Author Topic: Can I unrestrict Magic Pie controller?  (Read 7760 times)

Offline o00scorpion00o

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Can I unrestrict Magic Pie controller?
« on: June 29, 2010, 11:27:31 AM »

Does anyone know how I can unrestrict the Magic Pie controller from a max of 14 amps @ 48 volts? It's supposed to be 1000 watts but it's LIMITED to 740 watts MAX. I have used the usb cable to turn down the amps, and it works. But when I turn it up to 30 continuous, 50 max. It only  goes to 14 amps max.

I have thought of opening an external magic controller and installing the board in the pie. But I don't know if it's compatible? 

Maybe golden motor could offer a different firmware so people could turn the amps up more if they want to! But the controller is definitely limited to 14 amps max around 750 watts! 

Offline MonkeyMagic

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Re: Can I unrestrict Magic Pie controller?
« Reply #1 on: June 29, 2010, 12:10:21 PM »
Hmmm well that totally sucks balls...

Prompts me to do some testing ;) I just wrote a post about torque difference between the wheels I own but it could power related as your figures specify. I'm not really too fussed, would be great to get some more power but I'm tipping that is the most economic max rating for the motor/controller.

Well I'll get some current readings of my 16" cast MP and the new 20" cast MP and post it here when I get a chance.

Nice work sherlock!


Offline o00scorpion00o

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Re: Can I unrestrict Magic Pie controller?
« Reply #2 on: June 29, 2010, 03:20:34 PM »
Went for a 16 mile spin today with my friend who was using my old 1000 ebike kit. At full throttle he pulled out ahead of me and continued to do so. He got a good bit ahead of me. Now his kit is running at around 1100 watts pulling about 21-22 amps. My Magic Pie could not keep up with him at all. Even up hill. Obviously, as my Magic Pie will only pull 750 watts MAX. It's supposed to be a 1kw motor isn't it? or did I read it wrong? So GM what's the story? I want the controller limit removed!

The pie doesn't get hot only luke warm, even at max throttle for 16 miles. I believe it will take the same power of 1100 watts as my old motor. And even if it over heated then at least I should have the option of turning down the amps with the usb cable! That's the way it should be anyway!!!

Max speed on straight and fairly level with the Magic pie was 23-24mph, 30-31 with my old kit. And my friend is heavier! And that speed is gps verified!

I  have got to find a way to increase the amps of the internal pie controller, but I doubt Golden Motor will tell me how or at least send me a controller like the external magic controllers that will allow me the option to set the amps I want to set it at!  As the usb cable for the pie is useless really for that as the limit of 14 amps I can not remove with the usb cable and that annoys me! 

Offline windego

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Re: Can I unrestrict Magic Pie controller?
« Reply #3 on: June 30, 2010, 12:18:31 AM »
I have not seen the controller but if you make the shunt less ohms then the controller will think its less amps........ ;)

Offline Leslie

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Re: Can I unrestrict Magic Pie controller?
« Reply #4 on: June 30, 2010, 12:26:35 AM »
I have not seen the controller but if you make the shunt less ohms then the controller will think its less amps........ ;)

I think the new MP controller has no shunt and relies on software duty cycle controll to limit the amps.  Putting a restrictor resitor on the throttle output achieves the same result.  Slower speed and less full throttle torque.

Bring it on

Offline o00scorpion00o

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Re: Can I unrestrict Magic Pie controller?
« Reply #5 on: June 30, 2010, 12:32:42 AM »
Hmmmm We really need to get to the bottom of this! I thought all controllers had shunts? I'll take a pic tomorrow and maybe that will tell us something, but there is a copper bar joining some of the legs on the fet's and a long strip of solder on others if that makes sense?

It will be really hard to find where the limit is unless there is some feedback from GM!

Offline Leslie

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Re: Can I unrestrict Magic Pie controller?
« Reply #6 on: June 30, 2010, 12:55:07 AM »
Hmmmm We really need to get to the bottom of this! I thought all controllers had shunts? I'll take a pic tomorrow and maybe that will tell us something, but there is a copper bar joining some of the legs on the fet's and a long strip of solder on others if that makes sense?

It will be really hard to find where the limit is unless there is some feedback from GM!



http://endless-sphere.com/forums/viewtopic.php?p=168835#p168835

Quote
Notice a big difference between both boards is that most of the components are mounted on opposite sides,
and no shunt bar on the 48v. I added some wires from the negative connector to the fets on the 48v as there was only (wideish) foil trace before,
it had very poor acceleration and top speed but it now goes like the clappers! Harder than the GM 48v standard controller on my usual ride.
With a shunt mod these controllers do seem like "magic". Before the mod, the wattsup measured 22a max draw, haven't measured it since tho, feels like over 40a.

This magic controller had no shunts, over at the sphere Oldhaq put a bypass in to make it give more amps.

Who would know,  :-\ There are some differences from GM version to version everywhere.  It's getting hard to keep track to be honest.
« Last Edit: June 30, 2010, 01:00:52 AM by 317537 »

Bring it on

Offline Leslie

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Re: Can I unrestrict Magic Pie controller?
« Reply #7 on: June 30, 2010, 01:05:12 AM »
If you do have a shunt bar in your controller make sure the joints arent dry and there is plenty of solder leading to and from them to the fets.  ??? ??? ???
« Last Edit: June 30, 2010, 01:07:20 AM by 317537 »

Bring it on