Quote:
Originally Posted by Jared
I'd like to see a motor that was a little more powerful than the 775 but packaged the same way, so that it could be used instead of the CIMs for drive. The reliability of the CIMs is great, but they're really heavy compared to a 775, and not that much more powerful.
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One crucial difference between a 775 and a CIM is how they're cooled. The 775s (along with 550s, AM9015s, FPs, Bosch drill motors, etc) are cooled via convection encouraged via the fan at the tail end of their shaft. That's why you don't want to stall these motors, since they need to be spinning at a relatively high speed to draw enough air to avoid overheating under load. The CIMs (along with MiniCIMs and BAG motors) are not cooled by fans, and instead rely on having a larger thermal mass to "absorb" the heat and prevent the motor from overheating. The heat is eventually dispersed via convection, conduction, and/or radiation away from the exposed surfaces of the motor (so having a larger surface area is important as well).
Since drivetrains often experience stall or near-stall conditions, it's important to have a motor that can survive stall or near-stall heating. Fan cooled motors are a poor choice for this (thus why so many Bosch drill motors failed back in the day). As a result, you need the additional mass to help these motors survive in a drivetrain. Of course, if you were to install some other cooling system this could be worked around, but I'd venture that the additional mass and space of the cooling system would outweigh the benefits.
I don't think you're going to get your wish.