Friday, August 17, 2018

The drone saga continues...

The drone saga continues...  This morning I successfully attached the new propeller motor to my drone.  However, as I started reassembling the dozen or so parts I had to remove to get to the motor, I managed to put one back incorrectly.  The result was to smash and slice the teensy coaxial cable for the antenna that's mounted inside the landing leg (one segment at right).  Upon discovering that fact, I'm afraid my language for the next 30 minutes or so was most inappropriate for the Mormon community that I live in.  I'm fairly certain that many of the words and phrases I used are completely unknown to these folks.  Fortunately, I was alone at the time.

My first thought was that I'd buy the replacement part from DJI (the drone's manufacturer) and just replace the whole thing.  Turns out there are two problems with that idea.  First problem: I'd have to disassemble most of the drone to do it.  I figured this out by taking the top off the drone to expose the wiring (at left).  That antenna cable starts as one of the four gold connectors at the right-center of the photo.  Then it's threaded through a braided protective sleeve, which is in turn threaded through the carbon-fiber frame.  I'd have to disassemble the entire left side of the drone to thread the new one in – and then I'd have to successfully reassemble the whole mess without breaking anything.  I'll avoid that risk, if possible!  Second problem: DJI won't sell me that part.

So where does that leave me?  Well, I discovered that the coaxial cable is a standard type called RG-178.  So I ordered a 15' length of that, and then I'm going to attempt to splice a couple of inches into the antenna cable to replace the part that I smashed and sliced.  This is going to be a bit of a challenge, as that cable is just 0.072" thick (less than a tenth inch!).  It will be microscope and fixture time, 'cause my hands aren't going to be able to do it. 

And if I fail with that repair?  Fortunately for dummies like me, DJI has a mail-in repair service.  I can throw the drone in it's shipping container and send it back to them to be fixed.  If I have to do that, I'm guessing I will be the source of the day's entertainment for the techs...


  1. DJI Inspire 2 Teardown article.


    1. That article was my guide as I disassembled my drone. However, DJI appears to have changed some of the hardware since the article was written. For instance, the article calls out some Torx bolts for the cable covers, whereas my drone had Phillips-head bolts. There were four or five such differences. The ones that really caught me up were hex switching to Torx and vice-versa -- I need a microscope to be able to actually SEE the difference!