Use of Adhesive Foam during Gyro Installation

Vibration can do a lot of damage to a gyro, therefore it is important to mount the gyro to a surface where there is little vibration. It is also important to increase damping to the gyro, in order to decrease vibrations. For the best result, please follow these instructions for mounting the gyro using adhesive foam.

When installing the gyro, follow the steps regarding the use of adhesive foam below:

Using the two pieces of adhesive foam provided, attach one piece at each end of the bottom surface of the gyro, then adhere the gyro onto the mounting surface. Do not use one large piece of adhesive foam that covers the whole bottom of the gyro.

IMPORTANT: Do not use double-sided tape without foam padding.

TELEBEE HEADING LOCK GYRO

REPRINTED FROM ROTORY MODELER MAGAZINE

WWW.ROTORY.COM

The Telebee heading lock gyro is a relative newcomer to the US. However, because of its modest cost when compared to other heading lock gyros, it has quickly become a favorite with Sport and 3D aerobatic pilots.

The price of the Telebee Heading Lock Gyro has stabilized at around $100, which makes it a good buy since $100 is pretty much the price of some high-end Piezo gyros, without the Heading Lock feature. While the Telebee GR701 does not offer an LCD readout panel and the amount of control that say the GY501 Futaba gyro does, it does offer comparable results in the air.

The Telebee GR701 gyro comes packaged in two units; the controller and the actual Piezo sensor. The sensor is equipped with a reversing switch, an LED, and a manual gain control should an Aux. channel not be available. However, the gain control only works in the standard mode.

To install the gyro, mount the unit with the arrows pointing in the axis of rotation. Translated, it simply means you tape it down using the supplied foam tape with the label up. Make sure the gyro is on a solid platform, and in a well ventilated area, away from exhaust and or heat. While the manufacturer would like you to mount the gyro directly under the main shaft, it is not mandatory. The unit may be mounted in the canopy area with good results.

You will first have to “prep” your radio for the new gyro. Make sure the rudder trim is centered. Turn off any “Revo” (revolution tail mixing) or any tail mixing. Next, you’ll want to get rid of any “Sub-trims” that you may have on. Check that there is no tail rotor mixing in all other flight modes as well.

You will need to make three connections, first - you’ll plug your tailrotor servo directly into the Telebee controller, where it designates “servo”. The next connection (using the two supplied male-to-male connectors), you’ll plug in the “RX-1-4” into the tail rotor connection on your receiver. Finally, plug in the “RX-AUX” to an Aux. channel on your receiver, preferably the “channel five” (gyro channel). Next, the ATVs gain is set for channel five. I used 60% to start off with. As you switch the Aux. channel to over or under 50%, it also changes the mode of operation. This way, as you flip the gyro (channel 5) switch on the transmitter, it changes the mode of the Telebee GR701 from standard operation of a rate gyro to the “Heading Hold” mode.

For most, setting the gain of the gyro is somewhat confusing. The gain of both; Normal and Heading Lock modes, are adjusted by changing the ATV percentages of the Aux. channel that you selected. Keep in mind that your Aux. channel is divided into two parts, 50% up is one mode, and 50% down is the other.

After you select the Aux. channel that you’re going to use, go to the ATV setting on your radio and adjust the ATV of that channel from the default of 100% to 60% in both the up and down positions. After you trim your machine in the air, if you want to add more gain, then adjust the ATV gain by increasing the value more than the original 60% that you set. Let’s look at an example, if you flip the Aux. switch “up” for Heading Lock mode, and you want to increase the gain to make the tail more stable, then you’ll adjust the ATV gain that corresponds just to that portion of the channel (up or down). On some radio systems like the JR PCM 10, when you adjust the ATV of the channels, as you flip the Aux. switch, it highlights or activates just that portion of the ATV that is being adjusted.

If your transmitter does not have an extra channel for this use, you’ll have to select either standard operation, or Heading Hold. If you have never flown a helicopter before, I would recommend that you start with the standard mode of operation. After you acquire a feel for your machine, then you can start experimenting with the Heading Hold mode. Some pilots just start out with the Heading Hold mode with success as well. Keep in mind, there is a considerable difference between the two modes of operation. Also beware that the less you do with your tailrotor control now, the less you learn later. The point I’m trying to get across is; you should develop your reflexes to fly the tail and not rely only on the gyro to keep the tail where it needs to be. A good habit is to fly just as much in standard mode, as you do with the Heading Hold mode.

SETTINGS

I recommend the following settings for your initial flight. They will be altered afterwards as needed.

•  Tailrotor/Rudder ATV (travel volume) to 100%
•  Rudder D/R (Dual Rate) to 60%
•  Rudder Expo 25%
•  AUX Channel (ch5) Gain ATV to 60/60% at initial flight
•  AUX Channel Gain (ch5) ATV to approx. 75-90%

final settings.

Keep in mind that the ATV (Travel Volume) on the “AUX” channel controls the switching and gain of the gyro. The ATV on the rudder channel, controls how fast the tail rotor performs. To smooth out the the center of the stick, I added some expo to the tail rotor channel as well.

Another important aspect of the heading hold gyro is the connection to the servo wheel. I recommend making the connection about 12-14mm out from the center. If “hunting” still occurs, regardless of gain setting, try moving the attaching point out further on the wheel. Keep in mind that “hunting” will occur during approaches, if the head speed goes up too high. Adjust your Pitch / Throttle curves to help prevent this. Make sure that the servo arm is centered on the servo, and also pay close attention to the tailrotor input arm, making sure everything is symmetrical. Make certain that the tailrotor has plenty of travel but does not bind in either direction.

As you fire-up the gyro for the first time, you will notice a slight delay in movement while the system initializes. After moving the rudder stick either way, if the tailrotor servo moves somewhat normal then locks in a fixed position, you’re more than likely in the “normal” mode. If the servo has a slight movement towards one direction, and at times does not return to center, you’re probably in “Heading Hold” mode. While in “Heading Hold” mode, you’ll need to either adjust the rudder channel trim or your transmitters “subtrims” to stop the movement. Adjust the subtrim either up or down until the movement stops or moves as slow as possible. An acceptable range is 10-20 seconds to reach full travel.

Don’t confuse the above movement with temperature drift, like any Piezo gyro, there will be a bit of “drift” until the temperature stabilizes. This “drift” could continue for up to 5 minutes in some cases. The Telebee does have drift cancellation and temperature compensation circuitry, which helps considerably. I’m mentioning this last so it stays fresh in your mind - check to make sure the tail rotor servo linkage is moving in the correct direction, so right is right, and left is left.

SERVOS

In order to receive the full benefit from the Telebee gyro you should consider investing in a high speed servo such as the Futaba S-9205 or JR DS8231 or equivalent. For some of my testing, I used a standard Futaba 9202 servo with satisfactory results. However, when compared to high speed servos, there is a considerable difference in the crispness and feel of the tail rotor. During some demanding maneuvers the standard 9202 servo fell short, since it was not able to make corrections in the needed time span. Once the servo falls behind the request of the gyro, performance decays quickly.

FLYING

As you lift off the model for the first time in hover, you should be in the “Heading Hold” mode. If not, flip the channel 5 or Aux. channel switch to activate the Hold mode. More than likely you will need to trim the helicopter with the trims or sub-trims to move the tail in position. As you go back to the “normal mode” - if the machine turns to the left or right, do not adjust the trims to correct the tail, you will need to land and make a mechanical adjustment to the linkage to trim the helicopter.

To get the most performance from the gyro in the “Heading Hold” mode, you’ll want to increase the AUX gain until the tail wags, then reduce it slightly until the tail rotor is stable in both hover and forward flight.

I can’t over emphasize the importance of using the tail rotor control on occasion to continue developing your tailrotor skills and reflexes. The “Heading Lock” gyro will immediately spoil you. Maneuvers such as sideways loops, fast rearward flight, and reverse loops become almost “too easy”. As I have mentioned in past reviews, the “Heading Lock” gyro will change the way we fly helicopters forever. If you’re looking to test the water, to see what this is all about, I would definitely recommend the Telebee GR-701 gyro. It’s modestly priced and best of all, it works!

RM