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
Mine hovers at 50-60% throttle position with 5Ah 4s battery that weighs 500g. I'm guessing a BL gimbal weighs 200g, which should still be OK with the 3700 or 4000mAh batteries.
You could consider turning the frame around and mounting the camera on the wide end. That way the gimbal could point downward through the V-cutout without sitting too far forward.
Negative thing about the carbon props is that they block the video and telemetry signals more.
Apparently you can get about 22min with BL gimbal, full FPV, 5800mAh battery, 480kV motors and 17" props.
Well, I'm getting closer to actually getting started. I've sourced some 1/2" square aluminum tube and some C/F tubes that should fit snuggly inside...just have to place the orders. I'm still floundering on the motors. I'll probably wait until I have the frame assembled and can weight it out in full FPV setup and then pick the motors that should best handle the weight. I know it'll be heavier with a BL gimbal attached, but that might offset the fact I only have 4S 3700mAH and 4000mAh batteries.
What throttle setting does this seem to hover at with the battery, GoPro, 5010 motors and 15" props? I prefer a ~50% - 60% position...gives me a little extra headroom for emergency maneuvers if/as needed.
Aluminum behaves close to perfect electrical conductor (PEC) for electromagnetic waves. It will not attenuate the wave but reflect it very well. This can be a good thing or a bad thing. It can be bad if you are flying directly overhead and the aluminum is between you and the receiver antenna or tangent to a circle around you. It can be good if you are flying far away because it is then normal to a circle around you and it will cause an array factor on the antenna which narrows the radiation pattern (shrinks the 3dB angle in the e-plane).
I haven't yet used carbon but I have heard that it is conductive so it may not help much with EM. I think fiberglass would help a lot with EM though.
The thought of having Fly-Aways is not encouraging to start FPV.... Don't you have a failsafe RTL set up; or if it loses contact can't you tell it to loiter or orbit (so that you can move yourself closer)? I am just a NOOB, I think I desperately need to read "RTL for Dummies" before I go further...
The signposting material I have has a 0,3mm Aluminum layer, then 2,4mm PE, then 0,3mm Aluminum. It has the brand name of Dibond and is also used in modern walls and floors (sound proofing). This 3mm board has appr0x. 1,2g/cm3, I guess the 3K Carbon plate has 1,6g/cm3 (that’s what HobbyKings sheets has)
I have often heard of people who have used carbon being a bit disappointed because it being a bit heavy.
My guess is that carbon fiber sheeting will not shield EM waves very well. Any current induced in the sheet will flow in the direction of the fiber, making it have antennae property. A woven carbon fiber will be a bad faraday cage, because the woven strands are not electrically connected to each other. A metal sheet however, will build "rings" of current (similar to magnetic filings in a magnetic flux, but according to Lenz's law), and will attenuate the inducing EM wave. The Dibond has two metal sheets, and is not ferro-magnetic.
At first I wanted to use Balsa and do a thin carbon layup as mentioned earlier in this blog, but that might not work well with my future waterproofing plans so I just bough a 10"x10" sheet from a local hobby shop, Aerial Concepts. It is about 1mm thick.
Just using Balsa didn't work so well previously as the frame did sometimes bend a bit and the Balsa always had to be replaced after a hard crash. Especially at bottom where it used to rest on the battery. With plywood I could use a 5lb hammer and straighten the frame after a major crash onto tar.
I've found that if you plan on doing long range autonomous flights in a Southern direction then your compass setup and vibration levels need to be right or you can have flyaways and failure to RTL after about 1+km into the flight. On the other hand, the 53% interference I had on the 10" tester didn't prevent it from flying such flights perfectly.
This screenshot of a flight video made all the work on the copter worthwhile to me. I was standing on the far hill with the two watertowers and explored a nature reserve 1.5km away.
Does our top fuselge take strain, that you have to keep it rigid?
A very lightweight type of EM Shielding is the material used for making roadsigns and numberplates, I purchased some and will experiment later (maybe next year) with.
What about shielding the motor wiring, does anybody have a suggestion for a source or mateial brand?
22% ? Wowwwwww i have 83% of EM interference....is dangerous???
The quadcopter fly very well!!......What are the Jeff motors???
Thanks
I'd try the motors Jeff recommended (they weigh <100g) or the 530kV RCtimers as alternatives.
Yesterday I replaced the top fuselage plate which was 3mm plywood with 1mm carbon fibre. I only saved 6g weight, but the compassmot check showed EM interference dropped from 53% to 22%, which is below the acceptable 30% apparently.
By the way, there is an interesting discussion going on about whether it is good to hard mount the APM or use so-called vibration isolators
http://diydrones.com/group/arducopterusergroup/forum/topics/optimiz...
......but who wantso try !!!??!?!?!?!?
MOTOR 1
MOTOR 2
What do you think?
Yeah Alex, you're probably right. I've had many RCTimer motors and no real problems with them. I was thinking of buying 'quality' motors once vs good motors and then wanting to upgrade to better in the future...costing more money in the long run. I still have time as I've got to get the frame cut first, then assemble. That'll give me some time to make the power system decision. FWIW, for overall size I was thinking 14" props would be good, but not so good on those 360kv motors on 4S. I'm probably just thinking to hard and just get what's been a proven performer.
Can someone measure the length and width of the folded frame? I'd like to see how it'll fit in/on my FPV backpack. Thanks.
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