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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Will Moore on May 27, 2019, 04:45:35 PM
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Had a nice fun fly at Wrentham, MA this past weekend, with NEST friends. Good turnout. I have been away for 3 plus years, in Florida, and came back to New England for various personal reasons. A fellow flyer asked me what outrunners had 3 bearings. I use Plettenburg, which have 3 bearings, but they are expensive. Are there others, that might not be so costly? What’s the word on the street ?
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Cobra 2826, 3515, 3520, 3525 series motors.
https://rcdude.com/cobra-bearing-kit-for-c-2826-3515-3520-and-3525-motors.html
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Had a nice fun fly at Wrentham, MA this past weekend, with NEST friends. Good turnout. I have been away for 3 plus years, in Florida, and came back to New England for various personal reasons. A fellow flyer asked me what outrunners had 3 bearings. I use Plettenburg, which have 3 bearings, but they are expensive. Are there others, that might not be so costly? What’s the word on the street ?
Yes, for example long motors AXI 2830 and 2835 have the same system.
And to explain Chris - those cobra motors as well as AXI 2826 have number of bearing (count of pieces) 3, but in reality shaft is supported only on 2 places anyway. The bearing inside the rotor cannot have large diameter because of eddy current from rotating magnetic field and not too much space there, so solution is small doubled bearing. The same trick is used on "long" type of AXI motors like AXI 2826 "long" which is good for thin noses of hotliners so also front of that motor has 2 small bearings instead of one large because of small diameter of its front part.
In case of AXI 2830 long and 2835 long there are 5 bearings - 2 small in front 2 small inside and one large thin ring bearing on front of long rotor to prevent oscillation and risk of contact magnets with stator. The same is used on Plettenbergs.
Gray color on following picture shows 5 bearings on 3 supporting places (AXI 2830 and 2835 long version)
(http://file.espritmodel.com/newsletter/201612a/axi-sailplane-2835-10-v24.jpg)
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I'm sure that brushless motors progress is currently driven by the drone industry. Due to the high demand for drones, brushless motors are being developed more and more efficient. Cobra motors are no exception. Also the T-Motor is constantly improving its motors line. And look at this motor - why not the perfect candidate for CL stunt:
https://www.brotherhobbystore.com/tornado-t7-4215-motor-p0038.html
Regards,
Vitalis P.