HK401B Gyro - Delayed tail movement when giving rudder input

Arno1978

Member
Hi Guys

I recently completed my third build of an HK 450 V2, and the Gyro of choice of course was the HK401B from HobbyKing.

I am using a digital metal gear tail servo (HENGE MD933 MD922 ), but I have a huge delay on my tail movement when giving rudder input.

My gyro gain is currently on 55% and I am using a Spektrum Dx6i.

I also connected the pushrod to the top hole on the servo arm to ensure I get maximum throws on my rudder, but still the delay is very slow.

In the instruction manual it says that if you are using a digital servo that the gain and delay on the gyro must be turned down to Zero. I fly in Head holding mode as well, but just need that extra bit responsiveness from the tail.

I did do the HK401B hot glue fix, and I also added 3 layers of double sided tape to attached the gyro to the heli.

Any advise would be welcome.

Thanks

Arno
 

Arno1978

Member
It's bad when you have to answer your own thread, but I have no choice because I got my gyro working.

Excuse me, but I am a bit new to heli setups etc, but I just want to thank IvanBarb4 on youtube for his detailed instructions on how to setup your tail and 401 gyro.

I followed the instructions to the point and the misktake I made was not to setup my gyro in Rate Mode first. I spent the 5 minutes to trim out my rudder untill I had no more drifting in Rate Mode.

I then switched back the head holding mode, adjusted the gyro gain, and I can now even do pitch punches without the tail kicking out.

The response on the tail is also amazing, I can;t wait to go flying this afternoon.

Here is the YouTube video

 

Ak Flyer

Fly the wings off
Mentor
I have been thinking of trying the HX401 on a Century .30. Have you had any problems with it other than this one? Would you recommend this for a larger heli?
 

ZXRGreg

Junior Member
Hi I have a HK401 on a raptor 30 holds the head nice and true with no issues at all, really like it. I am flying a Futaba radio, not sure about the gain setup in a spectrum, but mine is set to about 47.
 

Ak Flyer

Fly the wings off
Mentor
Hi I have a HK401 on a raptor 30 holds the head nice and true with no issues at all, really like it. I am flying a Futaba radio, not sure about the gain setup in a spectrum, but mine is set to about 47.

Cool. Did you have to do any fixes to the gyro before you used it? I read about having to hot glue the insides of them before they were used.
 

ZXRGreg

Junior Member
No mine was just fine out of the box, tired it on a electric before put in on my 30. Seeing that people have been having to glue the board down makes me want to pull it off and check it though.
 

fred0000

Senior Member
the 2 I use on my helis's are not glue modded, I wanted to try it as it came so far so good.
 

Ak Flyer

Fly the wings off
Mentor
Good to hear. I already ordered a HK 401 and a high speed servo for the tail or my 30. Should be here in 6 months or so lol.