Wiring Gryphon Dynamics Retractables

[erobicheaux]

First of all, my background is accounting, not electrical engineering. I have some knowledge of electronics but probably enough to get me into trouble. Also, I am relatively new to drones. I have a Gryphon X8-800 and purchased their retractable landing gear for the frame. Flight Controller is DJI A2. The retractables, have a servo for each leg with each having a servo wire with 3 leads, negative, positive and neutral. The challenge for me was to figure out how to provide power as well as be able to make them go up and down. In reading some earlier posts on this site, some of the more experienced commentators advised of keeping retractables separate from the Flight Controller. So I went searching for a BEC that also had an on/off option and found a Mad Thrust 5V UBEC at HobbyKing. I connected the wires as shown below and when I plugged in the batteries immediately blew both servo's. I have been advised by Gryphon and a local dealer to just use a Y-Conector and connect the landing gear to the A2 and from Gryphon, "it is too complicated to connect the retractables to a separate BEC without better knowledge of electronics." I plan on following the above advice but I am also more than curious as to what I did wrong. I figured I should not have put each servo on a separate lead and should have put them on the one 5V out. I believe I had the jumper set appropriately. However, that didn't prevent the servo on that lead from blowing. Is the issue that the third, neutral wire was not connected? Any comments are appreciated. Thanks

 

[moonpie57108]

In the case of White, Red, Black; you are dealing with Black - Negative, Red - Positive, White - Signal.

I have never tried running a servo directly off a BEC, so I might not be much help but am curious if someone has an answer so I will hang out.

My thoughts:
- I wonder if powering the servo without a control signal is what fried them? If they would sit there and keep trying to spin at an end stop with no control until they fried. When you powered it, did you notice the servos doing anything? moving, smoke...?
- The voltage itself, 5 volts should not have cause any problems. Have you verify 5v out on the BEC?
- Powering them off two "separate becs"should not have caused any problems.
- Depending on what comes up for answer here, I have seen a fair number of diagrams on crawler forums as it is popular to run a bec powered servo on rc crawlers. Castle Creations also has wiring diagrams for powering a servo from one of their BECs.

 

[erobicheaux]

I had the frame sitting on a small box without the legs attached. It did not look like they moved, but both popped very shortly after connecting power, one after the other.

Perhaps that is a good part of the answer, powering the servo continuously. Here is a diagram that Gryphon sent me and they have a device between the power feed and receiver/A2.