Wednesday, February 19, 2020

Boxing Clever



When a man is to hang in a fortnight ~ and not necessarily from a drone ~ it concentrates the mind. So said Samuel Johnson in eighteenth century London.

Back in twenty-first century London we have to figure out a way of persuading British Airways to let us carry a helicopter as checked-in baggage.

The more I look at this, along with the competition, I realise our USP has to focus on making the world's lightest, most compact and above all most practical means of vertical transport.

Which is why I am still drawn to the idea of a seat.

But looking farther afield (or upwards in fact) I have long struggled with what configuration to arrange the propellers in, and the more I peruse the matter the more I am drawn to the conventional X-8.

If only for reasons of packaging.

Looking at a drawing extracted from the WIPO specification, it is clear that either a quad or else a pair of identical quads stacked one upon the other will fit in a box around one metre square whilst the alternative octocopter layout requires one around 133 centimetres square.

Even my school mathematics suggests the octocopter requires a package one third larger.

And in a flat-packed world, every centimetre counts.

Especially at check-in.

Monday, February 17, 2020

I Left My Art in San Fransisco


For the purposes of the GoFly challenge we're stripping the airframe down to fly as a quad, sneaking under the 25 kilo radar in order to operate it as a drone instead of a manned aircraft. 

People, I feel, will still get the picture.

And it's on this day that I decide that when it is re-equipped with eight propellers then this has to be in the conventional X-8 configuration, which is (at cost of aerodynamic efficiency) the most compact.

You have to ask yourself what your USP is, and ours is this: no-one makes it more compact.

Thursday, February 6, 2020

Wind Beneath My Wings


There's been a high-pressure system move over the UK in the past day or two and our head technician can't resist wheeling the Mark One out of the hangar for a spin. Red letter day as it's the first air we've seen beneath the phone-box. The good news too is that we're running an old set of batteries with only twelve cells at fifty percent thrust, and we've a new set to fit with fourteen.

Combined with this, the Mark Two airframe which I coincidentally finished today is around half the weight. It's still touch and go as to whether the drone will lift my weight, so last plate of fish and chips for me tomorrow evening!

Sunday, February 2, 2020

Weight's Eight


Well pleased with this update to the prototype as it's weighing in for the bout at eight kilos, or rather less than eighteen pounds. Scrolling back through the blog I see that this has halved the weight of the original... beside reducing its dimensions, improving its strength and looking more like a phone-box altogether.

There are designs which I've worked on that seem less credible once under development, and others that seem to keep on getting better.

And happily this is without doubt one that seems more credible with every passing week.

Thursday, January 30, 2020

Race What You Brung




Looking at what else is out there, we're likely to be underpowered but given the budget it's been a case of making do and mending. Would be a whole lot easier to build an airframe for my son, for instance, in which case it would be two-thirds the size and with a comfortable surplus of thrust. As it is the final cut (above) itself represents only half the size of a full-scale 'phone-booth', which would be of the order of two metres in height.

At this stage of the game however it's a question of readying whatever we've got to bring.

Monday, January 27, 2020

Brimful of Asha (on the 45 Centimetre Square)


I redesign the airframe to be showcased in San Fransisco to incorporate structural members where I thing they go best, taking the opportunity to reduce the foot-print to 45 cm square from 50 cm. Longer term these could realistically be put together like the traditional phone-box from four panels plus a dome and base, although for integrity I'm constructing the thing as a monocoque unit.

This is not least because it has to survive the aircraft cargo compartment intact. A flat-pack philosophy is great for the longer term, though in the shorter we're all familiar with the fact that IKEA furniture if not ideal for dismantling and reassembly.

Meanwhile Martin has pushed the power-train to seventy-five kilos of thrust using an old pair of batteries with six cells apiece. Given a new pair with the necessary seven cells, we should be in the ball-park for a demo flight.

Tuesday, January 21, 2020

Flying Red-stead




We're about ready to see if this flies, and as there are no hurricanes forecast for Somerset in coming days, we are 'go' for launch...