This is truly hopeless.
I consider any number of alternatives by way of suspension and undercarriage, which costs me not a little on eBay and Amazon, to little effect. I believe Edison trialed over 600 forms of filament before landing upon tungsten ~ or its equivalent back then ~ and this is the tragedy of reverse engineering... the product that is eventually copied represents the tip of an iceberg of both spending and effort.
As a consequence I ditch the idea of sprung undercarriage altogether, except for the inherent elasticity included in whichever structure I settle upon. This was a path worn by Volocopter, whose original prototype landed upon a gym ball set at its centre before ditching this in the institutionally-funded prototype that sports a conventional set of skids.
What I resolve upon instead is using the self-same module that forms the upper and lower drones to form the basis of a separate undercarriage fixed to the base. As a consequence I need to relocate the lower drone and to do so I shall remove the centre-body and slide it up the 'phone-booth' so as to support it like a traditional litter, or sedan chair. While I am at it therefore I might as well do the same with the upper quad.
It is something I did consider at the outset of re-designing the airframe subsequent to visiting California, although I abandoned it for a more modular design with separate units viz. pair of drones and passenger compartment that can be disassembled. The route I am taking now really calls for a prototype that remains fully assembled, which in turn will mean it has to be transported intact and that will likely involve a trailer.
The benefit is that the structural space-frame is simplified and is therefore both lighter and stronger, which are perennial requirements in aviation. The art of design is ever one of compromise, like life itself.
Sadly I snap both of my remaining 4 mm drill bits in short order, with no replacements to hand any more now that retail outlets beyond food are invariably locked down, and the mail is patchy. I'm having to substitute for the lack of bolts by using the threaded rods that I have left along with nuts that fit. In other words I am practically having to fabricate my own bolts.
Sobering how much we depend upon each other for all else except sitting around to worship our various gods. And even that depended as often as not upon taxes and charitable giving.
Nonetheless after a cup of tea and an Eccles cake and a moment of self-doubt, I've a solution. Realise am trying to run before I can walk. Shall therefore configure the uppermost module with the quadcopter and the lowermost with a set of skids, simple as. This 'lunar-lander' will be equipped with feet in the shape of ~ literally ~ frisbees. And happily they come in black, the sort they'd be using on the beach in an Ingmar Bergman film. And beside all this I've finally got visualisations of the thing without endless iterations in the workshop, courtesy of my cousin (airline captain and one-time architect). Things are looking up...
Nonetheless after a cup of tea and an Eccles cake and a moment of self-doubt, I've a solution. Realise am trying to run before I can walk. Shall therefore configure the uppermost module with the quadcopter and the lowermost with a set of skids, simple as. This 'lunar-lander' will be equipped with feet in the shape of ~ literally ~ frisbees. And happily they come in black, the sort they'd be using on the beach in an Ingmar Bergman film. And beside all this I've finally got visualisations of the thing without endless iterations in the workshop, courtesy of my cousin (airline captain and one-time architect). Things are looking up...
