What would you spend £1500 on?

Just the core hardware for Hermione?

  • CF Frame £240
  • 8 x T-motor P13x4.4 CF Props £145
  • 8 x T-motor U3 Motors £515
  • 8 x T-motor AIR 40A ESCs £215
  • 2 x Gens-Ace Tattu LiPo £180
  • Garmin LiDAR-Lite V3 £115
  • Scanse Sweep £270

Or 3 complete kits of these?

DJI Spark

DJI Spark

My advice, don’t try a DIY drone unless you are stupid as I am!

DJI Mavic shopping list

First, just pay the extra £350 and buy all the extras with your Mavic:  two spare batteries, multiple battery charger, car charger, phone charger, spare props.  No point going to an amazing location and taking only one battery and no chargers.  There’s also a bag, but it’s useless once you have the essential travel necessities too.

Instead I got a Peli iM2100 storm case.  There’s a B&W equivalent with laser cut-outs, but I prefer to do my own hole making for exactly the pieces I need. And the peli case was available unlike the B&W equivalent.



Joystick clamp: with a custom cutout peli case (and actually even with a laser cut B&W), it’s worth keeping the joysticks on the RC aligned in storage as the instructions say.

Launch pad: not a necessity but there is good reason – on take-off there’s a pause while the Mavic photographs the takeoff point; on return to home, GPS gets the Mavic most of the way home but the launch pad recognition gets it to within a few centimetres.

Landing Legs: unless you’re on a hard, dry surface you’ll need these little legs to keep the camera and gimble off the ground and away from the damp grass.

Cheap mobile: No point risking your iPhone or Samsung when a £60 Android will fit perfectly and provide a fantastic 5.5″ screen; no SIM required though if desired, this one supports 3G, and it’s £69 sibling adds 4G and LTE.

P.S. I’ve found a couple of other options worth mentioning:

For the joystick clamp, I’ve swapped to this one, which is injection molded rather than 3D printed. It’s a better design, a better finish, and cheaper.

For connecting the cheap mobiles to the RC, none of the standard adaptors supplied by DJI work. There are two choices:

Neither option is perfect, just make your own choice.

Pure, unbridled fun!

While building Phoebe, Chloe, Zoe and Hermione over the last 4 years has been fascinating, frustrating, intellectually challenging, educational, satisfying, and critically, a brilliant-boredom-blocker, it’s never once been fun.

When I first started this project, there were many DIY quadcopter projects and very few commercial ones, and the commercial ones absolutely needed a skilled human with good hand-eye coordination in the feedback loop.  4 years later, the DIY market is shrinking because the commercial market has caught up and overtaken them; they now support vast amounts of autonomy to protect themselves from less-competent humans like me.

The best ‘affordable’ one currently is the DJI Mavic Pro.  It has 24-core, GPS, several URF  and video sensors for object avoidance and vertical / horizontal tracking, return to home, tracking a target and a stable gimbal for great photos and videos.  It folds up tiny and so portable.  And it costs £1k; I’ve spent many multiples of this on the development of Phoebe, Chloe, Zoe and Hermione.  So I’ve bought one and it arrived today.  After two hours charging, setting up etc, it was dusk, so I only took it out for 5 minutes.  And came back in beaming from ear to ear!

DJI Mavic Pro

DJI Mavic Pro

P.S. Development of Hermione with compass and GPS, and ultimately Scanse Sweep, will continue in the background, but currently, that’s blocked by the fact the I2C errors came back last week, despite there being no code nor hardware changes between the day she worked and the day she didn’t. Blind paralysed sterile stag (still no-fecking eye deer) why 🙁