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Old Sep 14, 2012, 12:11 AM
Habitual Line Stepper
Cervanchez's Avatar
United States, WA, Redmond
Joined Dec 2011
698 Posts
Quote:
Originally Posted by MD2 View Post
What about using them with 9" props on 4s?
For some reason everyone always leaves out 9", they talk about 10" for 3S and 8" for 4S. I found that 9" Gemfans on 4S with the DJI 920KVs work best for me. 8" was too twitchy and seemed like the motors were being overworked. That was with 8" Graupners, maybe other 8's would have different results.
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Old Sep 14, 2012, 12:28 AM
Great Britain
MrBen.'s Avatar
Joined Dec 2008
1,586 Posts
Quote:
Originally Posted by Exploding Fist View Post
Wow. How much do you weigh without batteries (and with)? What size props?
1290g with 3s 3300 25c Gens ace
1010g with no lipo but including fpv gear and gopro

I was using 9" graupners but having major yaw issues couldnt turn in FF. Now Im on 10" graupners and its much better

This is with sunnysky 980kv motors, hobbywing 18a escs (stock fw), uhf rx, 2.4ghz vtx and board cam. Using a kk2

BTW thats 9mins of proper flying not hovering

Quadcopter KK2 Gopro - Dodging the Hay Bales (5 min 22 sec)
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Old Sep 14, 2012, 01:46 AM
Principal Member
compuatic's Avatar
San Francisco, CA
Joined Jun 2002
961 Posts
Quote:
Originally Posted by MrBen. View Post
1290g with 3s 3300 25c Gens ace
1010g with no lipo but including fpv gear and gopro

I was using 9" graupners but having major yaw issues couldnt turn in FF. Now Im on 10" graupners and its much better

This is with sunnysky 980kv motors, hobbywing 18a escs (stock fw), uhf rx, 2.4ghz vtx and board cam. Using a kk2

BTW thats 9mins of proper flying not hovering

https://vimeo.com/49122571
How do you like the sunnyskys? Have you tried 9" or 8" on a 4 S battery?
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Old Sep 14, 2012, 02:39 AM
Fly Chitty Chitty Bang Bang!
EarthOrbiter's Avatar
Central California USA
Joined Feb 2011
379 Posts
Battery life

Vantastically amazing
I did some battery life testing in this video. It was previously flown 1:43 in this video. Total was 12min 40 sec at the end.
It uses a Naza M with GPS for a controller.
The props are APC 10X4.7 with Rctimer 2836/9 motors with 40 amp Turnigy plush ESC's. They are a little big but do not heat up. 2 of them are in the sandwich.
The battery is a Gens ace 5000 mAh 3s 60-120c battery.
It was drained down to 9.7 volts many times.
All up weight is 1641g.
This test is a prelude to flying full Fpv in the future.
I determine this build to be a 10 min bird with 2 min reserve to land.
The video was taken with a Gopro strapped on my head using a cap.
For some action goto 4:25 where it almost crashes :-)
Hoverthings frame build testing (11 min 29 sec)


The video is currently uploading give it 30 min + Youtube finishing terrorist activity.
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Old Sep 14, 2012, 08:08 AM
LOAD "FLIP360FPV",8,1
vic20owner's Avatar
Joined Sep 2006
3,873 Posts
Quote:
Originally Posted by MD2 View Post
What about using them with 9" props on 4s?
There are no 9" props for DJI motors as far as I know, unless you use E-props which would probably work because they are more like 8"s.
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Old Sep 14, 2012, 08:29 AM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
Las Vegas, NV
Joined Sep 2003
17,870 Posts
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Originally Posted by vic20owner View Post
There are no 9" props for DJI motors as far as I know, unless you use E-props which would probably work because they are more like 8"s.
You can ream out the Gemfan 9" props to fit the DJI motors...I did it for a test. I ended up just sticking with the DJI 8" props on 4S with my DJI motors. I'm getting ready to swap them out for the NTM 750kv motors on unflashed ESCs and 9" Gemfans. I had the NTM's on before, with Simonk flashed ESCs, but they were really noisey...something about an odd pole count on the NTMs. I'll try them again with 'stock' ESCs to see how they do.
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Old Sep 14, 2012, 09:46 AM
Registered User
Nexus21214's Avatar
United Kingdom
Joined Feb 2008
453 Posts
Quote:
Originally Posted by Keddy View Post
Why are you posting this in the HTFPV thread?
Hey! I never posted this here, and dont know how it got here?

Regards
Nex
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Old Sep 14, 2012, 03:15 PM
Great Britain
MrBen.'s Avatar
Joined Dec 2008
1,586 Posts
Quote:
Originally Posted by compuatic View Post
How do you like the sunnyskys? Have you tried 9" or 8" on a 4 S battery?
they seem ok, I havent flown them a lot tbh, no I havent tried 4s with them as I believe they are only rated for 2s and 3s
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Old Sep 15, 2012, 08:23 AM
LOAD "FLIP360FPV",8,1
vic20owner's Avatar
Joined Sep 2006
3,873 Posts
Quote:
Originally Posted by Vantasstic View Post
You can ream out the Gemfan 9" props to fit the DJI motors...I did it for a test. I ended up just sticking with the DJI 8" props on 4S with my DJI motors. I'm getting ready to swap them out for the NTM 750kv motors on unflashed ESCs and 9" Gemfans. I had the NTM's on before, with Simonk flashed ESCs, but they were really noisey...something about an odd pole count on the NTMs. I'll try them again with 'stock' ESCs to see how they do.
Now that's something I haven't heard before...I'll have to try this.

How have your DJI motors been holding up to 4s?

Tom
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Old Sep 15, 2012, 12:47 PM
32 ft/sec^2 sucks
yoadrian's Avatar
Joined Nov 2006
153 Posts
I have been trying to figure out what OSD to go with on my FPV1. Is it better to have a "return home" function on the osd or on the controller? How does the osd interact with the controller eg: Naza? Does it have priority?
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Old Sep 15, 2012, 04:21 PM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
Las Vegas, NV
Joined Sep 2003
17,870 Posts
Quote:
Originally Posted by vic20owner View Post
Now that's something I haven't heard before...I'll have to try this.

How have your DJI motors been holding up to 4s?

Tom
Tom, I'm using the DJI 8" props on the DJI motors on 4S and everythings been fine with it. I do want to use 9", but I hate the idea of all the reaming to get the props to fit...hence why I'll be refititng the NTM 750's with stock ESCs again.
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Old Sep 15, 2012, 04:23 PM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
Las Vegas, NV
Joined Sep 2003
17,870 Posts
Quote:
Originally Posted by yoadrian View Post
I have been trying to figure out what OSD to go with on my FPV1. Is it better to have a "return home" function on the osd or on the controller? How does the osd interact with the controller eg: Naza? Does it have priority?
There are very few (if any) OSDs with RTH that will work on multi-rotors. I'd get a flight controller that has RTH ability (DJI Naza w/GPS for instance) and then an OSD for flight data information. I'm using a Dragon OSD with my Dragon Link UHF along with a DJI Naza w/GPS on my HT-FPV frame.
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Old Sep 15, 2012, 04:28 PM
LOAD "FLIP360FPV",8,1
vic20owner's Avatar
Joined Sep 2006
3,873 Posts
Quote:
Originally Posted by yoadrian View Post
I have been trying to figure out what OSD to go with on my FPV1. Is it better to have a "return home" function on the osd or on the controller? How does the osd interact with the controller eg: Naza? Does it have priority?
OSD is only for display. It can point the direction of home, but this isn't very useful for a quad because you are usually not flying far enough away that you need this. It's for RC airplanes which can be very high and far.

You really don't need an OSD, unless you want to monitor your battery voltage on display.
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Old Sep 15, 2012, 05:16 PM
KK4LIK
theSouthGA's Avatar
United States, GA, Ocilla
Joined May 2012
91 Posts
I had my first 2 FPV crashes today and they both happened on the same flight.

I knew it was going to happen eventually I just didn't expect a two-for-one deal.

I think it was all my fault but I'm not really sure. I was flying about 100 ft in front of me and when I switched from GPS to manual mode the quad dropped out of the sky like a rock, motors running. I have switched before in LOS and had to compensate for the switch and was prepared for this, however, I thought I gave it enough throttle to keep a solid hover as I was at least 75 ft up. Well... it slammed. Hard but not hard enough that I thought there would be significant damage.

At this point you may be asking yourself how is that two crashes? Its not.

The second crash came when I made the most rookie mistake any RC'er could make, the thing that is stated in most instructions and owners manuals. -UNPLUG BATTERY FROM AIRCRAFT BEFORE TURNING OFF TRANSMITTER-
Well suffice to say my motors were still running but being at the distance I was I couldn't hear them. Without thinking, I turned off my transmitter before walking over to survey the damage. WRONG. About half way to my quad the motors spun up and the NAZA went into failsafe. The (partially damaged) quad took off with the trajectory of a bottle rocket, went straight through a 300' pine tree and careened into my neighbors um.... airspace. It ended up on their um... groundspace and I quickly retrieved it with the motors still screaming, broken props and arm, it just wanted to go home.



Breakdown:
1. I don't feel it was pilot error on the first slam. Just not sure. Just didn't feel right.
2. I assume it was damaged before going into failsafe because of its bottle rocket like trajectory.
3. Didn't have the GPS superglued on the stick mount so it just got knocked loose (could have been knocked loose on the first crash) causing the second.
4. Frame held up well. Only broke an arm and dislodged a motor mount.
5. Tree rash.
6. Damaged some nice E-props
7. One motor wont turn any more. I wouldnt feel safe flying with the others now anyways.
8. Need to find a way to test my Naza to make sure its doesn't have brain damage.

The Plus Side:
1. I learned a good lesson.
2. I have really been wanting new motors!
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Old Sep 15, 2012, 05:51 PM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
Las Vegas, NV
Joined Sep 2003
17,870 Posts
I've found that flying in Atti mode and then switching to Manual (with the battery running low) ends up with an out-of-control copter. I had it happen to me twice now. Once I ended up in a bush and the other time I was just able to save it before making a puff of dirt. I think it's best to either stay in ATTI mode and just be close enough to home before it 'autolands' or fly in Manual mode and only 'visit' the ATTI modes. That's my my DJI Naza at least. My other controllers haven't exhibiting this kind of behavior. I think it's because the Naza takes over throttle for altitude hold at center stick.
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