Are you seeing that under load or under no load?kiwifiat wrote: ↑Apr 09 2019 2:34pmWith the Lebowski inverter FW works very well with both in SPM and IPM motors. In this video we see a 100% increase in Kv with FW.ElectricGod wrote: ↑Apr 08 2019 10:46pmFlux weakening to be very effective needs lots of exposed iron on the armature. An IPM inrunner is best for FW. Otherwise FW has a small effect. The controller can do FW, but it's not on since it provides a small increase in motor RPM. FW increases phase current and reduces motor efficiency.Dui, ni shuo de dui wrote: ↑Apr 08 2019 10:29pmIf your only problem is top speed, can't you find a way to do flux weakening? I don't know what controller you're using, so maybe it's not possible on yours, but I think that's the only way you could have both torque and top speed without having to use a mechanical gearbox.
There's a third way to get lots of torque and top speed...a bigger motor...and as it turns out I have one to use.
On my scooter that is fitted with a gen1 QS273 motor on 18S I get a 91% increase in Kv with Lebowski's recommended setting of 70% FW.
My experience with FW is that bench testing is waaaaay different from loaded testing. For example, I have an ASI BAC2000. On the bench I was able to set 200% FW. The HLD inrunner has 64kv so that's effectively 128kv. On the bench, the motor made 2X RPM's. However, on the EV, it was much less...maybe 10% more RPM's. Doing the same thing on a C80100 outrunner on the bench got me similar results as the inrunner. Under load, maybe 5% more RPM's. I haven't got a lot of good results for the current used to make me want to use FW in the real world.
I don't know ATM...I have to admit that while I have FW capability in the controller, that I've never tried it on this scooter. Maybe that's sufficient for the job to gear a little further from 1:1 for more torque and then use FW to retain 60mph.
FW with the HLD inrunner is somewhat off-goal for making this scooter sufficiently fast and retain 60mph. There's some significant hating of Revolt motors. I have issues with Revolt too. However, I want to try out the RV-120-regular for myself and see if it's truly a POS like several people have told me. I doubt their statements are 100% true. Bench testing has shown me otherwise. IMHO, I'll install the RV-120 on this scooter and I'll get the torque I want without any loss of speed. I bet the motor will run just fine! Once that's all known and I report whatever I find out in my Revolt thread, I'll then try out FW on the 120. If the RV-120-reg is anything like the C80100, it will get me 3 or 4 mph more speed at a significant current bump and not be worth it.
On the Currie scooter where the C80100 is located, the motor is geared more for torque. If I added a tooth to the motor sprocket, I'm sure I could top out at 50mph on level ground with no FW. I like being able to pull wheelies and to surprise people in cars as I leave them in my dust when I take off...so 45mph is it's top speed. It's well faster than any typical gas moped/scooter. I want that from the XB-502 and right now it just accelerates like most cars do.
The HLD inrunner is fine. It's plenty fast as is and destroys any gas powered moped/scooter around. For my expectations, it's not enough motor and still achieve 60mph. FW won't get me enough extra motor RPMs to get what I want either. Yesterday, standing at an intersection, there was a guy on a 50cc moped. I was curious to see him take off when the light changed. The cars were long gone and he had the throttle wide open. The engine was making that high pitched whine that these little engines are known for. There he was at WOT and barely making 3 or 4 hp. I immediately was thinking about the XB-502 and how even at 20% throttle, I'd be applying more power to the tire than he was at WOT. I felt sorry for him! Anyway, no one is going to call the XB-502 slow. It needs a bigger motor and while the HLD is so much better than anything gas powered remotely in this size, it's still not enough.