Well there are two carbon fibre spars in there the big one, is exactly that, big. We expect the airframe to fall apart around it in the event of an off.
The battery, a cheap Chinese job is 325g and camera about 150g add into that servos and receiver.
We used pretty dense EPP and whilst I think about it there are further stiffening spas in the tail.
Theres a balance between weight and strength. We are actually bringing a smaller one to the table!! Just able to lift a point and shoot camera for simple tasks. Its slightly smaller sibling can be seen to the left of the first version of the Observer. The one the wing fell off from ;-) hence the meaty mighty spar this time. The smaller one will be 1.6m a size that can be kept assembled and thrown on the back seat of a car. Going bigger has the problem of transport. Also I have a hunch keeping that all up weight below 3.5KG might be a plan for future regulation.
So 9.25" x 71" = 656.75 sq inches /144 = 4.5607 sq feet, lifting 4.2 pounds = 1.0858 pounds per sq foot.
or about 17 ounces pre sq foot, that seem a bit high, but your endurance is great or I made a calculation error.
any thoughts about a 2+ meter size?
Well its got a glider foil with 1.8m wingspan, we design based on the, "It looks right" principle so I don't have the wing area to hand, come to that I have not even weighed it.
The aircraft is completely made of EPP foam and that is what's causing the flexing issue in the tail, we just need to stiffen the fins up. In the underside shot you can see the strips we added to the moving parts for that very purpose. Its the rest of the fin that flexes!
A conventional tail will be easier to mount as well.
All of this has to be fiddled with and once we are happy the aircraft will go into production, We are also making a 1.6m version which will fit in the car a bit easier ;-)
Congrats!!, with 35 minutes, this platform has very good endurance, how much wing area ? wing loading ? is Aiptek HD ?
V-tail shouldn't cause too much drama ! Please try. Thanks
Yes I think it would Bryan, and thanks, we are keen to have a go with a conventional tail anyway so not a drama. These pictures are in with others and some video from a rocket powered Zagi on the RCgroups thread.
Managed 35 minutes with a 1 3S 4500 with an Aiptek onboard on one flight little assistance from thermals so looking good for an hour when we have two batteries on board.
Looks great Gary. I beleive Ardupilot now has the (untested) option in the .h file for V-tails that you could play around with instead of changing your tail. Could some carbon fiber take care of your stiffness issues?
What i meant to add, it has issues to do with the stiffness of the tail but I've got a little over two hours flight time with it now and its pretty good.
In order to resolve the tail issue we are going to put a conventional tail on which will allow us to use an Ardupilot on board.
I'm ordering it from Cool Components right now.
Hopefully in a month or so I can give some feedback with that all fitted and working.
I should also thank GingerAdam who took the pictures at RCAP09
Comments
The battery, a cheap Chinese job is 325g and camera about 150g add into that servos and receiver.
We used pretty dense EPP and whilst I think about it there are further stiffening spas in the tail.
Theres a balance between weight and strength. We are actually bringing a smaller one to the table!! Just able to lift a point and shoot camera for simple tasks. Its slightly smaller
or about 17 ounces pre sq foot, that seem a bit high, but your endurance is great or I made a calculation error.
any thoughts about a 2+ meter size?
Wings 180x23.cm or 71x9 1/4 inches
The aircraft is completely made of EPP foam and that is what's causing the flexing issue in the tail, we just need to stiffen the fins up. In the underside shot you can see the strips we added to the moving parts for that very purpose. Its the rest of the fin that flexes!
A conventional tail will be easier to mount as well.
All of this has to be fiddled with and once we are happy the aircraft will go into production, We are also making a 1.6m version which will fit in the car a bit easier ;-)
I shall go and weigh it now.
Yes the Aiptek is HD BTW
V-tail shouldn't cause too much drama ! Please try. Thanks
Managed 35 minutes with a 1 3S 4500 with an Aiptek onboard on one flight little assistance from thermals so looking good for an hour when we have two batteries on board.
Its all a work in progress!
What i meant to add, it has issues to do with the stiffness of the tail but I've got a little over two hours flight time with it now and its pretty good.
In order to resolve the tail issue we are going to put a conventional tail on which will allow us to use an Ardupilot on board.
I'm ordering it from Cool Components right now.
Hopefully in a month or so I can give some feedback with that all fitted and working.
I should also thank GingerAdam who took the pictures at RCAP09