WCU-4 jumps to close focus at infinity

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Posts: 2
Joined: Mon Jun 24, 2024 3:29 pm


One of our WCU-4 jumps to close focus when I turn the focus wheel to infinity. Otherwise it functions without issue.
Any suggestions on how to fix this?

Thank you!
Christian Kaufhold
Posts: 5
Joined: Wed Mar 02, 2022 3:23 pm

Hey Tamas,

what you could try, is to re-calibrating the end stops of the focus knob via the service mode of the WCU-4 .

See manual -> page 92 to page 95 ( https://www.arri.com/resource/blob/4288 ... l-data.pdf )

This could fix the issue you are experiencing.

BUT ! Please be aware that this could lead to the knob needing to re-calibrate the linearity of the knob. For this you would need the WCU-4 calibration ring (K2.0000848)

If this doesn't fix your issue you might need to get in contact with ARRI Service ( service@arri.de ).

I hope this is helpful to you.

Posts: 2
Joined: Mon Jun 24, 2024 3:29 pm

Hey Chris,

thank you for the quick reply! What you suggested solved the issue. Thank you!
But a linearity calibration would be necessary like you said. The calibration ring is discontinued. Any idea where to find one for sale?

Thank you again, this was big help :)
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