evo1087
100 mW
Is there a cached download of the site the original poster linked on the Emrax?
MOTOR PORN !! EMRAX 228 teardown !!
- Thread starter Doctorbass
- Start date
Just FYI, the motor teardown is back up. Attached is a PDF of the page that i've uploaded to the forum in case this data ever goes missing again.
I read some reports on testing segmented magnets and realized that this motor's secret sauce is probably the segmented magnets.
The ultra tight and precise copper windings is also part of the secret sauce.
I'd imagine this motor has ultra low copper losses and ultra low core losses. The power consumption during a no load run might be mostly bearing friction and air movement. The no load wattage of the 188 at 7,000 RPM is 1,200w, which is bombastic for a motor that's rated for 40kW!
Magnets being glued on means that you have to be within the design parameter of the motor's maximum RPM, and pushing it to much higher RPMs leads to a catastrophic magnet flingoff event. Yes, 7000RPM is awfully high for a glued magnet, but consider that at 40kw and 95% efficiency, you're dealing with 2kw of heat, so i think this motor is at it's best in liquid cooled form.
One note though is that the astro motors are rated to 10,000rpm maximum but have glued magnets. So 7,000RPM might not be worrying at all if these magnets are glued appropriately.
If you want to rule out what Luke was concerned about, put the motor on a big dyno and figure out at what RPM and load it takes to get those magnets to fly off. Anything other than a destructive test is just speculation.
Given the availability of a non-obtanium/custom controller, emrax would still be my #1 choice for an electric car or motorcycle conversion.
I read some reports on testing segmented magnets and realized that this motor's secret sauce is probably the segmented magnets.
The ultra tight and precise copper windings is also part of the secret sauce.
I'd imagine this motor has ultra low copper losses and ultra low core losses. The power consumption during a no load run might be mostly bearing friction and air movement. The no load wattage of the 188 at 7,000 RPM is 1,200w, which is bombastic for a motor that's rated for 40kW!
Magnets being glued on means that you have to be within the design parameter of the motor's maximum RPM, and pushing it to much higher RPMs leads to a catastrophic magnet flingoff event. Yes, 7000RPM is awfully high for a glued magnet, but consider that at 40kw and 95% efficiency, you're dealing with 2kw of heat, so i think this motor is at it's best in liquid cooled form.
One note though is that the astro motors are rated to 10,000rpm maximum but have glued magnets. So 7,000RPM might not be worrying at all if these magnets are glued appropriately.
If you want to rule out what Luke was concerned about, put the motor on a big dyno and figure out at what RPM and load it takes to get those magnets to fly off. Anything other than a destructive test is just speculation.
Given the availability of a non-obtanium/custom controller, emrax would still be my #1 choice for an electric car or motorcycle conversion.
