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RE: Nitromodels PREDATOR RQ-1B - 6/17/2008 8:52:58 PM   
GenesisFactor


 

Posts: 30
Joined: 6/15/2008
From: Huntington, NY, USA
Status: offline 		blfischer- lol, so i am guessing that it wasn't you i've been talking to on ebay. Funny enough, he lives in TX too. ah well, we came to terms.

kazki- thanks for your info. i guess i will have to ditch the large motorized lens and go a different route. This saddens me. I kinda want to hack a camcorder lens as they are worlds lighter. I was told to put in a 480 engine, get a 4800 mAh batt to power the thing, and a 30C batt with a 40C ESC. does that sound about right for an extra pound?

< Message edited by GenesisFactor -- 6/17/2008 8:54:15 PM >

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RE: Nitromodels PREDATOR RQ-1B - 6/17/2008 9:02:02 PM   
helomix


 

Posts: 16
Joined: 6/17/2008
From: , TN, USA
Status: offline 		I don't know where you got the idea I would be adding 39oz at. I had this system on a mini ultra stick powered by a park 450 and it flew fine, in fact the wing area is 50sq in smaller than the Predator. I read the Flying weight of the Predator is 1.2 lbs, and I will be adding approx. 7 oz of equipment and batteries..for a TFW of 27oz approx. After reading about the Park 480 I'm leaning towards it since the support for e-flight around this area is strong.


EDIT... I see you were replying to Genesis...sorry

< Message edited by helomix -- 6/17/2008 9:06:56 PM >

(in reply to kaziki)
       Post #: 527

RE: Nitromodels PREDATOR RQ-1B - 6/17/2008 9:09:58 PM   
OnTheRock


 

Posts: 5
Joined: 4/7/2008
From: Oak Harbor, WA, USA
Status: offline 		I just bought the FlyCamOne2 to use on my planes, at only 1.5oz I'm sure it will work just great... I know it's not a camera that will do a lot but from what I've seen on youTube it's good enough for me.

(in reply to kaziki)
       Post #: 528

RE: Nitromodels PREDATOR RQ-1B - 6/17/2008 9:35:11 PM   
blfischer


 

Posts: 7
Joined: 3/14/2008
From: Seabrook, TX, USA
Status: offline 		There is a predator in Isreal loaded with the FPV equipment and he has commented that it flies great loaded up... still like a glider. He has a 300W monster in the back as well....

http://www.rcgroups.com/forums/showthread.php?t=679502

The scale looks and his performance report (in some other link) leaned me in the direction of the Predator. He hasn't responded to any PMs... I wanted to see if he really needed all that power. The e-flite 480-1020Kv is rated at 275W, so it should be plenty... and with glider like performance, I am thinking loiter times to be in the 15 min or more range with proper throttle management.

The motor is quite heavy, which made me think about doing some more research about motor power to weight ratios... as in 275W to 3.1oz for the 480, or 88.7W per oz ... is there a better motor out that puts out more or equal amount of power that weighs less? I am really suprised the motor makers don't market that spec... unless the power comes from the magnets and the winds so mass is a direct correlation to max watts which would essentially have all motors equal.

If you use a 4800mah 3S for a battery, you will probably need to have it power everything. There is barely enough room for a 20703S and a 8002S up front in mine. You might want to measure it before you get it. I can't imagine how it would fit with everything.

< Message edited by blfischer -- 6/17/2008 9:39:58 PM >

(in reply to OnTheRock)
       Post #: 529

RE: Nitromodels PREDATOR RQ-1B - 6/17/2008 9:48:24 PM   
kaziki


 

Posts: 3
Joined: 2/12/2007
From: Bear, DE, USA
Status: offline 		It really comes down to watts per pound. You need to know how many watts you are going to put into the prop. That depends of course on the motor but also on the prop you use. If you plan on an all up weight of about 3 lbs, then you are going to need about 100 watts/lb to drive the load. You should still stiffen the wings, and the fuselage to handle the added stress. You would be sad if you ripped the wings off in flight.

I played with Drive Calculator (http://www.drivecalc.de/) and found that a Hacker A30-22S motor paired with a 40A ESC, a Kokam 3 cell 4000 mAh battery, and a 9.5x6 prop will give you about 1600g (54+ oz) of thrust and about 84 Kph (52 Mph) speed. The battery, ESC, and motor will weigh about 415g (14.6 oz). That's about 7 oz more than normal, so your all up weight would be about 53 oz.

It might work, but it would still be fast and twitchy.

(in reply to GenesisFactor)
       Post #: 530

RE: Nitromodels PREDATOR RQ-1B - 6/17/2008 10:22:32 PM   
papajeff



Posts: 423
Joined: 8/25/2004
From: Rochester, NY, USA
Status: offline 		Kaziki is right; "You should still stiffen the wings, and the fuselage to handle the added stress. You would
be sad if you ripped the wings off in flight." Also, it would be wise to use a carbon fiber wing tube and
consider the method of removable wings as discussed in post # 116. And reinforce the fuselage at the
point of the wing tube insertion. This should eliminate the posibility of the wings folding during flight.
Scale type flight is the best way to insure that there will be no stress issues or other flying problems.
For sure this is not a 3D aerobat! Regarding power, the 200W outrunner that Nitro included for the
review has been just great with over 50 flights on the airframe. The flying weight is about 33oz.
so I have 100W per lb. which is perfect for just flying around like an old Turkey Vulture. For your
FPV use I would recommend any dependable 400W outrunner which will give you the extra power
needed for the extra weight you plan to add with your equipment. Just some thoughts to consider.


< Message edited by papajeff -- 6/17/2008 10:39:02 PM >

(in reply to kaziki)
       Post #: 531

RE: Nitromodels PREDATOR RQ-1B - 6/18/2008 5:12:37 AM   
GenesisFactor


 

Posts: 30
Joined: 6/15/2008
From: Huntington, NY, USA
Status: offline 		i am all ears to everyone as i am a newb at this. My pred won't ship until the 28th, so motor considerations and things of that nature, we have time to find the right balance. Right now, i'm trying to program and make things play nice. for installation.

kaziki, you're right, i am going to have to probably over power this pred at 100w/lb and use the computer to manage the system. I have a friend who loved building these things before fam too over (MIT for aeronautics). He has pledged to help me.

Papajeff, I've read through those posts twice now. I loved the neoD magnet idea. Hehe, ifyou got them at a 30+, and gave those wings a settling stop, i don't think even a crash would break them off lol. Unfortunately, i definitely have to go the CF+ nylon method. Everything (but the big lens) i am thinking about using is solid state and industrial strenght, so i'm hoping that it will survive a 52mph crash into soft ground as there are usually tested for 3-10ft or so on concrete. I am also considering adding an emergency parachute and the steering wheel mod. I will definitely replace the landing gear with something sturdier.

You said i need CF tubes and plates, i was just looking at them. What do you recommend?
http://www.rcfoam.com/cart.php?target=category&category_id=93

These are my weights list (in oz)
14.9- CCD and compstar lens
3.2- FPV and ccd (it will get lighter with new lens)
3.0+6.6+7.4+4.6+3?- computer system and all major controlling parts+battery and power regulator these will be bottom mounted between the wings to add to reinforcements.

This is going to be a project and a half (or 4 individual projects). I am still researching gyro stabilization for the big cam.

Yes, there will be a ground station This is my summer project. Last summer was my carputer/stereo. I really appreciate any and everything you can add in with the info i have provided. You guys rocked throughout this thread with pics and vids and knowlegde, esp you papajeff and the guy in the UK and GG and a few others. You've given me the confidence to actually buy the plane without asking a question, i just hope that with questions, this sucker will fly

< Message edited by GenesisFactor -- 6/18/2008 5:24:31 AM >

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RE: Nitromodels PREDATOR RQ-1B - 6/18/2008 5:00:22 PM   
helomix


 

Posts: 16
Joined: 6/17/2008
From: , TN, USA
Status: offline 		Thanks all for the help, I will definately look hard at the wing/fuse renforcement. I'm still up in the air as to motor size, I'm really concerned to the flying weight of Papajeff's uav, you say its 33oz so mine will be in the neighborhood of 36-38, which will be pushing the park480. Is there any reccomended 400w motors out there for these birds? Also, what batteries are you using/ I thought 2500mah would be fine but it seems that a lot of you are in the 4000mah range.

Edit: I think I have found the motor I need:
http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLM4010A Its a bit heavy at 4.3 oz, but if I use a heavier main battery and mount the fpv batt and tx foward I should be able to balance everything out................ what do you think?

< Message edited by helomix -- 6/18/2008 5:09:13 PM >

(in reply to GenesisFactor)
       Post #: 533

RE: Nitromodels PREDATOR RQ-1B - 6/19/2008 4:49:32 AM   
GenesisFactor


 

Posts: 30
Joined: 6/15/2008
From: Huntington, NY, USA
Status: offline 		hehe i'm such a noob its not even funny sometimes lol. 5 mins ago, i found out where the ESC goes and exactly where you plug it in.

So i read earlier that there were 4 channels to this bad boy
1) throttle
2) elevators
3) ailerons
4) rudder

However, as this is a V tail craft, why doesn't that technically make it a 3 channel as it is integrating the rudder and the ailerons...or did i mix up something? I am picking up my servos today on ebay and my ESC. I posted a question about esky brushless motors, basically what is the difference between these motors cause i am missing something in the specs. I was looking at the monster 32, but the moster 10 has 375W as well.
http://www.nitroplanes.com/brmo.html

and these? and which should i think about getting?
http://www.nitroplanes.com/esky-brushless-outrunner-motor.html
(i know that they are sold out, but there are other sites)

Thanks guys. this thing is really coming along . i can't wait to get the model in hand.

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RE: Nitromodels PREDATOR RQ-1B - 6/19/2008 9:29:19 AM   
chrishornby



Posts: 68
Joined: 4/20/2007
From: PortlandDorset, UNITED KINGDOM
Status: offline 		the V tail integrates rudder and elevator. You still need 2 channels to do that, with the mixing in the TX if it is computerised. Otherwise you need a V tail mixing gizmo. You still need 2 servos, so yes it is a 4 channel ship. 5 if you need a channel to control the camera
Chris

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RE: Nitromodels PREDATOR RQ-1B - 6/19/2008 10:58:56 AM   
GenesisFactor


 

Posts: 30
Joined: 6/15/2008
From: Huntington, NY, USA
Status: offline 		thanks chris! I will need this as i will be using the co pilot 4 from FMA. any suggestions? hehe and no servos for cam control...that's a stepper motor's job

I am settling on the Monster Power 15 Motor at 425W. The 25 size, with 550W is too strong, and the 10 at 375W is too weak. This is a Goldilocks thing i guess. However...since they are the same price, should I spring for the 25 and ease off on the throttle??

Thanks all for bearing with me. I'm swallowing a whole lot of info and processing it pretty fast. Its funny, a couple days ago, i knew zippo on RC anything...other than you push a stick and my heli flew this way and crashed unless i pushed another stick that way .

edit:
springing for the 550W

ALSO...is a folding prop a good choice, or am i too heavy to be considered a glider and should just go fixed?

< Message edited by GenesisFactor -- 6/19/2008 12:01:47 PM >

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RE: Nitromodels PREDATOR RQ-1B - 6/19/2008 1:07:31 PM   
RC_AVIGATOR



Posts: 36
Joined: 7/6/2002
From: Sulphur, LA, USA
Status: offline 		GenesisFator, Where are you getting your predator?

(in reply to GenesisFactor)
       Post #: 537

RE: Nitromodels PREDATOR RQ-1B - 6/19/2008 2:57:24 PM   
Glacier Girl



Posts: 6973
Joined: 7/9/2004
From: SomewhereIn, PA, USA
Status: offline 		genesis, you had asked earlier about mounting a box on the bottom of the fuselage.

If you can look back my original carried a box for the camera between the mains on the fuselage. It flew just fine. My newer version has the camera with a tilt pan set up mounted same place. Doesn't seem to affect flight at all. Both also had much larger gear and wheels then the stock ones. And this didn't affect it either, flight wise.

As for all the motor suggestions/ ideas