Hermione’s frame

If you want a super strong X8 compatible frame that’s large enough for every possible sensor, there’s only one out there that fits the bill.  And it fits it well, and then some.  It’s designed and hand-made in Poland at quadframe.com by Jakub Jewula.

Hermione's frame

Hermione’s frame

The frame is carbon fiber throughout.  The arms are hinged to allow them to fold for transport, but lock into place amazingly sturdily for flight.  The kit comes complete with a simple but well designed power distribution tower, outer-plates for 5V power, WiFi and GPS as shown (or whatever you want to add) and various shelves for flight controllers, LiPo’s etc.  I love the way all the wiring for motors, power, GPS and WiFi can be fed down their tubes to protect them from blades during flight.

The standard legs aren’t strong enough for some of the catastrophic falls Hermione has had during her development, so I use these instead.

Hermione's closeup

Hermione’s closeup

I have a few bits of build advice:

  • Don’t be scared to tighten the bolts as hard as possible for brackets attached to the CF tubes
  • Don’t bother with the bolt to join the CF arm to the shoulder socket joint, just use epoxy resin glue; it gives a better distributed, stronger connection, and hence significantly reduces the chance of damage on impacts by ensuring forces are passed through to the frame itself.
  • Apply a little grease to the shoulder joints so they can’t lock up if you over-tighten them.
  • Wrap some duct-tape at the ends of each arm where the motor bracket joins to prevent hard side impact pushing the motors down the arms.
  • Add these foam rubber balls to the end of the legs to try to absorb some of any impact landings.
  • If you want a cover, this salad bowl is a perfect fit, shown in a previous revision of her frame build:

    Salad bowl

    Salad bowl

THBAPSA

Note that I was not paid for this advert and I paid full price for the frame.  I’ve written this post because the frame is simply the best DIY fold-able CF X8 frame available, period.

Body Snatcher

I’ve promoted Chloe’s HoG to house-sit Hermione’s frame:

Body snatcher

Body snatcher

She’s passed basic testing (like not blowing up when the LiPo is attached), and the HoG boots, and the motor rotation direction test works.  I’ve now got to jiggle the wires into the ESCs so all the props rotate the right way and we’re ready for a flight!

P.S. Notice the nicely plaited motors wires – keeps them tightly together which will be important when the extra four are added for the X8.

Rebuilding the ballerina’s legs

my new legs for the quad arrive today from quadframe.com to replace the ballerina’s twisted ankle that the last spiralling crash caused.  They don’t come with building instructions as (to quote the site) “Assembly guide: not needed IMHO :)”.  However, when I built my first set, it took several minors tweaks to get the holes that attach them to the DJI F450 frame aligned, and only 3 of the legs touched the ground – somewhere during the build, I’d added some distortion to the frame – certainly it was no fault of the legs themselves.

So even though I only needed the new landing skids to replace the bent ones from the last crash, I decided to build the complete set of new legs and put together some concise instructions how to build these legs onto your DJI F450 frame, and have all 4 feet touch the ground.

New legs

New legs

Underside

Underside

  • First loosely attach the leg plates together using just the the smaller aluminium tubes (leave off the aluminium brackets which join the legs to the frame – we’ll deal with those later) – each join should be bolt, [optional side plate], leg plate, aluminium tube.
  • Once you have these put together loosely, find a guaranteed very flat surface such as a kitchen work-top, and stand the legs on that
  • Now tighten up the bolts gently, carefully and bit by bit, starting from the 4 nearest the feet and working up to the platform, ensuring that all four legs remain in touch with your flat surface throughout
  • Next add the brackets which connects the legs to the frame – the order here is bolt, brackets, side plate, leg plate, washer, nut – this way the DJI F450 holes align with the frame holes
  • Once you’ve done this, now insert the rubber washers into the feet holes (don’t ask me how, I just swear at them until they go in) and slide in the landing skids – I’ve bought some 8mm carbon tubing from ebay cut to 25cm to replace the standard aluminium ones so my ballerina won’t twist her ankles again during one of my (normally) dramatic test flight landings
  • Now add the end-caps to these skids, and ensure all four end caps touch your flat surface – if not, some gentle twisting of the whole frame can resolve this at this stage.
  • Now double check everything is tight.
  • Only now are the legs are solid and standing on four feet can you add the platform with the cable ties; I have the breadboard velcro’d onto this platform – the heads of the cable ties must be underneath the platform or there won’t be space for the breadboard – tighten each of the cable ties bit by bit so the platform stands evenly on the top of the aluminium struts.
  • Once you’re happy, then snip the excess from the 8 cable ties
  • Finally, with the legs and platform tightly assembled, put the quad on top and bolt the two together using judgement to ensure they were aligned correctly – you’ll need some M3 screws bolts and washers that do not come with the frame nor leg kits.

The benefits of long legs.

Drone parading

Drone parading at the model show

  • Centre of gravity lowered significantly below the blades, by lowering the breadboard and batteries
  • lowered physical noise due to the gyro / accelerometer being further from the blades / motors and their noise – so hopefully this will be the final cure for the noises killing any chance of drone stability
  • lowed risk of vortex rings at take off – these reduce the power of the blades when the blades are near the ground as the air recirculates – this should lead to clean takeoffs!
  • finally, increased coolness!

I’d intended to get these legs anyway once I moved to adding the PiCam, but it became clear that they would also be huglely beneficial to the drone for noise reduction.

P.S. It’s a good job they win on the cool factor alone, as it turns out after testing the noise remains.  Again, more on that in the next episode…

P.P.S I got them from quadframe.com who also produces some other frantastic frames – take a look