Originally Posted by Daemon

for
what possible purpose would you go out of your way to make it so complicated?

ian

In this, I must agree. I went with a 3-bladed folding prop for my Scimitar purely to gain some ground clearance while maintaining thrust (smaller diameter blade, same thrust). The X8 doesn't have this issue as it is commonly launched by hand or by machine. Only a handful of examples utilize landing gear and these are primarily flown off paved runways.

Originally Posted by jb_bak

I'm exploring the idea of sending my X8 up to around 30K feet with a 1300g weather balloon. If this goes well I might try higher. I have an APM2.5 that will autonomously fly back overhead and circle while coming down.

I need to strengthen the wings and elevons to handle the higher true airspeed anticipated. I was thinking of .73 oz fiberglass cloth on wings, and kevlar on the nose (I already have some, just finish off the upper part and cover the holes)

Can anyone shed light on ideas on getting the X8 up for the challenge? Maybe running an extra carbon fiber spar or two?

This is getting into UAV territory, which are usually purpose built and very strong, made from metal and composites. I'm not so sure a "foamie" would be able to handle this kind of use regardless of how well you strengthen it. Good luck in your efforts.

There are plenty of foamies that can (and have already) handle these airspeeds (fastest
DS foamies have gone over 250mph in much thicker air).
The X8 is just about the last plane I'd choose to do it however. I dunno why
the X8 inspires so many unrealistic dreams.

ian

Originally Posted by jb_bak

I'm exploring the idea of sending my X8 up to around 30K feet with a 1300g weather balloon. If this goes well I might try higher. I have an APM2.5 that will autonomously fly back overhead and circle while coming down.

I need to strengthen the wings and elevons to handle the higher true airspeed anticipated. I was thinking of .73 oz fiberglass cloth on wings, and kevlar on the nose (I already have some, just finish off the upper part and cover the holes)

Can anyone shed light on ideas on getting the X8 up for the challenge? Maybe running an extra carbon fiber spar or two?

I hope you live in the Antarctic too, because I'm sure some authority or other Is adding your post to a watch list.

Originally Posted by Daemon

X8 spin testing
http://www.youtube.com/watch?v=nh8PbcFY_Gg

ian

Thanks for the video Ian it was very fun too watch and your right on the money here. I'm both a full scale aerobatic pilot and rc nut and do spins in my RV-8 ( full size ) all the time.

The only real world experience I would like to add here to help are: if or when a spin is induced, the worse, and most probably, in full scale the last mistake you will ever make is to pull back on the stick whist in a spin ! It's a completely natural reaction to most pilots, it took me a good few goes of retraining my mind to do the opposite correction. Pulling back in a spin ( ie: up ) will only tighten the spin to the point of making it a flat spin....

In your very helpfull video, at around 6:50 you see the effects of a spin that is becoming flat as you loose any authority on one elivon ( the dead, flat side ) but as soon as a real deep stall is established, in most planes but especially in flying wings or canards ( long ez series ) it's all over red rover !! Hope this help - G

Another thing that comes to mind is.... With RG variants being highly appealing but as of yet, lack real world proven use, and understandably a lot of people are concerned about giving up a didget or two to an angry prop... I'm starting to thing of a dolly launch.

This seems so ideal and low cost and ticks every box I can think of:

The dolly would stay on the ground, weight would be less important ( it still needs to be as light as possible obviously ) but you could build it with much much larger wheels that would be practical to take aloft with you and the launch angle coud be very adjustable..

As soon as I get home ( I'm sitting on an island in Thailand as I write this ) I'm getting to work. Thoughts ? G

Originally Posted by jayb1rdz

I hope you live in the Antarctic too, because I'm sure some authority or other Is adding your post to a watch list.

http://diydrones.com/group/team-prometheus

Originally Posted by jb_bak

I'm exploring the idea of sending my X8 up to around 30K feet with a 1300g weather balloon. If this goes well I might try higher. I have an APM2.5 that will autonomously fly back overhead and circle while coming down.?

i would chose a simple depron plane like POLARIS
or EPO like easystar

speed mean nothing in near vacuum space LOL any toy will handle it...

balloon lift is limited so your buffy X8 will be hard to lift up 30k !

polaris will not stall and glide down easy with any flight controler

i can fly my 133%XL with 3s4000 and you may go up to 3s5000
without motor+ESC wich would give you approx
8 hours of up+ glide flying time

fpv-ing 2400meters to visit some rc buddyes at other field

X8 first long range test flight (4 min 11 sec)

hi,

can the x8 be recommended for a unexperienced fpv'er? i flew the skywalker fpv for about 1 hour untill i made a stupid mistake and crashed it(some misprogramming in tx) , looking for a replacement plane...

the x8 looks really nice

-kristof-

Originally Posted by krikkens

hi,

can the x8 be recommended for a unexperienced fpv'er? i flew the skywalker fpv for about 1 hour untill i made a stupid mistake and crashed it(some misprogramming in tx) , looking for a replacement plane...

the x8 looks really nice

-kristof-

It is easy to fly, but I would not recommend it as a beginners FPV.
I used the Bixler as my first FPV plane. It is great. I still enjoy flying it, but now I have cut off the wingtips to make it quicker on the roll.

Originally Posted by G-Forced

Another thing that comes to mind is.... With RG variants being highly appealing but as of yet, lack real world proven use, and understandably a lot of people are concerned about giving up a didget or two to an angry prop... I'm starting to thing of a dolly launch.

This seems so ideal and low cost and ticks every box I can think of:

The dolly would stay on the ground, weight would be less important ( it still needs to be as light as possible obviously ) but you could build it with much much larger wheels that would be practical to take aloft with you and the launch angle coud be very adjustable..

As soon as I get home ( I'm sitting on an island in Thailand as I write this ) I'm getting to work. Thoughts ? G

You're not the only one... I posted a NASA video where they use this method for a UAV not dissimilar to the X8. It's on this thread somewhere...

Originally Posted by jb_bak

I'm exploring the idea of sending my X8 up to around 30K feet with a 1300g weather balloon. If this goes well I might try higher. I have an APM2.5 that will autonomously fly back overhead and circle while coming down.

I need to strengthen the wings and elevons to handle the higher true airspeed anticipated. I was thinking of .73 oz fiberglass cloth on wings, and kevlar on the nose (I already have some, just finish off the upper part and cover the holes)

Can anyone shed light on ideas on getting the X8 up for the challenge? Maybe running an extra carbon fiber spar or two?

Stiffen it up a bit with CF tow, on a 45 deg diagonal, about 3 inches apart on the upper and lower wing surface. FG tow will also be fine, with less RF issues. Easier is to use fiberglass filament packing tape. Quick, no mess and done in 10 minutes. Don't forget to do the winglets and control surfaces. You don't need to do the whole thing, just a 1-inch strip every 3 inches. Heck, plain old clear packaging tape should be stiff enough by itself. Don't waste your time with kevlar and epoxy since you'll probably loose the plane anyway.

Keep it a bit nose heavy and trim it to a slow speed cruise. You want the plane to be stable in pitch and have it quickly establish that slow speed cruise on it's own (yeah, like someone said, there are better planes for such a purpose).

If it's trimmed to less than 35 kts, your TAS should be less than 60 KTAS at 30,000 ft. (about M 0.1 if you're interested). Make sure the stiffness you added will allow 80 knot dives without wing or control surface flutter during your test flights. Without a motor and ESC, you should be pretty light.

Instead of full span elevons, you might want to use just the inboard half. Glue or tape the outboard half so it doesn't move. You don't need all that control surface for FPV anyway unless you do FPV akro.

Re-grease all your servo gears with low temp grease. Better yet, simply just remove all the grease. Don't want the grease to freeze up and jam the servos. Run an extra battery in parallel to make sure the cold soaked batteries have enough juice. Plug up all the holes to keep the cold air flow inside to a minimum, but don't make it airtight.

Pay attention to winds aloft forecasts. 100+ knots of wind is pretty common. Plan on losing the plane. If you get it that high, odds are that you'll lose it unless it's a rare day of winds being under 20 kts all the way down. Still, there are many other things that can go wrong. Install a free-flight tracker so that you have a change of chasing it downwind and finding it. Name, phone number and address with "reward" on the plane increase the odds of getting it back.

Find the nearest rocket club. They have places and times that allow for high altitude stuff and the airspace issues it causes. Stay within the legalities. The rocketeers have the scoop on going high and staying legal.

That's all I can think of for now. Remember, it's a "foamie". Don't over engineer it and don't worry about breaking it. You can always get another one. Just make sure it doesn't end up in the engines of my B-777

Ben Clerx

Pardon my spelling. Loose =lose.

Originally Posted by hans66

You're not the only one... I posted a NASA video where they use this method for a UAV not dissimilar to the X8. It's on this thread somewhere...

You can learn to throw it in far less time than it will take to build a dolly. Find a nice grass field and throw it a few times without starting the motor, and land it straight ahead in the grass. When you get good at that (5 throws), start the motor after you throw it. When that goes well. Start the motor before you throw (you don't need full power, half is fine. Throttle up after launch). By this time, you might just stick with starting the motor after you throw it.

Building dollies and landing gear robs you of the required learning of how to throw a plane. Having the belly scrapped from hundreds of successful landings is a badge of honor.

Ben Clerx

Originally Posted by Ben Clerx

don't worry about breaking it. You can always get another one.

But that 5 lbs of plastic explosives is really hard to replace. Careful, homeland security is watching.