500 Bunny Hop

[D.O.G.]

I went flying today and took my 500 and 550 before the rain settle in, raining season for us. The 550 flew wonderful but the 500 did the bunny hop...again. I'm not sure of the technical wording but I call it the bunny hop. Once I get the 500 all initialize, I spool up. Soon as the heli start spooling up and I'm almost ready to take off, the heli starts to bounce up and down, not high but enough to stop the spool up. Like it's doing jumping jacks, lol. I've checked all the wiring, connection and even pulled all the servos off the FBL unit, AR7200Bx clean them and attached them back to the FBL unit. This is the first time I've seen this and has me confused. I'm using KST servos with HW 100a ESC plus the FBL unit. Any ideas?

 

[Admiral]

I have had the same issues twice, once was excess vertical movement in the main shaft and the second was too high cyclic gain.
Hope this helps.

 

[D.O.G.]

I have had the same issues twice, once was excess vertical movement in the main shaft and the second was too high cyclic gain.
Hope this helps.

I thank you much for the quick reply Admiral. I have no vertical movement in the main shaft and /or too high cyclic gain. This is the same 500 I've been flying for awhile and I haven't done nothing to the bird or settings on the TX or unit, beside fly it. That's why I'm so confused. I do have a spare AR7200BX that I'll change out just for poop and giggles. The FBL units is about 7 yrs old. It could be time to retire the FBL unit?

 

[Geena]

When is the last time you changed the tape that`s holding the FBL unit on the helicopter? Sometimes the tape can dry out and cause vibrations to affect the unit. I usually change the tap on all of mine once a year.

 

[D.O.G.]

When is the last time you changed the tape that`s holding the FBL unit on the helicopter? Sometimes the tape can dry out and cause vibrations to affect the unit. I usually change the tap on all of mine once a year.

Hey Geena. Didn't even cross my mine about the tape on the FBL. Maybe because I never change the tape lol. I'll give that a try this morning and post up my result. I'm always learning something here .

 

[Geena]

If ya can`t get it sorted, maybe we can sort it out on the 4th.

 

[D.O.G.]

Hi there Geena. Well we don't have to wait til the 4th to sort it out. Your advice worked marvelous...Thanks!

 

[D.O.G.]

Hi there Geena. Well we don't have to wait til the 4th to sort it out. Your advice worked marvelous...Thanks!

Opps. I made the same mistake you did. It's the 5th. The fourth is Friday and your working. We'll get the date right Lol .

 

[Geena]

I meant to say the Saturday after the 4th.....hahahahaha. So, changing the tape worked then?

 

[D.O.G.]

I meant to say the Saturday after the 4th.....hahahahaha. So, changing the tape worked then?

Absolutely . From here on in I will be replacing the tape on the FBL unit at least once a year. I haven't changed the tape since I got the 500 . It's been about 5 yrs.

 

[Geena]

That`s awesome!, and I`m glad that took care of it. Most people never think about the tape being old and dried out.