swapping Magic Pie motor with internal controller for a GM 1000w HBS motor

[Andrew]

I would go out now and video the pie's performance but the streets by me are covered in black ice, it's like a skating rink. If it thaws out, I will try later. I have a mini dv thumb size camera I can cable tie to the handle bars


it's a bit like this near me at present..... http://www.youtube.com/watch?v=zMzeiMJQrvk

[Leslie]

OMG.  Its like watching destruction derby in slomo, glad no one was hurt.

Wouldnt you think they would give the car a miss and find some tire chains.

Warm your pack up wif some 15 min on off balance charging before you ride if you think its too cold.   Just a theory of mine that a normal temp batt works better than a cold battery and balance charging can get the temperature up inside the cell faster.

And leave the charger on over very cold nights and have the pack inside..

[Magzy]

Some hills near me are quite steep, but I have also felt the motor struggling on very slow slightly ascending inclines.  I tought above all  else that the PIE's main benefit would be hill climbing. top speed was not important to me.
I suppose that's why I'm curious to try a 1000w HBS

I feel your pain Andrew - my pie is slow up hills too

To the point that it will slow down until it comes to a complete stop.

I got a watt meter from here http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10777
$29 USD (and it's in Germany which means no tax for you)

Just to see for myself how powerful this thing is.

My instinct says that the controller is just sh!t and it doesn't do the pie any justice.

[Andrew]

hi Magzy .  glad you've finally got your pie on the road.  I'm happy with my pie as it still allows me to use my bike as a bike (just), but I am a little dismayed by the performance purely because what is advertised by GM.  As you say, the pie dies on hills even though it was designed as a larger 'torquier' motor to supersede the 1000w HBS. So why restrict it so much with the magic controller and why put on programmable adjustable paramenters when they obviously cannot be used and make no difference. It is as if the whole product once manufactured did not deliver what it was meant to and GM was stuck with a big bill and lots of pies with dodgy controllers and gimic software that just didn't work as it was designed to do.  why hasn't there been a torque figure put out on the pie in comparison to the HBS motors as here......
http://www.goldenmotor.com/magicpie/compare.html

I may get a 1000w HBS with external magic controller and do a back to back test

This is not really a moan, but just speculation and comments on my experience on the performance of the pie, and with all this said, the GM pie kit is still a lot cheaper than equivalent kits out there.

Andrew

[Magzy]

Personally, with the Magic pie, I was longing for an e-bike with great acceleration and stealthy noise. but I've got a children's toy that makes a lot of noise.

I agree I so wish I'd spent my money on something else now.

[MonkeyMagic]

Hey dudes

lol not poking any sticks guys! I'm a curious Monkey

Andrew - what's going on with the software? When you say it makes no difference at all, what kind of things is it doing/not doing? When you make the 24v setting, have you left it and gone for a ride? I'm surprised to hear that theres no difference. You must be an unhappy chappy.. I'm curious what's going on there.

Magzy - hey man did you get some readings on the Turnigy? Forgive my rudeness hehe, but how much does you + your bike weigh? And about acceleration, if you really want some juice on take off you need to get some more amps into the controller by modding it, or getting an infineon or something. Or check all of your power cables to see if they are minimum 12AWG (10AWG is ideal) you could get a noticeable difference there alone.

My GM battery has 12AWG going to the BMS, then 14AWG to the case Anderson connector. The first 2 GM power cables I have was 10AWG, and was DIY solder. The second 2 GM power cables I have were pre-soldered and 16AWG.... tisk tisk.... Haha I put that down to people complaining about the cables not pre-soldered lol

Using the 10AWG cable is far better, and since I have replaced the power cable inside the GM pack with 10AWG and also fitted a rear anderson connector hehe, All the cables are 10AWG now to minimise voltage drop.

I really don't know how quiet you want something to be, but anything over 500W is going to be loud - in your ears I think... I have a pedal scooter that is near silent, only a teeny tiny groan on take off, but only 32km/h top speed. It's 48v 500W, decent acceleration and will accelerate uphil to near 25km/h. Fun to ride but not for tracks...

The bigger wheel you go, the less torque + more load you are going to have for a given power level. 

My best and easiest mod so far I'm most happy with, is adding the front MP. Just slap the front wheel on, couple of wires and shazaam you're away meep meep

Anywho I hope something comes up that solves your worries... peace out

[Andrew]

Monkey, I'm not unhappy with the pie, infact if it was any faster or more powerful it would completely eliminate the light exercise that I actually want from my e-bike. I just feel a bit done over by claims made by GM and other distributors on the pies performance as well as  the magic controllers limitations compared to what's claimed, makes you wonder if the battery itself is what it should be.

As for changes in voltage with programming, i've tried riding at 48v for a few days, then 24 for a few, and then back again, and there is no difference - Honestly!  I know the software works as I have changed regen power and can feel big differences in the motor braking.

I probably should not expect too much from an electric motor, and i'm happy with 22 -24 mph on flat road. But feeling the motor dieing/losing momentum on slight inclines is a little disappointing as speed reduces quickly and before you know it you are doing 6 mph

[MonkeyMagic]

hmmm I can see your frustration... and don't know what to say lol

Going up those hills must feel like the battery is dying... Do you think you could try a thicker battery cable to your wheel? Both of my newer wheels came with pretty slim gauge and I only noticed the biggest difference changing it with dual drive. If you have a multimeter see if you can check the voltage drop when you put the wheel under load, if it is significant and your battery is full charge then I would look to increase the battery to wheel wire thickness, or look at monitoring the output of the battery you are using. It may not be the wheel at all if the battery cannot pump out the juice..

If you do have a few hills, or the hills are big/long then I would still look at getting a front motor because you would most likely get better range too plus never having to worry about going 6mph uphill hehe