Not much space if you're going on holiday with the family in a Renault Clio. This design fits into a 52cm toolbox with transmitter and all accessories.
Just thought I'll share my crash resistant design that has evolved through many drops and repairs. On impact it is now usually just a matter of replacing a rivet or a prop. The electronics and battery can quickly be removed for installation on another airframe.
The props are 15" RC timers and as shown I get about 23min flight time with a slightly damaged 5000mAh 4cell Lipo at 1500m above sea level, 25 deg C.
The difference in spacing between front and rear props doesn't have a noticable effect on stability and it flies waypoints very well.
I'll post basic plans if anyone is interested or if you want an airframe let me know.
Update: Plans for the airframe
Comments
@mdrm, the video DEFINITELY looks like your CG is off. You might also make sure you calibrated your esc's.
@Murray, the props do make it quiet. Thanks for the encouragement! I wish now (in retrospect) that I would have just copied your exact setup from the very beginning (valuable noob advice).
@ Murray and Daniel: Thanks for the feedback! The arms are shorter than spec as I built this frame for 12" props. I have another frame that is bigger but it was pretty mangled when my quad went inverted and plunged from a few hundred feet (drinking and flying don't always agree). I wish I had the video but my GoPro glitched on impact and corrupted the video file. On a positive note, the GoPro still works after a restart!
My flight maximum time is right around 20 minutes although I usually don't fly for that long without landing at least once. When I FPV fly, time seems to slow down which is probably because my adrenaline goes through the roof! Do you guys get that feeling too? Anyway, my flight time should continue to go up as I find ways to shave grams.
I am using 2.4GHz radio and 5.8GHz video so my range is a bit limited right now. I just ordered a 900MHz video tx/rx and I plan to move to 433MHz for radio soon. It is crazy how much money I have spent just trying to figure out what works.
Jeff, your quad looks badass! However those booms are definitely too short. What are your flight times?
mdrm, not sure where your flight controller is, but the CG should be no further than about an inch ahead of the back plate. Maybe experiment by moving it backwards?
Thanks Jeff, nice to see. I was also thinking of putting everything on a suspended plate including the camera that would then be on a cantilevered part of the plate which would help with vibration isolation. For that I'm also considering coil shocks.
Your arms seem a bit shorter? That could make you lose efficiency if the plates are in the downwash. What I like about the large props is that it is so quiet the neighbours can hardly hear it.
I am sure that I have a dud flight controller as I have checked everything else.
My AUW at the moment, without any FPV stuff, is 1205g (for a 650mm size quad). My build was not intended to be a weight saver; I used 2mm thick aluminum and the plates can easily be reduced in area; I think I can shave off 100g without much effort.
I don't have big motors or big props, but they should easily lift the quad; the KEDA 20-26 motors and 8x4“ props together will have about 4kg max thrust. I plan to put a bigger power system on it, when it works and as needed; these are just “maiden” items.
The COG is just fine, it is in the middle of the flight controller; the battery can be moved around so that is easy to setup up. I checked wiring several times; I will put on old working flight controller on it and see if that is the problem.
The QAV layered airbus concept is a really good idea. With the c-profiles I have used for the fuselage, all flight electronics fit easily in the middle. This means I have a thin profile and flat top surface. When I can fly properly I will put a FPV layer on top, but that will take a while.
I will probably add pool-noodle or zip-tie style boom landing skids until the system (myself included) flies properly.
The fold-up design is just so liberating, it really is a space saver and the way to go.
Well, I figured out my problem. My quad was just too heavy. I spent a lot of time making aluminum parts (like gopro holder, battery holder, and landing gear) so it would be really durable but the weight killed the flight characteristics.
In my latest effort I stole a page from QAV500. I liked how they have an undercarriage that contains the motors and esc and a sled that bolts on top that carries everything else. So I had the idea of using Murrays' design as the undercarriage and I just use a 16in long strip of aluminum to carry everything on the top. It makes it really easy to adjust the CG and protects the battery from hard landings.
I managed to shave like 700g and improve the flight characteristics. I also broke down and got some 15x5.5 CF props and those help too. I am going to continue focusing on weight savings and at some point use carbon or glass fiber for most of the frame. Here is a picture of my latest creation. I just strapped the top plate to the bottom with some memory foam in between at the front and back.
yeah I really need a skid or landing gear. I am having beginner’s problems.
http://youtu.be/3jhe9V-LdQY
I have broken a couple of motor mounts already and haven't even got off the ground ;). I am avoiding carbon because of costs and I will keep on crashing a lot. But I am very pleased with the design (thanx Murray), it's just my competency level that is keeping me from flying. I have used cheap alu profiles and plates, if there is demand I can post a build log as soon as the maiden flight is successful.
mdrm, I forgot to mention the landing gear you could add. I would suggest something like the skids of a Eurocopter EC120. The current half-tube cardboard with foam strips is very durable, but doesn't look so neat.
-
10
-
11
-
12
-
13
-
14
of 16 Next