I've limited resources in terms of time, energy and enthusiasm (beside cash) and so the choice of how to rig the frame for testing on water is not to be pooh-poohed... I leave pooh-poohing to the water utilities here in the UK.
There is ever a balance in prototyping between ambition and overreach, as often as not the simpler solutions proving the better pathway to follow in order to provide for a proof-of-concept; the concept here being that many boats are better off T-shaped.
There are six reasons for mounting contra-rotating props at the rear of the boat:
(a) as with torpedoes it is the best guarantee of proceeding in a straight line
(b) it eliminates the need for a separate rudder surface
(c) it counterbalances the nose-down pitch that we've seen at rest in water
(d) it allows in due time for a seat up front in potential crewed versions
(e) it is easily vectored in order to adjust trim on the plane
(f) I love the smell of turbines in the morning
I shall be using two means of fixing the motors, each of which appeared among the annals here somewhere or other. The forward-facing motor will be bolted directly to the cross-bar, a better name for which I've yet to come up with and which may yet go to Survey Monkey (with the prize being a monkey).
The rear-facing is more of a push-fit, which suits a pusher-propeller: to the rear of the motor I have glued a wardrobe support-bracket, and this slips over a wooden 'boss' or dowel where it is secured with oodles of adhesive and a grub-screw.
Note to self: never fly in an airliner whose jet-engines are fitted by these means.
It's beginning to look not so much a lot like Christmas, as something fairly fast?
