Compur (not so) Rapid

OK, so I am going back to do the things I shudda dun when I was younger, now that I am older. You can teach an old dog new tricks.

Four years ago I posted about the Rolleicord. At the time I did not have the knowledge to dig into the shutter, so I did not touch it. Recently I ran some shutter speed tests on it. The leaf shutter is running slow … so I need to investigate.

The Learn Camera Repair course covers servicing shutters … so now that I have gone through the course material, I can dig deeper … and so can you, AFTER you read the material.

With my Compur-Rapid shutter all speeds, except the two highest, are controlled through the speed escapement pallet and retard movement. If it is gummed up or not adjusted properly … or just tired, it will affect the shutter speeds.

So time to open it up.

The shutter does not have to be taken off the body … but I did so. To remove shutter … unscrew flash wire connection … then from the back unscrew the light baffle which is also the locking, with a spanner wrench.

Take note of the black slotted spacer + shutter release/cocking lever + copper spacer ring that sit between the shutter and body.

Ok, now unscrew the front group and rear element.

This one is a Triotar, a triplet, so a two element group in front and one in the back

The cover is held on by the centre plate

Turn the semi circle then rotate the plate to the cut-outs, to pull off.

Now the speed cam …

Note that there are three points that make contact with it … turn to different speeds and you will see the movement of these.

Also note the highest speed compresses a spring.

You can see the super spring on the left that is for 1/500s.

The shutter cocking ring (main lever) main spring is attached to the end of the speed escapement. Notice that this ring contacts multiple items in the shutter.

Unhook the end of the main spring and remove the main lever.

The retard speed escapement sits on the right side. It is secured at the top and bottom.

The retard escapement (which I also call the speed escapement) is what we are after. Remove it and clean it (ultrasonic).

Note that the top and bottom holes for the securing screws are oval … meaning that the escapement has adjustable positioning.

The retard lever, on the lower section has a special shape … feel the outside for any rough edges, as I had to lightly sand it to reduce the chance of the main lever catching on it when it pushes it.

While the escapement is out you can also check the movement of the shutter blades .. no sticking or slowness. If the shutter is not moving freely then this requires further disassembly to clean everything out … meaning no flushing.

Notice in the image above the retard has moved out of engagement with the gears, which will happen when the pallet lever is moved to its inward position.

Set the retard back in as noted in the Repair Course, and put it back in.

Note how both the pallet (red) and retard (green) ride against the outside of the main lever.

The position of the escapement (both top and bottom) control how the various speeds run.

You can put the speed cam back on. Ensure that the pallet lever and retard pin are not sitting under the cam, remember that they ride along the sides of the cutouts … then check the 1 second speed … if the escapement locks up then the bottom section need to be moved more to the outside. If the shutter stays open then move the top section more to the outside.

Once you have free movement you can start adjusting. The pallet and retard are combined for speeds 1/10s and below … for higher speeds the pallet is not engaged, just the retard is used to slow the main lever … except for 1/250s.

If the ~ 1/10s speeds are all slow then move the upper (pallet) end closer to the inside. If the upper speeds are slow the move the lower (retard) end further away from the inside.

This shutter’s highest speed is 1/500s, which is controlled by a separate coiled spring. The 1/250s is controlled by the main spring and does not touch the retard.

Getting the speeds right is a delicate balance of the position of the upper and lower sections, as noted in the course material … so have patience, as it can get frustrating when you try to make a correction. It does not require much movement of the escapement to make a difference.

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