Neu 1515 or 1521??

[jhautz]

Good point on the 1521 fitting down on the motor plate CHC. There is more to it than just the length though...

The 1521 is almost exactly 1mm longer than a Lehner 1950. so it should fit length wise. But... the 15xx series Neu motors are bigger diameter than the Feigaos and Lehners. I think like 40mm vs 36mm on the smooth motors. The finned Neus are even bigger diameter. I have my motor set up sitting flat on the motor nitro motor plate and pushed all the way over against the side plate. Set there with a 36mm diameter Lehner I can just get a 20T pinion to fit on a 47T spur gear. If you use the bigger diameter Neu motor it wont allow you to get that big of a pinion gear on it. Some quick math estimates 17-18T pinion would be the largest that would fit a 47T spur.

Do some quick estimates with BrianG's speed calc and make sure that you will be able to get the speeds you want with the kv motor you choose on the voltage you want to run. My Savage setup is spinning the motor about 37000rpm to get the speeds I mentioned on a 20/47 gearing setup.

The smaller diameter motors might be a better choice than a Neu for mounting down inside the chassis. For sure dont get a finned Neu for this application. Just something to think about before you place an order.