Has anyone had issues with the trailing edge of the 750 SD rudder developing a duck tail?  See picture.

IF so how did you correct? if not, what am I doing wrong.  I have clecoed almost ever way know.



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It looks like the bend isn't exactly in the right spot, not necessarily that your doing something wrong, from what I can see. 

That being said, not sure anyone would notice and it would fly fine, but I understand what your saying. 

Thanks for jumping in..This is my second rudder and its doing the same thing as the first, I just didn't catch it the first time around.  The bottom two ribs are the ones causing this lift.  Its about 1/16th off or have the rivet hole size.

It bugs me

I was under the impression that being matched drilled it should all line up..Am I wrong?

Nothing is perfect...I doubt that small twist will make any difference but if it bugs you enough you could request the two offending ribs from Roger, undrilled.  Had to do that on the elevator of my Cruzer, but that was off end to end by 10MM.

Great point. Thankyou. I just can’t believe it’s done this on both my rudders with match drilling. 

Hi Steve -

My Cruzer Rudder did the same thing.  It bugged me too but I moved on.  It doesn't even move the needle anymore and I have no plans to change it.  As you continue through your build, you will encounter other situations similar to this.   I believe what Zenith does is they cut/drill flat sheets, then bend the parts.  If this is true (I think it is), then hole matching on finished parts requires precision hole placement and precision bends too.  In general, parts fit amazingly well, but there are times when Zenith seems to "over do" the pre-drilled holes, and they don't leave the builders with any freedom to align parts and THEN truly match drill the holes.

I had the same issue with my elevator that Don did (and a few others).  Could not overcome twist using the factory holes and ordered undrilled end ribs, got the assembly flat, and THEN drilled the end ribs into place.  Worked fine.

Long journey ahead.  Best wishes and have fun.


Perfect Thankyou for the explanation. I thought I was doing something wrong.  I really appreciate the feedback. 

When encountering something this minor, you step back, close your eyes, and chant, "it's not a F-16, it's not a F-16 ..."  ;>)

Seriously, since it's the trailing edge of a rudder, it'll never be noticed either visually or as a control issue - we make minute rudder corrections almost constantly as we fly.

I once flew someone's 750 that had a TE/flaperon gap on one wing that was uneven and easily 10mm greater on one end vs the other - the plane flew straight and level hand's off!  Go figure!

Now get back to building!  :>)



Lol. Thank you it really helps and yes I lean toward the perfection side and FYI the 750 is better then a F16.  

Eagle Driver. 


Lol. Thank you it really helps and yes I lean toward the perfection side and FYI the 750 is better then a F16.  

Eagle Driver.

Ain't that the truth! :>) 

True story: Years ago, I was displaying an ASW-20 glider at an airshow at Millington Naval Air Station.  A guy walks up and is very interested and excited about the glider - peppering me with questions such as, "What does this do? How does that work?"  As I explained the controls, etc., he kept saying, "This is great!", "I'd love to do this!" and similar positive comments.  Noticing he was wearing a flight suit, I finally said, "Well, you're obviously a pilot, what do you fly?"

He said, "Oh, I just fly the F-18 in the airshow!"

The grass always is greener on the other side!  ;>)


Your question was a good one. Many builders, when starting out, think that because it is an airplane, everything must be perfect. This is perfectly normal. As you gain experience you will get better and better at judging how close to perfect is necessary in each situation.

Another bane of inexperienced builders is fear of making a mistake. Eventually they will come to learn that any mistake can be corrected, and that many mistakes are easily corrected. An inexperienced builder might be deathly afraid of riveting something before he should. By the time he's done, he will be expert at removing rivets and will chuckle when he thinks back on how removing rivets used to seem like a big deal. Yes, I speak from experience.

All great points and I thank you all..


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