On the record

In honour of World Metrology Day this week, we thought we’d share a bit about the development of a measuring and recording device we delivered this year for film industry specialists, Rec Motion.

Rec Motion provide equipment and services for motion control recording of action scenes.

Every movement through space of stunt vehicles or motion-control rigs can be recorded and then later played back so that a digital analogue of the vehicle can replicate the movement exactly.

Here they are doing just that for the latest Indiana Jones and Fast & Furious franchise movies.

Rec Motion came to Designworks to help develop their prototype recorder requiring a number of improvements to hardware and software. The team here embarked on a comprehensive redesign of schematics, PCB layout, manufacture and assembly process. 

The rigors of speeding and crashing vehicles meant our electronic engineering team had specific challenges in proofing the device against G-force, shocks and harsh working environments.

Keeping the existing model of Peli case enclosure from Rec Motion’s prototype device, we machined an acetal chassis and inserts to securely retain the battery assembly without adhesives that might fail under stress. Securing them in place facilitated direct board to board connection, instead of flying leads that might similarly fail with repeated shocks and vibration.

These batteries powered the updated design with switch mode power supplies to maximise efficiency, resulting in 15hrs recording time on a 3hr charge.

The PCB was similarly designed to fit the Peli case but used AEC-Q200 grade components. Common in the automotive industry, it is a global standard for stress resistance for passive electronic components. Additionally, components used soft termination to the board, providing physical flexibility to operate despite sudden shocks.

A rewrite of the firmware with special attention paid from the ground up to prioritise a smooth capture of the sensor data, whilst keeping accurate timecode and frame rate for improved data integrity.

The units were well received by Rec Motion, and we can’t wait to hear about the new films these devices have helped to create.

Image © Rec Motion