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[MostlyBonkers]

Cheers Doug. Love the bass-ackward. New word for my dictionary!

I guess the IPM motor is the real Eureka moment, and by Zero themselves. A performance factor close to 1, I gather from YouTube. Not much room for heat wastage if you're close to 100% efficiency in a motor. Astonishing really.

[dean mcneil]

Not sure what to make of the posts on water cooling. I  never claimed to be an engineer . I thought this forum was an opportunity for everyone novice and expert to discuss and work out problems.  Even if heat in the rotor is a big problem , the heat it transfers to the stator and stator temperature is the real problem. I don't care if the rotor glows red, as long as the stator stays within tolerance. Moving more of the heat to the stator with oil  only moves the problem, yes you can cool the oil. But I haven't seen good system for that yet. Im trying to cool the stator and water cooling is more than 7 times more efficient than air cooling. No , Im not using the motor set up on a street bike or a race bike, Im running it on a kart- total weight with driver less than 475lbs.  We are competing against gas karts in the TAG and Shifter class. If electrics can be shown to be competitive ,head to head, in kart racing, the potential market for the components  is more than current zero motorcycle production! It would be a huge WIN for electric motorcycles for there component sales to more than double.  The Rattlesnake guys are on the fore front of what could be a huge bubble that will benefit everyone. Everytime I take the kart out , everyone is surprised when I tell them what the components are off of. People have never heard of Zero or Lightning. And these are gearheads Im talking to.  They are unaware of the leaps that electric vehicles have taken.  I had hopes that the electric motorcycle community would welcome karts.  We  can help each other.

[Doug S]

Dean, speaking for myself, I had no intention of being derogatory in any way. I think what you're doing is cool as hell, I want one, and I'll probably get one when I've made my second million (assuming I ever finish the first one). And I'd be REALLY surprised if the rest of the guys here don't feel exactly the same way.

I don't know either, but I suspect you're right that the majority of the heat is generated in the stator -- that's where the coils are attached, after all, and they're what those 660-amp currents flow through. What you're doing is fantastic in terms of pulling heat out of the stator. But the rotor might give you some grief, too.

You might think since it's just a bunch of magnets epoxied to a shaft that there's nothing generating heat, but the magnets have "hysteresis" and when you put strong magnetic fields on them (like the coils do when the motor is being energized) the hysteresis causes a fair amount of heat to be created in the magnets as well. It's not as much heat as the stator generates, probably, but it's harder to get rid of (as we've been discussing) and magnets in general don't like heat very much. It's my understanding that higher-temperature magnets and the epoxy securing them to the rotor is what distinguished the SR motor from the S motor in 2014 and 2015. My bike (an early 2014 SR) was recalled along with several others because the first few motors failed to get the higher-temperature magnets and/or epoxy.

In addition to the great work you're doing, I'd seriously consider half-filling the motor with Automatic Transmission Fluid, as some have done, or maybe some of the new ferrofluids others have posted about. Make it easier for the rotor to get its heat to the stator and your stator cooling work will be that much more effective.

[mrwilsn]

I am by no means an expert but based on what I have read, for an SPM design the thermal challenge is in the rotor.  If the rotor gets too hot you can have demagnetization.  As has been stated, its not so easy to get heat out of the rotor.  The heat sinks and airflow around the stator help but you are really fighting that air gap in the heat transfer. Zero fights this in the 2014/2015 SR by using magnets that can withstand higher temperatures before they demagnetize. Hot rodders combat this further by slotting the side plates to allow air to flow through the motor and cool the rotor directly, which is great for removing heat but not so great for the long term life of the motor (dirt, dust, water, rust etc are not so great for the inside of the motor).

I think its important to keep in mind that the temp sensor on the motor is on the stator.  If you rely on the sensor to tell you if the mod you make is effectively cooling the part of the motor that needs to be kept cool (the magnets) its possible you could actually do damage to the motor.  The stator where the temp sensor is may be cooler and allow the controller to keep the motor at full power but the rotor may still be getting too hot and demagnetization starts to happen. And demagnetization doesn't occur all at once....does your Zero not seem as peppy as it once did?  Zero's engineers know the stator temps that translate to a rotor/magnets that are too hot. I am by no means a guy who discourages modding (I love it in fact) but if you mess with the equation you do so at your own risk....but I think that goes without saying 

IPM designs, on the other hand, do not generate a significant amount of heat in the rotor.  According to one website I found, "roughly 90% of the motor losses tend to occur in the stator, which can be easily cooled by heat sinking, oil cooling, or watercooling".

Thats why Zero's shift to the IPM design is so huge.  Even though the motor still gets hot, the heat sink and airflow around the stator are much more effective at removing the heat.  Here is a good commentary on YouTube from motorcycle.com on how a Zero rep described the process.

2016 Zero FXS - AIMExpo

Here is my source for info on SPM vs IPM....its a great read and has additional details about the benefits of IPM.

Interior Permanent Magnet Motors Power Traction Motor Applications

[grmarks]

I am by no means an expert but based on what I have read, for an SPM design the thermal challenge is in the rotor.  If the rotor gets too hot you can have demagnetization.  As has been stated, its not so easy to get heat out of the rotor.  The heat sinks and airflow around the stator help but you are really fighting that air gap in the heat transfer. Zero fights this in the 2014/2015 SR by using magnets that can withstand higher temperatures before they demagnetize. Hot rodders combat this further by slotting the side plates to allow air to flow through the motor and cool the rotor directly, which is great for removing heat but not so great for the long term life of the motor (dirt, dust, water, rust etc are not so great for the inside of the motor).

I think its important to keep in mind that the temp sensor on the motor is on the stator.  If you rely on the sensor to tell you if the mod you make is effectively cooling the part of the motor that needs to be kept cool (the magnets) its possible you could actually do damage to the motor.  The stator where the temp sensor is may be cooler and allow the controller to keep the motor at full power but the rotor may still be getting too hot and demagnetization starts to happen. And demagnetization doesn't occur all at once....does your Zero not seem as peppy as it once did?  Zero's engineers know the stator temps that translate to a rotor/magnets that are too hot. I am by no means a guy who discourages modding (I love it in fact) but if you mess with the equation you do so at your own risk....but I think that goes without saying 

IPM designs, on the other hand, do not generate a significant amount of heat in the rotor.  According to one website I found, "roughly 90% of the motor losses tend to occur in the stator, which can be easily cooled by heat sinking, oil cooling, or watercooling".

Thats why Zero's shift to the IPM design is so huge.  Even though the motor still gets hot, the heat sink and airflow around the stator are much more effective at removing the heat.  Here is a good commentary on YouTube from motorcycle.com on how a Zero rep described the process.

2016 Zero FXS - AIMExpo

Here is my source for info on SPM vs IPM....its a great read and has additional details about the benefits of IPM.

Interior Permanent Magnet Motors Power Traction Motor Applications

I always assumed the magnets got hot from the radient heat of the stator.  Are you saying a magnetic field applied to a magnet will make it heat up?

[MostlyBonkers]

This forum is absolutely for both novices, like myself, and experts to get together, discuss and work out problems. I'm sorry if I've played any part in upsetting you Dean. You really are in great company here, as I hope the last two posts demonstrate.

This thread is a great example of this forum at work. I presented what could easily be interpreted as a silly idea. I also like to think it had some merit, which seems to have resonated with a few. For others, it has been a source of amusement and that's fine too. I don't think a bit of humor does any harm every now and again. We all do stuff just for shits and giggles. [emoji4]

From my point of view, I was interested in both the overheating issue and the new IPM motor. I now have a good understanding of both, thanks to the posts here.

I think you'll find we're with you 100% Dean. People are in awe of what you have achieved with your Kart and it's great to see different uses for the Zero powertrain. Thank you.

I was doing some research yesterday and came across this video:



It's the application of an IPM motor in a kart.

The two key conclusions I draw from this topic are:

IPM motors are cool! If you'll excuse the terrible pun... [emoji6]

Seriously though, they were mentioned in the topic on the 2016 model announcements as probably the biggest improvement for this iteration.

Secondly, the point made about the thermistor living in the stator shouldn't be ignored. The best way to damage your motor, other than by drilling holes in it, is to let the rotor get too hot. Providing extra cooling to the casing, whether using water, dry ice, heat pipes or whatever will trick the system and likely result in damage. The exception to that being the use of ATF in the motor to pull heat from the rotor.

[MostlyBonkers]

I always assumed the magnets got hot from the radient heat of the stator.  Are you saying a magnetic field applied to a magnet will make it heat up?

Both of those. It's all in that article which is well worth a read. [emoji4]

[Lipo423]

Great information on the cooling…I was not aware of the ATF option…How many forum members have tried it?
Have we got any feedback? it looks like a good first step + external water cooling

I'm thinking in emailing Zero engineering with my cooling proposal…see photo 
Hope nobody gets offended…just trying to add some sense of humor to the topic...

I always assumed the magnets got hot from the radient heat of the stator.  Are you saying a magnetic field applied to a magnet will make it heat up?

Both of those. It's all in that article which is well worth a read. [emoji4]

[Ndm]

Wow, awesome reading, thanks for the link mrwilson, does anyone know if the zero ipm motor is a concentrated design or distributed

[mrwilsn]

Hope nobody gets offended…just trying to add some sense of humor to the topic...

LMFAO....is the fan for cooling or propulsion? Or Both? hahaha

[Ndm]

Most likely to get the 2 stroke exhaust away from the driver!

[dean mcneil]

I appreciate your positive comments. The support is greatly appreciated.  Zero currently has a setup that with a little tweeking can be competitive in karting. TAG and shifter karts are expensive to purchase AND expensive to maintain. They require constant maintenance. Thanks to zero, Hollywood Electric,Rattlesnake, and forums like this one, many in the karting field are finding out that its possible and cost competitive to build electric karts.  The initial cost is close to shifter class cost ,however there is very little maintenance. Some Shifter motors must be completely rebuilt after only 20 gallons of fuel and the cost is around $1000. The motors themselves cost $4500.  There is ever increasing pressure to reduce noise. The electric format eliminates many of the problems confronting karting today. Zero and other manufactures have a great opportunity to significantly increase there sales, component sales can provide a SIGNIFICANT source of needed funds to be used on R&D while also providing the manufacturers with a test bed for no cost R&D. This is a WIN /WIN relationship and the first manufacturers to support this will reap the benefits. Its now possible to simply convert a shifter kart to electric in a few hours, with little electrical engineering experience.  We just need to work out a few problems -COOLING.  Motor cooling- the ATF doesnt damage any of the internals? I not familiar with it. What about using the ATF to spread out the heat and water cooling to remove it. The radiator  set up is light , No heavier than the bilge blower and in my case a reduction transformer to run it. Next BATTERIES, are there any pictures of one of the power packs skinned. There must be a way to ventilated or liquid cool these things- they are bricks. Im very interested in a the cooling plate for the controller, for my application it will be the final component to require cooling.THere should be a way to integrate the cooling for all these components.

[Lipo423]

Hope nobody gets offended…just trying to add some sense of humor to the topic...

LMFAO....is the fan for cooling or propulsion? Or Both? hahaha

It is actually a high-tech bi-energy low-emissions model…the design is made in a way that when you go through exhaust/emissions inspection the internal combustion engine goes off automatically, and you ride the bike with the fan (not as sophisticated as Volkswagen, but pretty close

[Burton]

Dean,
Send a message to Doctorbass as he has taken apart 2012 model batteries and might have something to offer you.
Which batteries are you working with the FX modules or a monolith?

As far as cooling the controller it shouldn't be too hard to find a cooling plate for the controller. ATF is used to get the heat from the rotor to the casing easier ... what you do with it when it gets there is up to you If the ferrofluid ends up working on our motors it might be a better option as less would be needed and it likely won't damage anything.

Not sure on the ATF but I hear of people racing who have used it before (hope they are watching this thread)

[dean mcneil]

The batteries are 2014 power tanks. I will contact Doctorbass. thanks