Kinor 35: Removing & lubing the main drive shaft

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Created on Friday, 25 September 2009 20:00

Last Updated on Friday, 14 December 2012 20:15

Written by Terry Byrne

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Removing and lubing the Kinor 35 main drive shaft

Disclaimer: I take no responsibility for anything you do. Ever. This is posted as a narrative of my experience taking out the main drive shaft and lubricating it. There are many variants of the Kinor 35 and yours may not be the same as mine. Nonetheless, you may find this interesting and perhaps useful.

This camera has a mechanism drive shaft that is pulled by the motor via a timing belt and drives the pulldown and registration pin mechanisms by means of a a coupling to a gear train (visible on the mechanism side of the camera) and drives the feed and take-up sprockets by means of another rubber timing belt and two larger black pulleys on the motor side of the camera. The “drive shaft unit” as I call it is this rather small assembly that couples the two pulleys on the motor side of the camera to the mechanism coupling on the mechanism side.

Before I took the drive unit out, I took some time to think about how to re-sync the shutter with the pulldown mechanism. These cameras use both ends of the motor: the front couples to the shutter and drives it directly. The rear motor shaft is fitted with a pulley that drives the main driveshaft via a rubber timing belt. There is another pulley on the driveshaft that turns the two sprocketed rollers that feed and take up the film (before and after the pulldown mechanism) via another rubber timing belt. It is necessary to disengage the rubber belts to remove the main drive shaft assembly, so knew I would need to restore the shutter/pulldown sync when reassembling the parts. Before I began, I noted that there is a point in the pulldown claw’s cycle where the tip of the claw is even with the tip of the registration pin. At this point, the shutter is just closing, as shown in this photo. (There’s a small triangle open in the top right corner, but the shutter is almost closed.) This only happens once in each exposure/advancement cycle, so you can’t mistakenly get it 180 degrees off.

This shows the alignment of the pulldown claw and registration pin. It’s pretty easy to see. (Note that the gate and pressure plate are removed; I’m assuming most Kinor owners know how to do this!)

Now to the real work. I opened up the guts of the camera by removing the motor-side panel. Sean McVeigh’s post shows how to do this. I removed the two screws holding in place the main electrical connector. This allows access to a little piece mounted under the motor housing.

That little piece underneath the motor is the main drive belt keeper. It prevents the belt from slipping out of the pulley attached to the main drive shaft.

There are two very small screws holding the keeper in place. I didn’t need to remove them, just loosened them so the keeper shifted slightly away from the pulley. The reason to do this is that the keeper will catch on the pulley flange and prevent it from sliding out of the camera later.

I then removed the entire pulldown claw/reg. pin mechanism per Sean’s disassembly post. Then I removed the three screws holding the drive assembly in place.

Going back to the motor side of the camera, I carefully slid the belt that drives the feed and take-up sprocket pulleys (the big black pulleys) off its tensioner. I found that I didn’t need to loosen the tensioner to do this.

Still on the motor side, I loosened the main drive belt. To do this I had to loosen the bottom tensioner of the two. I then slipped the belt off the motor pulley.

Next I wiggled the belts away from the drive shaft pulleys. This required some coordinated pushing of the driveshaft unit out of its hole and snaking of the belts around it, but I didn’t need to remove the motor to do it.

Here is the drive mechanism coming out. I found that I could stick my finger in the hole and pull as well as pushing it from the motor side. It was pretty easy to remove with the belts and that keeper out of the way.

So here’s the little bugger out in the light. Those two dark spots are grub screws in threaded lubricating holes. I removed the grub screws in order to put lubricant into the holes. On the opposite side is the coupling to the mechanism drive shaft.

Bruce McNaughton says he found plugs of fiber substance in the oil holes; others have said there was foam in theirs. I found nothing and was hesitant to put anything in there that might foul the bearing surfaces, so I decided to pack them with Arri grease.

Reassembly:
The reverse of the above. Two things to note. The coupling between the main drive shaft and the pulldown mechanism has a locator pin that needs to line up to replace the pulldown mechanism plate. Also, the restoration of shutter/pulldown sync requires a lot of time and patience. I would try a particular setting, check it (and find that it was wrong), then loosen the bottom tensioner on the main drive belt, slip the belt off and try again. And again, and again.