Kodak Kodex Shutter     to list of articles  

     ©Infotech 2007  All Rights Reserved

Operation                                                                Removing the mechanism plate
Disassembly to reach the shutter mechanism             Reassembly    
Shutter operation                                                    Adjusting focus
Removing the shutter parts


 

Caution: This article is provided for information purposes only. Neither Infotech nor the author can be liable for any damage caused when following these instructions. Success in camera repair depends on the skill of the technician. If you're new to camera repair, please practice on equipment that has no value before working on a unit you want to save. We have checked the article for errors. However, if there are errors we didn't catch, the extent of our liability is to correct such errors when we learn about them. can be liable for any damage caused when following these instructions. Success in camera repair depends on the skill of the technician. If you're new to camera repair, please practice on equipment that has no value before working on a unit you want to save. We have checked the article for errors. However, if there are errors we didn't catch, the extent of our liability is to correct such errors when we learn about them.

The Kodex is a simple Kodak shutter used often in the early Kodak folding cameras. It's very similar to other Kodak multiple-speed shutters of the era such as the Dakon and the Kodon. The shutter has an single-action release—pushing down the release lever, Fig. 1, both cocks and releases the shutter.

There are three instantaneous shutter speeds—1/25, 1/50, and 1/100 second—with time and bulb. Set the shutter by moving the speed-control lever, Fig. 1, along the shutter-speed scale. When you push the release lever at the time setting, the shutter stays open until you push the release lever a second time. At the bulb setting, the shutter stays open as long as you hold down the release lever. The shutter closes when you allow the release lever to return.

That long metal strap in Fig. 1 connects the release lever to the release linkage in the camera. Pushing the camera’s release button then pulls down the release lever. A screw holds the metal strap to the camera’s release linkage—it’s necessary to remove the screw to take off the shutter. Next remove the shutter by unscrewing the retaining ring at the back of the film aperture.

Set the aperture by moving the diaphragm-control lever along the f/stop scale, Fig. 1. Focus the lens by turning the front-lens group (front-lens focusing). The infinity stop, Fig. 1, prevents the front-lens group from turning past infinity and from turning past the closest focus distance.

The Kodex has a front-cell focusing lens—the focus ring turns only the front cell to focus the lens. The front cell screws in or out along the threads of the stationary middle lens group. Focusing the lens just changes the separation between the front lens group and the middle lens group (the interlens distance).

At infinity and at the closest focus setting, the infinity-stop screw, Fig. 1, comes against the infinity stop on the nameplate. The infinity-stop screw screws into the side of the focus ring. Use a jewelers screwdriver to unscrew the infinity-stop screw.

The front lens group will now unscrew—but you may lose the focus adjustment. Shutters of this type often have multiple starting threads on the middle lens group. You may then be able to start the front lens group in different positions. To retain the focus adjustment, turn the front lens group slowly in a counterclockwise direction—try to note the position of the front-lens group when the threads disengage from the middle lens group. On reassembly, start the front lens group at the same position. You may not be that concerned about the accuracy of the focus adjustment—vintage shutters such as this one may never again be used to shoot pictures. So it's up to you whether or not you want to retain all the adjustments.

Only the middle lens group holds the nameplate, Fig. 1, in place. Unscrew the middle lens group and lift off the nameplate. The nameplate sits on top of—and keys to—the front plate shown in Fig. 2.

Four screws at the back of the shutter, Fig. 3, hold the front plate. Remove the front plate by taking out the four screws. Also unscrew the rear lens group, Fig. 3.

You’ve just uncovered the shutter mechanism, Fig. 4. Unless you need to reach the shutter blades or the diaphragm, this may be as far as you’ll have to disassemble the shutter.

You can still change the shutter speeds by moving the speed-control lever, Fig. 4. Two pins on the speed-control lever move the speed-control cam lever that sits under the main lever. The long pin on the speed-control lever also controls the time and bulb levers. In Fig. 4, we’ve set the speed-control fully to the right—the fastest instantaneous shutter speed, 1/100 second.

Over the range of three instantaneous shutter speeds, a cam surface at the end of the speed-control cam lever sets the height of the main lever—the end of the main lever that contacts the leaf lever, Fig. 4. The height of the main lever affects the length of engagement between the main lever and the leaf lever. The longer the main lever remains engaged with the leaf lever, the slower the shutter speed.

At 1/100 second, Fig. 4, the speed-control cam lever has moved the end of the main lever to its
highest position. The main lever now stays engaged with the leaf lever for the minimum amount of time. As soon as the main lever releases the leaf lever, the shutter blades close.

Examine the operation by slowly pushing the release lever. The end of the release lever, Fig. 5, pushes the main lever in a clockwise direction—until the end of the main lever moves to the left of the tab on the leaf lever—the position shown in Fig. 5. When you push the release lever a little further, its end moves past the main lever. Now the mainspring drives the main lever counterclockwise. The end of the main lever comes against the tab on the leaf lever and rotates the leaf lever in a clockwise direction—against the pressure of the leaf-lever spring.

A link on the leaf lever, Fig. 4, sits over a post on the blade-operating ring. As the leaf lever moves clockwise, this link moves the blade-operating ring counterclockwise to open the shutter blades. The end of the main lever then clears the leaf-lever tab. Now the leaf-lever spring returns the leaf lever in a counterclockwise direction. And the leaf-lever link pulls the blade-operating ring clockwise to close the shutter blades.

You can see that the sooner the main lever lets go of the release lever the sooner the blades close. And the faster the faster the resulting exposure time. Setting the end of the main lever at its highest point, Fig. 4, then provides the fastest shutter speed.

As you move the speed-control lever to your left, notice how the end of the main lever drops down.
The lower the end of the main lever, the longer the main lever remains engaged with the leaf lever. And the longer the shutter blades stay open for a slower shutter speed.

There’s some additional speed control provided by the inertia weight, Fig. 5. At the slowest instantaneous shutter speed, the leaf lever has to kick the inertia weight out of its way—both on the opening stroke and on the closing stroke. The inertia weight then slows the movement of the leaf lever, in opening and in closing the shutter blades. At the fastest shutter speed, the main lever disengages before the leaf lever swings far enough to contact the inertia weight. The inertia weight then has no effect on the shutter speed. And at 1/50 second—the in-between speed—the leaf lever barely moves the inertia weight.

To prepare for the next exposure, the release lever must return to its start position. As the release lever returns, its end passes under the left-hand end of the main lever—the release lever just pushes the end of the main lever up and out of its way. But the operation is a little different at the time setting.

At the instantaneous speeds, Fig. 4, the long pin on the speed-control lever prevents the time and bulb levers from moving. But at time (speed-control lever all the way to the left, Fig. 6), both the time lever and the bulb lever move unrestricted. When you push the release lever, the shutter blades open and the bulb lever moves into engagement with the main lever to hold the blades open—the projection on the side of the bulb lever engages the tab on the main lever. When you let up the release lever, the tab on the release lever pushes the bulb lever out of engagement with the main lever. But now the time lever swings into engagement with the main-lever tab, Fig. 7. The blades stay open.

Notice in Fig. 7 that the time lever also catches the release lever. The time lever now prevents the release lever from returning all the way to its rest position.

Push the release lever a second time to close the shutter blades. The tab on the release lever now pushes the time lever out of engagement with the main-lever tab. The main lever completes it release movement, allowing the shutter blades to close. And the release lever can then return fully to its start position.

At the bulb setting, Fig. 8, the long pin on the speed-control lever blocks the time lever—but not the bulb lever. When you push the release lever, the bulb lever stops the main lever as before—with the shutter blades in the open position. And, when you let up the release lever, the release-lever tab pushes the bulb lever out of engagement with the main lever. But now the time lever can’t move into engagement with the main-lever tab—it’s blocked by the long pin on the speed-control lever. The blades then close for bulb action.

Notice the connection of the time-bulb lever spring—the short end of the spring connects to the bulb lever while the long end connects to the time lever, Fig. 9. One spring can then move both levers. Disconnect the short end of the spring from the bulb lever. Swing the spring clockwise—away from both the time lever and the bulb lever. You can leave the time/bulb-lever spring on the mechanism-plate post.

Remove the screw holding the time and bulb levers, Fig. 9. Lift the time and bulb levers from their post. You can now separate the time and bulb levers for cleaning.

Next disconnect the mainspring from the tab on the mechanism plate, Fig. 10. Remove the screw holding the main lever. Lift out the main lever together with the mainspring.

You now have a clear view of the speed-control cam lever, Fig. 11. Notice the cam-shaped end that raises the end of the main lever according to the shutter speed. Lift out the washer that sits above the speed-control slider, Fig. 11. Then lift the speed-control slider up and off the post.

It’s not necessary to remove any of the remaining parts. In fact, it would be very difficult to remove the release lever or the leaf lever—both parts are held by rivets rather than by screws.

To reach the shutter blades and the blade-operating ring, it’s necessary to remove the mechanism plate, Fig. 12. One caution—after  you remove the mechanism plate, the diaphragm assembly will be loose. It’s desirable to keep the diaphragm assembly in place until you can scribe its position. First turn the diaphragm-control lever clockwise, Fig. 12, to open the diaphragm fully.

Now remove the four small, countersunk screws that hold the mechanism plate, Fig. 12. One of the screws sits partially under the release lever. Hold the release lever in the released (counterclockwise) position to reach the screw. The screw still isn’t fully uncovered. But you can leave the screw in its mechanism-plate hole—just make sure that it’s completely unscrewed.

Next carefully lift out the mechanism plate. Remember, you don’t want to dislodge the diaphragm assembly, Fig. 13, until you scribe its position. The speed-control lever, Fig. 13, is also loose. Lift out the speed-control lever.

With the diaphragm fully open, place a scribe line on the diaphragm-control ring and a matching scribe line on the base plate, Fig. 13. The scribe lines mark the rotational position of the diaphragm-control ring with the diaphragm leaves fully open. You can now lift out the diaphragm assembly. You’ll note that the diaphragm assembly is one unit—the diaphragm leaves attach to the underside of the diaphragm-control ring. The pins on the diaphragm leaves fit into the slots in the base plate, Fig. 14.

Five screws hold the base plate to the shutter housing. But notice that there are two different types of screws. Three of the screws have flat fillister heads and two of the screws have rounded—or pan—heads. Fig. 14 points out the positions of the two pan-head screws.

Remove all five screws holding the base plate. Then lift out the base plate, exposing the shutter blades, Fig. 15. There are actually six shutter blades—two of the blades go over the same pins. Lift out all six shutter blades. Remember to handle the shutter blades with tweezers—never with your fingers.

The blade-operating ring fits under the heads of five rivets, Fig. 16. Rotate the blade-operating ring until its semicircular cutouts align with the rivet heads. You can then lift out the blade-operating ring.

Lubrication:
The Kodex shutter needs very little lubrication. You may want to rub dry moly into the blade-operating ring. Be sure to blow off any excess--if you don't, the dry moly will find its way to the inside lens surfaces. You can also apply a tiny amount of shutter grease during installation to to following points:

• the slot in the speed-control cam lever which rides against the pins of the speed-control lever.
• the tip of the main lever that comes against the lug on the leaf lever.
• the tab on the main lever that's engaged by the time and bulb levers.
• the tip of the release lever that comes against the end of the main lever.
• the tab on the release lever that comes against the bulb lever and the time lever.

Install the blade-operating ring by aligning its semicircular cutouts with the rivet heads on the shutter housing. Then rotate the blade-operating ring until its long post—the post that’s engaged by the leaf –lever link—is at around a 3 o’clock position, Fig. 17. The blade-operating ring should turn very freely.

Next install the first shutter blade as shown in Fig. 17—the slot in the shutter blade fits over the post on the shutter housing, and the round hole in the shutter blade fits over the post on the blade-operating ring. Turn the blade-operating ring until the shutter blade is in the open position as shown in Fig. 17.

Install the next four shutter blades in counterclockwise rotation, Fig. 18 . Finally install the last blade—the cover blade—over the posts of the first blade installed.

Note the position of the base plate in Fig.19—the notch in the outer circumference of the base plate aligns with the release-lever cutout in the shutter housing. One of the base-plate slots fits over the long post on the blade-operating ring.

Be careful that you don’t dislodge the shutter blades as you seat the base plate. Before replacing the base-plate screws, you might hold down the base plate and check the operation of the shutter blades. Turn the blade-operating ring by moving its long post, Fig. 19—counterclockwise to open the shutter blades and clockwise to close the shutter blades. The shutter blades should open and close freely and evenly. When you’re sure the operation is correct, replace the base-plate screws—replace the three flat-head screws first and then replace the two pan-head screws. Once again check the operation of the shutter blades to make sure a blade hasn’t come out of position.

Note: Since the Kodex is a relatively simple shutter, we haven't used step-by-step reassembly photos. Fig. 20 shows the shutter mechanism completely reassembled for your reference. However, we have put links to the appropriate disassembly photos. Just click on a link if you need to check back.

Now for the diaphragm assembly—first make sure that the diaphragm leaves are in the fully open position (you can work through the center opening in the diaphragm-control ring to shift the blades to the open position). Then seat the diaphragm assembly by aligning the scribe lines you made during disassembly, Fig. 13. Put a slight downward pressure on the diaphragm assembly—you should be able to feel the pins of the diaphragm leaves click into their slots in the base plate.

Seat the speed-control lever on the base plate as shown in Fig. 13. Now carefully seat the mechanism plate. As you seat the mechanism plate, pass the hole in the leaf-lever link over the post on the blade-operating ring. Also make sure the release strap (the metal strap attached to the release lever) passes through its shutter-housing cutout as shown in Fig. 20. Shift the mechanism plate as necessary until its screw holes align with the screw holes in the base plate. You may also have to shift the speed-control lever—make sure that both of the pins on the speed-control lever pass through the mechanism-plate slot. When the mechanism plate seats fully and the screw holes align, replace the four countersunk screws (one of the screws may still be in place under the release lever).

Again check the operation of the diaphragm to make sure all the leaves are in position. Also check the shutter-blade action. Push the leaf lever to open the shutter blades. When you let go of the leaf lever, the leaf-lever spring should snap the blades closed.

Now seat the speed-control cam lever over its post, Fig. 11. Replace the washer on top of the speed-control cam lever.

You can now check the operation. Push down the release lever. The action should both cock and release the shutter. When you let go of the release lever, the release lever should return to its start position.

Next seat the time lever under the bulb lever. Replace both the time lever and the bulb lever at the same time—pass the free ends of the levers under the tab at the upper end of the main lever and seat the pivot ends of the levers over the mechanism-plate post. Replace the screw that holds the time and bulb levers.

Connect the time/bulb-lever spring as shown in Fig. 9—the long end of the spring to the tab on the time lever and the short end of the spring to the tab on the bulb lever. You can now check all shutter operations.

To complete the shutter reassembly, seat the front plate—the shorter slot in the front plate passes over the speed-control lever while the longer slot passes over the diaphragm-control lever, Fig. 2.  There's a locating hole in the front plate at around a 7 O'clock position--this hole fits over the post for the time/bulb-lever spring. When you feel the front plate seat fully, replace the four screws from the back of the shutter. Now seat the nameplate on top of the front plate. A downward-projecting tab on the front plate keys to a slot in the front plate. Screw in the middle lens group—the middle lens group holds the front plate in place.

Finally screw in the rear lens group and the front lens group. Screw in the front lens group fully. Then back out the front lens group until the screw hole next to the infinity calibration is counterclockwise of the infinity stop on the front plate. Replace the infinity-stop screw.

Note: If you have a way to check infinity focus, you can precisely set the front lens group. Locate the three setscrews around the outer circumference of the focus ring—these setscrews hold the focus ring to the front lens group. After loosening the setscrews, you can turn the focus ring without moving the front lens group. You may find that the lens reaches infinity focus before the infinity-stop screw comes against the infinity stop. The lens then goes past infinity. Or the lens may never reach the best infinity focus. Here's how you can adjust the focus:

• Lens goes past infinity. Turn the focus ring until the lens produces a sharp image at infinity. Then loosen the three setscrews on the focus ring. Hold the front lens group to prevent it from turning. Now turn the focus ring until the infinity-stop screw comes against the infinity stop. Both the front lens group and the focus ring are now at the infinity setting. Tighten the three setscrews.
• Lens doesn't reach infinity. Remove the infinity-stop screw. Now turn the focus ring past the infinity position until the lens produces a sharp image at infinity. Now loosen the three setscrews on the focus ring. While holding the front lens group to prevent it from turning, turn the focus ring counterclockwise--until the screw hole for the infinity-stop screw is just counterclockwise of the infinity stop on the front plate. Tighten the three setscrews and replace the infinity-stop screw.