Usually ammonia is better at cleaning petroleum-based stuff off. Or denatured alcohol.GCinDC said:
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Oil cooling your hub- NOT snake oil!
- Thread starter Spicerack
- Start date
motomech
10 MW
Yeah, sealed brg.ings would be better.bigmoose said:
Shielded or sealed, I always repack new bearings. It's really disconcerning how little grease the manufacturers use
Yep - essentially an immediate leak - wrong bearing type for the oil fill application. That bearing will need to be replaced with a sealed one for this to have a chance of working. Even so, the lips on the bearing seal are not equal to the effectiveness of a dedicated oil seal and so some weeping may arise, particularly as the sealing lips wear.bigmoose said:
bigmoose
1 MW
We are only trying to put 100 cc or so of oil in right? The fill should only go about 35% to 40% up towards the axle.
Also for ball bearings an ol' hydrodynamicist told me 20 or 30 years ago that he felt the optimum grease fill was about 40% or so of the cavity. Said that if you add more, the grease churns (at high speed) and just makes heat. Of course if there is water ingress and low speed, more grease is better. I have also seen the current Chinese bearings coming over with just enough grease to inhibit corrosion... not enough to lubricate.
Also for ball bearings an ol' hydrodynamicist told me 20 or 30 years ago that he felt the optimum grease fill was about 40% or so of the cavity. Said that if you add more, the grease churns (at high speed) and just makes heat. Of course if there is water ingress and low speed, more grease is better. I have also seen the current Chinese bearings coming over with just enough grease to inhibit corrosion... not enough to lubricate.
GCinDC
100 MW
lots more pics in my comedy of errors - i mean build thread..
so far, i've learned a couple lessons the hard way, some specific to the hs3540:
- only 100cc necessary although much more will fit (thanks for that)
- replace shieled bearings with sealed (thanks again)
- the motor will leak on the disc side if you leave just try to seal around the fabric tube:
- but it won't leak a drop if you caulk the whole wire slot and run them thru bare:
my questions:
- are there better ways to protect the wiring than shrinktube? after a week of usuage, it's starting to fall apart (note that this is midsurgery for a suspected hall issue):
or should it be completely covered in a deeper layer of jbweld?
- will wires drenched in oil ever be solderable again? or do they just need to be thoroughly cleaned in alohol and then soldering flux?
- suggesting on prepping metal surfaces already exposed to oil for jbweld/sealant? i'm not sure alcohol will be enough. i'm wondering if i have to grind the metal - the atf almost seems to penetrate metal surfaces...
so far, i've learned a couple lessons the hard way, some specific to the hs3540:
- only 100cc necessary although much more will fit (thanks for that)
- replace shieled bearings with sealed (thanks again)
- the motor will leak on the disc side if you leave just try to seal around the fabric tube:
- but it won't leak a drop if you caulk the whole wire slot and run them thru bare:
my questions:
- are there better ways to protect the wiring than shrinktube? after a week of usuage, it's starting to fall apart (note that this is midsurgery for a suspected hall issue):
or should it be completely covered in a deeper layer of jbweld?
- will wires drenched in oil ever be solderable again? or do they just need to be thoroughly cleaned in alohol and then soldering flux?
- suggesting on prepping metal surfaces already exposed to oil for jbweld/sealant? i'm not sure alcohol will be enough. i'm wondering if i have to grind the metal - the atf almost seems to penetrate metal surfaces...
TylerDurden
100 GW
I would wipe as much off as possible, then use brake-parts cleaner.GCinDC said:
What's going on with the heat shring tubing? It looks like the ATF is attacking the plastic.
Perhaps a different variety of heat shrink is needed (Teflon?).
Soldering wire contaminated with oil is difficult. The oil wicks into the strands and is very hard to get out. I think with the right solvent, you should be able to clean it enough. Alcohol might not be the best stuff though. Something like brake cleaner or acetone might work better.
Perhaps a different variety of heat shrink is needed (Teflon?).
Soldering wire contaminated with oil is difficult. The oil wicks into the strands and is very hard to get out. I think with the right solvent, you should be able to clean it enough. Alcohol might not be the best stuff though. Something like brake cleaner or acetone might work better.
hjns
100 kW
GCinDC said:
I think that there is more expensive heatshrink available. The cheap stuff usually is graded up to 80oC, which is obviously not enough. Try something rated up to 200oC like this (brochure).
For removing oil, try a little bit of degreaser, like this one. Very expensive at digikey, though.
GCinDC
100 MW
at the local hardware store, i almost got a general car motor cleaner/degreaser, but then they were able to find the brake cleaner and i went with that, and a couple sets of disposable gloves.
i'm so glad! the brake cleaner is AWESOME! i guess i was getting frustrated trying to clean oil with rubbing alcohol..
i'd started to worry i'd never be able to dry the stator out. i have no idea how it works, but it works!
after lots of paper towels:
after removing the silicone and a couple sprays of brake cleaner:
i can't wait to use the stuff on my oily brakes. :lol:
thanks, guys!
i'm so glad! the brake cleaner is AWESOME! i guess i was getting frustrated trying to clean oil with rubbing alcohol..
i'd started to worry i'd never be able to dry the stator out. i have no idea how it works, but it works!
after lots of paper towels:
after removing the silicone and a couple sprays of brake cleaner:
i can't wait to use the stuff on my oily brakes. :lol:
thanks, guys!
Regular household ammonia seems to do ok on taking oils off of surfaces, but it takes time and some scrubbing with certain things. Or "washing" with it, spray, let run, spray, let run, spray, let run, wiping if desired instead of letting it run off. Haven't tried it on cleaning out the ATF in the old 36V Fusin yet, but it seems to have done ok taking it off my rim and tire after the first leaks.
GCinDC
100 MW
ambient was ~22C.hjns said:
motor got up to 100C on the way home, but cooled down to 82C before i set up the camera and timer. i've edited it here to show the temp per minute. 27 degrees over 27 minutes, cools faster at first and slower at the end.
[youtube]ef6sMqrhOwM[/youtube]
anecdotally, the motor cools down nice and quick when it's cooler out. on hot days, it doesn't cool down as fast.
it cools down nicely when the motors spinning and drawing < 1.5kw though i'll need to demonstrate this somehow.
it heats up very quickly (up to and over 100c) when bogged down in sand or up steep hill drawing 4kw.
i'd be happy to run more tests if you want. just let me know.
my questions are:
- an oil cooled motor is not necessarily a more efficient or powerful one, is it? it's just overheats less, right?
- how would it respond if i threw say, 2x the current at it?
here's a pic of how i sealed the wire slot, btw:
and added jbweld over the hall wires before fastening them down:
more pics in my build thread.
parabellum
1 MW
GCinDC said:
Cooler motor is more efficient, cooper resistance grows with temperature.
Twice the current would have about 4x more heating. A cooler motor will be more efficient but the drag from the oil will add losses, so it might be nearly even.
GCinDC
100 MW
two weeks hard riding and commuting. no leaks. 
i'm thinking i could use some more oil in there. i still hit 100C after 3 miles of hard commuting, much less on trails and stuff. i don't expect more oil will change that but 100cc's really doesn't seem like that much in an hs3540, as i think a lot does get wicked into the windings. certainly doesn't feel like 1/4 full...
i'm thinking i could use some more oil in there. i still hit 100C after 3 miles of hard commuting, much less on trails and stuff. i don't expect more oil will change that but 100cc's really doesn't seem like that much in an hs3540, as i think a lot does get wicked into the windings. certainly doesn't feel like 1/4 full...
Sancho's Horse
1 kW
Sorry to be wading in without a working prototype, but I immediately knew I wanted oil cooling. I plan on using a hub motor in a mid drive set-up through a nuvinci cvt, and I will be hauling some weight on occasion. I am still working through some dimensional issues and calculating power (and cost) needs prior to placing a motor order, but I thought I might put my intentions out there.
I am going to install 1/4 inch 90* brass fittings at the periphery of the side cover, just shy of the spoke flange ring, and use aluminum tubing to connect fittings which lie directly across from each other on opposite sides of the motor...eh, hell...here is a picture:
My thoughts were that, if the fittings could be placed close enough to the periphery, perhaps some centrifugal circulation could take place bringing some of the oil out of the motor, into the greener thermal pastures of the aluminum tubing, maybe marginally decreasing some of the drag fechter mentioned, and have the added benefit of dumpng some of the cooler oil back across the motor while slowing and stopping. Who knows? If it works well, you could even start adding bends and fins to cool further.
It seems like some pretty readily available stuff, and fairly simple methods. What do you guys think? I am trying to decide if bucking the KISS rule is worth it.
If it turns out to be a complete failure, I could always call the holes... air vents :wink:
I am going to install 1/4 inch 90* brass fittings at the periphery of the side cover, just shy of the spoke flange ring, and use aluminum tubing to connect fittings which lie directly across from each other on opposite sides of the motor...eh, hell...here is a picture:
My thoughts were that, if the fittings could be placed close enough to the periphery, perhaps some centrifugal circulation could take place bringing some of the oil out of the motor, into the greener thermal pastures of the aluminum tubing, maybe marginally decreasing some of the drag fechter mentioned, and have the added benefit of dumpng some of the cooler oil back across the motor while slowing and stopping. Who knows? If it works well, you could even start adding bends and fins to cool further.
It seems like some pretty readily available stuff, and fairly simple methods. What do you guys think? I am trying to decide if bucking the KISS rule is worth it.
If it turns out to be a complete failure, I could always call the holes... air vents :wink:
I don't think there would be any force to circulate the oil through the tubing. As the motor spins, centrifugal force on the oil would be balanced at both ends of the tubes. Heat transfer from the oil to the air throught the motor housing (aluminum) should be quite good. Adding fins to the outside of the housing would probably be more effective.
GCinDC
100 MW
my hs3540 wire slot seal job lasted three weeks:
there were a couple 120C moments though rarely over 110, and some pretty hard hits, including yesterday, after which i noticed the rear brake losing grip...
can't wait to take it apart and see how it looks! :lol:
there were a couple 120C moments though rarely over 110, and some pretty hard hits, including yesterday, after which i noticed the rear brake losing grip...
can't wait to take it apart and see how it looks! :lol:
bigmoose
1 MW
Use a nice Automatic Transmission Fluid. Dextron III is a good choice. Anti oxidant, anti foam, thin, low viscosity. Don't over engineer this. We are not marketing STP or something that gives your engine eternal life... 
bigmoose said:Use a nice Automatic Transmission Fluid. Dextron III is a good choice. Anti oxidant, anti foam, thin, low viscosity. Don't over engineer this. We are not marketing STP or something that gives your engine eternal life...
Solid. Heard that name floating around. What about the bearings? should they go or stay
Thanks
bigmoose
1 MW
Well I think you need to keep the bearings. I would use sealed 2 sides bearings and not shielded ones.
Farfle
100 kW
Dual pie is aboit to get oil cooled, ill post up results between oil cooling and the johninCR style air cooling.
John in CR
100 TW
Farfle said:
I'd like to see these covers before you associate my name with it.
interior blades? if so how oriented? Single side exhaust or dual side?...my approach evolves with each iteration and a 37°C motor at the top of a miles long climb will be hard to top. How about a no-load speed, voltage, and current, sealed vs different amounts of oil fill ? ie very basic interesting and useful data still missing from this thread. The concept that only stator temp matters seems incomplete to me.
I look forward to your results. If there's climbing significant hills at speed involved for a significant average power it will be pretty lopsided, and not really even fair, since sealed with oil does have certain advantages over being open to the elements in wet and/or salty conditions. Mountains separate the men from the boys, just like in the TDF.
John
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