peter1 Posted March 30, 2021 Share Posted March 30, 2021 Hi I have purchased a Inside Glider which has a servo wing. I have Frsky Transmitter. My intention is to use Corona DS 843MG Digital servos x8 connected to a Frsky GRX8 Tx and the wing servos via 2x Sbus Decoder. Tho motor intention is the Hacker A20-22L. I am concerned about overloading the system with all those servos and have considered a Sunrise 45A ESC which has a Max sbec of 6A or a 4Max 40A Esc that has 5Abec at less cost. Can anyone advise if this is sensible please? Much appreciated. Quote Link to comment Share on other sites More sharing options...
Dickw Posted March 30, 2021 Share Posted March 30, 2021 (edited) I have several 2m electric gliders that reach speeds in excess of 150mph that I regularly fly for about 15 minutes. OK, they only have 5 servos (KST X08 - a similar size to yours) but a 15 minute flight will only use about 75 mAh capacity from the Rx battery, so an average current of about 0.3 amps! The average current is not the whole issue though, and the peak load/current is probably when using crow brakes and all 5 of my servos are working hard, so another example - before I switched to HV servos I use a homebuilt 5A linear voltage regulator that got quite hot if run at 2 amps for more than about 30 seconds, but it never got hot in use and I never had any problems in several years using it. I doubt if you will have any problems with a 5A BEC on the Inside, but it needs to be an SBEC not a linear BEC as you are running from the motor battery not a 2s battery like me. Dick Edited March 30, 2021 by Dickw Quote Link to comment Share on other sites More sharing options...
PatMc Posted March 30, 2021 Share Posted March 30, 2021 Have you considered 2 x Rx's instead of Sbus decoders ? One Rx in the fus running of the ESC's BEC along with the E & R servos, the other Rx in the wing using a 2s lipo or LiFe for the 6 A & F servos. This would also allow a possible degree of control to be retained in some failure situations instead of full failsafe. Quote Link to comment Share on other sites More sharing options...
Andy48 Posted March 30, 2021 Share Posted March 30, 2021 Why not go for a FrSky Neuron speed controller? While this may be somewhat more expensive it gives several really useful advantages: 1. You don't use a programming card, you use a USB linker which costs about the same as a programming card. 2. The ESC comes with full telemetry built in so you can monitor current and how much battery capacity you have used, which is useful for a glider. 3. The SBEC will handle up to 7amps, and through the telemetry monitoring you can see just how much current the SBEC is delivering at any one time. 4. It has many more programming options than a standard BEC including the ability to limit the current to avoid burning the motor out. 5. The red Neuron ESC is really tiny and weighs 20g less than the Sunrise ESC. Quote Link to comment Share on other sites More sharing options...
peter1 Posted March 31, 2021 Author Share Posted March 31, 2021 Thanks, more options and head scratching. Back to YTube & School. Will investigate further thank you. That all helps. Quote Link to comment Share on other sites More sharing options...
MattyB Posted March 31, 2021 Share Posted March 31, 2021 (edited) 19 hours ago, Andy48 said: Why not go for a FrSky Neuron speed controller? While this may be somewhat more expensive it gives several really useful advantages: ... 3. The SBEC will handle up to 7amps, and through the telemetry monitoring you can see just how much current the SBEC is delivering at any one time. ... 5. The red Neuron ESC is really tiny and weighs 20g less than the Sunrise ESC. Unfortunately that’s not quite correct - the larger sized original black Neuron ESCs have the 7A BEC, but the smaller red S versions only have a 5A one. An annoying and somewhat hidden aspect of the spec, but hey, this is Frsky, I should have learnt to check the small print by now! Edited March 31, 2021 by MattyB Quote Link to comment Share on other sites More sharing options...
Andy48 Posted March 31, 2021 Share Posted March 31, 2021 (edited) 3 hours ago, MattyB said: Unfortunately that’s not quite correct - the larger sized original black Neuron ESCs have the 7A BEC, but the smaller red S versions only have a 5A one. An annoying and somewhat hidden aspect of the spec, but hey, this is Frsky, I should have learnt to check the small print by now! I did read the small print before posting and you are not totally correct. Peak current is still 8amps. Given the nature of the current requirements for a model plane it is perhaps more reasonable to use the peak current as a worst case scenario. In any case there is the choice of a Neuron 40 or 40S depending on whether you need that larger continuous current, though the 40 is larger and heavier. Edited March 31, 2021 by Andy48 Quote Link to comment Share on other sites More sharing options...
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