Landing is Inevitable

Saturday, June 28, 2008

The big plane project: Putting together the high-power shunt

OK, I got really bored cutting out wood from the airframe and re-covering it so I decided to get some of the electronics on the plane done instead. This time around I'll be putting together the high power shunt, a safety feature.

What's a shunt you may ask? In short, it's a plug. It'll be located on the live (red) wire on the ESC. So when the shunt is not plugged in, there won't be a closed circuit and the motor will not be able to power up. The shunt will enable you to power the receiver and all the servos while having all the batteries connected without powering up your motor until you're ready at the flight line. Once ready, just plug the shunt in, let the motor power up and you're good to go.

Before I did any soldering, I did a simple mod on my clamp. This clamp has been a faithful servant in holding up my wires, dean plugs and gold connecters while I soldered away. Recently I read that metal clamps actually draw heat away from the stuff that you're soldering while holding it down. This may cause cold solder joints and basically making it difficult to get the object to the right temperature. I understood then why it was a PITA to solder anything metallic. Some balsa wood I saved from the Yak 54 proved to be exactly what this mod needed. I cut a small piece, glued it to the metal clamps with medium CA and in two minutes I'm done.

Less than 2 minutes work

I'm not so sure if it was just me, but I did find it so much easier to solder the deans onto my Rx pack. This simple mod really works, and to whoever who reads my blog (I dunno if there really is anybody): DO IT. 2 minutes is all you need.

OK, back to the shunt. The main component on the shunt is the AstroFlight Zero Loss connecter. I had originally planned to use Deans connecters, but since the current spikes might go up to around 80-90amps, I do not want the shunt to be the weak point in this setup. I figured this will be the best bang for my buck.

I'll just be working on the male part of the connecter for this post. The female part will come into play in the later stages while soldering stuff on the ESC. Stuff for the job: 1. Astroflight Zero Loss connecter (just the male part) 2. 14 AWG wire (black) and 3. soldering tools.

Firstly, I measured out around 4.5cm worth of wire for the plug. I took note of this so that I can have similar length extension wires on both the red and black leads of the ESC.

I then prepped the gold connectors and wire and soldered them together. The important thing to take note on this step is to get the wire and the gold connecter soldered as straight as possible. Or else, it'll be impossible to pull it through the plug. Once I'm done letting the solder joint cool, I pulled it through the plug and worked on the other side. I soldered the other side of the wire while it's in the plug and once that was done, mission accomplished.

Ta Da!!!

Fast, simple work all in the name of safety.

Signing Off,



Post a Comment

<< Home