Gyros on the camera mount

[cbergen]

To kick off this section, I want to describe what and how we're using standard, off the shelf gyros on the Observer camera mounts, including Observer EB, Twin Observer, and Turbine Observer. The function is the same, the mounting location may be different.

The gyros that we are using are Futaba GY 240 gyros, the servos we're using are the Futaba 9252's, modified for 360 degree rotation.

Now I also have to give credit where credit is due, Jody Prather from Helicam Solutions led me down this path of figuring out how to make this work. He did not explain it in detail, only gave me little hints and tips during many phone conversations until I figured it out in my own head. Thanks Jody.

Well, lets get started.

The Futaba GY 240 gyros are being used instead of GY 401, due to the ability to power them up without having to place them in HH mold. We are using these gyros in RATE mode, NOT HH mode. There's your first tip....

We use the Futaba 9252 servos, they have excellent centering, are powerful, and we can modify them very easily for 360 degree rotation. We plan on our customers using heavier cameras on this helicopter, and need the power and centering ability of these servos to control the pan, tilt, and roll functions available with this system.

[cbergen]

Installing the GY 240 gyros onto a camera mount is best done by installing them "one axis removed" from what they are controlling.



This pic shows the gyro mounted to control the "tilt" axis. Notice that it does NOT move with the tilt function. Also notice the axis of the gyro itself, which is the same as the tilt function.

If you chose to install a gyro for the "pan" function, place it on top of the extension arms, behind the servo, so that it also will NOT move with the "pan" function.

[cbergen]

When setting up gyros on the camera mount, particular attention to the settings in the radio is necessary.

We'll use the tilt (up and down) function as an example.

In your radio, find the Dual Rates/ Exponential pages. In some radios these are on the same page or in the same function, in other radios these are separate functions. Read your instruction manual to find out.

In Dual Rates, set your elevator rate to 10% as a starting point. Set your Exponential to 80%.

As stated previously, when using the GY 240's, set the mode to NON-AVCS or rate mode. DO NOT use the Heading Hold function. Set the gain on the gyro to 10% or less to start with.

Now turn on your radio systems and watch the direction of movement of the tilt function when giving a stick command. If backwards, then reverse that channel in the radio.

Wiggle the helicopter or camera mount in a nose up and down fashion and watch the response of the tilt movement. If backwards, the change the direction of the GYRO.

It is recommended that you work on one function (tilt, pan, roll) at a time. When the camera mount is going bonkers, it is difficult to know which way to go.....

Setting the dual rates and Expo as recommended gives you a slower, smoother, controlled movement of the camera mount system. Nothing worse than a video that jumps around very quickly, making the viewer seasick.

Adding the gyros helps, HELPS, to counteract the small corrective movements the pilot puts in when flying the helicopter.

Once you have everything working in the proper directions, then go back and fine tune the settings, the Expo, Dual Rates, and Gyro Gain to get the feel and action that you require. Remember to start slow and add in the dual rates and Gyro Gain as needed.

Too much gyro gain will start a feedback oscillation. When you see this, just back off the gain a little and try again. Usually between 5% and 20% is the magic number.

It does NOT hold a target in the camera viewpoint, and will not remove or diminish any vibrations from the helicopter. Your tuning and setup has to accomplilsh that.

[cbergen]

If you are having drift problems that cannot be resolved by adjusting the trims on the face of the radio OR by adjusting subtrims (might try doing BOTH), then try adjusting the travel limits of the particular servo that is drifting.

IOW, lets say the pan servo drifts one way with a click on the trim, AND drifts the other direction with one click on the trim the other way.

Add in some subtrim in one direction, then try the face trims again. You MAY find the magic spot that allows drift free operation.

If not, then try reducing the travel limit in the radio on one side, just a couple of points, AND increase the travel limit on the other side. For instance again, set travel limits at 95% and 105%. NOW again try to adjust out drift using the face trims.