MXS-R Flight Ready, Battery Changes

As I was getting the MXS-R ready to fly and charged the old NiMH 6V receiver and ignition packs, I got this feeling that they just were old now and needed replacing. They were holding a charge, but the meters were all showing different numbers (unloaded) and they weren't getting past 8.5V, and got there kinda quick. I cycled them on the charger down to 6V, and then recharged them, and they didn't take much to get there. Unlike LiPOs where an internal resistance can be very useful to indicate a battery is getting its end of life, I don't know of much else by which one judges the life cycle of an NiMH battery. I have been changing all of my aircraft on NiMH over to LiPO for the charge capacity, the voltage, and because I am more familiar with them, though I have been using NiMH for over a decade. So on a whim, and because I could, and because the 9 year old (few cycles, don't use it) 7.4V 2S 4000 mAh battery I have has IR of 14 and 15 and it takes a charge well, I decided last night was the night.

This is a post pic, but I removed the receiver pack pictured above, and the ignition pack that was just aft of the firewall, without any drama. Snip their ties, pull them off the Velcro (I never understood padding them). I didn't date these so have no idea how old they are, but I figure at least 4-5 years as I don't think I have ever changed them in the MXS-R. I built a small platform aft of the wing tube, CA'd it in place with a pair of servo screws (RTL Fastners, awesome utility screws!) for security, thought that thing isn't going anywhere. The net effect will be minimal weight difference and nil on the CG, I am confident. 

I "soldered"* a new harness using two "Futaba" J-connector servo power plugs and an EC3, and ran both through their relevant switches (bottom right), the EC3 of course going to the battery. Voila. New electrical power system in place. Tested perfectly. 

* I don't like large solder joints, I don't think you can reliably join them without a lot of heat, and the wire gauges were remarkably different, joined two black and two red small gauge wires from the Futaba plugs to their larger counterparts to the EC3 using these heat shrink butt connectors. I love these things! Have never had one fail. In this case the red ones worked, fitting the large leads just tight. Just use the air heat soldering iron or the heat gun to melt them. I then covered the two connectors (red, black) with that yellow shrink wrap.

The old packs. The greasy looking one was exposed, then newer looking one was under the front end covered behind the firewall. They are probably still good, I may use them for servo and ESC testing etc.

Forgot to mention a Pirate Captain Duckie has risen to the challenge of flying the MXS-R.

I mentioned I decided to paint the spinner "cub yellow". Damned if the paint, Rustoleum Golden Sunset gloss enamel, didn't match perfectly. A couple of coats of clear gloss enamel over that. It's a carbon fiber spinner that was scratched badly a ways back, but is otherwise in perfect condition. 

The spinner looks amazing!

So she is already to go, the DLE 30cc is rocking it, and I have also charged up a few batteries for the Twinstar with her new legs, and the Sukhoi is charged and ready to go as well. If I can get motivated, today isn't a bad day to fly, but a case of the blues is making it hard to get motivated. Wx has been so unreliably lately I almost feel forced to go, never a good mind set to fly with.