Bolex Rex 4 Service Manual?

[Matt Boese]

Does anyone have a link/pdf for the service manual for a Bolex Rex 4? Doing some service and looking for the lube points but unable to find anywhere online. Thanks!

[Dom Jaeger]

There was one selling on eBay recently I noticed, if no-one offers you a PDF.

But honestly, for a non-technician just wanting to know how to lubricate their Bolex, it can be more frustrating than helpful. There are no disassembly instructions, or simple diagrams pointing where to put oil. There are just multiple exploded diagrams with symbols relating to four or five different factory lubricants and a few adjustment procedures described listing the Bolex factory tools and jigs required to perform them.

To properly re-lubricate a Bolex, you unfortunately need to fully disassemble it to access most of the places that need lubrication, and to be able to clean off the old dried lubricants or any contaminants.

Without disassembly there are very few lubrication points you can access. The main places that need it are the plain bearings at each end of the gear axles. If you can see the end of a shaft turning when the camera runs, that’s a plain bearing. There are a few you can see inside the film chamber, which you can put a drop of oil on, but it’s about 3 out of maybe 20 that need lubricating. You can access the claw mechanism from the film chamber, which is lubricated with grease. The viscosity is important, since the drag on the claw spindle creates the force holding the claw against the gate - too stiff and it might move the film during registration as the claw drags back across between perfs, too free and the claw might slip out of the perf during pulldown. If the take-up spindle is a bit sluggish you can try some oil around the base, but it really needs to be removed to properly clean and lubricate it.

By removing the mechanism you can access more of the bearings, but without separating the plates you’re not able to clean any contamination or old lubricant away and you still can’t get to other important places like the take-up spindle shaft, or clean the drive belts etc. But it’s enough for a minor service. Gears are generally not lubricated unless they are helical, and don’t use oil on them, only grease. 

This guide I put together shows some of the steps involved in a complete service, including separating the mechanism plates to properly access all the gear shafts, belts and spindles that need cleaning and lubricating:

http://cinetinker.blogspot.com/2013/02/bolex-h16-rx5-disassembly.html
 

There are lots of things I didn’t go into: viewfinder cleaning, resetting the pull down timing after front removal, how to remake the light seal, checking the flange depth etc. If you’re handy you can probably work some of those things out as you go. It’s certainly a fun project for people who like to tinker with machines. For most people though, especially those wanting to use their cameras and rely on them to work properly, I think it’s easier and better to pay a Bolex technician to do the job.

[Robert Hart]

I understand that the governor bell and its pads need to be dry, not lubricated. Can you confirm or refute that as I only got the info secondhand.

[Simon Wyss]

Not necessarily

There are two types of brake pads, the older bigger ones and the younger tipped. I have experimented with many examples, removed everything several times, cleaned between oil, greases, and graphite. Oftentimes the governor needs to be dressed, the wire springs, the flyweights in their lugs, even the helical threads may cause trouble. I think at that point only an educated mechanic knows how to take care of that part of the gear train. But there’s more to an H than the laymen believes. I have found an almost dysfunctional clutch group just lately on an H-16. In ordinary running mode under spring energy no problems but when the spring was disengaged the mechanism was hard to turn. That took some work.

[Dom Jaeger]

3 hours ago, Robert Hart said:

I understand that the governor bell and its pads need to be dry, not lubricated. Can you confirm or refute that as I only got the info secondhand.

The service literature recommends dry lubricant in the form of graphite powder. I tend to use a light smear of dry moly paste. I would avoid oil or wet grease. 

[Robert Hart]

Dom. I am totally with you on that one. The calibration of the frame rate selector may be slightly out with moly paste. Once my camera had settled down after I roamed around inside, I loaded some clear leader and studied the shutter in the flicker of a PAL CRT TV screen. Without the pressure plate also dragging on the film it was pretty hit and miss as a test. I adjusted the speed until the flicker froze and the camera was synced up to 25FPS or 50Hz interlaced. My fixit was due to the camera having been heavikly dewed though it having been shipped to me in a freezer truck, then held for several hours before I was notified to go collect it. After cleaning out the moisture and adding lube where I tought it would be needed, The number on the control knob was just a hair past 24FPS which is pretty close. Not bad for a clockwork camera decades old. It holds sync for about fifteen seconds before drifting which again is not bad for clockwork.