Smart Pie V starts up with a jerk

[bikezen]

Hi all,

I have a Smart Pie V motor coupled with a Luna Shark 52V battery. For now I have the motor in a wheel truing stand for testing.

I had the motor installed on a bike briefly and found when I use the throttle, the motor goes from 0 to 1-2 mph with no ramp up. There's no gradation there at all, it's either off or jerks into rotation. Maybe it's not a huge effect but definitely noticeable down there on the end of the fork. Kind of a jerk forward when you activate the power.

If you feather the throttle in tiny increments you can perhaps get the motor to start up slowly but really it's just kind of fluctuating between no power and a steep ramp up to rolling. Is this normal for this motor? The other hub motors I've used didn't exhibit this type of abrupt on/off behavior.

Would the USB or Bluetooth programmer access be any use with this?

Thanks.

 

[chvidgov.bc.ca]

Isn't this just that you have a pedal first controller? That seems to be able to start the motor without any motion at all (jerkily). That fits the pattern of my 9 continent pedal first setup. It will only start smoothly if the wheel is moving forward very slightly. If not, could be jerky forward or even backward I have noticed. Hence I only apply the throttle after I have pedalled forward the smallest amount...

 

[bikezen]

Doesn't a pedal first controller need a sensor to know if the cranks are moving? I don't have that on this system.

 

[chvidgov.bc.ca]

Pedal first means there are no Hall sensors needed to start the motor, but it must be moving a little bit to operate. Pedal first equals sensorless controller. If it was sensored, you wouldn't need to pedal first - the motor could start smoothly from zero.

 

[TommyCat]

Would the USB or Bluetooth programmer access be any use with this?

Thanks.

I also have the Magic Pie V5 with 52 volt bottle battery. With the kit from Luna...(Hall throttle sensor) My start-up seems a bit abrupt also, though I like the torque! The parameters shown below are available thru the programming software. But I'm still waiting for an available programming cable (USB to 5 pin dongle) to give it a try...

As you can see there are other performance settings which may also smooth things out a bit...BTW the controller does have motor hall sensors. :wink:


Regards,

T.C.

 

[TommyCat]

Having received my USB connection cable, and making a few programming changes. I thought I'd bring this up to date.

Not all settings seen above in the software display are available on the Magic Pie v5. There are actually only 12 parameters that can be set. But of these I set the amperage and RPM to satisfy E-Bike law requirements in Illinois. That reducing the power output of the motor to 750 watts. (1 HP) and limiting the max RPM to 20 MPH. I also felt it would be a good idea to disable reverse, as I won't use it. And for safety, in case the reverse wiring became grounded accidently.

See available and factory setpoints on Magic Pie v5 ...

So with these changes motor start-up is very smooth, acceleration good, cruise smooth, and top end limited. I'm very satisfied. And the acceleration parameter was not even touched.

Regards,
T.C.

 

[Axolotl]

Having received my USB connection cable, and making a few programming changes. I thought I'd bring this up to date.

Not all settings seen above in the software display are available on the Magic Pie v5. There are actually only 12 parameters that can be set. But of these I set the amperage and RPM to satisfy E-Bike law requirements in Illinois. That reducing the power output of the motor to 750 watts. (1 HP) and limiting the max RPM to 20 MPH. I also felt it would be a good idea to disable reverse, as I won't use it. And for safety, in case the reverse wiring became grounded accidently.

See available and factory setpoints on Magic Pie v5 ...

So with these changes motor start-up is very smooth, acceleration good, cruise smooth, and top end limited. I'm very satisfied. And the acceleration parameter was not even touched.

Regards,
T.C.

Hello Tommy Cat,

I have been using this motor, but I´m very surprising that such advance motor has fewer parameters to change. One of the worst things is the PAS configuration, I have 5 magnets PAS and its a hell to get good setting in order to have a good felling between pedaling and motor. Do you use PAS? If so, how many magnets? I would appreciate your feedback. BTW I just get Regen breaking at 50 amps and it is great, you could save a lot in braking wear.

Regards

 

[TommyCat]

Hello Axolotl,
Always happy to give some feedback.

I have been using this motor, but I´m very surprising that such advance motor has fewer parameters to change.

I admit to being a bit disappointed myself. And with your desire to tweek PAS settings, more here would be better.
But that just proves how really smart they are, not to let us mess em up with settings to bad. :lol:

One of the worst things is the PAS configuration, I have 5 magnets PAS and its a hell to get good setting in order to have a good felling between pedaling and motor.

Do you use PAS? If so, how many magnets?

I do not use PAS at this time. Do you have a Smart Display? I have been very curious about PAS as I do use a Smart Display, so all I would need is a sensor. The display has levels of PAS that you can choose.
So please let me know how yours works and how you would like to see it made better! I assume you can't use a throttle...?
Right now I'll get to a desired riding speed and hit the cruise button. Then I pedal along as I wish if at all. :wink: Works great for me.
From my research it is indicated that the more magnets you have, the better results will be.
Also a combination of controller PAS and acceleration settings may be able to smooth things out. Trial and error from what I see.

There are also 3 types of sensors... GM type (hall sensor) I think the one your using now, voltage type that's tied into, or takes the place of the throttle input, and torque sensing. (Best but most expensive)
These are in the order of best working from opinions I've read. For a lot more opinions and information on the Pie series I would encourage you to go ...HERE. Search for Magic PAS. Be sure to listen to everything the master guru of Pie's tells you...Alan AKA- Bikemad. He is very good.

I just get Regen breaking at 50 amps and it is great, you could save a lot in braking wear.

One of my favorites also! Had to turn it down to 40...it can get aggressive.

Regards

If you need any clarifications or questions...let me know.

Regards,
T.C.

 

[theFalcon]

Hi TC - I'm replying to an old post and hope this reaches you. I picked up a magic pie five last September and I'm disappointed in its performance. I haven't fooled with any parameter settings yet, and I'm not concerned with regen breaking or limiting any performance. Where I live I'm not restricted as far as output power. I've had several hub motors, and have a half a dozen bafang mid-drive motors that I've used on different projects over the years.
Straight up, the magic pie five is a dog even compared to similar 1000w eBay hub motors - it'll top out around 22 or so, but it's sluggish, slow to come on and lazy. I've tried to find programming cheats at the GM forum, similar to all the bafang cheats out there, but there's nothing definitive available that I can find.
What do you suggest I do to improve peak performance on my magic pie five and my 52 volt battery stack?

 

[TommyCat]

Hi Falcon,
And welcome to the "Pie" club!

it'll top out around 22 or so

MPH?

I've tried to find programming cheats at the GM forum

I don't know anything about "cheats"... But just want to make sure that you know that Golden Motor programmable controllers have a dedicated software program that allows modifications of performance parameters.

I also run the MPv5 with a 52 nominal voltage battery with 11.5ah capacity. But unfortunately in my state there are restrictions on performance. As a result, I have modified the controllers peramters to keep operation under 1hp, and limit the speed to 20 MPH.
Perhaps this the case if you got it previously used, or it's not set-up for the performance you desire.

With maximum settings this motor was easily able to instantly lift the front wheel of my bike from a quick start at a stop sign.
Much to my startled amazement, and bit of embarrasment.
Of course, performance is a bit relative, but your description seems a bit lacking.

My recommendations would be as follows...

Check for any mechanical issues first. See that the wheel spins freely with just a bit of electro-mechanical resistance.
I.E. No brake pads rubbing, bad bearings, too long disc mounting bolts ECT.

I would encourage you to have a means of verifying voltage input, and battery current draw. It does have a dedicated display if desired, BAC-601, but that doesn't even give actual voltage.

By all means start communications with the controller to check the existing parameters. And identify changes that would increase performance and better operation.
A dongle is required between the computer and harness.

A great source of information, including the latest software and how to use it. Is the Golden Motor web site linked here...

GoldenMotor.com Forum - Index


Also see my build using link #4 below in my signature for helpful ideas.

For more in-depth discussion, I think it would be wise to open a new ticket with the specifics (battery specs, pictures, ECT) of your build. So that specific questions can be answered as accurately as possible.



Regards,
T.C.

 

[theFalcon]

Hey TC thanks so much for your help! (belated but totally appreciated!)