blake26m

Hmmm.. Not the wheels so. Alex is the noise at only certain throttle positions? There is a resonance somewhere that could be causing it.
Might it be your extension leads to the tail servos? Also dose it make the same noise when a full throttle on the ground or is it just in the air?

blake26m

Finally a bit of good weather for test flight. All i can say is just WOW. Really is a beautiful plane to fly. Its tracks like my F3P machine. Yesterday was in strong breeze so will wait for a calm day to do final trimming.

Question: what mixing are you guys using for downlines and Knife edge..if any?

Mikey

Astropattern

I have 3% down elevator mix to throttle for the downlines that works well.
I don't use any knife edge mix and it tracks very well on both sides, but then again, only at most 5% rudder throw (more just stick pressure than stick movement) needed for knife edge.
I use -3% aileron differential to get axial rolls.

John

blake26m

Great thanks John. My rudder rate was to high so need to lower it. I will add a downline mix to. Thanks

Astropattern

Actually, I forgot to mention the rudder...
I have put the rudder on VTR (Variable Trace Rate) of 15% for 70% of stick movement, and then it goes to 100% with the remainder of the stick movement after that. This gives the Episode a much tamer feel for most flying situations and still allows full deflection for stall turns.

The Ailerons and Elevator can be more standard D/R and Expo to your taste...nothing special required.

John

vbortone

My Feedback: (2)

Hi John,

The mixes make sense based on my own experience. The T-Can in general makes the rudder more effective so we need less rudder movement and the net effect is to reduce the amount of mixing. I like your idea using VTR on rudder. I need to try that this year if the winter ever goes away....

HotFlyAlex

Yes, it is only at certain throttle positions. On the ground, everything sounds fine, no matter what throttle position.


You hear it only in the air. In snaprolls the noise is very loud. It sounds as if it would be the canopy. Now I have reinforced it with CFK tubes. Also fixed with tape brought no improvement ...


Meanwhile I regret to have installed the Q80. With my C50 I never had such problems!

blake26m

Yes I am running the Hacker C50 with no issue.
Ok I would suggest to throttle up again on the ground and run your hand over the entire airframe. You should be about the pick up a resonance on the airframe by feel. Try it at different throttle settings also. If it’s very loud on snap it sounds like a reverberation effect through the hollow fuselage.
Are there any signs of fatigue or tiny cracks in the fuselage around points of weakness such as the air vents?

EHFAI

I've two Episodes equipped with the Q80 and neither demonstrate the noise you're experiencing. Your diagnoses of canopy noise may still be correct - just not caused by the canopy being loose on the fuse. It may be generated by a vibration of the TE of the canalizer (which has forward mounting) against the canopy. Try making an "isolator" of silicone sealer (RTV), which will also provide a better fitting "seat" for the canalizer.

Probably the exciting force of these vibrations is asymmetrical prop loading produced by P-factor. The frequency of which will obviously vary with rpm / prop and the severity with yaw angle. The noise generated may be prop resonance only, and quite high at the critical frequency with some props. Of course, with a solid mounted motor, aircraft parts will be excited more easily.

HotFlyAlex

Yesterday I made a flight without the canalizer. Same noise... I will try a few things today!

EHFAI

OK, so much for that idea.

What is the production number of your Episode? The later versions have more material in the top fuse between the canopy and the fin. The early ones were very light and might resonate more easily - a Depron former or two is a good idea on these. I have production # 12 with the lighter fuse, and a 48 which isn't - so it was an early change.

Also, I'm using Mejzlik props - 21x13 or 20.5x12W.

A vibration can occur with the Q on accel if the acceleration setting in the controller is too low. In the worst case, the controller will interpret this as a commutation error and shut down the motor. The severity of this varies with prop load and throttle advance rate. I doubt this is your problem, as it usually only occurs during accel of the motor, but you've pretty much excluded the usual items.

HotFlyAlex

Other props I already tested. No improvement. Today I have the camera on the rear of the fuselage. It can be seen clearly that one side of the canopy goes up and down. Impressive that these so still holds on the fuselage.

Here you can see the video: https://www.youtube.com/watch?v=mzN-...e_gdata_player

Hope this is my problem!!!

EHFAI

Good idea to use the camera!

I've a 4-40 "safety" screw installed in the top of the fuse that projects downward through a CF plate inside the rear of the canopy at an angle to supplement the canopy latches. I was concerned about the load the canalizer places on the stock latches - probably prevents having vibration also.

HotFlyAlex

I hope this solve the problem!

underdw

My Feedback: (2)

Thanks for the video!
I don't (yet) use a switch for radio power, so am reluctant to add screws. I may add a pin-in-slot at the top/rear of the canopy (where a hatch latch typically is).
(haven't flown my Episode yet)
Dan

shannah

My Feedback: (5)

Hi Hotflyalex

I think your problem with the buzzing noise may be due to the outrunner. I had no such noise with my plettenberg advance powered Episode and I haven't heard that on other plettenberg or neu powered Episodes. However, most outrunner airplanes I have flown or watched fly have made the noise you are describing. I don't know why outrunners do that but I have heard it on many different outrunner powered airframes.

Portlandflyer

I had the exact same sound with my Nuance with a Himax outrunner. I think these light weight glass fuselages act like a drum and magnify the sound.

HotFlyAlex

But sure is that the canopy is not locked securely with the original click-on system in my episode. This can be seen exactly in the video! Hope this made the noise...

ram_z

I have two Episodes with Brenner CD and I don’t have noise problems other than the standard "wha wha" of the drive…
In my opinion, the noise from outrunners comes from the fact that they are fixed to the fuselage with bolts and there is no soft mounts to lower the vibration noise like intunners has.

HotFlyAlex

My motor is mounted on shock absorbers. Have also tried to install it completely fixed without any rubber. The engine noise was much louder, but the hum was still there. Today I will test the new canopy attachment... ;-)

HotFlyAlex

Unfortunately, no change again.

omsflyer

Alex, I suppose you have checked the landing gear, wheel pants moving??? Wish you could record the noise you are hearing!!

blake26m

Alex,
could it just be down to motor vibration through a faulty bearing when lateral forces during a snap put pressure on the motor?? Could it be your timing of the esc? Would you have the luxury of testing another hacker Q80 just for a flight to see if it still makes the noise?

Mikey

nonoleptitrobot

Hi everybody,

I have bought an episode, and I want to use a Q80 14XS.

Could you supply me the plan of the couple ?

Thanks a lot

Astropattern

You might also try to adjust the canopy clip locks/retainers. I developed a similar noise last summer on my Episode/Contra and couldn't figure it out. Turns out that the clips are adjustable, so you can simply screw them in or out to fine-tune the depth that they engage in the fuselage sockets. Too little engagement and you risk the canopy coming off. Too much engagement and the male component will rattle in the socket, the canopy will be loose. That made the humming go away for me, assuming it was the same hum.

John