Another … Seiko shutter.

There is s shutter hiding somewhere under this mess …

I gotta Mamiya … and it has busted parts … so I got another Mamiya … and it also has busted parts but not the same busted parts as the other Mamiya with busted parts.

The Mamiya Magazine 35 is the camera I am talking about. It has a Seikosha MXL shutter that is not working.

A number of older Japanese cameras used this type of shutter like the Minolta Autocord … hmm, this image I took 9 years ago when I first started this blog.

Ok, so back to this Mamiya … I got one and it had a problem (yeah what else is new) with the front of the lens. The front ring dials were loose and the lens label plate was missing … the aperture was hard to move …. shutter does not fire and who knows what else is really going on under that.

Ok, so lets get going … so first remove the magazine.

To just take a look at the shutter mechanism you can get access just from the front … but probably you will need to get deeper so you might want to jump to the section where I describe taking the lens/shutter off the body.

Unscrew the front element group … there could be notches for a spanner or you might have to use a rubber tool to grip it.

The front rings are supposed to be attached to the shutter cover plate but in this case some of the screws are no longer attached … ah, now I know why the front rings wobbled.

For some reason the design has the screws on the underside … hmm, the screws must be somewhere in the shutter … well that would probably be the cause of the shutter not working properly.

The shutter cover plate has a locking D thing … so turn it to the open position and then turn the plate to mate with the cutouts.

The speed cam sits under this. Note its position on the shutter and then remove it.

Note how the various rings fit together.

Now we can see the shutter to look for those missing screws … and also clean it up.

Remove the bottom end of the high speed spring on the cocking ring.

Lift off the shutter release lever (at 8 oclock) … note the spring attached to it.

Remove the high speed spring (it is beside the red lever)

[Yeah, I forgot to take a picture] Remove the shutter cocking ring to be able to manually open/close the shutter. The leaf lever is at 11 o’clock and has a tension spring on the right side, and a flash trigger contact on the left. Move both out of the way so you can push the leaf lever an keep the shutter open.

At this point I am able to feel and see the movements of both the shutter and aperture blades. In this shutter’s case, both have a nice shiny coating of something.

Best to remove the entire shutter from the rest of the body.

… from the back, remove the long aluminum L bracket – three large screws.

Take the back cover baffle off – four screws … pull it off.

Note the two springs … easier to unscrew the central post and then remove the springs.

Unhook the spring on the right lever.

From the front remove the four large screws and pull the shutter/optic assembly from the body

Ok, back to the back … with a spanner unscrew the outer notched ring (the inner one is the rear element … you can take that off first if you want)

Pull the shutter/optic off.

The various rings and levers may fall off … if they have not, look at where/how they are positioned.

Lift off the shutter charging ring/lever.

Lift off the outer casing

Lift off the shutter release ring/lever.

Lets just get straight to the shutter blades and aperture

Unscrew the flash socket attached to the side of the shutter.

From the back remove the three large black screws (short screw is by the flash lever)

Push the shutter out …

the shutter blades should fall off if they are clean.

… note that there are 6 blades and 5 posts … the last blade sits over the first blade.

Ok, in this image the shutter lever (with the spring) is still attached as I forgot to remove it.

The aperture blades are under a cover plate.

Set the aperture wide open

Remove the three screws lift off the plate

Remove the 5 aperture blades

Mark the bottom plate so you know what position it sits at when you put it back on.

To remove the bottom plate … go to the back and remove the two screws holding the aperture ring/lever on .

Now clean up all the components of the shutter … ie. blades, retard escapement, levers … and put it all back. Now that it is clean you can check the shutter timing.

Remember … the Learn Camera Repair website has the Nat Cam course on how to repair cameras and shutters (like this one).

Ticking time …

One of the early Japanese shutter manufactures was Seiko.

So back in 1881 Hattori Kintarō opened his watch making shop Hattori Tokei-ten. In 1892 he opened his Seikosha plant to make watches and clocks. By 1901 the company was the largest clock/watch dealer in Japan.

The company primarily made clocks and watches … but in the 1930’s they company started distributing cameras … also during this time the Seikosha plant starting making their own leaf shutters.

The first was the Magna shutter based on the Gauthier Vario shutter. These appeared on many cameras made by Kuribayashi. Then around 1935 they make a Deckel Compur copy called the Seikosha.

The Seikosha Rapid came out in the early 1940’s. It and it’s variants where found in many Japanese cameras … like the Minolta Autocord and the Mamiya Magazine 35.

Hattori Tokei-ten evolved into different companies … like Topcon, Epson and of course Seiko.

A leaf brief

One thing that commonly find with the many cameras that I have worked on is the shutter … the leaf shutter.

Leaf shutter

The leaf shutter that we see today first appeared in 1890, created by Voigtlander. It had four blades. Bausch & Lomb also produced many leaf shutters just after this.

Steinheil, was an optical company that got into the shutter business. Christian Bruns, in 1899, made their first 4 bladed leaf shutter.

Friedrick Deckel and Bruns got together (after leaving Steinheil) and created the Compound shutter in 1905 … the speeds where pneumatically controlled.

1910 Bruns created a mechanical retard mechanism to control the shutter speeds, and this became the Compur shutter.

When you see references to a Compur # something shutter … it refers to it’s physical size … leaf shutters were made in different sizes.

Another name in shutters was Gauthier … created by Alfred Gauthier in 1902. They are known for their many shutters, including the well known Prontor shutter.

Now the Japanese came much later to market their own leaf shutters based on both the Compur or Prontor design … in 1935 Seikosha shutters appeared and later on in 1946 the Copal shutter.

Other names in the shutter business … Wollensak and Ilex, both American companies.

Seikosha MX shutter

One thing that I have commonly encountered are cameras with shutter problems. Shutters that don’t work at all, ones with incorrect speeds, or ones that don’t have working slow speeds.

Many older cameras had Copal or similar type shutters.

Restoring these to working order is not that difficult … though getting into them may be difficult in some cases.

This is a Seikosha MX shutter. Very similar to a Copal.

The lower section controls the slow shutter speeds, usually less than 1/30x. These gears get gummed up. The easiest way to clean them is to use Rosonol. Apply the lighter fluid and then work the slow speeds. You probably will have to do this numerous times … and then you might have to do it again after the Rosonol evaporates.