Project/steadycam

Steady Cam
This page is for full details of a low cost, high quality camera stabilisation system that we can make in the space.

Theory
A passively stabilised mount is designed to damp out unwanted motion in as many directions as possible, while allowing intended motion. A passive system strongly wins out over an active (motorised) system in almost all cases.

There are 6 types of motion to account for in the system. X,Y,Z and Pan,Tilt,Yaw.

A gimbal will allow correction of P,T,Y using gravity as a reference. To do this you need a counterweight below the camera. The counterweight should provide a greater torque around the gimbal as possible. The greater the torque, the more effort is needed to set the camera rolling in any given plane. There are 2 ways of increasing the torque, increase the distance, or increase the mass. Both of these need to be played off against other factors.

Under acceleration, P,T and Y can be disrupted. The best method of dealing with this is to apply forces at the effective centre of mass. Since the forces will be applied by the camera operator's hand, then handle must therefore be exactly at the centre of mass.

X,Y, and Z are more difficult to damp. Since we need to be able to move in those axis in a controlled manner. The best damping available is therefore simple mass. A larger mass to the whole system makes it harder to adjust the motion, but also damps out unintended motion. Taking the strain of the camera op's arm also improves this, as well as allowing more mass. This is why professional systems have a vest and spring loaded arm, to transfer the weight to the op's core.

Gimbal
This is the core of the design. The gimbal should allow roll in both the Pan and Tilt plane. The Yaw will be linked to the handle to allow the camera to rotate. Bearings will improve the response considerably, and so improve overall quality.

Camera Mount
The camera should be mounted with it's centre of mass directly above the centre of the handle. This will help minimise unbalanced forces.

The mounting should use a standard 1/4" screw mount, inside a slotted base. A bubble will also be useful for balancing the camera.

Counter Weight
The counterweight should be positioned such that the torque on the gimbal is at least 2-3x that of the camera above. It should also be positioned so that the torque around the handle is equal to that from the camera. The counterweight should also be exactly in line with the camera and handle's centre of mass. This will eliminate the roll and tilt from the system.

The simplest counterweight is a metal mass. It is easy to balance and work with. A better method is to use excess kit. A spare battery, Microphone receiver, or even a small monitor can also be used, greatly enhancing the system's capability, for no weight gain.

Handle
The handle needs to be comfortable and robust. The system will weigh at least 2x the weight of the camera alone, and so will put more strain on the arm. A good grip allows this to be born with less discomfort and less unintended motion. It should also be possible to 'hang' the handle from a mount. This makes balancing the system a lot easier. The simplest way to do this is to have a hollow core to the handle, and an arm/rod it can sit on.

Materials
The best way to make the form accurately is with a mix of laser cutting and 3D printing. The main body should be laser cut for speed and size, while complex or detailed parts are printed. Since we have an abundance of 8mm perxpex, this will be the material of choice.

Overall
The overall design should follow this aproximately.

It should also be designed to be folded/compacted for storage and transport.