ARRIFLEX 16S Tachometer/FPS Issue

[Aldo Melendrez]

Hi,

I recently bought an ARRIFLEX 16S (an earlier model). Apparently it was one of the cameras used by the film department at School of Visual Arts in New York. It's in really nice condition overall and everything seems to be working well, except for one thing, the tachometer consistently reads around 22ish fps. It's very steady, but it never goes up to 24 fps.

At first, I thought it might be a power issue. I was running it from a V-Mount battery through the DC8 output, so I picked up a Du-All 8.4V NiMH battery to test it and... the tachometer is still showing the same reading.

I'm wondering if this is a common issue with these motors, if it could be something in the camera itself, or if perhaps the tachometer is simply out of calibration while the camera is actually running at 24 fps.

I'm based in Vancouver and don't know of any places locally that could check or service the camera. If anyone has recommendations, I'd really appreciate them. As a last resort, I could send it to the US for service, but between shipping, customs, and repair costs, it could end up being more expensive than buying another motor or having it serviced somewhere in Canada.

I've attached a short video showing the issue.

Appreciate any help or advice. Thanks!

https://drive.google.com/file/d/1Un61anLCkbfPrDd_UZKuXz9v--bQEjhK/view?usp=sharing

[Dom Jaeger]

The older Arriflex 16St constant speed motors use a mechanical speed governor that is adjustable.

 

Duncan Brown did a nice tear-down guide for one, including speed adjustment:

http://backglass.org/duncan/arri/constant_speed_motor_24fps_teardown/

 

This cinematography.com thread has lots of discussions about 16St motors:

https://cinematography.com/index.php?/forums/topic/68504-arriflex-16-s/page/4/#comments

 

[Aldo Melendrez]

2 hours ago, Dom Jaeger said:

The older Arriflex 16St constant speed motors use a mechanical speed governor that is adjustable.

 

Duncan Brown did a nice tear-down guide for one, including speed adjustment:

http://backglass.org/duncan/arri/constant_speed_motor_24fps_teardown/

 

This cinematography.com thread has lots of discussions about 16St motors:

https://cinematography.com/index.php?/forums/topic/68504-arriflex-16-s/page/4/#comments

 

Voila, the tear-down guide worked pretty well, I fixed it!

Time to do a film test and check how close to 24fps it is.

Thanks, Dom.