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Old Nov 23, 2010, 08:18 PM
KB3VOJ
cherokee180c's Avatar
USA
Joined Sep 2007
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Yea, but you ended up with a great conversation piece picture. Let me know what you think after fixing your servo / hinge issues. Others have reported this plane flys great even with the extra weight. I am on the fence on weather to buy a flying wing or a Skywalker for my next fpv plane. I may just buy both, LOL. I really think I am going to buy the GR, but just want another flight report from somebody using for FPV.
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Old Nov 23, 2010, 08:23 PM
KB3VOJ
cherokee180c's Avatar
USA
Joined Sep 2007
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Quote:
Originally Posted by chicken hawk View Post
I don't know if this helps at all. I dont have a current sensor but here is a video. I would swear that I'm getting around 10min with 1 2200 mah pack but as you can see from the timmer in the lower right of the screen, I changed batteries but did not reset the timmer.
http://www.youtube.com/watch?v=hBWIi_9BoZg
If that was on (1) 3S 2200, you flew for 15 minutes just on the section of video you showed that started at 9 minutes and ended at 24 minutes. How do you like for fpv as the video looks great?
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Old Nov 29, 2010, 02:25 AM
Flying with the eagles
etman's Avatar
Eagle's nest
Joined Nov 2008
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Advice needed for tweaking the power system

Now I feel that the battery life is too short <8 mins, and there isn't much power to climb to altitude.

1. So I'm upsizing the battery to a 3000 mah 3s. Ordered 3 of those.

2. I also bought some props. But I don't know which to change to.
10 x 5
10 x 7
11 x 5.5
9 x 4.5
9 x 6
My motor is rated for a 10 or 11 inch sized prop.

I want to reduce the amps at cruise speed. 10 x 5? or 9 x 4.5?
At the same time I want to increase the power for climbing. 11 x 5.5?
Please give me advice.
I have a wattmeter which I can monitor the amps.

Quote:
Originally Posted by etman View Post
AUW 1.34 kg
1400 kV 40A Brushless Motor
10 x 6 prop
3s 2200 mah slim battery
40A Towerpro ESC
Turnigy 3A UBEC
72 mhz RX
Cameras: GoPro Camera, CX-161
Video: Lawmate 1.2 Ghz 1000 mW TX, RX
OSD: RMILEC $10 OSD

Ready to FPV!

My FPV setup is short range only. Though what you see is like a Trappy-style FPV wing.
Can't wait to try this out.
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Old Nov 29, 2010, 03:22 AM
Flying with the eagles
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Eagle's nest
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Since the amps is too high even for the cruise, I'm going to downsize the prop dia and the pitch.
So I'll try out the 9 x 4.5 first.

Quote:
Originally Posted by etman View Post
Now I feel that the battery life is too short <8 mins, and there isn't much power to climb to altitude.

1. So I'm upsizing the battery to a 3000 mah 3s. Ordered 3 of those.

2. I also bought some props. But I don't know which to change to.
10 x 5
10 x 7
11 x 5.5
9 x 4.5
9 x 6
My motor is rated for a 10 or 11 inch sized prop.

I want to reduce the amps at cruise speed. 10 x 5? or 9 x 4.5?
At the same time I want to increase the power for climbing. 11 x 5.5?
Please give me advice.
I have a wattmeter which I can monitor the amps.
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Old Nov 29, 2010, 09:42 AM
Plane Insane RC.com
chicken hawk's Avatar
Spanish Fork Utah
Joined Mar 2005
1,327 Posts
Quote:
Originally Posted by cherokee180c View Post
If that was on (1) 3S 2200, you flew for 15 minutes just on the section of video you showed that started at 9 minutes and ended at 24 minutes. How do you like for fpv as the video looks great?
I like it for FPV. Mine gets up and goes pretty well with a 3530 1700kv and 7x6 prop. Itís by no means a rocket but that is likely why Iím getting the longer flights. With that said, I bought a skywalker that Iím now using for FPV and I have turned my GR back into a combat wing with a gopro. Once I get some cash together Iím going to get another GR so I can use one for FPV and the other for combat. They really do make great FPV planes.
Ryan
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Old Nov 29, 2010, 11:18 PM
KB3VOJ
cherokee180c's Avatar
USA
Joined Sep 2007
2,591 Posts
Is anyone else flying this plane on a 3530-1100kV motor? I have a Turnigy sitting upstairs waiting for a plane. I imagine you just have to turn a more agressive prop? I am also thinking about designing to use the new (2) 2650mAh nanotech cells for 5300mAh total.

Why do you have to cut anything off the trailing edge of the plane? I see some cut 1", some 2", but wouldn't you have more lift to carry more weight with the additional wing area? Just a bit confused about this. Does the kit come with the shock cord? Lastly, isn't the wings already cut to the proper sweep, or do you have to make that cut manually? Thanks, I am just about to pull the trigger on buying this plane.
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Old Nov 30, 2010, 02:47 AM
Flying with the eagles
etman's Avatar
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Quote:
Originally Posted by etman View Post
Since the amps is too high even for the cruise, I'm going to downsize the prop dia and the pitch.
So I'll try out the 9 x 4.5 first.
Ok I tested my GR with a new prop.
9 x 4.5 prop with 2200 mahv 3s battery is just fine. I'm getting 12A at half throttle cruise.

I used to get 18A for the 10 x 6. Now it should be more endurance.

I'm also going to try the 3000 mah 3s to see what performance I get. AUW is now 1.5 kg with the 3000 mah 3s.
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Old Nov 30, 2010, 05:38 AM
Lee
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We are using a combat set up with the 3530 1700s. I have 3X of the 3530 1400s but have not tried the 3530 1100 yet. The lower KV does have some advantages. The prop noise decreases and it does cruise with less power. I was using a 9x6 with the 1400 and it felt about right.
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Old Nov 30, 2010, 12:59 PM
KB3VOJ
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USA
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ET, I am surprised you are fine for takeoff with the 9x4.5 and the extra weight. That is where I would expect the issue as you need the full thrust to accelerate fast enough to generate the larger amount of lift required to carry the weight. I have an EZ* now that is pretty heavy and taking off is a Bitc_. I have never crashed doing anything else, but I crash almost once a day taking off. I currently went up to a 6x5.5 which helped on takeoff, but I use way to much power climbing to altitude if I am not watching the throttle. I am going to drop back down to 6x4 and see if that is the sweet spot.

Thanks Lee, I just purchased the 1700 this morning, but I will probably try the 1100 first. I have good results with lower KV motors as you can always load up the prop. Any comments on my trailing edge and sweep questions above?
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Old Nov 30, 2010, 05:01 PM
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USA, TN, Nashville
Joined Oct 2009
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I assume you're talking about cutting off the corners of the elevons... That's so in a cartwheel the elevons don't get bent or torn off. It just helps protect them. It's not enough area to worry about. If you're talking about having to cut out some of the trailing edge by the motor it's so that you have room to turn a bigger prop. I've never ever seen anyone do it on any of these wings but I've seen it in other threads. I mention this because it may be what you're talking about since you're using such big props....

The wings are cut with the proper sweep yes. But you're free to change it however you want. People have swept the GR and Titan's a little more and liked it. It's up to you. I don't know how it affects the flight characteristics. I've heard with more sweep it becomes a little more stable and more like a traditional triangle delta plane?... I may be completely wrong that's just what I remember.

Note that the more you sweep it obviously the smaller the wingspan will be. The wing area won't change too much though I don't think.

Edit: Yes the kit comes with the shock cord. It comes with a lot of it actually. At least my Titan and Assassins have. And plenty of covering too. Again - more than enough. Enough that if you screw up a small piece you won't be in danger of running out.

You won't be disappointed with these wings. It's amazing how durable they are and how good they fly... I don't have a GR yet but I want to add one soon. I'm debating on another Titan or this. The Titan is by far my favorite plane but it's pretty beat up. I'm considering giving/selling it to my friend or brother and have me a new pretty one.

I was flying it this weekend in a field out in the middle of nowhere and had at least three or four out of the maybe ten cars that drove by stop and watch me fly. I was literally doing loops around the power lines, flying low and slow a foot off the ground, and then jetting over them at 80 mph. My favorite thing to do is go full throttle at something and pull up at the last second going full vertical until it's a tiny dot. A guy who flew big gassers and turbine jets turned around after he had left and came back to ask me about it. I guess he couldn't get it out of his head. :P

Second Edit: By the way... I'll bet there's a sweet spot somewhere that you can get a really low cruise amp draw. My Titan has flown on a tiny little welgard microjet motor and honestly didn't even feel underpowered... I realize that the GR is going to be a lot heavier but still... My Titan will slow down really well and stay up at much less than half throttle on the 3530 1700kv
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Last edited by rdbell; Nov 30, 2010 at 05:13 PM.
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Old Nov 30, 2010, 06:53 PM
Registered User
Chattanooga, TN
Joined Sep 2010
59 Posts
Hey Cherokee,


My setup is very similar to what you are planning to do. This is my second plane and first flying wing.

Current setup:
-1700kv hk motor
-CC Thunderbird 54
-2x Zippy 2200mah, about to switch to 3300mah though
-Gopro w/ live out
-Dpcav 500mw 900mhz TX with Inverted Vee
-Dpcav RX with patch
-DOSD V2
-Dlink on a 9chp

Here are my observations:

This was my first wing and build so I was a bit nervous(I am a Noob). With each step of the build I grew more and more confident. I was amazed by the strength of this wing. Maiden wasn't too scary either!

My Grim Reaper flies great even with all this weight. It rolls quickly but also tracks very well (with no fins!). Obviously it doesn't glide as well as it could, but definitely acceptable considering the payload.

I would definitely try the 1100kv first, my 1700kv struggles a bit on launch to get my GR moving.


I haven't setup my AP/RTH yet because school is dominating my time, but I have a good feeling the DOSD will have no problem guiding this aircraft.


I am very happy with my setup right now.


-Lex
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Old Nov 30, 2010, 07:03 PM
KB3VOJ
cherokee180c's Avatar
USA
Joined Sep 2007
2,591 Posts
Thanks guys.

Lex, I assume that you are going to go to 2x3300? How long are you flying now on 2x2200? Wow, that should be real heavy compared to what I planned, especially with a fully covered GoPro. I have a black Box HD camera now that I might throw on there, but it weighs a lot less than the GP with housing. Launch is definitely my biggest concern as the EZ* gives me fits being so heavy. I have the EZ* now for going slower, and my buddy just got the new Radian Pro that we are turning into FPV, so if I like that better for slow flying I will retire the EZ and switch to that. I am looking for the GR to do more agile fast flying down low and also longer distance stuff. I have so many wires in the front of my Ez* that I can only fit 2650mAh max and it is a bit too heavy with that setup.
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Old Nov 30, 2010, 07:57 PM
Flying with the eagles
etman's Avatar
Eagle's nest
Joined Nov 2008
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Quote:
Originally Posted by cherokee180c View Post
ET, I am surprised you are fine for takeoff with the 9x4.5 and the extra weight. That is where I would expect the issue as you need the full thrust to accelerate fast enough to generate the larger amount of lift required to carry the weight. I have an EZ* now that is pretty heavy and taking off is a Bitc_. I have never crashed doing anything else, but I crash almost once a day taking off. I currently went up to a 6x5.5 which helped on takeoff, but I use way to much power climbing to altitude if I am not watching the throttle. I am going to drop back down to 6x4 and see if that is the sweet spot.

Thanks Lee, I just purchased the 1700 this morning, but I will probably try the 1100 first. I have good results with lower KV motors as you can always load up the prop. Any comments on my trailing edge and sweep questions above?
Simple, I just have to use more throttle for the take off. Then throttle back for an efficient cruise. Yes it does stall more easily on take off. Just have to be careful and give it a harder toss.
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Old Dec 01, 2010, 05:30 PM
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USA, TN, Nashville
Joined Oct 2009
903 Posts
I'm curious how the GR compares to a ritewing Zephyr which looks like a pretty popular FPV plane.

Edit: Ehhhh.. I'll take the GR!
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Last edited by rdbell; Dec 01, 2010 at 11:24 PM.
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Old Dec 01, 2010, 11:16 PM
KB3VOJ
cherokee180c's Avatar
USA
Joined Sep 2007
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It looks to cost about $110 less. I am going to pick one up soon.
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