John in CR said:
That axle looks too small to me. HubMonsters are built with 25mm axles with much larger flats cut at 15mm+ spacing.
It looks to me like those hubs are ventilated with 2 slots under each of those red pieces that act like blades. We need to see what the other side looks like. Base on my results with ventilated strategies, those exhaust vents and blades won't be very effective. Blades should be at and/or beyond the perimeter, and should have a much steeper angle to the blades, which would greatly increase flow. Since the blades on that motor bolt on, it would be simple to DIY better blades and at least double the fresh air flow.
No info on the axel size...hard to say much about it and I don't trust my ability to guess from pictures where the axel has red heat shrink on it.
The red scoops are screwed on and they face the right direction for cooling in the forward direction for motor spin. They are on just the one side of the motor it looks. There's a picture of the motor from the rim and I see no red scoops sticking out on the right side. I bet they are on the left side only. Maybe there are vent holes on the right side and no scoops? My motor lacks scoops at all and I'm seeing peaks of 309 amps in the phases and 200 phase amps is super common without it getting too warm. Maybe the scoops on the one side offset the need for venting on both sides like I did? There has to be exit holes on the right side or else the motor heats and cools unevenly. I sure hope there is air flow on the right side...something like I did. My venting works really well!
https://imgur.com/Aaa6pJy
https://imgur.com/buWMudV
You've seen mine...show us yours. I want to see how you vented one of these motors.
BTW...I have a couple of 150v FOC controllers coming soon. They will see evaluation on my Zap scooter at 82v. I'm getting them so I can do a 32S EV build. I like what ElectricGod said about making one of the hubmonsters into an outrunner. I can machine parts and turning a hub motor into an outrunner should be within my skill set. I think he said he would rewind it for a higher Kv too. That sounds like a good idea. I'm going to start exploring how to do this to my 55mm motor. It has a cast aluminum bell/rim on it so that will machine off easily. I can then use the reworked motor at 32S for the next build as a mid-drive. I think this would be a unique build. No one else is likely to rework a motor this much.
A bit of eRPM calculations. John, you have lots more knowledge about these motors than I do. Tell me what you think if this will be a problem.
16kv x 131v x 10p = 20,960 eRPM
60kv x 131v x 10p = 78,600 eRPM
80kv x 131v x 10p = 104,800 eRPM
Nucular does 90,000 eRPM and VESC does 100,000 if I remember right. I think as far as controllers go 60kv ought to do well and adding FW to that won't exceed any eRPM limits. I'm more concerned about motor losses at higher eRPMs. What do you think?
Do you know the turn counts for these motors at 16kv? How about for any other Kv?