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Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 2:49pm
by fechter
Super Loctite was sort of joke. They do make many different flavors though. I used some green "wicking grade" stuff that was almost like welding the parts together. I don't remember the number. It was more like super glue.

Yes, any kind of anaerobic locking fluid doesn't work well if there is much clearance to start with. Epoxy might work.

Another option would be some kind of clamping arrangement like a Taper-lock bushing. If the parts are held together tightly enough, the whole shaft would shear off first.

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 2:57pm
by larsb
I've used the loctite retaining compounds:
https://www.henkel-adhesives.com/us/en/ ... ounds.html
worked well to fit loose shaft to bearing in that application

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 2:59pm
by fechter
larsb wrote:
Mar 21 2019 2:57pm
I've used the loctite retaining compounds:
https://www.henkel-adhesives.com/us/en/ ... ounds.html
worked well to fit loose shaft to bearing in that application
Which one? There are many.

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 3:20pm
by larsb
sorry, i need to look for it in my garage...
it was loctite 648

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 3:58pm
by ElectricGod
dead thread

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 4:20pm
by madin88
As already mentiond, it is the Loctite 648 which should be used for that.
The feather key should be up to the task for what the motor is capeable to deliver to the shaft, but i agree that it is a little bit undersized.
btw: it is the torque which will shear off the key and not the power! :wink:

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 4:52pm
by liveforphysics
madin88 wrote:
Mar 21 2019 4:20pm
As already mentiond, it is the Loctite 648 which should be used for that.
The feather key should be up to the task for what the motor is capeable to deliver to the shaft, but i agree that it is a little bit undersized.
btw: it is the torque which will shear off the key and not the power! :wink:
You would be correct for static situations of a powertrain loading, like climbing a smooth flat hill. In practice, the torque the motor delivers is largely irrelevant to the peak loads a powertrain experiences. This is because the inertial loading when the wheel leaves the ground and freely spins up, and then re-contacts the ground again can easily be 50x or more of the peak loads seen by electromagnetic generated torque forces.

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 5:43pm
by ElectricGod
dead thread

Re: Revolt RV-series motor review and comparisons

Posted: Mar 21 2019 5:54pm
by ElectricGod
dead thread

Re: Revolt RV-series motor review and comparisons

Posted: Mar 22 2019 1:47am
by liveforphysics
Shock loads from impacts, even potholes hit by the tamest of riders put so much higher loads on the powertrain than propulsion torque loads, you don't design a powertrain around the torque loads at all, but the shock loads.

Re: Revolt RV-series motor review and comparisons

Posted: Mar 22 2019 3:21am
by Punx0r
I've not seen someone put a figure on drivetrain shock load Vs. steady state before so thanks for that :thumb:

Re: Revolt RV-series motor review and comparisons

Posted: Mar 22 2019 7:24am
by madin88
liveforphysics wrote:
Mar 22 2019 1:47am
Shock loads from impacts, even potholes hit by the tamest of riders put so much higher loads on the powertrain than propulsion torque loads, you don't design a powertrain around the torque loads at all, but the shock loads.
Do you think that size of the drive sprockets or pulleys would have an influence on the shock loads (the feather key sees)?

If we take for example a drive train with 1:5 reduction. one with 10/50T and the other one 20/100T. Same type of chain or belt.
ElectricGod wrote:
Mar 21 2019 5:43pm
Undersized...lol...can you present a motor that a typical EV builder such as myself would use that isn't undersized in the keyways or union between bell and shaft?
On my Neu 8057 the shaft is attached to the bell with 6xM5 bolts and inherently glued with loctite:
neu1.jpg
neu2.jpg
neu2.jpg (4.16 KiB) Viewed 2982 times

Re: Revolt RV-series motor review and comparisons

Posted: Mar 22 2019 8:16am
by fechter
madin88 wrote:
Mar 22 2019 7:24am

Do you think that size of the drive sprockets or pulleys would have an influence on the shock loads (the feather key sees)?

If we take for example a drive train with 1:5 reduction. one with 10/50T and the other one 20/100T. Same type of chain or belt.
I'm sure that has some effect. With smaller sprockets, the chain or belt can absorb more of the shock. It might just mean your chain or belt breaks before the motor shaft.

Speaking of which, on some motorcycles they use a rubber buffer between the sprocket and the hub to reduce the shock loading. Some of these are pretty simple. The sprocket floats on the axle and engages the hub with rubber covered pegs. If you have serious shock load, these things will help a lot.
Rubber-buffer.jpg
Rubber-buffer.jpg (84.14 KiB) Viewed 2977 times

Re: Revolt RV-series motor review and comparisons

Posted: Mar 22 2019 10:33am
by ElectricGod
dead thread

Re: Revolt RV-series motor review and comparisons

Posted: Mar 22 2019 3:03pm
by larsb
LFP quote:
Shock loads from impacts, even potholes hit by the tamest of riders put so much higher loads on the powertrain than propulsion torque loads, you don't design a powertrain around the torque loads at all, but the shock loads.
I never had any issues with keys failing even though i see the point above, for the RV120 motors i am sure the grip fit on axle vs bell did a good job. Before that i used freewheel so no shock loads like described could transfer through to the motor key.

It wouldn't be too hard to do an ok calculation on the forces that can result from the shock loads.

Re: Revolt RV-series motor review and comparisons

Posted: Mar 24 2019 2:00am
by ElectricGod
dead thread

RV-100E stuff

Posted: Mar 24 2019 2:38am
by ElectricGod
dead thread

Re: Revolt RV-series motor review and comparisons

Posted: Mar 28 2019 1:29am
by ElectricGod
dead thread

Revolt RV-120-regular

Posted: Mar 31 2019 11:21pm
by ElectricGod
dead thread

Revolt RV-100E bell to shaft reinforcing

Posted: Apr 07 2019 7:50pm
by ElectricGod
dead thread

Revolt RV-120-regular

Posted: Apr 14 2019 11:12pm
by ElectricGod
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Revolt RV-100E shaft to bell reinforcing

Posted: Apr 16 2019 11:00am
by ElectricGod
dead thread

Re: Revolt RV-series motor review and comparisons

Posted: Apr 16 2019 12:48pm
by drc
Look like you have worked very very hard on these motors EG. You should build your own motor from scratch! Are you going to test the RV100s on an EV to do a practical comparison?

Re: Revolt RV-series motor review and comparisons

Posted: Apr 16 2019 3:23pm
by ElectricGod
dead thread

Revolt RV-100E shaft modding

Posted: Apr 17 2019 2:17am
by ElectricGod
dead thread