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Old Apr 02, 2015, 10:58 AM
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Originally Posted by mike55 View Post
My dear friend.
Nice to hear from you. You are not right, he joined at June, 2012, but the post is from Oct 16, 2014, 04:00 AM.
I saw his picture, but i cannot se on it if the flap is "locked" at the neutral position or at another position (Maybe up a bit). I don't unterstand why the flaps has to be fixed at neutral position, because they seem to be good fixed. So i cannot follow his meaning that this piece of wood solves the problem with nose down.

I bougth the plane with mounted motor out of the box, so I don't think that the motor angle or the thrust line are not right.

Thanks anyway.

Mike
DOH! You're right. I looked at the wrong date.
I don't think it really matters where those flaps are set as the first trimming flight will get the elevons to compensate.
I made operational flaps because on these sorts of planes, I like a little reflex (about 3 to 5 degrees of UP) to make for a safer and easier launch. I've got that dialed in on my "gear" channel. I also have the usual flaps set with some UP elevon mix as air brakes for landing.
If you have good power on your plane or you use a catapult launch, you shouldn't need much reflex for take off. I hand launch. If you have a good long landing zone, you won't need flaps either.
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Old Apr 02, 2015, 03:37 PM
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Ok, thanks a lot. Maybe I try to increase the angle of the motor. I will report after weekkend.

Bye, Mike.
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Old Apr 03, 2015, 06:25 PM
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I've read a lot of confusing and conflicting stories about 3, 4,5 and 6 cell setups, so anyone with a 6 cell 5000+ mah setup have anything to say about it? coming from 3 or 4 cell setups? I have a bunch of 5000 mah 3 cells i could use for a 6 cell setup.
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Old Apr 04, 2015, 01:44 AM
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Originally Posted by raptor357 View Post
I've read a lot of confusing and conflicting stories about 3, 4,5 and 6 cell setups, so anyone with a 6 cell 5000+ mah setup have anything to say about it? coming from 3 or 4 cell setups? I have a bunch of 5000 mah 3 cells i could use for a 6 cell setup.
It pretty much boils down to weather or not you're able to obtain the "correct" final RPM (i.e. matching motor KV rating to flight pack voltage and desired final RPM).

Whatever works with (just an example) a 1200KV motor on 3S, will work with a 600KV motor on 6S.
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Old Apr 04, 2015, 10:19 AM
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The lower kv is more efficient right with a bigger prop and less pitch?
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Old Apr 04, 2015, 10:50 AM
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The lower kv is more efficient right with a bigger prop and less pitch?
Depends. You can't just look at # of battery cells or KV. Pushing a big, lumbering plane around like a big wing set up for FPV may require a set up with low cell count, slightly higher KV, big prop, high or low pitch to suit. You also need a large motor (big diameter, longer body, with more windings inside) for more torque to drive that big prop and push all that weigh through the air while using as little battery juice as possible.
Generally, a high cell count and high KV is meant for lighter planes built for speed. For these, you need a smaller prop, lower pitch to get the kind of performance you need. Or high cell count, low KV, big prop, big ESC if the plane is big and heavy.
Take a look at some planes that come equipped to fly on different battery cells. For example, the HobbyKing EFX comes right out of the box able to fly on 3s or 4s. They give you 2 different sizes of props. While the motor and ESC stays the same (this is not in all cases), the 4s requires a smaller diameter prop with same pitch. If you want the EFX to go even faster, without changing anything else, you go with a bigger diameter prop and less pitch. Note the size and rating of the motor and ESC.
Now go take a look at a larger plane, using big props and see what size motor is used and # of cells it uses. Look at the ESC used, the flying weight of the plane. Compare the differences and it'll start to give you a hint as to what's involved. It's not as simple as just looking at KV, battery and prop.
If it was simple, everybody would fly this plane on one set up and be done with it. There are calculators online for working out all these parameters.
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Old Apr 04, 2015, 11:21 AM
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Good info thanks. I think hand launching my 5lb plane without being on a hill is going to be imposable with 3 cell setup, i know the 4 cell will get it up ok but i dropped 400g and added a cell to get it up last time by hand launch. I'm going to find some tubing and make a bungee launcher and try the 3 cell setup first, if i don't like it i'll have to take my big 3 cell batteries and turn them into 4 cells. I have four 5ah so i'll make three 4 cell 5ah out of them. i have a 5ah already so i'll be back up to 4 for that plane. I like to have 4 to 6 batteries for each plane i own
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Old Apr 04, 2015, 01:47 PM
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I currently fly mine on 4s, 4500mah. I've got a 60A ESC. I think I'm running the stock 850KV, motor. They claim it's a 35mm motor but it seems much bigger than that (measures at over 50mm diameter. I use a 10 X 8 fixed prop. I could go bigger but that's all I had laying around. I didn't like the stock prop as it was too soft and flexed too much. Besides, it was very hard to balance for 4s speeds. I used to fly my old X8 (7' wing span) on 4s, using a 1200KV motor and a 3-blade folding prop. That thing was a lot faster and easier to hand launch than this one.
I was flying it FPV but found it was a bit light and hence, didn't give me the solid, stable platform I wanted. Perhaps if I loaded it up with more batteries to make it heavier, it would have been good. I now use it mostly as a sport flyer and camera platform for aerial video. It's a fairly imposing plane when doing low fly bys and loops and rolls. Inverted flight is also really weird to watch.
As is, I need fairly heavy throttle and a short running hand launch to get it to go. It also needs a few degrees of reflex on the inboard flaps to help it from nose diving. With a hill or a catapult, it should be no problem on 3s and no reflex and medium throttle.
Hand throwing this thing is not for everyone. There's that constant fear of mincing the top of your throwing hand.
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Old Apr 18, 2015, 10:53 PM
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Primer vuelo de prueba FX-79 Buffalo (6 min 10 sec)
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Old Apr 22, 2015, 05:18 PM
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Here is my new FX-79 with some modifications:
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Old Apr 22, 2015, 06:47 PM
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cfcf muy bien tu buffalo, de donde eres? yo soy de puebla, y tengo una igual ya la vole a 20 kms de distancia
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Old Apr 25, 2015, 07:24 AM
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There's that constant fear of mincing the top of your throwing hand.
Is ther a real danger with a 12x8 prop?
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