Run ACL I at 75fps

The main enhancement in the camera body from the ACL I to the ACL 1.5 was the Shutter Shaft Bearing design, which allowed the camera to run reliably at 75fps.  It is possible to replace the English ACL I’s Shutter Shaft’s Bearings replaced with an enlongated Bearing (MIN 41) to give it the same specs for running at 75 fps as the FRENCH ACL 1.5/ACL II.

There are additional adjustments which will improve the camera movement as it runs at hi-speed.  The gear tolerances are more strict for hi-speed filming.  At 24 frames, there is a certain amount of latitude allowed between the gears. At hi-speed, if that latitude/tolerances were not adjusted, the movement would run itself to death rather quickly. So the gears are not allowed the wider latitude when at 24fps. This tighter adjustment will, however, increase the amperage draw of the motor and it will run less efficiently in the electronic sense, but much more efficiently in the mechanical sense. The bigger motor has no problem with this increased amperage draw, however the smaller, original motor will struggle.

These adjustments should generally be done by a qualified camera technician.