Magic Pie II Updates

[GoldenMotor]

Dear Who42,

Yes, your suggestions have been implemented into this MagicPie II enhancement. Thanks for your continuous support to Golden Motor.
 

I was wondering if any of the below suggestions were implemented in the Magic Pie II  
I did these mods to my two Magic Pie"s easly using a lathe and a 7 speed sprocket will fit also plenty of clearence for hydrolic brakes   and the hub is much better centered  
I would love to make a Tricycle using 2  20'' Magic Pie IIs  I think they are realy cool


Magic Pie Needed SOME MODIFECATION in order to make coversions more easy with out the need for spaces for the sprocket and disk and this also got the wheel more centrol this is what I did see Photo's
on the sprocket side with this mode there is no need for the 42mm washer also a 7 speed sprocket will fit now  and no need for spacers behind the disk  The only extra washer that was added was an extra inner washer on the disk side but this could be eliminated later by buy extending the round part of the axial on the disc side  

[Who42]

Thanks Yao Yuan
Looking forword to the Pie Mk II
Hope one day you get more into EV Car Conversions  

[myelectricbike]

The one piece mag wheel overcomes the problem of nipples breaking through the rim due to the absence of a nipple adapter to accommodate the extreme torque and angle imposed by the spoke. However, I was wondering if this modification has been made to the rimes which still use spokes so that damage to the nipples holes can be avoided or prevented?

Also on the the idea of centering the wheel to accommodate 7 gear sprockets. Its a good idea but I was forced to install a single gear sprocket on the older hubs to satisfy US law but I didn't care. A single rear sprocket makes the bike less cluttered which goes along with the idea of putting the controller inside the hub.

[Aavee]

Yao,

Please let us know when MP II will be available. Information widely needed.

[MasterCATZ]

I am woundering why you still use Bicycle spokes ( that do not handle the torque at all )

why not use Motor Bike Spokes (twice the thickness ) with an Double walled RIM Bicycle wheel you can easily Drill them out a bit to take the thicker nipples and not worry about punchering the Tube as they sit below the 2nd wall

Just one quality and safty thing I can no seem to get my head around ...

[Bikemad]

I am woundering why you still use Bicycle spokes ( that do not handle the torque at all )

why not use Motor Bike Spokes (twice the thickness) with an Double walled RIM Bicycle wheel you can easily Drill them out a bit to take the thicker nipples and not worry about punchering the Tube as they sit below the 2nd wall

Just one quality and safty thing I can no seem to get my head around ...

You say that bicycle spokes "do not handle the torque at all", yet there are many millions of bicycle spokes being used daily that would seem to contradict your statement.

If you could measure the tensile force acting upon a spoke of a conventional wheel fitted with a small hub and disc brake, you would probably find under heavy braking, that it is subjected to a tensile force of at least 10 times the amount of the average hubmotor spoke being subjected to full power.
Due to the significantly larger hubs used on hubmotors, the actual force on the spokes during braking is also reduced considerably.

Standard 14 gauge bicycle spokes (the thin ones) are more than capable of transferring the amount of torque generated by these hubmotors, and thinner spokes also help to absorb road shocks.

If motorcycle spokes are twice as thick, they will be four times as heavy and probably a lot more expensive too.

I also think that the larger head diameter of motorcycle nipples would be too big to fit down inside the narrow "V" of the double walled rims.

As far as safety is concerned, the 12/13 gauge spokes used on these wheels are more than capable of doing their job.

I would suggest that the weak point on most hubmotor equipped wheels is the sideways force exerted on the threaded portion of the spoke due to the excessive angle at which the spokes exit the rim.
This particular problem has finally been addressed on the MkII Magic Pies by achieving a much more suitable spoke angle.

If I were offered the choice, I would much prefer to have the thinner and lighter standard 14 gauge spokes in my wheels, but if you really want to fit motorcycle spokes to your rims, please don't let my opinion put you off.

Alan
 

[myelectricbike]

While a 14 gauge spoke may not break under conditions of the extra weight of the motor and rear mounted battery in addition to motor torque and spoke angle the alloy rim simply can not handle the small nipple. A slightly un-tensioned "hammer jack" spoke and the rim will begin to spider crack from the hole. Try to keep your spokes tensioned.

If I were going to experiment though I'd look for ways to improve the nipple/rim contact area and angle. Perhaps an indented hole adapter would do the job. Once the rim starts to crack around a hole though you might as well through it away.

[Bikemad]

Before anyone jumps to the wrong conclusion, I would like to point out that this is a serious reply to myelectricbike's post, and is not a job vacancy being advertised!
 
If you have a problem with the rim cracking around the nipple seat area, then perhaps nipple washers could be used instead of throwing away the rim:


With the correct spoke angle, the nipples should seat correctly in the holes, thus spreading the load more evenly to the rim.
Therefore a correctly tensioned spoke with a properly seated nipple should not cause these localised stress cracks in the rim that you have described.

Using thicker spokes (which are more rigid and have less give), will transmit more shock-loads directly to the rim, and in my opinion, this is much more likely to result in stress/fatigue damage to the the rim or the threaded portion of the spokes.

Alan
 

[rossasaurus]

Hello Yao Yuan,
Will it be possible to be connected via USB interface while operating?
That is, update parameters such as regen % on the fly?

I would love to have a trimpot on the handlebar to adjust regen level as I ride downhill.

Your changes , and the fact that you are incorporating some features we've asked for, is great, thanks.

Will the MP always have the "impeller blades" on the motor pointed opposite the spokes on the 20" cast version. Do they need to run a certain direction?

OMG, 90v, you guys are nuts!

[Leslie]

Spoke rim and nipple strength needs to suitable to the task  

I ride pretty hard with a lot of weight with no back shock absorber.  If I used a lithium battery and light full suspension frame mtb and rode on a city rode the original GM rim would of survived.

But I built a huge steal bike with no back shockies and decided to lug a ton of lead and shopping on the frame along a very bumpy road.  14 gauge and its nipple width would fail me soon enough.

Single wall alloy rim with 13 gauge spoke.  Failed.  Ding in rim and nipple pulls through rim

Single wall steal rim 13 gauge spoke.  Success.  Occasional spoke failure but was better with a lower tension.

Single wall, deep nipple well, alloy rim, 12 gauge, never had a problem since.

But the 14G spoke non-ebike motor wheel on my front is going fine with front shockies.

[Leslie]

Hello Yao Yuan,
Will it be possible to be connected via USB interface while operating?
That is, update parameters such as regen % on the fly?

I would love to have a trimpot on the handlebar to adjust regen level as I ride downhill.

Your changes , and the fact that you are incorporating some features we've asked for, is great, thanks.

Will the MP always have the "impeller blades" on the motor pointed opposite the spokes on the 20" cast version. Do they need to run a certain direction?

OMG, 90v, you guys are nuts!

Interesting suggestion.

I think the chip needs to be restarted every time you make changes to the parameters of the program.  There is no reason the program cant be designed to do this on the fly but the USB cable is not needed for this function.

The older GM controllers had almost landed the perfect solution of regen off the throttle.  All you would have to do is back off the throttle and regen would kick in, the more you back off the throttle, the more regen would occur.  All that was needed was a way to switch it off or make the variable regen trigger off the brake switch.

The spokes should be faced in a direction to maximise aerodynamics of the wheel spinning.  And the impeller blades are directed for visual effects and embossed into the surface I believe to increase internal air convection and oppose the air flow on the outside to improve thermal dissipation from the Pie case.  

Even if you look at the tire of a bike wheel, there is an arrow pointing to the direction it should be installed to rotate.  Reason being is wind resistance and tread irrigation flow.  The smaller things don't add up over a single trip but over a few thousand KMs it all adds up to something worth building right.

[Leslie]

Something's wrong with this picture?

You have the crank cog on the right side of the hub and the power cable loose on the right side of the hub and no gears.

Has this been doctored or this being designed to run in reverse.  The spoke direction could be better faced the other way.

[Who42]

Something's wrong with this picture?

You have the crank cog on the right side of the hub and the power cable loose on the right side of the hub and no gears. A:  No its the disk side of the hub with the cable and yes you would have to have one wheel revesed so that the cable comes out the each side of te trike and both gear cogs are on the inside

Has this been doctored or this being designed to run in reverse.  The spoke direction could be better faced the other way.

yes it has been doctored 

I said I would love to make a Tricycle using 2  20'' Magic Pie IIs  I think they are realy cool

[Leslie]

He he Good damn job there.

It looks like the same MP2 wheel in the first pictures but with a tire and the wire cropped.

I thought you were saying you want a second MP2.

This is where I got confused,

And I thought I was the only person in the world that has that sort of time to dreams up such things in paint programs (jke).

Seems I need to move over.

 

[MasterCATZ]

any how my newly made wheel has been finished I will see what it is like .. so far just about every E-Bike floating around here is falling apart from Broken Spokes .. aparently their were 5 E-Bike shops around here .. now all Gone bust .. and all the Cycle Places did not even want to put their name to re spoking an E-Bike due to all the spokes breaking after short persiod of time


It cost me $100 for an Rear Double wall RIM and $200 to get the motor Bike Dude to respoke it with motor cycle Spokes ... will see how it goes

for now jsut trying to hunt down a good stand for the miss's bike ... which I forgotten to do this week yet again !!

i think I have almost thrown $1k into getting her old 10 yr old supermarket bike retro fitted ...


only the frame has been left untouched .. E-Bike HUB @ Fron and upgraded the Rear to take Disc brakes ect ...