Much More Powerful Pie Now!!!

[Leslie]

I don't have or know where I could get shunts of any kind in this country! lol honestly it's the hardest place to get anything! The fet's had to be ordered from the U.K!

317537
what about leaving the resistor wires as shunts? and trying the software to limit the amps or remove one of the three?

Also I did replace all 6 fet's. I just replaced the same one that blew last time.

I just want to say that I'm disgusted with the lack of support from GM. I e-mailed Tom, fair enough he replied, but is not interested in sending spare parts by the looks of it. yes I messed up my pie's cable, but at my own expense and I'm not asking for spare parts for free!!!
There should be spares available for the pie on the website!

Yes I unserstand.  You wanted your new hub to perform at least as good the old hub so you tried to make it right.  Setting your pie to default 30 amps max with a 15 amp shunt may not of been the best configuration solution anyway.

Maybe just order straight from sales.  And ask what you want.

sales@goldenmotor.com

[Leslie]

Did you install 3 15 amp shunts.

Here?

The bigger picture tells more.

Your idea leading the fets to caps via the shunts is a good one.

Make the shunt as close to the same length.

I can still send you something rated and tested if you want.



Beef up the track where I marked in red with solder.

[o00scorpion00o]

Did you install 3 15 amp shunts.

Here?

The bigger picture tells more.

Your idea leading the fets to caps via the shunts is a good one.

Make the shunt as close to the same length.

I can still send you something rated and tested if you want.



Beef up the track where I marked in red with solder.

yes I removed the original shunt and installed he lead from the resistor, and then the 2 you showed in the picture. I think I'll just wait until I get the cable and turn the amps down and see if it works and if not then I will go external, and hopefully be able to get all the cables through the axle! I'll beef up the track as you suggested now, connect up and see is the wheel spins then wait until I get the cable.

[Leslie]

Did you install 3 15 amp shunts.

Here?

The bigger picture tells more.

Your idea leading the fets to caps via the shunts is a good one.

Make the shunt as close to the same length.

I can still send you something rated and tested if you want.



Beef up the track where I marked in red with solder.

yes I removed the original shunt and installed he lead from the resistor, and then the 2 you showed in the picture. I think I'll just wait until I get the cable and turn the amps down and see if it works and if not then I will go external, and hopefully be able to get all the cables through the axle! I'll beef up the track as you suggested now, connect up and see is the wheel spins then wait until I get the cable.

Yer this is the mad mod forums here.  We crazy.  The mod you did before could do 120 amps peak.  I see no need to put yourself through any more work.

Just do 30 amps shunt and leave well enough alone, if it works ride it and ride it some more.

I posted the last pic as that could be considered what you would do iwth a shunt mod.  not nessarily going to make any difference you know.  Maybe to someone who wants more than 15 amps or more than 60 amps say.

[o00scorpion00o]

No go I'm afraid. I have been busy with it. I even managed to get the usb cable working and turned the con and max amps down to 10. I took a guess where the 3 cables went and it worked. It's about the only thing that worked!

Thanks 317537 for all the advice, I really appreciated it. We could have made the pie fly, but I made it die! LMAO 
All part of the fun I suppose. It would be interesting if someone would connect a cycle analyst to their pies to see on 48-52 volts what amps they are pulling, I would LOVE to know this info, or are GM selling handicapped pies to European buyers. If you are then that is a disgrace!!!

This motor has unbelievable torque when fed with around 30-40+ amps. I would sacrifice some of this torque for more speed!

I think when I get this motor running I will start saving for a BMC v3 motor and controller. I know they are expensive, but they are efficient because of the gears. You get better torque with higher speed.

For most people the pie is a decent quality kit, far from perfect but it will be perfect for most. I just feel hard done by by GM.

Anyway enough said, Now it's time to Re cable the pie, for the external controller and forget about it.

I will post whenever I get it going again.

[Leslie]

Matey.  You woudlnt be the first to blow up a controller board and certainly not the last.  Dont hold grudges against GM because out of every honest person with the skin you got posting your experience in mods, there is a dishonest person that screws their kit up and tries to get warranty.

There seems to be a culture here of fault finding on the forums and then asking for returns, you were a little fast in finding your fault and fast to try to fix it. 

You and me are the same in this way I cant wait to get the bike out on the road.

You just havent learned about the Pie you have learned a lot about a lot of things about ebiking and it's new culture.

I fried my first controller on the first day when I connected it to my SLA and was looking for a spot to put it on my bike.  I then shorted another wire against the positive terminal.  The second controller lasted a week when my SLA's were too heavy and bike the stand broke and the bike fell over squished the wires and stupid me switched the controller on to test it.

I rode out without pumping my tire hard enough up and screwed the rim on day one hiting a sharp concrete corner in the grass.

I blew two chargers up day one  not GM chargers.  Because my battery was a self help design I had to get the polarity right.  Yeah it helps to have your multimeter probes in the right holes hey.  After the first one went popers,  You think I'd learnt from that.  I went ahead and blew up the next one the same way,  I rang up the seller a little upset.  It was another hour before I figuired out where I went wrong.  At least they were easy to fix.

These are my failures but I am here to maybe save someone else the grief or even pass on my never say die attitude onto the next poor soul in trouble..

Smile, Its oly an $60 controller, and you have not lost the most of your purchase only a small part.  I bet the Pie outlives both of us.  Some people in a worse situation than yourself think its the END OF THE WORLD when something fails.  They give up and in spirit lose there whole purchase and deem it as a pile of junk.  This thread remains a good example of what value remains left in a GM purchase after a failure.  So lets end this with sucess, even if you had to buy a new controller.


I think if you had got away with the mod for another day you would of been able to get your max amps down or maybe not.  Its hard to go to an awesome party and suffer a boring party the next time..


It was like when I overvolted my hub to 60v, going back to a 36v brushed motor was a big step down.  I still have a working GM hub Im just waiting to put a decent pack on it and even a new pie.

Good luck with the new controller and I would get another one as a spare.  You know what its like to be off the road and away from everything.  I rely on these bikes to feed my family.  It cost me $20 in a cab even if I want milk and bread without the ebikes.

[o00scorpion00o]

I'm only annoyed of the fact I bought a 1000w motor and ended up with a 750 watt. And I don't think it's fair!

OK time to move on to the next project! 

I tried fitting the cables through the axle lol no go. So I have ordered some thinner 12g cable from England. Of course I can't get anything here so I hope it fits!!!

I just checked my e-mail and I got one from Tom just checking which cable I need, MUhahahahahah you know what I'm thinking? Yes indeed. I asked him to send cable + controller. I will do mod again and this time turn amps down and see if it works. If not then I will put it back to stock and keep it as a spare, and use external controller!

I know I'm crazy but I got to know if the Mod will work by turning it down in the software! I will do the mod this time as with your suggestions 317537, with the resistor wire?


Has anyone noticed that on GM's order page, the option of external controller pie? has anyone got any information on this?

[Leslie]

I'm only annoyed of the fact I bought a 1000w motor and ended up with a 750 watt. And I don't think it's fair!

OK time to move on to the next project! 

I tried fitting the cables through the axle lol no go. So I have ordered some thinner 12g cable from England. Of course I can't get anything here so I hope it fits!!!

I just checked my e-mail and I got one from Tom just checking which cable I need, MUhahahahahah you know what I'm thinking? Yes indeed. I asked him to send cable + controller. I will do mod again and this time turn amps down and see if it works. If not then I will put it back to stock and keep it as a spare, and use external controller!

I know I'm crazy but I got to know if the Mod will work by turning it down in the software! I will do the mod this time as with your suggestions 317537, with the resistor wire?


Has anyone noticed that on GM's order page, the option of external controller pie? has anyone got any information on this?

I just used an old extension cord AC wires, the extension cord was made for power tools.  The earth wire in some is a little thicker.  I don't know why some need huge cables.  The phase cables are fine rated at AC because its PWM.

The MP controller is based on the MC controller you maybe able to replace the MP controller with an Magic Controller.

[o00scorpion00o]

I just used an old extension cord AC wires, the extension cord was made for power tools.  The earth wire in some is a little thicker.  I don't know why some need huge cables.  The phase cables are fine rated at AC because its PWM.

The MP controller is based on the MC controller you maybe able to replace the MP controller with an Magic Controller.

That is interesting, I never thought of using AC mains cable for fear of melting phase wires, surely they couldn't handle 30 amps or more? I hear so many scare stories of melting wires!

The external magic controller is different to the internal controller. some of the components don't allow for the external pcb to be mounted in the pie! And there are a few missing components in the internal. Maybe one reason I noticed a power difference???

[Leslie]

I just used an old extension cord AC wires, the extension cord was made for power tools.  The earth wire in some is a little thicker.  I don't know why some need huge cables.  The phase cables are fine rated at AC because its PWM.

The MP controller is based on the MC controller you maybe able to replace the MP controller with an Magic Controller.

That is interesting, I never thought of using AC mains cable for fear of melting phase wires, surely they couldn't handle 30 amps or more? I hear so many scare stories of melting wires!

The external magic controller is different to the internal controller. some of the components don't allow for the external pcb to be mounted in the pie! And there are a few missing components in the internal. Maybe one reason I noticed a power difference???

I melted the motor before the ac wires.  I have the pics to prove it too.

My wife towed a ton of shopping home one week and the wires were cool as, and the motor needed hosing down it was soooo hot..

Oh edit:

Yes to say that 50hz AC is equal to 50khz in DC is like comparing a truck to a mustang.  The AC wall is practically DC compared to BLDC PWM output.  So, yes AC ratings are too low.

Yer I think my cables were rated at 10 amps AC at 50hz.  They kicking the motor along and never once had warm wires.

I think I did 20,000 hard KMs on the ac wires too.

So where did you hear these stories?

[o00scorpion00o]

I melted the motor before the ac wires.  I have the pics to prove it too.

My wife towed a ton of shopping home one week and the wires were cool as, and the motor needed hosing down it was soooo hot..

That is interesting! I remember my old 1kw kit phase wires got fairly warm but not hot after a few miles full throttle. Motor got warm too.

Do you have 110 v AC there or 220? That might make a difference?

[Leslie]

I melted the motor before the ac wires.  I have the pics to prove it too.

My wife towed a ton of shopping home one week and the wires were cool as, and the motor needed hosing down it was soooo hot..

That is interesting! I remember my old 1kw kit phase wires got fairly warm but not hot after a few miles full throttle. Motor got warm too.

Do you have 110 v AC there or 220? That might make a difference?

We have 220 AC.  


Was the 1kw kit using 220v rated wires or 120v wires.  Its not the same as VXR=I.  Voltage rating in wire is calculated by the thickness of each fibre and materials used and current is calculated on how many wires that make the gauge in the cable.  Voltage resistance only comes into the math of watts when you consider the length of the wires.

12awg copper wire has a resistance of 0.0055 per meter.  Lets run that by ohms law.

V/R=I

50v/0055=9090 amps over a meter of 12awg.  Well it aint resistance that is stopping the current.

Now lets do some math on the watts that will create over the wire.

I²XR=Watts

9090²X.0055= 454454.55 watts, wow that burning up.


Ohms law doesnt work for awg does it? >>> ¿  

Now lets try 20 amps pure DC which is close enough to 12awg current capability.


20²x.005= 2.2 watts over a 1 meter cable. ahhh thats more like it.


Maybe your motor was passing heat up the wires.  High voltage over small fibre wire doesnt melt the wires it causes atrophy and the voltage cant go deep enough into the small fibre so it can create arcs along the current pathways.  Lack of resistance does not create large voltage drops over the length so watts are not created.

Use a good thick fibre wire for voltage with many wires for current pathway.

I tried some 50v 50 amp DC rated cable for my battery power cable, it was huge, I think 4awg, but the filament was very fine with lots and lots of filaments.  No heat at all, just after long use the filament became brittle all along the cable and breaking up inside the insulator and you could see the copper going green, impurities were being arced into the core of the copper wire.  If I continued to use this cable the resistance would of became too much and heat would of became the next issue.

It wasnt the motor use aging the wire so soon when riding, it was the damed 60v 3 amp charger.  Wow 3 amps wrecking my 4awg wires .  NOT! it was the 60v.



To give you an idea of what is happening here I thought of a good model.

 

Try to fill up a box with big balls through funnel into a pipe facing downward.  Weigh how much is able traveling through per second.  Then make the balls tiny and allow them to travel through the pipe at the same speed.  Which is going to transfer more weight per second? The tiny balls or the large ones.

Current actually requires surface area, well kind of.  The more surface area of a conductor the more current is allowed. SO by increasing the amount of filaments in a cable you increase the suface area for current. Thats the best I can explain it. I'm getting tired.


Voltage issues.

Now think of skimming a stone over a lake.  If you throw the stone slow it sinks to the bottom without bouncing off the surface.  Throw it fast and it bounce many times off the surface disturbing the surface tension all along its path.

So to voltage bounces along the wire.  If the voltage is too high, for the want of a better metaphor, it bounces higher and tries to land deeper into the filaments damaging the surface tension of the wire all along.

But with voltage if you can allow it enough width of bonded conductive ionic molecules,  it can get its zap into the filament and wont arc.



Above is some high voltage transmission wire, look at the filament core and how thick each one is.

LeZ

[o00scorpion00o]

That was a lot to take in, I'm not sure if I got it, I always thought the thicker the wire the higher the current it can handle?

[Leslie]

Yessss


But I used very thick 4awg wire and yes the current was spectacular but each of the wires that made up the gauge were tiny almost like hair.  The voltage was making a mess of these tiny hair wires.

You know how cables are made up of a bunch smaller wires inside (filament) Current has no problem running along lots of fine wires.  Voltage does have problems running along lots of fine wires.

More surface area requires a larger gauge to give better current but this has not much to do with the individual wires that make up a very thick cable...




Like in the picture above if we replaced the individual massive filaments with tiny wires but made the entire cable the same width it would be great in current, much better than the cable in the above picture.  But you would lose the "ultra high" voltage rating.  In fact it would be usless in high voltage applications.

[MonkeyMagic]

Hey there

Hmm I think if I get the 16" cast wheel going again [need to test it on a bike] I'll be doing some tinkering!
Les - awesome points mate, I think those cables in the pics would be suitable for like 50KV+ though... Now that's what I call a Magic Pie

This table I'm posting is good for upto 400VDC [AWG] -->