensor input and with a little googling I found this thread! I've read through and it doesn't seem too hard to make the actual bracket to hold the three hall effect sensors on the outside at 17.1 degrees (or so). The major issue I'm having is how to wire the three sensors up to this speed controller! I realize I'm a complete noob here but a little help would be very much appreciated.

Personally I think it will be ok with out the sensors on a mountain board application, But the info you are asking for is the + pins of the hall sensors get joined together to a common wire +, all the - pins joinded together to a common wire -, and the output of each hall has it own wire so you have 5 wire in total, have you got any more info about the esc i.e how many pins is in the socket that the sensor plugs into and is it defiantly a hall sensor input ? and what pin does what, this is going to be the tricky bit.

Cheers.

 

[JuicyBurger]

Thank you! I did not know that all the + and all the - were placed together. I have not ordered this ESC yet but I'm assuming it's the 5 wire sensor input as some RC brushless motors still come with sensors (for car applications). Determining which is which is going to be the problem... Maybe I can find an existing sensored brushless motor with this plug and figure out what pin goes where.

If I get the positive and negative correct, is it possible to just play around with the other three to find out which combination works best? Or will getting this wrong somehow mess the ESC up?

I know that a sensorless will be fine for my application, however it would be nice to have the added torque + slower speed capable. (I sometimes ride next to people walking, saves carrying it).

Thank you for your help

 

[JuicyBurger]

http://www.teamnovak.com/tech_info/brushless/sensor_vs_sensorless.html

This shows a Novak with hall effect sensors spaced 120 degrees, but mounted at the end of the motor instead of around the outside. The different mounting position will not affect the signal, will it?"

 

[gwhy!]

Thank you! I did not know that all the + and all the - were placed together. I have not ordered this ESC yet but I'm assuming it's the 5 wire sensor input as some RC brushless motors still come with sensors (for car applications). Determining which is which is going to be the problem... Maybe I can find an existing sensored brushless motor with this plug and figure out what pin goes where.

If I get the positive and negative correct, is it possible to just play around with the other three to find out which combination works best? Or will getting this wrong somehow mess the ESC up?

I know that a sensorless will be fine for my application, however it would be nice to have the added torque + slower speed capable. (I sometimes ride next to people walking, saves carrying it).

Thank you for your help

Yes That will be your best bet to find out the wiring try to find a motor with the sensor and look at the wire colors red =+ black =- output of sensors tend to be yellow, green and blue. I think it will be ok to play around with the sequence of the outputs ( but dont quote me on that as Im not totally sure ) if you do try playing with the sequence then use the min cell count and dont go giving it full throttle to test ( just the bare min to see if the motor works ) the motor should turn over with the slightest of throt input if the sequence it correct. hope this helps.

 

[JuicyBurger]

Thanks! That actually helps quite a bit. As for the hall mounting, as long as the three are 17.1 degrees apart I can mount them anywhere around the motor and have it work? How much fine tuning does this part take?

 

[gwhy!]

Thanks! That actually helps quite a bit. As for the hall mounting, as long as the three are 17.1 degrees apart I can mount them anywhere around the motor and have it work? How much fine tuning does this part take?

Yes they can be mounted anywhere around the motor BUT the same will apply in my last post it will be trial and error to find the correct wire connections ( sequence ) so the motor will spin in the direction that you require. Once the motor runs in the correct direction and starts with very very low throt input then you would need to tune the position of the halls for optimum performance ( lease amount of current draw ) this normally only involves moving the sensors about +- 5 degrees from the point at which the motor runs.

 

[oatnet]

Thanks for the work guys, this thread is a big help!

-JD

 

[ub3r]

Ive also added hall sensors to my Turnigy as can be seen here:

http://www.youtube.com/watch?v=3EiDExMfxq0

The ESC is a custom 200V 300 Amp unit i developed last year for EV application. Has current limiting and thermal shutdown (if you can get it to heat up).

Will post more details soon.

 

[liveforphysics]

ub3r-

This is outstanding!!!!

Beautiful work, and I love that you went with TO-247 packages.


For only 22v (if I'm seeing that correctly), that 6amp no-load is about 2-2.5x higher than it needs to be, you may find that a very small adjustment of the hall sensor position could make the no-load drop by half or more.

So cool to see this though! I'm excited! Welcome to ES!