Safety plug

[Geoff S]

I looked at those earlier threads and eventually decided that the easiest option to try was putting an arming connection in one of the motor leads as I queried right at the start of this thread. I used gold-plated 4mm panel mounting connectors intended for HiFi loudspeakers which are very substantial. They're mounted on the front cockpit instrument panel of my Gypsy Moth 30mm apart and easily accessible without being too conspicuous. I made up a short lead with a normal 4mm male connector at each end.

It works perfectly with no obvious detriment to the motor's performance (I tested both direct connection and via the arming plug). It means that once I've connected the battery I can check the controls without the risk of the motor spinning. If I inadvertently both enabled the throttle and actually moved the joystick on my transmitter (possible but unlikely) the motor merely kicks a few degrees. There is an outside chance I could damage the motor but that's highly unlikely unless I try hard by leaving the throttle open for some time which isn't going to happen.

The only drawback I found was that I dropped the arming plug after the maiden and thought I would be unable to fly again. Fortunately I found where it had dropped out of my pocket and flying resumed. I've now learned just to disconnect one side.

Geoff

[Old Geezer]

I've been following this thread and suddenly it became very relevant to me. I've just finished refurbishing an ancient Junior 60 - the battery (3S 3000) is accessed by removal of the wing. Doh! Battery fitted and wing banded on - the motor - AND prop are live! I didn't feel the built up fuze of the J60 would be up to the repeated stresses of connecting either an XT or Deans plug. So break into one of the wires connecting the ESC to the plug, solder a 4mm female plug to each cut end, pass both through the (pretty substantial) longitudinal stringer below the window and epoxy in place with 2-3mm of the plug standing proud - take a 3-4cm piece of wire, solder a 4mm male connector on each end. Job done - just remember to remove the wire loop before loading the LiPo into the fuze, replace to fly, remove when retrieving from the strip after landing.

A further "refinement", for lack of a better word, plug an extension balancer cable into the LiPo and trap the cable under the wing such that you can connect it to your battery checker of choice, and you can determine whether you have sufficient fuel on board another flight or two, Without the need to take the wing off !

Edited By Old Geezer on 08/05/2018 01:58:49