Or mineral ATF which has a few additives to prevent foaming, among other helpful things. And is also dollars a bottle.ian.mich said:...or mineral oil? it's petroleum based, does not conduct electricity, has a fairly low visosity and is dollars a bottle.
neithermovingnorstill said:I'm thinking Glycerin over Mineral Oil, for better heat dissipation and sound reduction:
Thermal Conductivity:
Mineral Oil = 0.133 W/mK
Glycerin = 0.290 W/mK (more than twice the heat dissipation of Mineral Oil)
It is more viscous, so it will produce more drag, but the viscosity will dampen sound more, and it's a very effective lubricant.
Like antifreeze, it will absorb a tiny bit of moisture over time, but it can be replaced yearly (it's fairly cheap). Probably needs more frequent changing in wet/humid area, depending on how well sealed the motor is.
It's so nontoxic that you can buy edible Glycerin (food grade). It's got a lot of uses, including as a plasticizer for soy resin*.
*soy resin: biodegradable homemade resin made from soy protein concentrate, water, baking soda, and glycerin, which can be soaked into hemp canvas or fibers, dried, and baked at low temp (240f) to make biodegradable composites.
GCinDC said:how can i clean ATF out of the windings? can i use brake cleaner or will that damage the windings?
in vented side covers, the motor gets so hot now. my dry hs3540 stator (now dead) got nowhere near as hot in the vented side covers, and when i replaced it with the one that had been in the oil, it gets much hotter! i'm worried the ATF has now dried and gunked in the windings so it can't cool down.
thx
neithermovingnorstill said:Re Viscosity of Glycerin at cold temps:
I ran an experiment by putting some in my freezer overnight.
It does become more viscous, but not in the same way that sugar syrup does. If I tip the container, it moves slowly, but when I stir it, it's very easy to stir, very little resistance, so it is still effectively a fluid. Which is what you'd expect from something they put in antifreeze, because that wouldn't work if it became considerably more sticky at cold temperatures. It's a strange fluid, I'm confident it will work.
Re: GCinDC:
If you are confident that there is no glue used in the stator, you can probably use almost any solvent, as long as you remove the stator from the rest of the motor housing, and disconnect or cover any wires (the plastic shouldn't be soaked in solvent).
I like using orange oil for smaller jobs, but you'll likely need to soak your whole stator, so something cheap like gasoline should work fine.
If you think there is glue, and don't want to use solvent, I'd use a hair dryer rather than compressed air. Compressed air is very cold, but the hair dryer will make the ATF more runny. If it doesn't produce enough air pressure to push the ATF out, you could alternate with the hair dryer and a vacuum cleaner. Use gloves, the copper will be very hot.
Re: Liveforphysics:
That might be true, but even if the ATF doesn't dry, the motor running could heat it up and splatter it all over the stator, and since there isn't enough ATF to conduct the heat to the casing, and ATF isn't as conductive as Copper (almost nothing is), that might lead to some extra heat? There could be other stuff in there though, if it's a geared motor, fiberglass/resin powder from the composite gears, metal powder, dissolved plastic, etc. Probably a good idea to strip it by soaking it in solvent just to rule that out, because it's an easy fix if that's the problem.
I'm quite sure you're right.My guess is that if you fill the motor up to the point it's nearly to the axle, when you spin the motor, the oil slings in a ring around the stator, submerging the copper all the way around the perimeter.
GCinDC said:Temp C on left and minutes on bottom axis:
dang it. i can't find original video of oil-cooled run, to compare with longer vented run! :x i'm pretty sure the oiled motor started cooler, but got hotter and stayed hotter than vented, tho i should shut up till i find that vid.
notes:
the 'no oil' line is for the unvented/unoiled motor.
ambient temp was ~5C hotter when the vented run was conducted.
except for a couple sections, i was trying to pull as much current (4kw) as possible, esp going uphill, to make the motor heat up as fast as possible.
Punx0r said:Sorry if I've got the wrong impression here, but didn't some temperature testing data a few pages back disprove this method of oil cooling as effective?
i found it incredibly effective compared to no cooling at all!Punx0r said:Sorry if I've got the wrong impression here, but didn't some temperature testing data a few pages back disprove this method of oil cooling as effective?
is that common? any way to test for it?liveforphysics said:You might have a shorted turn or something somewhere.
ZOMGVTEK said:I don't have any thermal monitoring on my 5404. I've been going with a good guestimate of winding temps based on recent activity and ambients, plus its generally noticeable when the windings get too hot, as the motor looses power. I plan on running about twice the power I'm running now, so it might not be a bad idea to assist the cooling a bit. I have been considering just drilling and tapping a hole in the side cover, pouring in some Honda DW-1 ATF and sealing it with a small set screw.
Sound reasonable? Is it going to be constantly slinging ATF everywhere no matter how well its sealed? Think I even need to bother sealing much? The side covers are super thick, and I don't have a mechanical rear brake to get ATF on.
Ah...that I didn't think of, but you're right--it shoudl be corrosive to bare metals like that. In my case I simply used it on the wheel and the tire, not on the motor, as I ahven't disassembled the motor yet to add the temperature sensor (once I find one I can use) and seal it back up.neithermovingnorstill said:Amberwolf / Re ammonia:
Not speaking from experience, but ammonia is corrosive to copper and if the air contains moisture, steel.
Do you do anything to remove the residual ammonia, or does it evaporate off or something? If there was noticable corrosion, it would cause the copper to produce blue-green stuff.