hk401b no movement in HH mode

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I have a similar problem but reversed (sort of). I can adjust my gyro sensitivity on AVC by changing the values but on NOR (rate mode) the gyro is on full sensitivity no matter what value I set.
I'm switching between UPRATE & DNRATE on the gear switch but on DNRATE  which I have on NOR (rate mode) no matter what I set between 001 ana 100 the gyro is on full sensitivity. Yours sounds like it's on 0 sensitivity.
I've tried servo reverse on the gear channel but it remains like this.
I think it's a Tx programme fault.
Any suggestions ?

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plasticbaldy Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (AU) USERID: 575948 Bargain Addict! Joined: 25/Jul/2010 Online Status: Offline Posts: 49	Quote Reply Posted: 31/May/2011 at 5:20pm
	I have a similar problem but reversed (sort of). I can adjust my gyro sensitivity on AVC by changing the values but on NOR (rate mode) the gyro is on full sensitivity no matter what value I set. I'm switching between UPRATE & DNRATE on the gear switch but on DNRATE which I have on NOR (rate mode) no matter what I set between 001 ana 100 the gyro is on full sensitivity. Yours sounds like it's on 0 sensitivity. I've tried servo reverse on the gear channel but it remains like this. I think it's a Tx programme fault. Any suggestions ?

cgriffith Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (US) USERID: 818146 Bargain Addict! Joined: 19/Feb/2011 Location: Orlando, FL Online Status: Offline Posts: 21	Quote Reply Posted: 06/Jun/2011 at 10:19pm
	Update: So I finally got the bird in the air long enough to add some detail. Being new to this means that 1) it is hard for me to keep the heli in the air long enough to test, and 2) What the hell do I know how a gyro should work. Anyway, what I have noticed is that the tail will stay pretty well where it is pointed at. But not necessarily where I want it to point. Meaning, I can use the rudder to move the heli to point say 12 oclock. Then the wind will move it to 2 oclock, and stay at 2 oclock. Then I move it back to 12 oclock. Then wind blows it back to 2 oclock and it stays there. I have the HH gain at 85. I did not try rate mode. Is this a defective gyro? Any help would be appreciated. Thanks for reading.

Sooty Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (NZ) USERID: 173750 Hobbyking Addict Joined: 10/Mar/2009 Location: Christchurch NZ Online Status: Offline Posts: 2587	Quote Reply Posted: 07/Jun/2011 at 6:12am
	cgriffith Going back to your first post you say there is no movement when you move the model on the bench - yet the HH led is on and the tail responds to normal stick input. That tells me that you have a bad gyro. I have a number of the HK gyros and have struck the odd crook one.

cgriffith Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (US) USERID: 818146 Bargain Addict! Joined: 19/Feb/2011 Location: Orlando, FL Online Status: Offline Posts: 21	Quote Reply Posted: 07/Jun/2011 at 9:43pm
	thanks Sooty for confirming my suspicions. What is the process to get this resolved with HK?

Sooty Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (NZ) USERID: 173750 Hobbyking Addict Joined: 10/Mar/2009 Location: Christchurch NZ Online Status: Offline Posts: 2587	Quote Reply Posted: 08/Jun/2011 at 4:39am
	Don't bother - just write it off and get another. You would have to send it back to them so they can check what is wrong with it and will take forever. Pull it apart yourself and check for dry or solderless joints. That is most likely what is wrong. I would run a soldering iron over every connection on the PC board and it could very likely come right. Get a magnifying glass and examine every connection - there aren't that many. Add solder if needed but not too much on the iron or you will bridge/short over onto another connection.

cgriffith Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (US) USERID: 818146 Bargain Addict! Joined: 19/Feb/2011 Location: Orlando, FL Online Status: Offline Posts: 21	Quote Reply Posted: 11/Jun/2011 at 11:10am
	Well, I was about to write it off as you suggested until I figured this thing out. Turns out not to be the gyro, but the Transmitter. See the solution here http://www.hobbyking.com/hobbyking/forum/forum_posts.asp?TID=18485&PID=132150#132150

billius Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (GB) USERID: 242238 Hobbyking Addict Joined: 23/May/2009 Location: Sheffield UK Online Status: Offline Posts: 425	Quote Reply Posted: 11/Jun/2011 at 6:37pm
	Glad you got it sorted, I'm just suprised that nobody came forward with that solution for you in the TX and Rx thread. You know that this makes you an expert now and people will be looking to you with god like reverence.
	Billius Spencicus Ground Crew to Pontius the Pilot

raindancer Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum (GB) USERID: 319374 Newbie Joined: 20/Jun/2010 Location: United Kingdom Online Status: Offline Posts: 9	Quote Reply Posted: 24/Jul/2011 at 6:54pm
	Hi billius, I've seen numerous references to the 'hot glue' mod for the 401B gyro. I've trawled the web looking for the origin of this mod, and for examples of failure due to wires and circuit boards detaching. Thus far, apart from the preventative measures done by the guy who posted his procedure on Hobyking, I've not found any. I have a Xmhobies G401B gyro, prior to using, I opened it for inspection and nothing looked in need of attention. I mounted it on one of my T-rex 450 SEV2 clones, first off mounted the gyro with just a single layer of double sided foam pads and the tail was unstable. Remounted using two foam pads of different densities 5mm medium and 2mm soft and the heli is now completely stable. Have set-up on a 35mhz Walkera WK-0701; also set-up on 2.4ghz Flasher T6EH-M paired with a Radiolink receiver, did not experience any problems with neither set-up.