magic pie, dh bike, 110v, 80kph so far

allways thought that hub motors need all the stator diameter you can get, and the biggest ive seen (in the medium/lightweight? category) is the magic pie, ive had 134nm of torque from one of these so thought it would have some potential for power when properly fed.

between 200w and 1000w these motors work sweet from the factory with the inbuilt controller but only to 60v max, so we've set up a couple of these to run on external controllers, the guys at golden motor dont appear to be fans of this handiwork and say its not what what the motor is intended for, wtf?
anyway, this stator was from an 18inch cast wheel that ive spoked up into an alloy "14"inch moto rim and put on the back of a downhill bike.

using one of kewins 18fet controllers at about 40amps todays ride was on about 110volts and pulled a max of around 4320w from the pack, downhill i got 88kph max and on a flat it wandered between 77 and 82kph and the motor is outputting a bit over 3.5kw.

it was not a bad effort from the pie, as the winding temp stayed below 100deg c (they will take 150 without damage) and i reckon a slicker bike would have maby done another 10kph on the same power as this bike is not really for road use, with off road downhill front tyre and a 14" 4 ply motorbike knobby on the back its set up for dirt not road, but the geometry and suspension travel was kinda helpfull..

im pondering another 25volt pack for a touch more speed, but this is here in oz where its 200w max so obviously this was not done on the road, in a 50 zone :wink:
ill try get some photos/vids/dyno runs up shortly.

awesome!

if you do bake the magic pie, post up some photos of the windings

how are you running the 18 fet controller to handle 100+ volts? anything special?

yes, photos please.



Sounds like fun, good to hear someone torture testing the pie. I'm keen to hear how much it can take before reliability becomes an issue.

That's good going for sure. Take care, hope you got a good torque arm on that and I'd even be tempted to wear a helmet and some protective gear on a push bike doing 80plus kph

toolman2 said:

ive had 134nm of torque from one of these so thought it would have some potential for power when properly fed.

using one of kewins 18fet controllers at about 40amps todays ride was on about 110volts and pulled a max of around 4320w from the pack, downhill i got 88kph max and on a flat it wandered between 77 and 82kph and the motor is outputting a bit over 3.5kw.

Click to expand...

Toolman, How did you masured the torque (Nm) of your magic pie hub motor?

( BTW.. it's Nm and not nm :wink: ... nm is a unit for nanometer typically a wavelengh.. and Nm come from Newton meter... Isaac Newton.. since it's a name of a respectable person, i think we must spell it properly ! :wink: )

At 40A.. it is 3.35Nm per Ampere.. for 134Nm wich is very high!.. and surprize me!.. I know the diameter is higher than the one of the X5.. but.. i mean the difference is high!

Can you please ellaborate on the way you tested it?

Doc

toolman2 said:

allways thought that hub motors need all the stator diameter you can get, and the biggest ive seen (in the medium/lightweight? category) is the magic pie, ive had 134nm of torque from one of these so thought it would have some potential for power when properly fed.

between 200w and 1000w these motors work sweet from the factory with the inbuilt controller but only to 60v max, so we've set up a couple of these to run on external controllers, the guys at golden motor dont appear to be fans of this handiwork and say its not what what the motor is intended for, wtf?
anyway, this stator was from an 18inch cast wheel that ive spoked up into an alloy "14"inch moto rim and put on the back of a downhill bike.

using one of kewins 18fet controllers at about 40amps todays ride was on about 110volts and pulled a max of around 4320w from the pack, downhill i got 88kph max and on a flat it wandered between 77 and 82kph and the motor is outputting a bit over 3.5kw.

it was not a bad effort from the pie, as the winding temp stayed below 100deg c (they will take 150 without damage) and i reckon a slicker bike would have maby done another 10kph on the same power as this bike is not really for road use, with off road downhill front tyre and a 14" 4 ply motorbike knobby on the back its set up for dirt not road, but the geometry and suspension travel was kinda helpfull..

im pondering another 25volt pack for a touch more speed, but this is here in oz where its 200w max so obviously this was not done on the road, in a 50 zone :wink:
ill try get some photos/vids/dyno runs up shortly.

Click to expand...

40 amps .. thats all

not even 100amps ... commmooonnn

-steveo

steveo said:

[
40 amps .. thats all

not even 100amps ... commmooonnn

-steveo

Click to expand...

THIS GUY! Not averyone can strap the contents of a nuclear fission reactor between their legs and haul ass like you.

Wow! Sounds great!

Can't wait to see the pics! 8)

icecube57 said:

steveo said:

[
40 amps .. thats all

not even 100amps ... commmooonnn

-steveo

Click to expand...

THIS GUY! Not averyone can strap the contents of a nuclear fission reactor between their legs and haul ass like you.

Click to expand...

muhhahahahhahaha

the controller has 4115 fets etc for about 140v safe.

the 134Nm was from the early batches of magic pie (lower speed) running 90v and about 35amps on a 24" dh tyre, its the red one on the dyno sheet. at 5kph it produced about 600w output and this calculates out to 134Nm, also i got 44kg towing force from a test like your own doc , that seemed to back up the figure.

but im not sure that Nm per Ampere (at the battery) is much of a measure as it doesnt take into account the voltage in, and current multiplication resulting -ie this setup ended up with over 100a phase current to the motor with only 35a at the battery. plus you could have a low speed motor wound for 20+ Nm per Ampere, you know all this i am sure.

we all know the advantage of gearing these hub motors for more torque (apart from the stripped gears) and i too have used one of those (only 1.2kg) purple turnigy motors that can do 6.5kw by revving real fast, but here we have a direct drive motor of that aims to achieve the same outcome by a narrow stator of very large diameter -made for good torque.

and yep safety is a bit of an issue, but the hospital care here in oz is free..

acctually the photos are 1.5mb each and wont go up (3 of them) can i send them to someone to put up here, im not a big computer fan. -i should also thank you lot as i have been gathering good info here for a while.

toolman2 said:

the controller has 4115 fets etc for about 140v safe.

the 134Nm was from the early batches of magic pie (lower speed) running 90v and about 35amps on a 24" dh tyre, its the red one on the dyno sheet. at 5kph it produced about 600w output and this calculates out to 134Nm, also i got 44kg towing force from a test like your own doc , that seemed to back up the figure.

But im not sure that Nm per Ampere (at the battery) is much of a measure as it doesnt take into account the voltage in, and current multiplication resulting -ie this setup ended up with over 100a phase current to the motor with only 35a at the battery. plus you could have a low speed motor wound for 20+ Nm per Ampere, you know all this i am sure.

Click to expand...

Have you tested on a real motorcycle dyno? or a DiY dyno?.. have you took any pics you can share here?.. very easy to do btw...

I agree with the battery current vs Nm.. this is an unprecise way.. and it also depend on the winding turn count of the stator..etc.. What is very interesting is getting the Nm at different speed, ex: 0, 10, 20, 40, 60kmh..

I am using a Beltronic FX-2 car Performance computer i hook on my ebike. It measure the G force with accelerometer and knowing the weight and friction of the ebike it can calculate the real power output and datalogg everything... it's a very great tool!.. I benched 5.4kW output at 40kmh during acceleration if i remember correctly.

You definitively should try the Delta WYE configuration!!.. that magic pie seem to have the righ caracteristic to match with DELTA with stilll good performances!

Please post pics!

Doc

toolman2 said:

and yep safety is a bit of an issue, but the hospital care here in oz is free..

acctually the photos are 1.5mb each and wont go up (3 of them) can i send them to someone to put up here, im not a big computer fan. -i should also thank you lot as i have been gathering good info here for a while.

Click to expand...

You can upload them easily with sendspace.com then just reply with the download link that they give. No need to register or provide email addresses or whatever.

I'm happy to then resize and repost smaller versions on the forum.

Cheers!

ok, thanks people hope this works,

the pic of the bike is a while ago before the magic pie -these cast 18" wheels can shatter landing from jumps,
the empty motor is the pie spoked up to a 14" moto wheel -much stronger (same rear 14" moto tyre in both cases its just pushbike and motorbike use different numbers)

and theres a few runs, done on a new dynojet motorbike dyno in various configurations, i videod some of these runs (the CA screen) so i could piece it all together



http://www.sendspace.com/file/zy3bya

http://www.sendspace.com/file/har9d2

http://www.sendspace.com/file/08o61y

OMG These are the shortest spokes i ever seen!!!

that motor is 14" diameter you said?

I see you had a X5 before right?.. How it compare with the same power?

BTW your ebike setup is nice too, you finally found a way to mount near kWh battery into a DH frame with still low center of gravity.. What is your DH bike?

And finally, can you post that video showing the CA and Dyno?.. WE WOULD LOVE !!! :wink:

Doc

steveo said:

toolman2 said:

allways thought that hub motors need all the stator diameter you can get, and the biggest ive seen (in the medium/lightweight? category) is the magic pie, ive had 134nm of torque from one of these so thought it would have some potential for power when properly fed.

between 200w and 1000w these motors work sweet from the factory with the inbuilt controller but only to 60v max, so we've set up a couple of these to run on external controllers, the guys at golden motor dont appear to be fans of this handiwork and say its not what what the motor is intended for, wtf?
anyway, this stator was from an 18inch cast wheel that ive spoked up into an alloy "14"inch moto rim and put on the back of a downhill bike.

using one of kewins 18fet controllers at about 40amps todays ride was on about 110volts and pulled a max of around 4320w from the pack, downhill i got 88kph max and on a flat it wandered between 77 and 82kph and the motor is outputting a bit over 3.5kw.

it was not a bad effort from the pie, as the winding temp stayed below 100deg c (they will take 150 without damage) and i reckon a slicker bike would have maby done another 10kph on the same power as this bike is not really for road use, with off road downhill front tyre and a 14" 4 ply motorbike knobby on the back its set up for dirt not road, but the geometry and suspension travel was kinda helpfull..

im pondering another 25volt pack for a touch more speed, but this is here in oz where its 200w max so obviously this was not done on the road, in a 50 zone :wink:
ill try get some photos/vids/dyno runs up shortly.

Click to expand...

40 amps .. thats all

not even 100amps ... commmooonnn

-steveo

Click to expand...

Steveo.. His setup seem respectable too!.. just look at the lastest pics

Doctorbass said:

steveo said:

toolman2 said:

allways thought that hub motors need all the stator diameter you can get, and the biggest ive seen (in the medium/lightweight? category) is the magic pie, ive had 134nm of torque from one of these so thought it would have some potential for power when properly fed.

between 200w and 1000w these motors work sweet from the factory with the inbuilt controller but only to 60v max, so we've set up a couple of these to run on external controllers, the guys at golden motor dont appear to be fans of this handiwork and say its not what what the motor is intended for, wtf?
anyway, this stator was from an 18inch cast wheel that ive spoked up into an alloy "14"inch moto rim and put on the back of a downhill bike.

using one of kewins 18fet controllers at about 40amps todays ride was on about 110volts and pulled a max of around 4320w from the pack, downhill i got 88kph max and on a flat it wandered between 77 and 82kph and the motor is outputting a bit over 3.5kw.

it was not a bad effort from the pie, as the winding temp stayed below 100deg c (they will take 150 without damage) and i reckon a slicker bike would have maby done another 10kph on the same power as this bike is not really for road use, with off road downhill front tyre and a 14" 4 ply motorbike knobby on the back its set up for dirt not road, but the geometry and suspension travel was kinda helpfull..

im pondering another 25volt pack for a touch more speed, but this is here in oz where its 200w max so obviously this was not done on the road, in a 50 zone :wink:
ill try get some photos/vids/dyno runs up shortly.

Click to expand...

40 amps .. thats all

not even 100amps ... commmooonnn

-steveo

Click to expand...

Steveo.. His setup seem respectable too!.. just look at the lastest pics

Click to expand...

it is 3.5kw!

not enough for me ..

-steveo

Doctorbass said:

OMG These are the shortest spokes i ever seen!!!

that motor is 14" diameter you said?

I see you had a X5 before right?.. How it compare with the same power?

BTW your ebike setup is nice too, you finally found a way to mount near kWh battery into a DH frame with still low center of gravity.. What is your DH bike?

And finally, can you post that video showing the CA and Dyno?.. WE WOULD LOVE !!! :wink:

Doc

Click to expand...

righto doc,
the magic pie motor is about 12" diameter and 6.2kg total, this bike has not had an X5, but safe to say the pie has 2 to 3 times less copper and magnet weight and can prolly make 2 or 3 times less power maxxed out.

the bike started as a norco a-line 03 model, but i had to hack half the frame away and weld alloy back to fit around the pack.
its the only electric bike ive had that you can treat like a dirtbike and gas it on the streets and through rough tracks etc, and i think its all about keeping the weight central and low and having nothing hanging off to get snagged or broken -its not really a power monster, im more trying to keep the bike to around 40kg and its not usually set up for more than 2.5kw and 50kph max, as it also needs to cover a fair distance.

having said that, im currently just tapping on wads of extra batteries just to see what happens.

heres an attempt at showing the dyno run (the 2.5kw red trace from my earlier post) videod showing the CA and the dyno kph (top left in blue) from all this info you can piece everything together like torque, efficiency etc: http://www.sendspace.com/file/b5auh9
this was a pie in a 24" wheel with about 1.95m circumference.

and i would agree about the switch to delta but in this case the motor im using is allready too fast in star!
as in during the 80kph run the motor wanted to do 130+ kph but lacked the actual power (4320w in) to go faster.

also i thought i would try a test like the docs own, 0 to 50kph took 7 seconds and it sits around for the first 20kph with only half the 40a limit, the motor phase currents stay right on 100a and dont settle down till 60kph, it only really pulls hard from 20kph + and i reckon i need a higher turn count/slower speed motor, THEN feed it more volts for 5300w in and about 4.5kw out at 90 to 100kph.

you have me curious now about the potential for running delta on the magic pie, plenty of room inside for relays but is the emf a sine wave? no-one probly knows yet.

I’m not sure about your question for the Electro magnetic force being a sinewave?

All I know is that the X5 can’t be used in Delta due to the shape of the magnetic tooth of the stator ( angeled). The scooter golden motor and the Nine continent that are very similar desing as the magic pie, work well with Delta.

Many here tried that. Just search for my posts and the one of Steveo and Rksiorek, you will find a lot of interesting data.

Some use internal relay, some use external.. like I did. I had great aerospace grade sealed 3PDT 60A relay to play with.

Now some used the typical Bosh car 12V style relay inside the hub and it seem to work well. The DC contact rating of 32V are far higher in AC so this is not a problem. I also found a new version of 80A in the SAME SIZE !!.. now Steveo will probably try some with SERIE-PARALLEL stator winding on X5 using them!

Here is the main thread about Delta WYE and serie parallel stator of the forum: ( more than 30 nice to read pages)

http://endless-sphere.com/forums/viewtopic.php?f=2&t=9215


Just look at some of my video about Delta /WYE experiences using my third ebike setup:

http://www.youtube.com/watch?v=TAaTO67zWfw

http://www.youtube.com/watch?v=p3mm4hMAHwU

http://www.youtube.com/watch?v=zEsQmCRsu8o

http://www.youtube.com/watch?v=AmBvM2Q76_0

http://www.youtube.com/watch?v=VboRceBoJYw

Doc

Doctorbass said:

I’m not sure about your question for the Electro magnetic force being a sinewave?

All I know is that the X5 can’t be used in Delta due to the shape of the magnetic tooth of the stator ( angeled). The scooter golden motor and the Nine continent that are very similar desing as the magic pie, work well with Delta.

Doc

Click to expand...

yep, i think we both mean the same thing, the result of the angled tooth etc in the x5 is that a phase doesnt make a clean sine wave and when you merge it with other phases (delta) then they work against each other to make currents, heat, etc.
its the distribution of windings in the older golden motors that gives a sine wave and delta goodness, they acctually went to a lot of trouble to wind 3 teeth then 3 then 4 etc to make the voltage rise and fall smoothly (so that partial magnets arrive and leave over various teeth to make a near sine wave).

as for the magic pie, at the moment, who knows?
also the bike pictured has 1.5kw/hours of mangenese cells about 10kg and good for about 3kw (2c) continuous.
and does current multiplication ever go much above 3 times the batt current?

as for the magic pie, at the moment, who knows?

Click to expand...

You know that the stator tooth are straight and not angeled right?

also the bike pictured has 1.5kw/hours of mangenese cells about 10kg and good for about 3kw (2c) continuous.

Click to expand...

I guess it's the 26650 Emoli cells ( LiMn) ?.. 2.9Ah.. but only 2C cntinuous is surprizingly low!.. Usually these LiMn.. just like the Makita use are 10 or 15C!..

Ex: my setup use 432 Makita 18650 LiMn cells of 1.5Ah 10C configured in 24s 18p for around 23-24Ah at 88.8V nominal. that's 240A max and 120A continuous capability!.. and my pack desing distribute heat thru the cells with great uniformity. I matched each cells to get each of the 24 parallel packs with the same exact RI and capacity and that make it to have no need of balancing. it always stay balanced so i can charge it with my 1700W Meanwell psu directly without any problem.


and does current multiplication ever go much above 3 times the batt current?[/quote]

I think not. that was discussed many times and some measured the phase current and it generally correspond to 2.5 to 3 times.. but it's not continuous so the average reactive current is lower.

Doc

Cool
I kinda gave up on the pies because I thought for their extra expense (especially considering you'd have to ditch the internal controller) the torque of the large diametre hub wasn't really that much more than their old 48v1000w one.

The slow wind motor in that tiny rim would make for some huge torque though, especially with the high voltage you're running!

And how the hell did you lace it into that rim ?! It's almost all nipple with only a few mm of actual spoke! Did you cut the spokes and threads yourself ?

Phase currents can go 4 times higher than battery currents at low speed during battery current limiting. Once you reach the point the BEMF stops the need for current limiting, phase currents roughly match battery currents.

With your voltage, its very likely you have higher phase currents than a 5305 for all operation over 20-30mph or so.

I really like the massive magic pie rotor. Efficiency develops directly with the rate the magnets move past the coils, so your giant rotor diameter is kinda like having the advantages of efficiency and torque multiplication of a geard motor, but with the silence and better cooling ability of a direct drive hub.

I like your build a lot, great work!

-Luke

liveforphysics said:

with the silence and better cooling ability of a direct drive hub.

Click to expand...

I never did get around to making a video before I sold off all my pies but they're actually quite noisy, the loudest I've heard for a direct drive hub. They have an almost geared like sound to them and it's loud enough to hear even cruising along at the top speed(with stock controller on 63v) of ~50km/hr over the wind noise and the sound of passing traffic.

toolman2,
great job on your magic pie modd.very impressive..
you should get some vids of it in action on utube..
your wheel build,looks good and sturdy.top job
can you give me link to where you got the controller to modd the pie from/store.
i just cant seem to find keywin controller for sale thru google search.


thanks for posting your work with the pie so far.as your the first i now of that has dissected the pie..

ive got the high speed version pie.bought it from hyena,thanks mate.hyena is a really good bloke & knows his stuff.+ he provides a life time warranty with his pies

the pie is definatly louder than any other dd motor ive ridden..its got a turbiney/jetplaney sound..i like it
i would love to hear what it sounds like at 100v

anyways thanks again toolman and good work
Alex

-thanks people,
doc, yep i know that the stator tooth are straight and not angeled, but this alone doesnt ensure the BEMF is a sine wave (and therefore would run well in delta) it not known yet if the pie will like delta, but not an issue at present as is too fast in star! (the phase resistance is .0847ohms in star)

the 26650 manganese cells ive been using are actually 4ah each not 2.9ah (and obviusly the same package size as 2.3ah a123s) so that makes them some of the most capacity for weight of ANY e-bike capable cells (1.5kwh 10kg pack) -but theres i big downside, they have a cycle life of less that 100, ask me about the the joy of this discovery..

the rim was i bit of effort to spoke, i had to make a thread cutter and make up the tiny motorbike spokes, and re drill the motors spoke holes to get a good lace up with reasonable angles, hope this one takes the hits.

im with you about the goodness of a big diameter motor, i know that hub motors can get massively out done for power to weight -i too had a bike running a hall sensor converted turnigy 130kv 6.5kw motor and i know that (like aspirated petrol engines) for more power you just have no choice but to rev them harder, so when i heard about the pie i just thought "awesome someone finally gets it" -the magnet speed is up and gets you into an efficient zone quickly just like a geared motor but no stripped gears etc.
ideally we may want a 26" rim as the motor but there are big challenges in scaling up to this diameter so the pie seems like a good realistic advance in this direction, i spose they then thought theres room for a controller inside so for under 1000w use, so in stock form you only need a battery and throttle and bugger all wires. -they seem to have been overlooked..?

and the controller, kewin is a fine dude, i took the risk of sending the 150v fets to him in china and he came through, awesome, reliable controllers and cheap, email: ecrazyman@gmail.com and heres his work: http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=260478648914&ssPageName=STRK:MEWAX:IT