QS273 temperatures

[gabry]

With fins and 120ml of oil seems to work very well, max 80°C, but when I stop some oil is leaking from the PTFE sleeve, it acts like a funnel, I thought it was better sealed

 

[scianiac]

I think part of the issue with oil is as the motor warms up pressure inside increases so any tiny place will get air and oil pushed through it, what we need is like a vent that only lets air through but not oil, an oleophobic membrane of some sort. Which as it turns out they do make membranes that are specifically designed to allow air but not water OR oil, just have to find where to buy some on how to fit it?

 

[gabry]

I think part of the issue with oil is as the motor warms up pressure inside increases so any tiny place will get air and oil pushed through it, what we need is like a vent that only lets air through but not oil, an oleophobic membrane of some sort. Which as it turns out they do make membranes that are specifically designed to allow air but not water OR oil, just have to find where to buy some on how to fit it?

This is not an issue as I have two vents with a oleophobic membrane, you can see them in the previous pictures, oil comes out from PTFE cable wrap as I assume it's oriented facing up inside, so it acts like a funnel to catch any drop of oil when I stop.

 

[gabry]

I removed the black PVC wire cover and the oil was in fact leaking from the white PTFE/fiberglass wire protection tube that comes out of the motor. By applying positive pressure in the motor (0.2bar) I could see air escaping from there without much effort.
Cleaned as best as I could the inner tube with IPA/degreaser and injected with a 1mm needle some very fluid RTV silicone inside the sleeve and around it. Also I flipped the motor axle so the cable now goes upwards.
With the cable going up water intrusion may become a problem, but as I sealed everything with silicone it shouldn't happen, and any minimal water trace that may enter from the axle should be vaporized from the heat of the motor and expelled from the vent plugs (air and water vapor passes, oil and liquid water no).

 

[j bjork]

Get a smaller wheel and ferrofluid. Not much use with fins when the outside of the motor isnt hot.

 

[gabry]

Get a smaller wheel and ferrofluid. Not much use with fins when the outside of the motor isnt hot.

As you can see from the pictures you can't fit a smaller wheel, it's already a 19" rim.
The motor is filled with oil so the outside is getting hot and the fins seems to do their work. At the moment i never got over 80°C with an average temperature of 50°C, before i had the aver to 70°C/80°C with max of 120°C.
By the end of july i'll do some longer ride on the alps to see how it performs now.

 

[gabry]

update from 1 month later:
Everything is working fine, i did a trip on some of the highest dirt roads of the Italian/French Alps of 240km in 12h reaching altitudes of over 3000m and i got a max motor temperature of 102°C with an average of 56°C.