Motorised Nano-Light Hang glider Trike

We are working, all be it slowly, on development of a carbon fibre nano-light hang glider trike base for use with a standard king-posted or topless glider. This project was started a few years back one winter by myself, Ian Duncan, and Gavin Griffiths (from New Zealand). Unfortunately Gavin moved back to New Zealand and progress since has been sporadic at best. Most work is now completed to fill any down time in the working week.

The concept is to design and build a carbon/paper honeycomb trike base that was small enough to fit into the back of a station wagon yet light enough to allow attachment of a larger more reliable engine than is conventionally used. The all up weight needed to come in under 35 kgs. thus enabling an all up glider/trike weight of <70 kgs. We also wanted a small storage compartment, parachute deployment tube, fuel bladder and electrics to be internal and the rear of the trike to be somewhat aerodynamic.

First thing we needed were some concept plans and a weight/force analysis. This was Gavin's area of expertise and quickly we had some basis plans to start with.

We started working weekends building a timber/plywood/fibreglass vacuum mould to produce the front seat panel. This was to be made with pre-impregnated carbon fibres, vacuum bagged and cooked at 85 degrees C. We therefore needed an oven, which was quickly made by insulating the underside of our cutting table and rerouting hot air out of our normal curing oven (which is to long and low to fit the trike).

Gavin was keen as hell and this kept us pushing along. Thanks Gav.! It was somewhat harder for myself after working composites all week and having a desire to go surfing instead on the weekends. We soon had the mould and front panel completed.

About this time Gavin moved home to New Zealand and things slowed up...dramatically.

The next step forward involved bonding large blocks of Styrofoam to the rear of the front panel which were then hand shaped to the finished shape of the rear of the trike. This was completed at a reasonable pace then......I looked at it for about 5 months!
I decided that I didn't like the shape. So on with some more foam for a reshape. Months later the reshape was completed and that's how the trike stayed for another few months.

We had a bit of quiet time with work at some stage, can't even remember when, so I had my employee Paul Button laminate over the foam with 2 layers of carbon cloth. When this was cured the rear carbon skin was removed and all the foam was cut away from the front panel. Finally we had a front and a rear.

Months more passed before we got around to adding structure to the rear skin. Lots of umm-arr what do we need and where do we need it !!!! Meanwhile I had to design and acquire a custom fuel bladder, build a test stand for the engine, test fit engine electrics, battery box, fuel lines and internal mounting plates for the custom flexible engine mount that I had made, what now seemed like years earlier.

I had purchased a Konig 430cc 3 cylinder 2 stroke radial engine around the time we started the project. This little beauty does not require a re-drive reduction as it only does max. 4200 RPM but puts out approx. 24 HP. I have attached a Powerfin 51" x 3 blade ground adjustable carbon propeller. This may need cutting down in practice but it seems fine when run on a test stand. It produces approx. 80 -85 kgs. of thrust. It nearly blows my neighbours trees out of her yard !!!

The trike is designed so that the last part of the rear aerofoil shape is actually an aluminium fabrication that houses the muffler. This required that we custom fabricate a stainless steel manifold.

Next thing we needed was a pair of aerodynamic lower rear wheel struts. More fun for Paul 'the proto type technician'. I found some light weight wheels and some front forks off a kite buggy that seem to suit fine. Meanwhile I made some aerofoil struts
to go vertically between the rear axle and the engine bed. These struts have a reduced section at the top to attach to a spring
housing, at the engine bed, to take some shock from a bad landing.

We added a parachute tube through the rear body and a flush hatch into the internal storage compartment. It be came obvious that it would be difficult to get to the battery, if need be to jump start the trike, so we added a small quick connect fitting, that exits flush with the exterior, to which a set of modified jumper leads can be connected.

At time of writing we still need to make, rear axles, rear suspension mounts, a glider support mast/attachment and seat belts before bonding the front and rear together. Then its finish fairing and a paint job before final assembly.

Don't hold your breath!!!!  

  
This photo shows the trike as complete as it has been, in a simulated
landing position with the front wheel approx. 250mm above the ground
when the rear wheels touch down.