540 XL motors
 

Hi guys do I still need to put a flat spot on it? I'm currently running c50 maxx on 4s lipo ,Is it worth the money to upgrade it to 540 XL on 4 s lipo for racing? What is the advantage ? what about top speed wise?

Any one??

It appears that the "C50 MAXX" is a C50S Series motor and generally equivalent to a Feigao 540S series. An L or XL motor offers lower RPM/V ratings but sustantially more torque and less heat.

If you're running the Quark 125b with the C50maxx I'd recommend looking at the Lehner 1940 or the NEU 1515 motors. Much more efficient especially for racing applications. I have the NEU but the Lehner is excellent. Lehner is 2-pole and the NEU is 4-pole. It's a coin toss really.

Does anyone have the average efficiency for the 540 motors?

I know the Lehner's are roughly 90%, maybe more. I don't know what the Neu's are, but I here they are about the same?

I would like to buy it from here what do you recommend for neu motor? for I'm not familiar with it? Are they in stock here? Are they also 5mm shafts and already has a flat spot on it?

Mike stocks them

The shafts DO NOT have a flat

The NEU 1515/1y is a nice motor. It is rated under load for 2200 rpm/volt. They offer a version with 1700 rpm/v and others if those don't meet your needs.

The info I have indicates 94% on the NUE 1515 series.
I've seen reports on the Lehner's between 92 - 94% depending on the series in question.

I believe the 540XL's are lower, on the order of 88-90% possibly even lower.

The feigaos run at about 80% efficiency, hence the increased heat.

I run a 7XL in both a truggy and a buggy, with an 8XL in a Monster GT conversion and heat is always a problem on long runs. I use the RC Monster heatsink and fans on all of the motors and they still run hot on long runs. What I usually do is to gear to keep the esc in the heat range that I want and then just try to manage the heat on the motor. That's about all you can do. My club runs 30 minute mains, and even during practice sessions, it's not unusual for the motor to get up to 200 degrees F after long runs.

If you have the money and are running a quark or MGM controller, I'd get a better motor. Either one of the Neus or a Lehner, although the Lehners are about impossible to get right now.

The advantages would include much cooler running, a bit more runtime, and a bit more power when comparing a better motor to a Feigao/Wanderer of the same kv rating.

For a truck, I'd stay in the 2000kv range. In the Neu motors, that would put you in either a 1515/1Y or 1515/2.5D. If you went with a 1512, then there is the 2000 or 1900kv models. In the Lehner line (if you can get one) the 1940/8 hi-amp is a hellava motor, from what I understand; although I have yet to get to run one. I've seen the Neu motors in action in helicopters and the power on demand is just phenominal.

I highly doubt the Fiegao's run 80% efficiency, they would melt at that efficiency.

And the 94% is the max efficiency for the Lehner, that's at higher rpm, and higher torque. I'm talking typical efficiency, it could not be 94%.

On the Lehner website, they have the 3060 at 15,000 watts @94%, and peak efficiency was 95%. I wonder, with the right combo of voltage and motor turns, the efficiency could reach 96% peak?

There was a solar team a couple years ago that had a slotless, halbach array brushless motor, it had a very broad efficiency of 98% , that's what we need! We would have motors the size of a 380 can motor, and power a big MT.

Keep in mind that brushed motors vary from the mid 60's to the low 80's in efficiency. They don't melt.

On a pinion with one grub screw it is not a necessary to have a flat spot. A lot of people will say you do. I have run for a long time with no problems. If you have a pinion with 2 grub screws, forget it, you need the flat spot.

OK guys I just orered this one http://www.rc-monster.com/proddetail...515_1yF&cat=20 I talked to Mike and said that you dont need to flat the shaft,He said that to drill the existing hole on the pinion with 1/8" bit and then use a 4mm set screw or grub screw whatever you might call it.I'm very excited now to test it.

Awesome! Good choice.

Thanks bro! :027:

I don't really understand what you mean about getting it to work without using a flat spot.