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First SPAD, total failure

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S.P.A.D. Aircraft - Coroplast design Discuss the growing area of S.P.A.D.S. (Simple Plastic Airplane Designs). Coroplast type aircraft, pizza box planes, etc..

First SPAD, total failure

Old 05-18-2004, 09:20 PM
  #26  
ChrisSpad
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Default RE: First SPAD, total failure

your tail heavy, and your ailerons need to be reflexed up. Add a heavy hub to it, and reflex the ailerons up 1/8" above parallel to the fuse. If you haven't already, taper the last 5" of the ailerons from full width to nothing at the tips.
Old 05-19-2004, 07:12 AM
  #27  
xjavro85
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Default RE: First SPAD, total failure

I doubt very much that a tail heavy condition would cause all these problems, I have flown balsa models for many years and prefer my models slightly tail heavy. This just seems likes that whole plane flexes under high speed conditions. I may say the heck with spads if this is the kind of performance I can expect. I am hoping this is just a problem witht he demon as someone stated earlier. Anyone have a suggestion for another spad. I like them aerobatic but I do not like profile type aircraft so the spa3d does not appeal to me. The spazzler looks nice but not sure if it will suit me. Anyone have any ideas? Thanks
Old 05-19-2004, 07:55 AM
  #28  
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Default RE: First SPAD, total failure

No, that is not typical performance. My SPADs will move along very fast. I did exeperience flutter pretty bad, even on the elevator until I trimmed the tips back and an angle, then no problems at all. When I first switched to low wing SPADs with the wing saddle cut out I was having a heck of a time trimming the plane. It would balloon on landings, be OK at one speed, and totally suck at another. It all ended up being that I cut the saddle with about 5 degrees of positive incidence. I shimmed about 1/4 inch of rolled up tape on the leading edge and I had one sweet flying plane. I thought I had built it square, but I was in such a rush to get it done, I obviously didn't.

My advice is to look at my webpage:
[link=http://quicker.rchomepage.com/plans.html]http://quicker.rchomepage.com/plans.html[/link]
and look at how I made the low wing SpadStick. It has a bigger wing and longer tail than the deamon. Make it about a 48 inch span and a good 40 would be nice (heck, a 40LA will fly it) and a hot 46 would be killer. If you hava 60 laying around, then make it a 55 inch span. I loved mine with a MDS 68 on it.

If you don't want to customize like this yet, then make the stock SpadStick. It's a GREAT plane.
Old 05-19-2004, 07:33 PM
  #29  
ChrisSpad
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Default RE: First SPAD, total failure

sigh. ya build a couple hundred spads, several demons among them, you'd think i might have an idea of what they do when they're tail heavy with the ailerons drooping.
Old 05-19-2004, 08:40 PM
  #30  
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Default RE: First SPAD, total failure

Yeah, chrispad is one of the original dudes. He is a walking SPAD reference book. Listen to him. But if you don't...the SpadStick is my favorite
Old 05-20-2004, 11:16 AM
  #31  
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Default RE: First SPAD, total failure

Hello ChrisSpad,
I built my first spad, spa3d, and have flown it several times. Followed the spadtothebone plans except for this: 32" span, 32" length, OS40LA. Can you tell me what would cause it to alway want to climb? My ailerons are set up from level with the fuse about 1/4 inch. The CG is at the forward stiffening rod. I have considerable down elevator trim and it still likes to go up![:@] Do you have any suggestions? Anything is greatly appreciated!
Old 05-20-2004, 11:23 AM
  #32  
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Default RE: First SPAD, total failure

I am building the same spad3d with 32" by 32" as well and will be using os.40 la. Does it have enough power to hower?

Thank you
Old 05-20-2004, 11:39 AM
  #33  
StallN
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Default RE: First SPAD, total failure

Yes it will hover when I can make it. I'm not very good at it. Mine takes about 3/4 throttle to hover. I have tried MAS 10x6, 11x5 and another brand (can't remember) 12x4. Not much difference.
Old 05-20-2004, 12:13 PM
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Kripto
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Default RE: First SPAD, total failure

ROLF.... His first SPAD and he is questioning Chris's advice! If Chris, Tatoo, Kraut and a lot of other spadders give you advice or suggest trying something then you should do it!!!

Ed
Old 05-20-2004, 05:54 PM
  #35  
ChrisSpad
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Default RE: First SPAD, total failure

ORIGINAL: StallN

Hello ChrisSpad,
I built my first spad, spa3d, and have flown it several times. Followed the spadtothebone plans except for this: 32" span, 32" length, OS40LA. Can you tell me what would cause it to alway want to climb? My ailerons are set up from level with the fuse about 1/4 inch. The CG is at the forward stiffening rod. I have considerable down elevator trim and it still likes to go up![:@] Do you have any suggestions? Anything is greatly appreciated!
1/4" might be a bit much, but, the problem could be one of several things. A spa3d doesn't fly like a conventional airplane. It likes being flown nose high, and very slow. If your spending alot of time trying to trim it out for level flight, your missing the whole point of a spa3d.
Here's a video of me flying my 3dt.
http://users3.ev1.net/%7Ecdjump/main...a3dthphigh.WMV
http://users3.ev1.net/%7Ecdjump/main...pa3dthpmed.WMV
Old 05-21-2004, 12:17 AM
  #36  
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Default RE: First SPAD, total failure

ORIGINAL: ChrisSpad
Here's a video of me flying my 3dt.
Nice, Chris! Real Nice!!!
Old 05-21-2004, 09:50 AM
  #37  
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Default RE: First SPAD, total failure

Yes!! Great video! Thanks for the reply, you're absolutly right, I am not flying my spa3d like you do. That will change the next flight!! I will trim the ailerons down a bit and just 3d!![>:] If I crash, so what?? That is what SPAD is for!![8D] No flying around like a boring trainer. I think my spad is a little heavy for the 40LA. I think around 3.5 lbs & needing 3/4 to full throttle to hover. I'll try to lighten it some this weekend. Do you have a suggested prop size? Thanks again!!!!
Old 05-21-2004, 10:11 AM
  #38  
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Default RE: First SPAD, total failure

I like the APC 11x4 or APC 11.5x4. For the 40LA, the APC might be a little heavy for it to spin up fast, so you might try a Zinger 11x4.
Old 05-21-2004, 02:51 PM
  #39  
xjavro85
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Default RE: First SPAD, total failure

I wasn't questioning the advice of the resident "spad god". I have already played with the ailerons and they are far from drooping. I simply said that the problem is more complex then just being tail heavy. After over 10 years of flying models you get a feel for an out of balance model. Anyways, yes Chris I have already tried moving the ailerons up and the CG around with no luck, all the CG shifting did was increase the landing speed when it was forward as I suspected. I think its just the coroplast I used may be a bit flexible. I am considering making a balsa tail set to see if that will help which I think it will. I also need to play with the side thrust.
Old 05-21-2004, 03:51 PM
  #40  
ChrisSpad
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Default RE: First SPAD, total failure

The tri faceted airfoil is very peculiar. it has a defenite point that with the cg behind it, it does odd things. Depending on how the wing is built, its normally right at the trailing edge of the front spar. Sometimes, it can vary forward as much as 1/4". Unlike most smooth airfoils, its not a gradual transition from flying ok to a little tail heavy. it goes from great to crap in 1/8". If the ailerons are positioned level with the fuse at the root, often times due to the flight loads on the wing, they'll droop towards the tips in flight. If you've ever had a spad for awhile, you'll find that as time goes by the ailerons will develop this curve on their own, and to keep it flying properly, you'll keep raising the ailerons.

Now, the other possibility that i overlooked is downthrust. The plans call for 5 degrees, which is an awful lot. If you've got the full 5 degrees downthrust, it may very well be making the plane tuck. try remounting the firewall, or engine mount with no more than 2 or 3 degrees.

If none of that helps, its possible your getting flutter. Due to coro being flexible, sometimes its not really audible over the engine, but the plane does weird things at high speeds. Usually, some bamboo skewers in the offending surface along with some polyurethane glue will fix the problem.

When they're set up right, they don't fly any different than any other sport plane. However, the setup isn't quite like you would set a balsa plane up, due to the odd airfoil.
Old 05-21-2004, 04:37 PM
  #41  
xjavro85
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Default RE: First SPAD, total failure

5 degrees? The plans I got from spadtothebone.org says 0 thrust down or right...Right now I have it at 0 degrees, I think I may play with the thrust a bit more, I am also thinking of stiffening up the ailerons using strapping tape under tension. The technique works very well when converting a 5 foot foam glider to R/C. Anyways, thank you for the advise, I will go out this weekend and mess around with diferrent cg's and engine thrust some more.
Old 05-21-2004, 07:37 PM
  #42  
ChrisSpad
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Default RE: First SPAD, total failure

the old plans showed 5 degrees of downthrust. I think when Minnesnowta Jim made the new version, they updated them. Or maybe Frank's done it recently, i don't know. At any rate, 0 degrees is fine, and what most people prefer. I usually run a couple degress of downthrust on flat bottomed wings, but reflexing the ailerons generally does the same thing as adding downthrust to the engine.

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