JR 8103 and HK401B Airplane Rudder Setup
 

Last month, AMA's Model Aviation magazine had an interesting article about using HH gyros to control squirrelly take offs that I experience. That article used an Efliet G110. A similar inexpensive product I found at Hobby King's HK401B which was hailed as a great buy and competitor to the Futaba GY401B by some folks. A mod was recommended and I did it.

So, I bought one, and set it up per instructions with non-digital servo setting, delay and limit settings per instructions. I turn on the JR 8103 with Gear switch in the HH position, I turn on the receiver, the HK401B blinks initializing, immediately the analog servo moves to an extreme position from center. It stays there and continues jittering while in that extreme position. The red LED light just keeps blinking intermitently.

I move the Gear switch to Rate mode which is set at 0%. The LED goes off. In this mode, movements to the rudder stick do nothing to the jittering servo in its extreme travel position. The servo does not respond to stick movements at all.

For the past couple of days, I have been sifting through topics dealing with gyros on airplane rudder. Every successful installation always includes a Futuba radio with AVCS. There must be a reason why not one of them mentions setup with a JR radio. Searches for many combinations of keywords including "JR" and "HK401B" yield helicopter setups or setups with modern JR radios.

What am I doing wrong or not doing at all? Or does this gyro only work on Futaba's?

Can anybody offer me some help?

Thanks in advance.

San Antonio Flyer

RE: JR 8103 and HK401B Airplane Rudder Setup
 

What receiver are you using and is your receiver battery pack 4.8v, 6v, or something else? What servos are you using? Where is the red LED, on the Gyro?

RE: JR 8103 and HK401B Airplane Rudder Setup
 

The receiver is a JR NER-549X (analog type) and JR NEH-531 analog servos.

The transmitter's Gear servo direction is on Normal and so is the HB401B. The Sub-trim is on 0 (zero). Travel Adjust for Gear is +65% and -1%. Rudder Trim is set to 0 (zero).

On the gyro, the Delay is on 100%, and the Limit is on 80%.

The blinking LED is on the HB401B gyro.

RE: JR 8103 and HK401B Airplane Rudder Setup
 

What is the voltage of your batteries? Your NEh-531 servos and/or your Gyro may not be compatible with 6v or higher.

RE: JR 8103 and HK401B Airplane Rudder Setup
 

Just to clarify, the HK401 is nowhere near comparable to or competition for the Futaba 401.

RE: JR 8103 and HK401B Airplane Rudder Setup
 

Receiver battery pack is 4.8 volts.

Sorry, I was in a hurry this morning and forgot to include the battery voltage.

RE: JR 8103 and HK401B Airplane Rudder Setup
 

It turns out that the only change I made was going from a 4.8 volt battery pack to a 6.0 volt. Thanks for the nudge BuschBarber!

The road to success was when I came upon a post that mentioned a 3 part YouTube tutorial on setting up an airplane gyro. After many viewings following that man's 3 part instructions, the gyro was working on the table. Per those instructions, changes were made to my JR 8103's Travel Adjustment and Sub Trim settings. The HK401B's only adjustments were setting the Delay to 100%, the Limit dial to 100%, and nothing to the DS and Reverse switches. Servo jitter had me wondering if it was due to the absence of a Voltage Regulator On/Off switch, or if it was due to the cheap Chinese quality. Don't answer that, please.

Now, to get the HK401B installed into my airplane with the squirrelly take offs down the runway. For certain, that next step will have more obstacles to overcome before testing it live (without wings first).

I will admit that I did not have much to offer anyone to help solve my issue. Being new to gyros, I just did not know what info to provide.

I am not worried about crashing the plane as I only need it for a straight travel down the runway. Like the magazine article said, after it gets airborne, the Gear switch will be moved to the "off" position. Hopefully, nothing else jinxes the flight. I wasn't going to blow a lot of money on this project. Anyone can reverse-engineer anything on the market. It's just that the first generations will have some negative issues. I may be interested in getting the next product up from this one. The Detrum GY48V mentioned in www.mycoolrc.com

Hasta la vista!
San Antonio Flyer