Ever increasing pendulum effect,,, why

[66tbird]

So far I've run through four setup combination's, hard and soft damper, two different mechanical resolution setups and each flew fine first flight of the day.

I need to repeat that 'each flew fine first flight after setup'.

After that the pendulum swing thing starts up. Starts as a slow rocking then by battery 4 it's un-flyable. I've tried multiple reboots, then waiting an hour, then over night. But if I jump into program mode and run through the a,b,c's without a change then fly it's good for one flight. When I say good its hands off for 5-10 set steady. Then the rocking starts on aileron and it becomes a battle to fly.

specs:
clone 450 well balanced no vibs
scorp -8 10t pinion on 4s at 3200-2900
spectum 8?00 w/sat
cyclic's exi D213 (new- the old ones lasted over a 100 flights-they just got loose)
blades, CF 3D 335
head-- HK $9 conversion (nice for the price- works)
dampers - yellow works best, soft black in head kit worse, align blacks ok also

I've done the setup enough I don't need the book. It even worked well the first time when I did the setup by eye.
Gain pot 1 doesn't seem to have any big effect high or low.

I'm at a loss:arggg:
I need to repeat that 'each flew fine first flight after setup'.

[JustPlaneChris]

Quick question: What frequency are you using for the cyclic servos?

[Andyzboy]

Grease your dampers, have you tried different mounting tape?

[66tbird]

50?hz on the servos- the lowest.

yes, I've lubed the dampers. Vasaline actually:o I'm out of ky

Yes on the mounting tape. two piece of red 3m with a metal plate in between

[JustPlaneChris]

Those servos should easily support 65hz, so you might want to try bumping it up. I've got cheap Corona DS929 servos in my Mini Protos and I run them at 120hz. They don't even get warm.

I had to slightly reduce pot 1 and 2 on my Mini Protos, they are both at around 8 o-clock position.

You've certainly got enough headspeed, so that shouldn't be the cause. Very strange. :thinking

[66tbird]

Fixed it:banana It took a digital angle finder to get center stick spot on at 0° for both blades. One blade was <1° off one turn of the link either way. so I kinked the rod a tad and its good to go. Did three flights with no change.

Another slight improvement I make to the head was to remove the 008 vertical end-play between the main-shaft and the main rotor housing by inserting a brass servo grommet screw holder inside as a self centering shim. Perfect fit, perfect solution.


Now comes fine tuning. I use a 9303 (X9ll actually but they're 99% the same) and I can't figure out how to get the cyclic a little less sensitive.

[JustPlaneChris]

Excellent! :thumbup:

To make the cyclic less sensitive first set your Microbeast's Control Behavior to 'transmitter' mode in Parameter menu B (blue light). This lets you fine tune the roll, flip and piro rates with end points (or dual rates) and use expo to soften the response. Try adding 15% + expo on AIL and ELEV and see what that feels like, then experiment from there.

[ollie2893]

It took a digital angle finder to get center stick spot on at 0° for both blades. One blade was <1° off one turn of the link either way.Let me get this straight. Are you saying your blades did not track (by 1°)? I don't recall you mentioning vibrations? Yet you must have had quite some shakes in your tail fin. Also, it is rather curious that the MB should have been able to overcome these vibrations by going through the setup. I wonder what could possibly make the 1st flight after setup more immune to vibrations than every other...

Oh well, glad you sorted it out :thumbup:

[SidewaysLS4]

+1, I was thinking the same but the 're-boot' thing had me wondering. I saw a similar back-forth wander on ailerion at certain headspeeds when my T250 was running fluttering plastic blades that shakes could be felt in the airframe when holding it. A change to CF blades that smoothed out the heli cured that. Excess vibration is not good

[66tbird]

Let me get this straight. Are you saying your blades did not track (by 1°)? I don't recall you mentioning vibrations? Yet you must have had quite some shakes in your tail fin. Also, it is rather curious that the MB should have been able to overcome these vibrations by going through the setup. I wonder what could possibly make the 1st flight after setup more immune to vibrations than every other...

Oh well, glad you sorted it out :thumbup:

I agree, blades on or blades off the vibs were the same, very minimal. Matter of fact I've never dinked with a setup as much as I have this one as far as balancing goes. It flies spooky quiet even with the 'poker chip' main gear. thx Chris great reference. Why it did what it did I don't know. Tried different blades and it's even better flying.

As far as my other problem, I didn't mean to say cyclic, I meant collective. It's to sensitive for me at the moment:mad:

[Andyzboy]

You can put an "S' in your pitch curves or lower you pitch endpoints (if you don't mind losing some collective)

[66tbird]

You can put an "S' in your pitch curves or lower you pitch endpoints (if you don't mind losing some collective)

Good, Thanks, I was hesitant to add expo anywhere after the warnings. I've done it in my FB but can't remember if I saw that ability in single servo collective mode on the 9303. I gave the pitch curve menu a scan a didn't notice the typ scroll for more expo setup. Must be a more manually direct of an input.

[66tbird]

After almost giving up on the MB I was doing another(last) setup on the heli and I just happened to notice my digital pitch gauge not really acting right. Went to a friends and we placed our gauges on the blade of a t-saw and start turning the wheel. Seems my unit was over 2° out at the magic 6° point. It started going slow at 2° and sped up at 11° till it equaled at 15-ish. :clap Finally the reason.

Then setup with his gauge and its a new machine. Now why it would fly ok first flight of the day then go south is another question I really don't care about any more.

Gauge was the AngleCube. Went in for replacement today.