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        Discussion RQ-11 Raven type spad plans?

#1 chaleau Feb 07, 2013 01:57 PM

RQ-11 Raven type spad plans?
 
I want to build a Raven type spad. Anyone have a plan for a top mounted pusher similar to this drone? Or does anyone have a suggestion for an easily modified spad that could get me there? I was thinking a downspout fuselage with aluminum tail boom with a motor mount made of cutting board.

#2 Mig Man Feb 07, 2013 08:05 PM

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You can always join the Army. They're buying them up. You can fly one of theirs. :rolleyes:

Or design one of your own and put up the plans when you're finished. Shouldn't be too hard. Much cheaper too.

#3 Extreme Sports Feb 12, 2013 01:23 AM

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Is this what you have in mind? Its a SPAD pusher version of the popular 1970's 1/2A trainer. I did not make new plans, but all dimensions are as for the Q-Tee, except or a longer nose to get the CG right. Search Q-Tee and you will find plans.

I can provide construction details and suggestions for improvements if you want to try and make a Ravin like version of this one. It makes for a nice tough trainer, and would probably be even better if scaled up 120% - 150% with a polyhedral wing added.

#4 iggy809 Apr 07, 2013 12:32 PM

I want to build a Raven also. Can't find anything for the Q-TEE. Is it in the SPAD plans?

#5 iggy809 Apr 07, 2013 12:40 PM

Want a Raven
 
I want to build a RQ11 Raven also. Looks a lot like the Blue Beagle in the scratch foamies section. I tried looking for the Q-tee and have not had any luck. Is the Q-tee a SPAD?

#6 aspeed Apr 09, 2013 07:42 AM

Airtronics made the QT. for an .049 I think. I found something here that may be the same. http://www.rcgroups.com/forums/showthread.php?t=1178815 post #11. not the Pong but under it. It isn't a pusher though.

#7 Extreme Sports Apr 09, 2013 10:22 AM

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Here are the Q-tee plans that I got off another RCGroups forum. I have shown very roughly (in red) how I changed the outline to turn it into a pusher configuration. Basically I used the proven dimensions of the Q-tee, but extended the nose to about 200mm (8") in front of the wing to get the CG right now that the motor was behind the wing.

Construction is very simple. The fuselage uses a 20mm x 20mm (approx 3/4") aluminium channel bent to follow the rough outline of the bottom of the Q-tee fuselage (side view) with some ply formers and 2mm correx added to make up the area below and foreward of the wings. A block of carved foam is used for the nose. I had two versions - on one the aluminimum was bent up to follow the exact profile of the fuselage (in other words the horizontal stabiliser ended up in exactly the same position as on the plan) while the other left the aluminium as a straight edge (in other words the horizontal stabiliser ended up lower than on the original). Either should work - the second is probably easier to build and would look more like the Raven in the picture. The only thing of importance is to keep the tailplane angle of incidence the same as on the original and the same distance from the wing. Note that the resulting fuselage is narrower than the original...but wide enough to accommodate 2 9g servos one behind the other. The aluminium is drilled out at regular intervals to reduce weight. The tail surfaces are 3mm foamboard, but could just as easily be 2mm correx with a skewer to add stiffness.

The wing follows the Q-tee more or less exactly but is just a single layer of 2mm correx with foamboard ribs. Power is a std 2812 2200KV parkjet motor with a 6x4 prop and a 1300mAh lipo. I also sometimes fly with the original balsa wing - this config gives an AUW just a few grams over the balsa version (<20oz). Some downthrust was needed, but was kept to a reasonable amount by having the thrust line run below the wing (not possible if you go up to a 7" prop...hence the use of a high KV motor)

I can post more photos if someone wants to try something similar. There are probably ways to improve the performance...and a larger, 3mm correx version might be a good idea...plus adding some polyhedral to look more Ravin like etc etc.

#8 chaleau Jul 28, 2013 09:41 PM

That is exactly the type of thing I'm hoping to build Extreme. I'm thinking of using some of that rectangular down pipe for fuse with rail tail boom. I'm inspired now.

#9 Extreme Sports Jul 30, 2013 12:40 PM

Did some googling on the Raven II and some quick calculations. My numbers suggest that if you build it to 100% size and primarily use 2mm correx and an aluminium channel (not sure how much down pipe weighs - I assume you are referring the pvc electrical conduit variety), you should come in at an AUW of between 850g and 950g (~28-30oz)...approx half the weight of the real one (1.9kg) Also, the predicted wing loading of about ~11.5oz/f^2 and a CWL of 7oz/ft^3, suggests it could be suitable for flying at the local park.

You could get the weight down a bit by using a single skin wing, CF instead of aluminium for the tail boom and a smaller Lipo (I assumed a 2200mAh)...which would turn the model into a floater capable of taking a payload.

What motor do you have in mind using?

I'd suggest designing from scratch so that you get a more exact replica - it's a simple enough design. Bear in mind though that getting the thrust angle right on a pusher of this configuration might take some persistence...


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