I thought it was time I built something conventional to prove to the angry mob that I don't need logarithmic controls on a canard twin to fly a decent pattern.  Chuck Lee gave me a solid (I thought) wing around 700 squares and a nice thick airfoil.  The tail feathers from Endgame III (the first canard) needed a home.  So I grabbed some balsa and the plans from Endgame II and here is the result.  It is inline and the controls exit the bottom of the wing.
The BA 3520-790, Spin 66 ESC and Fiorotti timer all were unemployed survivors of Endgame III.  Even the wheels had a prior home.  I was challenged to build something light and simple, so I set a target weight of 65 ounces.  Stripped all of the old finish and started chucking everything I didn't need.  Replaced solid flaps with built up carved away everything that I could.  Net gain on the wing and stab - 4oz. 

It wasn't until I mated the wing to the fuselage that I discovered a major flaw in the wing.  The LE sheeting out to about 2" had been over sanded and had cross grain cracks that did not show until you put pressure on them.  I replaced all of that wood and added some bracing, but the reality was that it was going to fold someday.  I was going to put a contest finish on it but opted for China coat instead.  So, it joins the ranks of the lighter "10' finish".

All up the plane tops out at 53oz (33 w/o the power train and battery).  The trim will be a flaming LE on the wing and stab ala Jerry Pilgrim.  Very simple and it's name is "Spare Parts".

Ken

Quote from: Ken Culbertson on August 19, 2026, 06:50:07 PMI thought it was time I built something conventional to prove to the angry mob that I don't need logarithmic controls on a canard twin to fly a decent pattern.  Chuck Lee gave me a solid (I thought) wing around 700 squares and a nice thick airfoil.  The tail feathers from Endgame III (the first canard) needed a home.  So I grabbed some balsa and the plans from Endgame II and here is the result.  It is inline and the controls exit the bottom of the wing.
The BA 3520-790, Spin 66 ESC and Fiorotti timer all were unemployed survivors of Endgame III.  Even the wheels had a prior home.  I was challenged to build something light and simple, so I set a target weight of 65 ounces.  Stripped all of the old finish and started chucking everything I didn't need.  Replaced solid flaps with built up carved away everything that I could.  Net gain on the wing and stab - 4oz. 

It wasn't until I mated the wing to the fuselage that I discovered a major flaw in the wing.  The LE sheeting out to about 2" had been over sanded and had cross grain cracks that did not show until you put pressure on them.  I replaced all of that wood and added some bracing, but the reality was that it was going to fold someday.  I was going to put a contest finish on it but opted for China coat instead.  So, it joins the ranks of the lighter "10' finish".

All up the plane tops out at 53oz (33 w/o the power train and battery).  The trim will be a flaming LE on the wing and stab ala Jerry Pilgrim.  Very simple and it's name is "Spare Parts".

Ken

The way it goes with planes like that?  Probably be the best flying airplane you've ever had.  Then you'll wish you had a finish on it.  But then, would it still be the best flying airplane?

Dave

Models don't fly right until they are so beat up that the earth doesn't want them anymore

Maden flight Friday.  Complete success.  Needed tail weight and a bit fast at 4.8. An 1/2 ounce to dreaded tail weight got it to Saturday and after a second 1 min hop at 5.2 I went for two min and gave the acid test - triangles outside squares and an hourglass. Still in one piece!  Opened up the handle and went slowed it down a bit more to 5.4 for it's first pattern.  Success!  It doesn't hunt, and it tracks rounds as well as my twin, maybe better.  I am already regretting the MonoKote finish. I was surprised that the 650sq" wing and small flaps cornered as well as it did.

 

My buddy Mike did just the opposite. He put a GeeBee wing in a SV profile.
He named it SV-GB.
Said it flys great.

53 oz all-up weight is incredibly light for an electric powered airplane.  That's why you don't need much flap to corner well - low wing loading!

You will get an earful from Crist Rigotti, however, about placement of that canopy.  Mine are typically situated over the flaps, and that is still not forward enough for him..

Quote from: Mike Alimov on September 23, 2026, 11:31:47 AM53 oz all-up weight is incredibly light for an electric powered airplane.  That's why you don't need much flap to corner well - low wing loading!

You will get an earful from Crist Rigotti, however, about placement of that canopy.  Mine are typically situated over the flaps, and that is still not forward enough for him..

  Crist got an earful from me for putting his canopy so far forward!  Got about 20 flights on it now and I am still amazed how little battery it uses. Last 2 patterns in calm air 1500mah used.    I was concerned about a weak center section in the wing Chuck Lee gave me before he died.  I have been flying AMA corners, but it has shown no reluctance to go F2B. So, I tried a few on the last flight and much to my surprise it didn't fold the wing but instead did a crisp F2B type corner and locked like it knew how.  I also figured out how to take off!

I flew Crist's latest Agenda, and I am going to build one.  So easy to fly.  Life is good...

Ken

Quote from: Ken Culbertson on September 23, 2026, 12:32:35 PMI have been flying AMA corners, but it has shown no reluctance to go F2B.

Ken

What is the difference between "AMA corners" you "have been flying" and what an "F2B" corner would be?

Keith 

In my case it is about 3'

Ken

Quote from: Ken Culbertson on September 23, 2026, 05:31:30 PMIn my case it is about 3'

Ken

Radius or altitude? There should be zero difference. Steve

Quote from: Steve Helmick on September 28, 2026, 03:06:09 PMRadius or altitude? There should be zero difference. Steve

F2B has a corner range of 1.5 to 2.1 meters somewhere in their judging guide.  If you ask AI that is what it says as well.  That means a 90 degree change in two plane lengths going 55 mph. 2.1 meters is less than 7'.  Yes, there should be zero difference, but in reality, when a sq8 counts the same as level flight in AMA and double that or more in F2B the emphasis is different.

Ken 

Quote from: Ken Culbertson on September 28, 2026, 05:24:35 PMF2B has a corner range of 1.5 to 2.1 meters somewhere in their judging guide.  If you ask AI that is what it says as well.  That means a 90 degree change in two plane lengths going 55 mph. 2.1 meters is less than 7'.  Yes, there should be zero difference, but in reality, when a sq8 counts the same as level flight in AMA and double that or more in F2B the emphasis is different.

Ken 

Yes the emphasis is very different and AMA rules eliminated the "five foot" rule or any specification some time ago.  However It still calls for "of sharp radius" so I wouldn't try to fly or describe them any differently.  Good your ship turned out well.  Sometimes just simpler is better.  You may be more inclined to fly it more and improve your flying because of it.

Dave

Quote from: Dave_Trible on September 29, 2026, 06:03:58 AMYes the emphasis is very different and AMA rules eliminated the "five foot" rule or any specification some time ago.  However It still calls for "of sharp radius" so I wouldn't try to fly or describe them any differently.  Good your ship turned out well.  Sometimes just simpler is better.  You may be more inclined to fly it more and improve your flying because of it.

Dave

True Dat!  My comparison was more aimed at scoring rather than what should be.  I don't see corners under 10' in most AMA patterns.  Most are larger but my base for now is local and watching video. I slow motion and measure a lot.  In F2B they are approaching 8' (about 2 plane lengths).  It takes a totally different trim to achieve that corner, and you are giving up tracking to get that radius.   I am regretting using that comparison because it has taken the thread away from the main point that the plane has IMHO a weak center section and I didn't what to fold the wing.

Ken

Quote from: Ken Culbertson on September 29, 2026, 07:12:31 AMTrue Dat!  My comparison was more aimed at scoring rather than what should be.  I don't see corners under 10' in most AMA patterns.  Most are larger but my base for now is local and watching video. I slow motion and measure a lot.  In F2B they are approaching 8' (about 2 plane lengths).  It takes a totally different trim to achieve that corner, and you are giving up tracking to get that radius.   I am regretting using that comparison because it has taken the thread away from the main point that the plane has IMHO a weak center section and I didn't what to fold the wing.

Ken

Yeah 1/16" shear webs woulda gone a long way and not cost much weight. The primary failure mode of that kind of structure is buckling and shear webs stop the buckling. Or at least limit it.

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