Samd
10 MW
About 1500usd macribs but it is packing a bit more punch than the stock dlc28
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John in CR said:Jestronix, you're asking for the wrong thing. The best way to deal with heat is to not make it to begin with. That means a more efficient motor. People jump thru ridiculous hoops to make crap motors disperse heat better, when for the same price they could have had hubmotors to run at up to 10-15kw in stock sealed form without unnecessary and barely effective liquid cooling of an outrunner. Sure they took some work to fit, but that pales in comparison to the effort needed to make low efficiency motors dump their heat. Ask for better hubmotors, not motors with liquid cooling.
macribs said:Jestronix get in touch with the dude behind this motor, according to some of the comments it seems he does custom work too.
Iirc his 45kw motor with water cooling is 17 kilos, 3500 RPM. But if he builds custom motors I am sure you get to decide what factors to prioritize so that you get a kv that suits your need. This is not dd hub but would work for mid drive.
[youtube]2LNfDI3QUpQ[/youtube]
Me either. For some reason the one that published the video has made it private.me can't play the video.
Jestronix said:Just thinking mid drive, it interesting that no one has developed a pure off the shelf frame for 10kw up power. There was some Russian frames ?
Offroader said:Jestronix, What I don't get is everyone who is trying this Ferro FLuid + hubsinks are claiming that they do not have any overheating issues. While you are the only person claiming that you overheat with oil + heatsinks.
I agree that FF + hubsinks will be limited, but just saying you are the only person who still overeheats with oil + sinks. Maybe you need to add bigger sinks or something.
atarijedi said:QS makes watercooled hub motors, but only for larger vehicles. I can't see them ever shrinking it down for e-bikes.
Jestronix said:atarijedi said:QS makes watercooled hub motors, but only for larger vehicles. I can't see them ever shrinking it down for e-bikes.
Yeh I was hanging out for them to shrink one down, however it leans me towards a moto build
atarijedi said:I think we need to try and take it upon ourselves to do it. Not necessarily water cooling, as that would necessitate in creating a new ported axle shaft, and then sealing the motor. But we can certainly try to just seal the motor and fill it with an oil, like mineral oil, so that more of the surfaces act as heatsinks. Especially the 2 huge side covers. It seems to me it would only necessitate sealed bearings and some RTV liquid gasket.
Ohbse said:What you're describing has been extensively tested and while it works, it's hard to seal and makes a mess. FF delivers essentially the same results with much less mess and less parasitic drag. Oil cooling is no longer relevant with FF available.
atarijedi said:Ohbse said:What you're describing has been extensively tested and while it works, it's hard to seal and makes a mess. FF delivers essentially the same results with much less mess and less parasitic drag. Oil cooling is no longer relevant with FF available.
I've read the forum entries from others, a majority of people never really put the effort into properly sealing the hub motor, and those that did, have no real issues with leaking.
I also can't imagine FF would deliver anywhere near the same results, as it only provides a radial heat path, whereas an oil filled motor would provide both radial and axial heat paths, and the axial heat path would be far more important as heat the side covers provide massive surface area compared to the radial "ring".
Another issue is that regular oil can be drained out of the hub. FF, while technically it can be done, would be a huge undertaking in comparison. Heat destroys oil, so at some point you need to replace it, or do a complete flush and replace it.
Offroader said:I can't see how FF can do better than a strong airflow constantly directed through the windings.
Chalo said:Offroader said:I can't see how FF can do better than a strong airflow constantly directed through the windings.
Would it cook a steak faster to position it vertically over a burner so that hot gas was streaming over it, or would it cook faster if you plopped it in a fry pan of hot fat on the same burner? The heat source is the same; only the heat transfer efficiency is different.
To me, it seems obvious that air cooling will only beat liquid cooling if there's a whole lot of forced air moving through at high speed.
But all this nonsense is just that: nonsense. If you're heating up your motor too much, you're doing it wrong-- probably using the wrong motor for the job.
WoodlandHills said:If I was going to cool chicken I would drop it into a pan filled with ice and water, I could put it on the shelf in the refrigerator but it would take a lot longer. If I was going to defrost chicken I would drop it into a pan filled with water. I could leave it out on the counter, but it would take a lot longer to defrost.
Can anyone explain why?
macribs said:While I am fairly certain FF + heat sink will win, I applaud the effort Offroader. Now lets hope there are riders with FF+heat sink in the north east that will do a ride along to compare real life results. The result will speak for itself.
Where have you dug your thermistor in the motor? I guess thermistor is required to get results worth comparing?