How To Ice Up Your Motor? (Cooling Ideas)

[docnjoj]

Maybe alcohol/H20. Definite experiment coming up with small garden sprayer and small aperture nozzle. Drill a hole in and outlets. Regrease regularly. My oven thermometer with probe. Temps before and after. Reminder: must have spare motor on hand!!!!!! But Alky may help dissolve grease?!?!?!?!
otherDoc

 

[safe]

Maybe alcohol/H20.

Pure alcohol is flammable though... I suppose a mix that was known not to be flammable might work. I just don't see the need to risk anything dangerous.

But my experience has been that you have plenty of time to simply apply an ice pack to the outside of the motor. (while charging) It doesn't even have to encase the whole thing because the metal transfers heat so well. I had about 25% of the motor touching the ice bag and it thorougly dropped the temperature way down.

Just try it... get some ice, get a bag that doesn't leak, and then apply it to the outside. If the motor is already hot from a previous ride then it will just cool it off faster.

 

[Link]

I don't see the problem with injecting highly flammable liquids into a motor. 8)

 

[docnjoj]

Nah! Water mostly and a small amount of Alky! Wont burn, but will help cooling some! It may do more damage to the motor than just plain H2O????????? Decrease the heat of vaporization a bit, but might involve "destructive testing" which I would like to avoid!
otherDoc

 

[safe]

Icing Does Work

I think the main thing is that in winter I had theorized that icing up your motor shell was a way to lower the motors temperature and we had no way to verify it's truth.

Now having actually tried it we can know from experience that icing does work and does lower the temperature of the shell to a point somewhere between outside temperature and freezing. It felt with my hand like about 40-50 degrees F when the outside temperature was near 90 degrees F. I also can reach back and feel the motor shell while riding and I found that after 5 miles the motor was still not hot and after 10 miles the motor was only luke warm. On that same route in the morning without pre-cooling the final temperature was enough to nearly burn the hand on contact... and I did the ice ride at full power, so it wasn't due to slacking. (my rides are becoming very precise since it's my testing laboratory)

So while there might be alternatives we can conclude that at least for "ice on the shell" this does work.

 

[HAL9000v2.0]

For a hub motor how about Al coolers/spokes ? :lol:

 

[safe]

For a hub motor how about Al coolers/spokes ?

You ought to read the RC motor thread. (seriously)

That's the future of ebike motors... high rpm, light weight, "Swiss Watch" type precision gearing. The "Big Iron" will not be on the high end bikes in the future. (and since you seem to like futuristic bike designs you should start to think about the better solution)

And those highly tweaked RC motors are bound to need cooling so this topic has a long future ahead of it.... :wink:

For the same power would you rather have:

25 lbs of hub motor

or

10 lbs of RC type motor

??????

 

[HAL9000v2.0]

In one you are right, this type is outdated but I don't think that high rpm is solution. I 'we been on ice bikes all my life(mostly italian 2 strokes) and after 1km with hub motor I 'll never go back on something that turns on 10krpm or more. Just can't stand that noise any more. U can call me old...
I think that future bikes will be based on high diametar low amp hub motors.

 

[recumpence]

In one you are right, this type is outdated but I don't think that high rpm is solution. I 'we been on ice bikes all my life(mostly italian 2 strokes) and after 1km with hub motor I 'll never go back on something that turns on 10krpm or more. Just can't stand that noise any more. U can call me old...
I think that future bikes will be based on high diametar low amp hub motors.

How about magnets all the way around the rim with coils mounted to the frame at various locations on teh dropouts? That would be relatively light weight and HUGE diameter. The pole count count be extremely high!

A neighbor of mine and I looked into this a few years back, but never pursued it. Neither of us are motor builders. 8)

Matt

 

[recumpence]

In one you are right, this type is outdated but I don't think that high rpm is solution. I 'we been on ice bikes all my life(mostly italian 2 strokes) and after 1km with hub motor I 'll never go back on something that turns on 10krpm or more. Just can't stand that noise any more. U can call me old...
I think that future bikes will be based on high diametar low amp hub motors.

My bike is very quiet even at 9,000 to 10,000 RPM.

The future may not be high RPM with reduction. But, noise is definately not the reason why. Complexity would be the limiting factor along with reduction losses.

Matt

 

[JEB]

After reading all the posts, I did not notice anyone addressing the following: When using air as a cooling medium, there is a surface air insulating film on all objects that is hard to disturb- so in most cases you start with a delta T of about 15 deg. F, that takes a very forceful flow of cooler air to remove or exchange heat from an object. (i.e. a direct blast of high pressure air directed at the surface from an air compresser nozzle, anything else will prove to be not very successful) This is what I have found when working with water to air heat exchangers. Jim

 

[Link]

After reading all the posts, I did not notice anyone addressing the following: When using air as a cooling medium, there is a surface air insulating film on all objects that is hard to disturb- so in most cases you start with a delta T of about 15 deg. F, that takes a very forceful flow of cooler air to remove or exchange heat from an object. (i.e. a direct blast of high pressure air directed at the surface from an air compresser nozzle, anything else will prove to be not very successful) This is what I have found when working with water to air heat exchangers. Jim

True, but an armature is turning at several thousand RPM.

A hub won't be turning so fast, but still manages to keep relatively cool.

 

[safe]

...that takes a very forceful flow of cooler air to remove or exchange heat from an object.

That's the point of the thread.

Direct application of ice to the shell of the motor produces heat transfer that is something like 25 times faster than air. In addition since the ice is capable of taking the shell below outside temperature you actually can pre-cool your motor.

My testing has really shown this to work well... it's actually no longer necessary for me to think about any type of cooling because even on the hottest days if I pre-cool the motor I end my rides (even though they are hard rides) with a motor that is only luke warm. Without pre-cooling the motor ends up very hot. I have to make a note here that I have a 10lb motor, so that's enough mass to be able to pre-cool it. If you were using a smaller motor it might not work as well. (I have the Unite 1000 watt motor)

To use the MythBusters terminology this one is:

"Confirmed"

 

[TylerDurden]

Direct application of ice to the shell of the motor produces heat transfer that is something like 25 times faster than air. In addition since the ice is capable of taking the shell below outside temperature you actually can pre-cool your motor.

My testing has really shown this to work well... it's actually no longer necessary for me to think about any type of cooling because even on the hottest days if I pre-cool the motor I end my rides (even though they are hard rides) with a motor that is only luke warm. Without pre-cooling the motor ends up very hot. I have to make a note here that I have a 10lb motor, so that's enough mass to be able to pre-cool it. If you were using a smaller motor it might not work as well. (I have the Unite 1000 watt motor)

To use the MythBusters terminology this one is:[/color]

"Confirmed"

"Confirmed" in this case = "Mission Accomplished"

No hard data.

That's called anecdotal reports, or hearsay.

 

[vanilla ice]

Exactly, like he said "confirmed" just like on mythbusters. :wink:

 

[safe]

Exactly, like he said "confirmed" just like on mythbusters. :wink:

It works on my motor... maybe others won't get as good of results. I plan to do more formal tests some day that will make use of a thermometer so that I can actually document the data better.

By feel of my hand it's an absolute fact for me... without the pre-cooling my very regimented and predictable ride will leave the motor on a hot day so hot that it threatens to burn my hand after about 5 seconds.

Do the pre-cooling and even on a dreadfully hot day the motor ends up luke warm even though my ride times are the same. After a ride that started with pre-cooling I can hold my hand on the motor indefinitely.

For those that still doubt the idea despite my evidence I propose you do your own independent testing. Find some ride that will overheat your motor... then repeat that ride EXACTLY THE SAME after you had done a half hour of ice cooling on your motor shell. Then learn the difference.

Skeptics are part of science... I welcome them... but you need to actually test this to have any strong say to the contrary... (put your efforts towards verification rather than negative "idle" speculation)

"Theories are made to be tested."

 

[TylerDurden]

Exactly, like he said "confirmed" just like on mythbusters. :wink:

[]It works on my motor... maybe others won't get as good of results. I plan to do more formal tests some day that will make use of a thermometer so that I can actually document the data better.

By feel of my hand it's an absolute fact for me... without the pre-cooling my very regimented and predictable ride will leave the motor on a hot day so hot that it threatens to burn my hand after about 5 seconds.

Do the pre-cooling and even on a dreadfully hot day the motor ends up luke warm even though my ride times are the same. After a ride that started with pre-cooling I can hold my hand on the motor indefinitely.

For those that still doubt the idea despite my evidence I propose you do your own independent testing. Find some ride that will overheat your motor... then repeat that ride EXACTLY THE SAME after you had done a half hour of ice cooling on your motor shell. Then learn the difference.

Skeptics are part of science... I welcome them... but you need to actually test this to have any strong say to the contrary... (put your efforts towards verification rather than negative "idle" speculation)

"Theories are made to be tested."[]

That's what data is for. All assertions should be validated by empirical evidence.

BTW, The burden of proof is on the "pro-sayer", not the nay-sayers.