Black edition vibes

[bullet3030]

Hi,

I have about 12 flights on my black edition now and I am notecing some vibes on the back of my canopy. Changing blades did not change it. I loosend the blade bolts that did help a bit.

The vbar isn't showing a very bad log. Some vibes on moves no extremes.

I know this version uses hard dempening so maybe this is acceptable. Anyone has this?


Peter

[Raptorapture]

I noticed some vibes on the back of one side of my canopy as well on my 700. I'm suspecting they show up due to a previous crash the canopy survived which caused a bend which accentuates the vibe on spool up. Is it visually evident in flight?

[bullet3030]

Yes in a hoover. Not the hole canopy but just the 2 non closing parts in the back. I just connected the vbar but all looks good.

Verstuurd vanaf mijn SM-G920F met Tapatalk

[Raptorapture]

I had the same experience but didn't bother about it as I was happy I had a successful maiden

[Nick Maxwell Products]

Mine will do this as well sometimes, in initial hovering only though.

I believe there are 3 causes:

1) The rotor blades are not fully aligned (one is slightly leading or lagging compared to the other one until the model gets some form of load on the rotor disk
- Fix #1 - Run the blades a little looser
- Fix #2 - Pump the pitch or click into a higher RPM to cause a major change in the lead/lag of the blades
- Fix #3 - Grease the blade spacers for smoother lead/lag
^^^^ That is the cause of mine - I simply put a little grease on the blade spacers before mounting them and this is fixed.

2) To some degree I think rotor thrust/dirty air can cause this if the canopy is mounted loosely
- Fix # 1 - Glue the rubber grommet to the canopy to add rigidly at the mounting point in the rear
- Fix #2 - Add a washer under the retaining pin to compress the rubber damper with the pin inserted to shim out any possible movement

3) There could be some sort if low frequency vibration in the model if it NEVER goes away. Or a higher frequency vibration that is being transmitted to a softer part on the model.
- Fix #1 - Low frequency vibration is usually rotor head induced or caused by parts turning the slowest. Take the main blades off and see if the helicopter/canopy stays still
- If the helicopter is smooth with the main blades off, its likely rotor head alignment (rotor hub pinch bolts not equally tightened, or the head axle is not shimmed/spaced well) or the blades are just out os balance. If it is RPM dependent (only shakes at low RPM or only at high RPM that is usually cord wise CG.
-Fix #2, if the canopy shakes on the ground with the blades off check the heaviest fast turning components first. Tail assembly, motor can, and first stage gear balance (the higher RPM gear).

Nick

[bullet3030]

Thanks! I will follow the list and go step by step. Some I already did.

Change blades(no results)
Loosen the main blades(litle improvement)
Greasing shims
Changing headspeed(only higher freq vibs shown on the canopy)
Check vbar log ( no excessive vibs)

Edit;

vid from the analyser on the bench no blades.

Vbar vibe analysing. (1 min 11 sec)

Test 2 with no blades canopy on.. canopy vibes but not noticable. Just some mechanical vibes of the drive train.

Test 3 loosend the head bolts and retightend them. No change also no real vibes noticable.

Test 4 Regreasingblade shims and tighten the blade bolts. Have to check at the field.

All did this yet no results. Canopy still shakes.


I must say that my xnova stator is touching the upper edge of the frame because its a very big motor



Edit; I adjusted the frame so the motor no longer touches the frame sides.

Have to make some test flights

🤘



Verstuurd vanaf mijn SM-G920F met Tapatalk

[Nick Maxwell Products]

One thing I would also strongly suggest is using some wide O.D. washers on the motor plate screws. It will add some rigidity to the motor section in my opinion.

Nick

[satsuma]

All that carbon dust off the frames going in the motor lol, glad you EASED the frames

[bullet3030]

Yes good idea. Will ad some washers right away! No dust no nothing. Unfortunally all the above done did not make a solution. Will try my other canopy

Verstuurd vanaf mijn SM-G920F met Tapatalk

[mgaproduction]

Originally Posted by Nick Maxwell Products

One thing I would also strongly suggest is using some wide O.D. washers on the motor plate screws. It will add some rigidity to the motor section in my opinion.

Nick

How are O.D. washers?

[Luvmyhelis]

Originally Posted by mgaproduction

How are O.D. washers?

Basically any larger washer that will fit around the bolt and add more surface contact area. My Diabolo has them on every single bolt, as do all my helis in my entire collection. I also opened up my frame to clear my own Koz motor. Super easy.

Such as these. http://www.helidirect.com/helicopter...0-700-770.html

Or these. https://www.amainhobbies.com/sworkz-...01010a/p387959

There are dozens of different colors and styles. I tend to use polished aluminum versions.

The best I have found are called SeCraft, and are much larger in diameter but now very hard to find.

[Raptorapture]

Originally Posted by mgaproduction

How are O.D. washers?

OD stands for outer diameter. The washers in the pic for mounting the motor mount to the frame are the same diameter as the bolt head. Ok for a normal bolt holding frame together which don't even have washers to begin with. But not such a good idea for both a movable mounting point as well as for the motor where vibration will concentrate at the bolt/washer against the frame. Mine are at least twice the diameter of the bolt head on my 700. Not sure if they came from minicopter or I sourced/given them seperately.

Edit: already addressed, didn't refresh browser first

[mgaproduction]

Thanks.
I didn't know how means O.D.