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Old Nov 19, 2012, 04:44 PM
Chris Lee
United States, MO, St. Louis
Joined Oct 2005
323 Posts
Z06 Tony,

Yes! Very nice platform you built there. And running 6s, very cool, I take it those MT motors are working well for you? I was leaning toward the Avroto 2814 on 4s that I saw you also carry. I'm sure you've got a very happy customer.

So, are you running the same blade pitch on all the motors, or did you vary the pitch on the lower props? And if so, did you go through a phase of trial and error or more the TLAR method?


Chris
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Old Nov 19, 2012, 09:14 PM
My RC builds in my profile.
daign's Avatar
United States, CA, Los Angeles
Joined Feb 2011
2,563 Posts
Quote:
Originally Posted by lineofsight View Post
I question the notion that a Y6 configuration is "half" as efficient as a standard hexacopter, can you offer some evidence for this claim?

No one would be doing Y6 conversions of the DJI F550 frame (or making Y6 configurations at all) if that were the case; 50% efficiency is a major loss for an aircraft propulsion system where power-to-weight ratio is at a premium. I've seen numbers reported from 10-40%, but no indication if any optimization was done for "balancing" the motor thrust between each coaxial pair. Hence this thread.

I'm willing to do the tests myself, as long as some of the experts out here can verify my logic that there should be a connection between amp draw and a "balance of powers."
yes. Bambucopter quad and bambu copter y6 frame. Exact same motors, props, escs. 7 minutes vs 12
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Old Nov 19, 2012, 11:17 PM
Chris Lee
United States, MO, St. Louis
Joined Oct 2005
323 Posts
Thanks for your thoughts, 7/12 is a 42% efficiency loss, right on the high-side of what I've heard. Not really the scale I'm looking at though.

Also, you didn't vary prop pitch, which is what this thread is about: determining how much more prop pitch is best for efficiency. It's a foregone conclusion that increased pitch on the lower motor is necessary.

I will try some tests with an amp meter and see if I can learn a bit more about how the two ESCs and motors work in combination. I've considered building a thrust meter as others have done, but that gets a bit more complicated/time consuming than I really wanted.

Chris
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Old Nov 19, 2012, 11:33 PM
My RC builds in my profile.
daign's Avatar
United States, CA, Los Angeles
Joined Feb 2011
2,563 Posts
Very true...

One of these days maybe I'll try a heavy lift Y6. I still have those avroto 2814s I bought a while back from you. I just haven't found an airframe worthy of them yet.

Perhaps my Flyduspider or a rusty frame.

-D

Quote:
Originally Posted by Z06 Tony View Post
I am assuming he wants to build a camera ship not a micro Y6.

Big difference.

Your Y6 is loud as you are prolly running 5" props with 2000kv motors.

As far as efficiency its def not 50% with a typical Y6.

I have built many Y6's and they are my favorite platform for AP.
They cut through the wind better than a flat hex.

Here is 1 I just finished for a customer running 6s spinning 14" props.

I dont think its loud at all

http://www.youtube.com/watch?v=g9ieKB_bz-Q

http://www.youtube.com/watch?v=_KZNs10KQrE
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Old Nov 20, 2012, 02:33 AM
Z06 Tony's Avatar
United States, NY, Rochester
Joined Sep 2008
7,076 Posts
Quote:
Originally Posted by lineofsight View Post
Z06 Tony,

Yes! Very nice platform you built there. And running 6s, very cool, I take it those MT motors are working well for you? I was leaning toward the Avroto 2814 on 4s that I saw you also carry. I'm sure you've got a very happy customer.

So, are you running the same blade pitch on all the motors, or did you vary the pitch on the lower props? And if so, did you go through a phase of trial and error or more the TLAR method?


Chris

Yes same pitch/prop size top and bottom on every Y6 and X8 I have built.
I have yet to see "proof" that a coaxial setup will fly any better with different size/prop pitch for upper and lower.

I am 100% confident that if I put 2 exact same coaxial setup in the air and 1 had all the same props and 1 had diff prop pitch on the bottom you would never ever tell the difference.


If this is true is it really worth the effort worrying about it?
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Old Nov 21, 2012, 12:18 AM
Chris Lee
United States, MO, St. Louis
Joined Oct 2005
323 Posts
Quote:
If this is true is it really worth the effort worrying about it?
If it were true, then the answer would be no.

But I don't know that for sure. I hope to know more after some experiments.
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