Golden Motor Magic Pie - first taste

[Hyena]

Assuming it has them, would this be the location of the halls ??

On an unrelated note, I can't afford to keep this and the higher speed motor I have on the way. Is anyone in Sydney interested in buying this street legal 25 km/hr pie ? If so send me a PM.

 

[317537]

Haaa you beat me to it I posted almost the same pic about 5 mins ago at GM forums.

BTW nice pictures.

 

[317537]

The fet bridge is in the centre of the board.

 

[317537]

Whats this blob of stuff on the windings?



Is that solder?

 

[spinningmagnets]

I think GM will sell a LOT of these...but the majority of those customers will not be posting on any forum. Or, if they do post, it might be at the GM forum...

E-bikes are HUGE in China, and are growing in popularity in India. Between those two countries, thats about half the population on the planet. Most people have their hands full raising a family and doing their jobs. They are not "passionate" about their refrigerator. A fridge may be vital to their lifestyle, but...they dont know how it works. They just want one thats affordable, and when you plug it in...IT WORKS!

I very much appreciate hyena posting the pics and review, but I was disappointed by the protocol. The MP was clearly stated to be designed for 36V and 48V. The red/black wire issue may be a prototype gllitch, but when faced with that, I would investigate before attaching power. And to use 60V immediately is completely unfair to GM.

Good to know it has polarity-protection, all E-bikes need this from the factory (and honestly, on the assembly line, how much extra does that design feature cost?). With the controller integrated into the hub, that eliminates one of the potential customer screw-ups (and customer screw-ups make potential dealers wary of a product that will have likely returns due to no fault of the manufacturer).

But of course, that specfic feature makes hot-rodding difficult. I'm sure most ES posters are not interested in a boring refrigerator, but last year China exported over 12-Million fridges.

I consider the MP to be the 1967 VW Bug of E-bikes. If I was going to hot-rod something, I would put a turbo on an early '90s Mustang or Civic. But, I had a stock '71 Bug for many years, and I was happy with how it did exactly what it was designed to do.

 

[GoldenMotor]

I'm sorry guys, the typical chinese businessman is smart and wise, however i have failed my mechanics and electronics, oh wait... i didn't even take that course. I promise a hall answer before the promotion ends. If anyone of you decides to buy a pie but didn't make it in time, please message me and I will work it out for you, since I have complete power in writing reports, i'll just say it was a time lag, and the customer didn't realize the time was according to US timing.

 

[Hyena]

Whats this blob of stuff on the windings?
Is that solder?

Jesus eagle eyes, you're lucky I have a good DSLR camera
It could be, looks more like glue or something in this pic though.



Spinning magnets - I dont think its unfair to test at 60v. GM has hyped this motor for a while now and I thought most people would want to see it at its best, particularly on this forum! My 60v was actually 58v in the end, which isnt that much above what some 48v lithium packs run at anyway so its not like I ran at 72v and traded it off as 48v. Aside from that I dont have a 48v battery, but I did rewire mine for 36v which I also used. I would think the 36v results would be highly relevant to the majority of consumers out there.

Re: the power thing, yeah I was tempted to come inside and shoot off and email to GM to verify the polarity but I figured I wouldnt get an instant response and I wanted to get the review done in time for the release day for people that wanted to see it before ordering.

As it turned out that didnt go exactly to plan with the motor mix up but GM has posted a video since verifying the speed differences in the motors that will be shipped out, and Yao has said that every one will be checked before shipping. I've just ordered a few more on the slow boat.

 

[dnmun]

yao, you have to immediately go find out why they reversed the polarity on the controller wires between the controller and the labeled ends, most likely in that plug.

i don't know what better evidence of how big a problem this will be for you than reading how hyena went ahead and actually did wire it up backwards in spite of the label tape your assembly people put on it.

i repeat, it is obvious from the picture that the red wire on the controller in that picture is going to the positive input to the controller.

this will happen to everyone, the urge to connect red to red is too strong. everyone looking at it is gonna assume your people screwed up on the tape label. this should be clear proof. they will stop at this point, and over here the urge to sue comes first in most people's mind, along with demands to send it back on your dime.

this is the marketing feedback you should use, not the other stuff where you just have people living in their negative world.

 

[oldhaq]

here's a bit of background on the internal controller;
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=11015&p=203391#p203391

 

[317537]

It's like they got the colours wrong the first time why couldnt they get the lables wrong.

To fix it easy, if the hubs are all ready made up, is slap a sticker on each hub that explains it.

warning red is ground and black is positive.

 

[317537]

It looks like glue to me too, possibly harmless but you want nothing acidic on the windings.

 

[biohazardman]

Great post! Lots of werq there and I appreciate it. Looks to be a great motor as well. Quality looks very good throughout and you got plenty of Customer service from GM. I would agree with spinningmagnets and others the motor is designed for the masses. Can't beat the easy install and looks of this one at the time. I think it will be a big hit. I see no negative with keeping these motors at legal speeds. People don't have as many problems and things in general last much longer. The evil modders can take them to warp 10 if that is their wish. ;^)

Yes, it's very plain it has the halls where you expect. Five thin wires on the right of the controller board are likely the connections from the halls.

GM has updated their site since I have last been there and it looks much better and has much more information. They have improved just about everything since I bought my first motor from them a couple years back. Have to love ES for all the info available.

 

[GoldenMotor]

Ok... that was a hell lot of questions, I just reached the office. Can someone consolidate all those questions I haven't answered into one post and I will make a reply to each question.
For the part on the website, that was a temporary solution because the webmaster couldn't finish the scripting in time. There will be an even more eye-opening website update in the near future. Frankly, I was the designer for the website, do you think black and silver color theme works for the website? and also i made everything look crystal like with the PS effects and all.

 

[fechter]

Yes, it's very plain it has the halls where you expect. Five thin wires on the right of the controller board are likely the connections from the halls.

I think those are going to the throttle, the ones on the bottom look like they go to the halls. It will be obvious once the controller is removed.

Great video from Goldenmotor. In the last second or so, it looks like some kind of music concert. Don't cut that off next time

It looks fairly easy to swap the red/black battery wires on the controller. If it was mine, I'd do that for sure.

 

[amberwolf]

Assuming it has them, would this be the location of the halls ??

That's what I assumed when I posted previously, but I can't tell for sure from the pic.

 

[Bikemad]

Yes, it's very plain it has the halls where you expect. Five thin wires on the right of the controller board are likely the connections from the halls.

I think those are going to the throttle, the ones on the bottom look like they go to the halls. It will be obvious once the controller is removed.

It looks fairly easy to swap the red/black battery wires on the controller. If it was mine, I'd do that for sure.

I think this should help to clarify things:

Notice the similarity with the colours and positioning of the wires:

The biggest problem with reversing the wires on the controller might become apparent if you ever needed to replace the two pin offset connectors.
If you simply chopped them off, you would need to ensure the new connector you fit joins the Black controller wire to the Red battery lead etc.
And what are the chances of remembering this at a future date?
I know it would not be very good in my case!

Here are a few things I've also spotted from this comparison:
There is nothing connected to the horn connections. (The horn was used for the alarm function and audible warning of faults etc.)
It looks like Reverse is not wired up, therefore Reverse is no longer a simple option.
The anti theft device does not appear to be be wired up, so presumably it will not automatically lock the wheel.
The Pedelec must be piggybacked off the throttle connection in the main harness to pick up its 0v and 5V supply, presumably done that way to reduce the number of wires passing through the axle.

I wonder if the controller board is populated and programmed to still support these missing functions, if you wanted to add the extra wiring/switches etc.
It would be nice to know.

Presumably the front wheel axle could be machined on both side to allow additional wiring to be fed through if necessary. Probably not so easy having wires exiting the freewheel side of a rear wheel.

Alan

 

[fechter]

I think this should help to clarify things:

Alan

Thanks Alan, that is very helpful.

 

[Hyena]

here's a bit of background on the internal controller;
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=11015&p=203391#p203391

Thanks for the update, they do indeed look to be very simlar controllers (as you'd expect)
I wonder how the MP controller will respond to the usual controller mods to up the current. GM says it has over current protection but I'm not sure how that's implemented. Given it also has over temp protection if you add more solder to the traces / add extra wires to increase the current the temp cut out should protect the controller and coils from burning. No one likes burnt pie If it works at all (ie there's not fancy current limiting) I guess you're likely to have the controller shutting down alot if you give it a hard time, but I suppose that's better than cooking the controller and/or windings.

A project for down the track, I think a 35-40 amp limit would give decent gains in performance without too much harm to the internals (hopefully!)

On more pie review related matters, I wired up the brake leads to the button on the throttle today to test the regen. From around 20-25km/hr (running the 40v battery) the braking was quite good, it very quickly and smoothly pulled me up but without and hint of locking up. I also tested it on a fairly steep hill on grass and still no loss of traction. I wouldn't want it hooked to my normal brake levers as the braking is quite purposeful and sometimes you only want to slow down gradually. I was going to fit rear discs but I think I'll be happy with regen + rear V brakes for now. Given how I ride I think I can get by with regen alone for 75% of my braking. I'll throw on a cheap hydro disc up front for more 'precision' braking though.

I didnt try it on higher voltage because my bike is alloy and has QR drop outs that don't completely surround the axle and I don't want to push my luck. As it was I could feel a very minor inital jolt as the brakes kicked in, as if the axle rocked in the drop out. I don't think it did, but having had my front wheel come off before with regen braking I'm not keen to repeat the experience! I'm in the process of making a torque plate which I'll fit when the new motor arrives.

 

[amberwolf]

I wouldn't want it hooked to my normal brake levers as the braking is quite purposeful and sometimes you only want to slow down gradually.

What about using one of those RC-throttleizer boxes, and putting a hall throttle sensor on your brake levers? Then the hall throttle output would be changed into a PWM modulation of the brake line, giving you a greater degree of control over braking?

 

[Hyena]

Sounds like a neat idea, and something the manufacturers should eventually offer.
I'm not sure if the PWM idea would work though, it seems to take a half a second or so to kick in from the time you press the button. It's not a big deal as far as braking is concerned, but if you were going to try to pulse the signal it may not work well or smoothly. I'm more than happy to be proven wrong though if someone else has or does manage to get it working smoothly.

I'd be happy with a 2 speed regen to be honest, one to hold you back a bit when coasting down big hills and one for all out stopping.

Also a follow up on the speed issue, a guy on the GM forums who didn't receive the slow wound motor that I did has reported speeds of 42 km/hr and 52 with a tail wind on 48v, measured with GPS. That's more like it

 

[amberwolf]

I'm not sure if the PWM idea would work though, it seems to take a half a second or so to kick in from the time you press the button. It's not a big deal as far as braking is concerned, but if you were going to try to pulse the signal it may not work well or smoothly. I'm more than happy to be proven wrong though if someone else has or does manage to get it working smoothly.

Well, that probably means there is either a time-constant programmed into the MCU, or there is a simple RC filter on the brake input. If the latter, it would be very easy to defeat, or at least modify. If it's in the MCU, someone'll have to figure out how to reprogram it (assuming it's possible).

As for a two-speed regen, I can't think of any way to do it if the controller is designed for a 1/0 brake input.

But here's an experiment you can try: hook up a (separate from actual throttle) hall-based throttle to power and ground, then put it's throttle wire to the brake input. See if it engages the brake at other than just full-on at some threshold voltage, or if it actually does it gradually at some point up to full.

Theoretically it shouldn't damage anything in the controller or hall throttle, but it is possible their design is *capable* of partial regen but not *designed* for it, and I don't know what the results of that would be.

EDIT (added): A potentiometer based throttle will do the same thing as the hall, if you don't want to risk a hall throttle.

 

[Jerome Daoust]

From this posting:
"I had some wind in my back today and got a top speed of 52 km/h on my speedo and 51.6km/h (32mph) on my Garmin gps. Riding against the wind was 45km/h and this is also gps sertified."
And 2 posts above he says that he was running it at 48 V (normal).

So averaging his downwind/upwind speed at 48 V: 48.3 km/h (average of 51.6 and 45) (29.8 mph)
This validates the manufacturer's expectation of 47 km/h (29 mph) at 48 V.

 

[Bikemad]

And 2 posts above he says that he was running it at 48 V

I know that's correct, as he was using the 48V 12Ah version of this rack pack:

It would appear that the Magic Pie is also a good hill climber:

well I tried a couple of hills but there was one long hill but it still went 35 km/h and a very steep hill of 50 degree, 4 meter long. From a still stand it could still climb the hill easely.

I then had to ask the obvious question," Do you have a special technique for climbing a 50 degree hill without flipping over backwards?"

ooh I ment % , i don't know how to measure it or say it so it was 0 meter high and I drove up the hill and there it was 3 meters higher and the hill was 4.2 meters long.

Whichever way you interpret the description, that hill does seem to be rather steep!

the hill was steep! I don't know how steep but you'll not find a steeper hill here.

We may not know exactly how steep the hill is, but at least we know the Magic Pie can climb it easily, and from a standstill!

Alan

 

[317537]

Second review of the Pie on the GM site isnt very detailed but the acceleration is awesome for a gearless. 0 to 45kph in 5 seconds. This means hills shouldnt be any problem. Also reported is a 50kph top speed.

 

[Jerome Daoust]

Second review of the Pie on the GM site.

Thanks for the heads-up.
Direct link: GM Forum: Golden Motor Magic Pie review