This was the first fly of my baby, it was my first build, I like it because it's very strong and allows me to learn without crash damages, and a great code that support all design errors, but now I'm on a second stage, I learn somethings and now I want a more efficient cuad.
a) 20 min flying time at least (today 14 min)
b) More stability in windy days.
c) reach 1km min with r modem.
d) Resolve mag field limit.
e) Mantain the portability (no much bigger)
f) Beauty is important for me too ;)
I started this work last year (2014),
First I ligthweight as much as possible, only cup -90 grs, take away an extra floor, etc, total -200grs and reduce vibrations but I have many work to do yet and I think that a post it's the best place to share with you and recive your help, any idea is welcome.
First thing that I'm going to do to continue is to change motors, it has Turnigy 2836 950kv they are old cheap plane motors with bearings near limit with 10.47 CF props and 30A esc, I test them with my ligthest batteries two Multistar 5200 and gives 26 A consumption
Ship weights now 1.47kgs without batteries, with FPV and Dragon receiver and this is the photo
Replies
I measure motor center to motor center, any coincidence :( ; time to change frame.
You mean they are different? How much?
One side to the other 1.5 cm; front to back one cm; one side to back 4.5 cms; I remember I have an extra arms, I'm going to check them
No question is silly!
I guess I'd say if you could get a copter to hover at below 1/2 throttle maybe even 1/3 your doing pretty good. That landing gear you have there is kinda heavy. My son had some like that. very nice the way they bend but don't break! But they are heavy. Anything you can do to lighten it up is good. Shorten wires where you can. Every little bit adds up to a longer flight time.
ps I would not try and shorten carbon fiber props. That could weaken them and perhaps they would then fail. Just wanted to clarify that. But the plastic ones no problem.
Agreed on shortening CF props, its not worth the hassle.. Unless you really want to deal with cutting them, sanding them, balancing and sealing them back up with epoxy (and balance again), its just easier to get the proper sized propellers...
Also on shortening the wires, long wires make more interference, so twisting and making them as short as needed (not too short, that you cannot work with them) help as well..
If you can hover at under 50% throttle, and motors/escs are cool, then things are going well for you. Less prop size, or flatter pitch can help...
Thank's Richard for the tip, I wasn`t shure if that possible you confirm it is, I'm going to do more test to evaluate them better, i notice that flies under 50% trottle, that indicate me that, or props are little big or I can carry more weight? for example the camera with gimbal or more batteries to fly more time? Sorry the silly question, how I know that motor is not over demanded? for heat?
While I continue searching the 13 props (perhaps I can have CF ones) I 'm doing some test with this ones, I assemble the four motors and get a surprise :O , looks photos, my cuad isn't simetric
I fly a little in th late afternoon and fly, consumption didn't looks much efficient but a very little test.
Hi Cala,
I'm sorry I didn't notice that earlier too, I had noticed something off about them, but thought it was just an illusion based on the different colors of your arm.
Now, blowing up your picture and using a ruler I get 3" of clear space from the edge of the black booms to the edge of the center plate and 2 1/2" on the gold arms for the same distances.
Of course those aren't actual measures since there is no way to judge actual quad size comparatively.
But the ratio is correct (and it won't work!)
You might be able to get it to fly, but no amount of tuning can actually fix that kind of assymmetry.
If the front and back prop tip clearances / distances are the same and the side to side are also (even though different than front to back, you can tune out the asymmetry by separating the roll and pitch control PIDs.
I do that on my H style copters all the time.
But that isn't what you have and it produces an asymmetry insoluble by our PIDS you would actually need to separate out each motor and we don't have that.
In your case, if possible, I would just make the gold arm lengths the same as the black ones with the same motor mount to center plate clearance, then you can even use the bigger props without problem and yes the 14" props will generally give 10 to 20% higher efficiency than equivalent 13" ones.
You really need to fix this in any case, you could also shorten the black arms to the same as the gold, but then you would need to use 13" props.
Best Regards,
Gary
Thank's Gary, that true, I never can tune well this copter, It never flies as good as he have to do it, that's one of the main reason that impulse me to build a complete new one, perhaps this frame was exellent to learn because is crash very resistance but now it's not adecuate to optimize it, many defect, I'm thinking that it's time to build my first Diy frame, I like Forrest build tecniques and now I have a lot of help in this forum; I worked a lot last year trying to find defects and recently discover :O , thank for your explanation
Forests build techniques are very lightweight and strong.
It is very important to use the Epoxy adhesive that he recommends and to roughen the carbon fiber and any other materials you use with 200 or so grit sand paper before trying to get a bond, but done properly with that excellent 3M Epoxy adhesive it forms a very strong bond.
That particular glue is the secret of his success.
It mixes in a 1/3 - 2/3 ratio which is weird, but it is quite forgiving of imperfect mixing.
I love the stuff myself and use it for all kinds of things (dynamite on glass).
Most Epoxy glues/adhesives do not work nearly as well as the one he recommends.
Best regards,
Gary
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