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Lack of flight from flying wing (Sledge)

Old 07-20-2008, 12:07 AM
  #1  
jhoyda
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Default Lack of flight from flying wing (Sledge)

I just tried to maiden my Ohio Combat Sledge, the results were less than satisfactory. I couldn't find the instruction CD that came with it, so I guessed on the control throws and CG. Pretty sure I was wrong, can someone give me this information?

Also, how on earth do you launch these things? I can throw my Zagi a mile before I have to power up, I couldn't even get the Sledge in the air unless it was under full power. I'm frustrated, I'm going to go hammer some laps on the MX bike, atleast I can get that to FLY!
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Old 07-20-2008, 03:55 AM
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woolebugr
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You should email Jeremy at Ohio Combat and ask him about the cg. CG on flying wings is VERY important and I'm sure that is probably what the problem is. PM me for his email address or pm Laine (lmopar69) for his phone number (I lost it).
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Old 07-20-2008, 04:28 AM
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Buzz_Man
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Yeah, if the c/g is right wings generally glide surprisingly well when tossed.
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Old 07-20-2008, 12:00 PM
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Thanks, I will try and get a hold of Jeremy. I have his e-mail somewhere.
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Old 07-25-2008, 12:29 AM
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Whathappened
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I believe the CG is recommended at 9 inches to 9 3/8.
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Old 07-25-2008, 02:26 AM
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lmopar69
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CG should be 9 1/4 from the nose. Control throws should be set roughly 1/4"-3/8" up and 1/4"=3/8" down. more later... gotta run.
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Old 07-25-2008, 06:31 AM
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Ok, sorry, had to run, my house was flooding... grrrr.... my mid-tour R&R has not been too relaxing yet! Oh well, one pipe, one valve, a couple fittings, a 70 mile trip to town, and 2 hours of work later I can elaborate more for you.

The aircraft center on the Sledge is 9.5" from the nose, the CG is 9"-9.25" from the nose. You can push it just a smidge back from 9.25" but if you go past 9.5" it just wont work. So, I typically set mine up at 9" for the first couple shakedown flights. Then gradually move it back a smidge at a time till you find the sweet spot.

The thrust angle will also have to be set just right so it does not climb or dive power on vs power off. That just takes a little trial and error once you have the CG spot on.

Sounds like a bit of work, but trust me, once you have it all set perfectly, you will be rewarded with one of the best flying wings you have owned! Nothing flys like a Sledge.

Bye the way, what power system you have on yours? Do you have any pictures handy?

Laine.
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Old 07-27-2008, 02:46 PM
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jhoyda
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Thanks for the info! My CG was just past 9.5" so know wonder it flew like absolute junk.

I am running 4S on a 4W with a 5.5 x 4.5, I have some 6 x 4 laying around too. I don't have any pics, nor do I want to take any as the wheat stubble ruined the nose on the first maidens.

Looks like I have to get some lead, I moved the batteries fully forward and was unable to get the CG where it was supposed to be.

So future plans include: repairing the nose, adding lead and recovering. Lucky me!

Thanks for the help everyone.
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Old 07-28-2008, 05:02 PM
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lmopar69
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No problem. Glad to help. I ran my first Sledge on that same power system. 120ish mph is where you should end up. The 5.5x4.5 prop is the faster of the two by far.
Well, its a noticable difference anyway. In fact my original Sledge (General Lee scheme) is still flying down south with a buddy of mine. After seeing it, he had to have it.

Laine.
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Old 07-28-2008, 05:15 PM
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jhoyda
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120's?? Yikes!

I was hoping for around 100, looks like she will be a handful!

What should the AUW be? This thing is alot heavier than the Zagi, but I assume that is expected since you need higher wing loading to go fast.

One more thing, what is the preferred method of launch? I couldn't seem to get any traction on the Monokote when I tried to chuck it the first few times.
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Old 07-28-2008, 07:32 PM
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Whathappened
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Here's what Jeremy said about my set up, which is practically the same as yours.
"Depending on the extent of the glassing method, the AUW could be as low as 35oz and as much as 42oz.
My builds using the whole process weights about 30oz covered with servos and close to 60oz. Thats with 23oz of batts though.
-Jeremy "

Last edited by Whathappened; 07-28-2008 at 08:32 PM.
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Old 07-28-2008, 11:53 PM
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I have what some people call a wierd way of launching. Its not very comfortable, but it has always worked for me. Im right handed, so I grab the leading edge near the nose (usually just right of the nose on the wing) with my thumb on the bottom of the plane. Then I kinda "stiff arm" shoulder throw it with forward with just a touch of up angle. There are a few videos on my you tube that show it (user name Lmopar69 on there too). The videos are mostly of my orange "General Lee" Sledge so, you can kill two birds with one stone if you wanna see mine flyin.

As far as the weight goes. Its not so much that you "need" weight. The thing is, the batteries that can handle the power system are heavy and making the wing strong enough to handle the speed and G forces really adds to the weight.

Although, I like the way a heavy-ish plane flies. They just seem to fly smoother and cut through the air better than light ones. Granted, I always have a ton of power on tap too. That always helps.

Laine.
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Old 07-29-2008, 12:50 PM
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Well, I started to delve into the problem last night and found out how much damage had actually occurred.

When the nose hit the ground after several failed attempts the EPP gave and the screen/poly glue didn't. So, the nose was all cracked and had seperated from the foam substrate. So, I cut the nose all apart and will have to reapply spackle, glue and screen to the nose, add weight and recover the whole nose.

Put it this way, I was not the happiest person yesterday. Looking like this plane won't be flying anytime soon, I have too much other fun stuff to be doing when the weather is nice. Oh well, I might get an urge to finish it, but for now it's going to sit.
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Old 07-29-2008, 02:14 PM
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Use Plumbers "GOOP" to make your repairs. It sticks like stink to EPP and adds some weight where you need it. I also use sharpened wooden skewers coated with Loctite Sumo glue as reinforcing rods when making repairs. Planes take even more abuse after repairs without damage!!

It is good to use 3M reinforced fiber tape along the leading edge under the screen covering.
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Old 07-29-2008, 03:43 PM
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Sticks well and is heavy!? I might have to go to the hardware store after work, perhaps this plane may fly this summer.

I think part of my problem stems from the fact I am only using 2200 mAh batteries. They don't weigh nearly as much as the 3200's. I can't bring myself to shell out any more dough until I get the thing in the air!
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Old 07-29-2008, 03:55 PM
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Put it this way, I was not the happiest person yesterday. Looking like this plane won't be flying anytime soon, I have too much other fun stuff to be doing when the weather is nice. Oh well, I might get an urge to finish it, but for now it's going to sit.
Don't give up - the best things in life are the things you work the hardest to achieve. Eventually, you'll probably have a great flying machine, one that will provide many hours of enjoyment. It's often good to take a break and then return with a fresh outlook.

There's no luck involved - good flyin'!
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Old 08-02-2008, 02:21 PM
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Here's a video of how I launch my Sledge, its also a build vid so just skip towards the end of the video to see the launch and flight.




Hodakaguy
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Old 08-03-2008, 10:28 PM
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that is cool , great video!
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Old 08-04-2008, 05:15 AM
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lmopar69
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Hey Hodakaguy, hows your Sledge doin these days anyway? I still have not built my new one since I sold my first. I'll get to it when I get back from Afghanistan Im sure. I have been flyin my Battle Axe a little while Im home on R&R leave though. LOVE these things.

Laine.
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Old 06-08-2009, 02:51 PM
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jhoyda
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It flew, it flew!

Now that I have a viable airframe, I have some questions. CG was right at 9 inches. I chucked it, power-off, then powered up, and it flew away, then got on the step and absolutely zoomed away.

It seemed a little slow on the controls, which brings me to my first question: by moving the CG back to 9-1/4" will the wing become more responsive? I had positive control, but had to move the sticks more than I am used to.

Addition of power caused a down-pitching moment, I assume that means I need to shim the rear of the motor upward, correct?

Stalls resulted in one wing falling off rather abruptly, recovery took about 50 feet and usually included a course reversal, normal?

All I can say is wow! This thing goes, I had three go-arounds because this airframe will not bleed off speed I am happy, and wish I had gotten it flying sooner!
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Old 06-11-2009, 11:49 PM
  #21  
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Moving the CG to 9.25 will make it more responsive for sure.

IMO, the first step would be to move the CG to 9.25, see how it flies. Since the nose is pitching down with power on, most likely the thrust angle is off just a bit. If it is still pitching down after you adjust the CG (and I would bet it does), raise the prop end of the motor just a bit and try again. Continue to move the prop end of the motor up until it flys strait and level with power on or off.

As for the stall causing it to fall off to one side or another, check your lateral balance. Hold the plane with two fingers. One on the nose, and one on the motor shaft. If one side falls down, add a bit of weight until it balances out.

Once you have done those things, I would bet it will fly like a dream... a very fast dream that glides forever and ever, but still a dream!

Glad you got it in the air. Im building a new one right now too.

Laine.
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Old 06-12-2009, 12:18 PM
  #22  
jhoyda
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I moved the CG back to 9.25" last night, bad idea. It flew awful, not as bad as last summer, but a lot worse then when it was at 9". I also need to shave the ailerons because I do not have near enough down travel. That is my goal for tonight.

Also, what about a 6 x 4 prop. I broke my only 5.5 x 4.5 last night and new ones won't be here until Wednesday.
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Old 06-17-2009, 06:09 AM
  #23  
lmopar69
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Well, keep it up there at 9" from the nose then! Sounds like thats its "happy spot"

As for the prop, a 6x4 will work fine, more thrust, a bit less speed is all. 6x4 is a good screwin around prop for it. 5.5x4.5 is a great speed prop for it.

Laine.
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Old 07-09-2009, 05:16 AM
  #24  
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The Cg for the Sledge is about 9in for 25% and 9 3/8 max for 27%.
9.5 is the AC as Laine stated and about 30% mac. I don't expect to many wings to fly at all that far aft.
When you push it back to 9.25 or 9 3/8 back you have to make sure the thrust angle is set properly.

Dialing this wing in does require a small amount of down thrust due to the motor being slightly higher than the thrust line.This does not affect the performance as far as I can tell. The max throws at 9/38 back should be about 1/8 up and 1/8 down on elevator. To put it one way is that this is as close as a pylon plane you can get without actually buying one.The throws may seem small but it will pull 90 from level and turn on a dime.

I generally get mine in the air and if the Cg is between 9.25 or 9.375 back you should be able to trim the wing to the point that there is no neutral position using your trims.
THIS IS A GOOD THING. Make sure once this point is achieved return the trim so that it climbs with one click of up. Land and add down thrust.

We will have OHC back up and running at full capacity within a month or so. Foam being our biggest issue due to a lose of a local supplier,I now have one.I will be putting up what inventory I do have here within a week or so and will include the same hardware as well as the low prices we offered in the past.
Jeremy
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Old 07-09-2009, 06:33 AM
  #25  
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Sounds good Jeremy!

Shamless plug for Ohio Combat aircraft:

www.FastFlyingWings.com
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