N601LL is 100 hours now and only remaining item was needing some up elevator trim for level flight and not enough up trim for a proper flaps down engine out glide.  The incidence of both wing and stab were good but as it does take quite some force to lift the elevator I decided to try a simple fix.  I put an eye hook on stab, drilled a hole in elevator horn and installed s-hook there.  Then connecting the two using #64 rubber bands discovered that seven was a good balance. 

I have not test flown due to weather here but hope to tomorrow and will update the post.  Note elevator approximately centered and the trim is what was needed for level flight.

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Comment by Joe Hopwood on July 21, 2020 at 2:01pm

I have not heard of elevator flutter with the Zenith planes.  Think that may be on ailerons only when cables are too loose.  I did not use cables for ailerons.  Chose to go with push rods.  I am very happy with plane @ 112 hours in 22 months.  Have had a few issues with Jabiru.  I used the connectors for alternator that came on engine and I guess there was a high resistance crimp as it overheated and melted the wire which caused a dead short and burnt out the alternator.  Both connector pipes to muffler cracked.  One all the way through.  I have rewelded and will keep a good check on them.  And oil pressure sender failed.  Before I even flew the started solenoid failed.  I am not impressed with Jabiru quality.  That being said the engine itself is perform well so far.

Comment by Larry Zepp on July 21, 2020 at 11:13am

Hi Joe,

Simple and elegant solution to heavy elevator. I like the mounting by the elevator horn and the adjustability of the rubber bands. The rubber gives it some damping against possible elevator flutter- or am I over thinking this?

Getting my Viking 110 engine close to first run in my Zodiac 650B. Larry Zepp, Fort Wayne, IN

Comment by James Machin on July 13, 2020 at 8:02pm

Hi Joe,

Borrowed your rubber band idea for my 601XL and installed this weekend.  Worked like a charm but I am probably where you were after your first test flight - huge improvement but not quite hands off with full flaps.  I originally did the spring on the stick thing but wasn't happy with all the load it put on that front thrust bearing on the stick assembly - 40 lbs for the up cable, 40 lbs for the down cable and another about 40 lbs for the spring.  I could feel the friction in the ailerons go up so I removed it.  Back on the elevator bellcrank doesn't really add any extra load in the cable system.  I also like how easy it is to fine tune the force.  

Great idea, Thanks!


Comment by Joe Hopwood on June 22, 2020 at 7:03am

Test flight showed considerable improvement but trim still not zero.  I added two more rubber bands and bingo.  Cruise level with zero trim and full flaps, full up trim and throttle ides it files a hands off approach.

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