Weird Behaviors Solved through Troubleshooting

[Alky6]

Thought this would be a good thread to start. Essentially a place to post interesting or odd behaviors that presented a challenge but were eventually sorted out. There is definitely no substitute for experience. But I sure have learned a lot on these forums and hopefully this is a way to give back.



To get it started:



I recently completed a a Bridi Utter Chaos 40 Kit (I know it is a bit small for this site, but you have to start somewhere). Upon its maiden, it was a bit windy, there was a whistle, or a high pitched harmonic that occurred at speeds higher than 1/4 throttle. The right wing also repeatedly and randomly stalled. Maybe too windy, so I tried again another day. After a few more flights, the whistle got progressively worse, occurring at slower and slower speeds and the uncontrollable stall got worse. The wing incidences were fine. I tried putting tape on the aluminum landing gear, thinking that was maybe the source of the obnoxious sound. I was getting more and more frustrated and was close to giving the airframe a viking burial. When I took the wing off and put in my pickup, I noticed the leading edge of the blue starburst covering on the right wing was delaminated. A small area about 1/8" deep by about 10" long. Difficult to see. Apparently I didn't do a very good job ironing on the ultracote in that one area.



Long story short, I cleaned and re ironed that area down and all my problems went away! The airframe is very stable and I now have a great time flying it. This is one of those times that if I had more experience, I would have known where to look.



Hope others can share similar experiences. Thanks!

-Paul

7580=2869-image.jpg

 

[Ken-H]

Alky6;7580 wrote: Thought this would be a good thread to start. Essentially a place to post interesting or odd behaviors that presented a challenge but were eventually sorted out. There is definitely no substitute for experience. But I sure have learned a lot on these forums and hopefully this is a way to give back.



To get it started:



I recently completed a a Bridi Utter Chaos 40 Kit (I know it is a bit small for this site, but you have to start somewhere). Upon its maiden, it was a bit windy, there was a whistle, or a high pitched harmonic that occurred at speeds higher than 1/4 throttle. The right wing also repeatedly and randomly stalled. Maybe too windy, so I tried again another day. After a few more flights, the whistle got progressively worse, occurring at slower and slower speeds and the uncontrollable stall got worse. The wing incidences were fine. I tried putting tape on the aluminum landing gear, thinking that was maybe the source of the obnoxious sound. I was getting more and more frustrated and was close to giving the airframe a viking burial. When I took the wing off and put in my pickup, I noticed the leading edge of the blue starburst covering on the right wing was delaminated. A small area about 1/8" deep by about 10" long. Difficult to see. Apparently I didn't do a very good job ironing on the ultracote in that one area.



Long story short, I cleaned and re ironed that area down and all my problems went away! The airframe is very stable and I now have a great time flying it. This is one of those times that if I had more experience, I would have known where to look.



Hope others can share similar experiences. Thanks!

-Paul

Still looking for a like button, this will be a great thread.

 

[Astrohog]

Okay, here is one that I recall from a couple of years ago. A few of us camping at the field for the weekend. One buddy was having problems with his (I think) ZDZ 80. Couldn't get it to run smooth. Couldn't get it to hit peak RPM. Couldn't get it to idle. Would get it running just okay an the ground, but as soon as he took off it would act up and he would have to limp it home. Re-plumbed fuel tank and system. Tried different gas. Check and replace plug. Spent HOURS over two days trying to fiddle with it. Finally decided to pull carb.......INSIDE the reed block was a 1" long section of outer nyrod guide tube that he had glued in the motor mount to help guide a screwdriver to the needle valve adjustment screws! WTF???!! I have no idea how it worked its way in there, but there it was! I can say this; no amount of tuning was gonna get that sucker running right with that hunk of plastic in there!



Looking forward to some more good stories!



Regards,



Astro

 

[Alky6]

Yikes! That would definitely make me pay attention to how well things are attached around the firewall. Thanks for sharing.

-Paul

 

[49dimes]

Thought this would be a good thread to start. Essentially a place to post interesting or odd behaviors that presented a challenge but were eventually sorted out. There is definitely no substitute for experience. But I sure have learned a lot on these forums and hopefully this is a way to give back.



Long story short, I cleaned and re ironed that area down and all my problems went away! The airframe is very stable and I now have a great time flying it. This is one of those times that if I had more experience, I would have known where to look.



Hope others can share similar experiences. Thanks!

-Paul

7580=2869-image.jpg

That design taught me how to handle high performance and control it smoothly. It was my first low wing. I put the tower ARF version together this past summer and flying it brought back some great memories. Your plane in the picture looks great and I know it flies "like it's on rails" now that the covering is not allowing "dirty air" on the wing. I got mine to do about 135mph.

 

[Alky6]

That design taught me how to handle high performance and control it smoothly. It was my first low wing. I put the tower ARF version together this past summer and flying it brought back some great memories. Your plane in the picture looks great and I know it flies "like it's on rails" now that the covering is not allowing "dirty air" on the wing. I got mine to do about 135mph.

Nice Kaos! 135? That is smokin fast and without a pipe? And yes it does fly on rails. It has taught me a lot and enjoy flying it. It is really fast but lands like a dream and glides forever!
-Paul

 

[49dimes]

Nice Kaos! 135? That is smokin fast and without a pipe? And yes it does fly on rails. It has taught me a lot and enjoy flying it. It is really fast but lands like a dream and glides forever!
-Paul

Yep 135! DZ70 12x10 APC. Mikeee.."Try it you'll Like it!"

 

[Alky6]

Yep 135! DZ70 12x10 APC. Mikeee.."Try it you'll Like it!"

LOL. might just have to...

 

[IMAC FANATIC]

Cool thread ! Fought a comp ARF super extra with aileron trim, always dipped a wing right after a few minutes of flight, After replacing servoes ,getting mechanical throws dead on up and down on ailerons and elevators, removing mixes, checking and rechecking incidence, replacing matchboxes etc. Went back to basics and did lateral balance, upright ,inverted and on the gear using digital scales found that right wing was 1.8oz heavier somehow at wing tip, which given a 3.1m wingspan gives quite a bit of leverage out there . Added some lead shot in left wing and rebalanced. Flies straight and true now. That old tower hobbies pre flight instruction manual from pt-40 applied could have saved me tons of work and money had I followed the steps pre flight with this one too.

 

[Alky6]

Cool thread ! Fought a comp ARF super extra with aileron trim, always dipped a wing right after a few minutes of flight, After replacing servoes ,getting mechanical throws dead on up and down on ailerons and elevators, removing mixes, checking and rechecking incidence, replacing matchboxes etc. Went back to basics and did lateral balance, upright ,inverted and on the gear using digital scales found that right wing was 1.8oz heavier somehow at wing tip, which given a 3.1m wingspan gives quite a bit of leverage out there . Added some lead shot in left wing and rebalanced. Flies straight and true now. That old tower hobbies pre flight instruction manual from pt-40 applied could have saved me tons of work and money had I followed the steps pre flight with this one too.

Thanks Brian. Interesting problem and resolution. On the bright side, you had some extra servos lying around!