Gimbal Balancing Machine Series

Product Details

Gimbal Balancing Machines

Space Electronics’ gimbal balancing machine series is the world’s only comprehensive set of machines for balancing gimbaled platforms. It combines both static balancing and dynamic balancing methods.

Many parameters influence the set of balancing instruments and methods needed to achieve the mission requirements. Depending on the application, Space Electronics will offer a set of static and dynamic balancing methods to achieve the best balance solutions for one particular gimbal.

Typical Applications

Our gimbal balancing solutions apply to all types of gimbals, with as many axes of rotation as desired. Typical applications include missile seekers, fast steering mirrors, missile jammers, and airborne cameras mounted on UAVs, helicopters, aircraft.

Description
Specifications
Literature

Static Balancing

Static gimbal balancing is performed using a specific gimbal balance machine and a proprietary process to statically balance a gimbaled assembly about its own axes. This eliminates most of the jitter in gimbaled assemblies.

Gimbal Balance Machines are highly sensitive, automated, center of gravity measuring instruments used to achieve static balance of gimbaled sensor suites such as missile guidance seekers, gimbaled cameras and sensors, and tracking devices. A high degree of balance is needed so that acceleration of the vehicle will not apply excessive torque around any rotation axis of the gimbal. Space Electronics gimbal balancing machines will quickly balance a gimbal about each rotation axis within a tolerance as small as 0.1 gram-centimeter (0.0001 lb-in). The gimbal can be balanced in its fully assembled “ready-to-fly” configuration with wire bundle and fiber optic guide masses included. Learn how to choose the right gimbal balancing machine for your application.

Learn more about the advantages of the Space Electronics gimbal balancing Method. We invented the concept of orienting the gimbal axes at 45 degrees to the horizontal and measuring the change in horizontal CG position as the gimbal is rotated about its axes. Also, the concept of “permanently calibrated” moment sensing using a closed-loop servo to return the mechanism to its original state, and many of the conventions and standards used to define gimbal balance were originated at Space Electronics. All the gimbal balance machines in use today were manufactured by us.

Dynamic Balancing

Dynamic gimbal balancing is highly dependant on each gimbal. Space Electronics has developed a set of methods that cover a large range of gimbal configurations. Parameters such as allowable residual unbalance, maximum travel angles on each axis, mass and inertia distributions of subassemblies, gimbal type, rotational speeds, and range of gimbal configurations influence the choice of an appropriate balancing method.

Visit our explanation page to understand the difference between static and dynamic unbalance. Contact us via the form below or by phone to get started on your balancing process.

Gimbal Balancing Machine Specifications

The two primary factors affecting selection of a Space Electronics gimbal balance machine are weight of the gimbal and its unbalance tolerance.

Maximum gimbal weight. The machine must accommodate the maximum weight and size of the gimbals to be balanced. However, it should be no larger than necessary since large machines are more expensive and less sensitive than small machines.

Sensitivity to unbalance is defined by Space Electronics as the smallest unbalance moment that can be repeatably measured for a gimbal with a rotation angle of ±45 degrees. If the gimbal rotation angle is smaller than this, sensitivity of measurement will be reduced. The table below illustrates this effect.

You should select a gimbal balance machine which is at least 5 times more sensitive than the balance tolerance for the gimbal. To calculate the rated machine sensitivity (S) required when given a balance tolerance (G), use the following formula:

S = 1.4(G)(F)SIN(a)

where a is the maximum rotation angle of the gimbal (measured from the midpoint of rotation) and F is the ratio between machine sensitivity and gimbal balance tolerance requirement (typically 0.2).

Rated Machine Sensitivity	Effective Gimbal Unbalance Sensitivity (g-cm) as a function of gimbal rotation angle
(g-cm)	±90^o	±45^o	±10^o	±3^o
0.1	0.07	0.1	0.41	1.4
1.0	0.70	1.0	4.10	14.0
10.0	7.0	10.0	41.0	140.0

EXAMPLE: If the gimbal must be balanced to a tolerance of 10 g-cm, a maximum of 20% of the allowed unbalance may be used up by the machine sensitivity limit, and the gimbal rotation angle is ±25 degrees, then G = 10 g-cm, F = 0.2, a = 25 degrees. The required machine sensitivity:

S = 1.4 x 10 x 0.2 x sin 25o = 1.2 g-cm

Therefore, a machine with a sensitivity better than 1.2 g-cm should be purchased (such as the Space Electronics Model GM904 with rated sensitivity of 0.5 g-cm).

Optional automated gimbal rotation. The measurement process requires that the gimbal be rotated precisely to four positions. This can be done by hand. However, if the machine is to be used to balance a large number of gimbals, then it is convenient to have this rotation accomplished electrically. In addition to its convenience, this option generally improves the sensitivity of the measurement, since electrical rotation has less disturbing influence on the instrument than manual rotation. Space Electronics can provide the electronics necessary to do this automatically via commands from the computer. This option includes the software necessary to interface with the drive electronics provided by the customer. It also includes a beryllium copper flex strip to provide power to the gimbal without reducing the sensitivity of the measurement. We can also provide a means of electrically reading the actual rotation angle. This true angle is then used in the calculation of gimbal unbalance.

Gimbal Balancing Machine Options & Accessories:

Weight Correction Software
Drive/Read Interface

Product Sheets:

Gimbal Balance Machines (Imperial Units)
Gimbal Balance Machines (Metric Units)
GM904 Series Options

Technical papers:

Gimbal Balancing Series