If you’re a collector of old cameras, you may have several Kodak Ball Bearing Shutters—even in different sizes. Kodak introduced the Ball Bearing Shutter, Fig. 1, in 1909, and many of Kodak’s folding cameras have used the Ball Bearing Shutter. Since the Ball Bearing Shutter is so plentiful, it makes a good first shutter for people learning about camera repair and restoration. In fact, many years ago National Camera used the Ball Bearing Shutter as one of the first learning projects for students.

The Ball Bearing Shutter gets its name from the ball race for the shutter blades. The blade-operating ring (the ring that carries the shutter blades) rides on the ball bearings. As a result, the shutter blades open and close very freely.

Set the shutter speed with the speed-setting lever at the top of the shutter. The Ball Bearing Shutter features one of the simplest of speed-control systems—variable spring tension. As you change the shutter-speed setting, you're changing the tension of the mainspring (the spring that drives the main lever). The greater the mainspring tension, the faster the shutter speed. Pushing the release lever both cocks and releases the shutter. There’s no cocking lever.

The shutter also has time and bulb settings. At bulb, the shutter stays open as long as you hold down the release lever. At time, the shutter stays open even when you let up the release lever. To close the shutter, push the release lever a second time.

REACHING THE BALL BEARINGS
If the shutter-blade movement seems sluggish, the ball race may be dirty. You can reach the ball bearings by removing the flange at the back of the shutter; four countersunk screws hold the flange (these are the screws at the inner edge of the housing—the screws at the outer edge of the housing hold the front plate. Careful—with the rear flange removed, the ball bearings will be loose.

Take out the four countersunk screws and carefully lift off the flange. Don't turn over the shutter—the five ball bearings and the five spacers will fall out.

The ball bearings and the spacers fit within a channel in the blade-operating ring, Fig. 2. If you remove the ball bearings and spacers, be very careful to avoid loss. You can get generic 1.5mm ball bearings. But you can't buy the spacers.

Don't use any lubrication here—the ball race should be clean and dry. As you replace the ball bearings and spacers, fit the parts within the blade-operating-ring channel. Alternate the spacers and ball bearings as shown in Fig. 2. Then replace the rear flange.

You could have scribed the position of the rear flange to note its proper position. However, you can’t make a mistake here—there’s only one position at which all four screw holes will align. Replace the rear flange and the four countersunk screws.

REMOVING AND REPLACING THE FRONT PLATE
Removing the front plate disengages the speed-setting lever and the diaphragm-setting ring from the parts they control. However, you should not have trouble coupling the parts on reassembly. In some versions, the diaphragm remains with the front plate rather than on the mechanism plate. It's then only necessary to couple the speed-setting lever during reassembly.

Take out the five screws at the back of the shutter—the screws at the outer edge of the shutter housing, Fig. 2. Then lift off the front plate. Fig. 3 shows the shutter with the front plate removed. A pin on the speed-setting lever (remaining with the front plate) fits into the slot in the control lever, Fig. 3. The diaphragm-setting ring also remains with the front plate; a slot in the diaphragm-setting ring fits over the upturned tab on the diaphragm-control ring, Fig. 4 (except in versions that have the diaphragm assembly in the front plate).

To replace the front plate, first turn the diaphragm-control ring, Fig. 4, fully clockwise; the diaphragm opens to the largest aperture. Also turn the diaphragm-setting ring in the front plate to the full-open position—fully clockwise as seen from the front of the front plate. Again, there's no diaphragm coupling to worry about in versions with the diaphragm assembly in the front plate.

Set the control lever, Fig. 3, to its center click-stop position—that’s the 1/50-second position. Align the pointer on the speed-setting lever (on the front plate) with the “50” calibration.

Gently seat the front plate on the shutter housing. You can watch the pin on the speed-setting lever passing through the slot in the control lever. Turn the front plate slightly until you feel it “click” into place (a slot at the back of the front plate then fits over the post for the main lever, Fig. 3—that’s the click you can feel). When the front plate seats fully, check the diaphragm coupling—make sure the diaphragm opens and closes as you turn the diaphragm-setting ring. You can look through the small slot in the diaphragm-setting ring to make sure it fits over the tab on the diaphragm-control ring, Fig. 4. Then replace the five front-plate screws at the back of the shutter housing.

OPERATION OF THE BALL BEARING SHUTTER
With the front plate removed, you can observe all of the operation. Slowly push down the release lever. Note that the release lever moves the main lever in a clockwise direction—this is the cocking cycle that tensions the mainspring, Fig. 3.

The slotted lower end of the main lever rides up and over the sloped lug on the blade-operating ring. When the main-lever slot clears the blade-operating-ring lug, the main lever snaps down to its normal position. Now the slot in the main lever straddles the lug on the blade-operating ring, Fig. 4.

As you continue pushing down the release lever, the release cycle begins. First the end of the release lever—the end that’s been pushing the main lever clockwise—clears the end of the main lever. Now the mainspring drives the main lever in a counterclockwise direction. The slotted end of the main lever pulls the blade-operating ring in the same direction, opening the shutter blades.

When the blades reach the full-open position, the end of the main lever slips off the blade-operating-ring lug. Now free, the blade-operating ring moves clockwise to close the shutter blades. The blade-operating-ring spring, Fig. 4, drives the blade-operating ring in the clockwise direction.

SPEED CONTROL IN THE BALL BEARING SHUTTER
The end of the mainspring hooks to the control lever, Fig. 3. Set faster shutter speeds by moving the control lever clockwise. The spring-hooking end of the control lever moves down, adding tension to the mainspring.

At the same time, you’re adding tension to the blade-operating-ring spring –the spring that closes the shutter blades. The short end of the blade-operating-ring spring hooks to the mainspring, Fig. 3. Increasing the tension on the mainspring causes the shutter blades to open faster; increasing the tension on the blade-operating-ring spring causes the shutter blades to close faster. The system is ingeniously simple. But it can only give a limited shutter-speed range—1/25 second through 1/100 second.

The bulb lever, Fig. 5, adds bulb operation to the shutter-speed range. At the bulb setting, the control lever allows the bulb lever to move up far enough to catch the tab on the main lever—before the main lever frees the blade-operating ring. The bulb lever catches the main-lever tab when the blades reach the full-open position. As long as you hold down the release lever, the shutter blades stay open.

When you let up the release lever, the bulb lever disengages from the main lever. Notice the upturned tab on the release lever, Fig. 5. As the release lever moves clockwise, its upturned tab pushes the bulb lever in the same direction. The bulb lever frees the main lever. And the main lever completes its release movement, allowing the shutter blades to close.

At the time setting, the control lever frees the time lever; the time lever mounts on top of the bulb lever, Fig. 5. The bulb lever catches the main lever with the blades open—just as it does during bulb operation. But when you let up the release lever, the time lever catches the tab on the main lever. Now the time lever holds the main lever to keep the shutter blades open as shown in Fig. 5.

Another lug on the time lever now blocks the release lever--the time lever prevents the release lever from returning fully to the start position. When you push the release lever again, the tab on the release lever comes against the upper lug on the time lever. The release lever now pushes the time lever out of engagement with the tab on the main lever. The main lever completes its release movement, and the shutter blades close.

DISASSEMBLY OF THE BALL BEARING SHUTTER
1. Disconnect the long end of the time/bulb-lever spring from the edge of the time lever, Fig. 5. Let off the spring tension by allowing the long spring end to move clockwise. Then lift the time/bulb-lever spring from the post.

Note: The time/bulb-lever spring may resist coming off the post. You can use a jewelers screwdriver and work from the bottom of the spring coil. Gently pry up one side of the spring coil from the post. Then gently pry up another side until you can remove the time/bulb-lever spring. Be sure to keep a finger on top of the time/bulb-lever spring—just to prevent the spring from flying elsewhere.

2. Lift out the two-piece lever (time lever and bulb lever).
3. Disconnect the long end of the release-lever spring from the hole in the mechanism plate, Fig. 6.
4. Push the release lever to the released position (fully counterclockwise). Then lift out the release lever together with the release-lever spring. The release-lever spring is now loose.
5. Disconnect the bounce spring from the main lever, Fig. 6 .

Note: The bounce spring prevents the shutter blades from bouncing open after the exposure. As the main lever pulls the blade-operating ring in the opening direction, it swings the bounce spring away from the blade-operating-ring tab. Then the main lever completes its movement and moves the bounce spring back into the path of the blade-operating ring. The shutter blades close. When the shutter blades then try to bounce open, the bounce spring blocks the blade-operating ring.

6. Disconnect the blade-operating-ring spring from the mainspring, Fig. 6.
7. Disconnect the upper end of the mainspring from the control lever, Fig. 6.
8. Lift out the main lever together with the mainspring. The mainspring is now loose.

Note: This is a good time to check the freedom of the blade-operating ring. Push the tab of the blade-operating ring to open the shutter blades. Then release the tab. The blade-operating-ring spring should snap the shutter blades to the closed position. If so, you may not have to go any further in disassembly. But if the blade action appears sluggish, you’ll probably have to clean the blade-operating ring and the shutter blades.

9. Disconnect the lower end of the blade-operating-ring spring from the hole in the blade-operating-ring tab, Fig. 7
10. Remove the control lever by taking out its shoulder screw, Fig. 7.
11. Remove the blade-operating-ring spring by taking out its shoulder screw, Fig. 7.

Note: Two screws and the control lever hold the diaphragm assembly in place. Before you remove the screws, turn the diaphragm-control ring clockwise to fully open the shutter blades. Then scribe the position of the diaphragm-control ring—put one scribe line on the diaphragm-control ring and a matching scribe line on the mechanism plate. It’s possible to install the diaphragm assembly in any of several positions. But only one position is correct. You’ve scribed that position—when the diaphragm is fully open, the scribe lines should align.

12. Remove the two silver-colored screws that hold down the diaphragm assembly.
13. Lift out the diaphragm assembly—the diaphragm leaves stay with the diaphragm-control ring as one unit.

Note: You can now see the mechanism-plate slots that receive the pins on the diaphragm leaves, Fig. 8. How do you know which pins go in which slots? That’s why you scribed the diaphragm-control ring.

REMOVING & REPLACING THE SHUTTER BLADES
If you want to remove the shutter blades, proceed as follows:

1. Push the blade-operating-ring tab from left to right to open the shutter blades. There’s a better chance the blades will now stay in place when you remove the mechanism plate.
2. It’s not necessary to remove the bounce spring. Take out the five screws holding the mechanism plate from the front of the shutter, Fig. 8.
3. Carefully lift the mechanism plate up and out of the shutter housing.
4. If you’re gentle when lifting out the mechanism plate, the shutter blades should stay in place, Fig. 9. You can now note the starting-blade position and the direction of rotation. Chances are you'll encounter variations on the blade positions. Your notes will then be handy for reassembly.

Note: Once you remove the shutter blades, the blade-operating ring will spin freely in either direction. Here’s another place a scribe line will facilitate reassembly—scribe the shutter housing to note the position of the blade-operating-ring tab with the blades in the opened position. Or, after you remove the shutter blades, put a scribe line on the blade-operating ring and a matching scribe line on the shutter housing. This scribe will both help you start the blade-operating ring in the proper position and tell you which way is right side up for the shutter blades. If you start with the blade-operating ring in the opened position, you know to install the shutter blades in the opened position. What if you install a shutter blade upside down? That blade will then be in the closed position rather than the opened position.

5. Lift out the six shutter blades. Six? Even though there are only five blade positions, there are six shutter blades. One blade serves as a cover blade, an additional insurance that no light will leak through the closed shutter blades.
6. The blade-operating ring should now spin freely—very freely, because it runs on ball bearings. If you want to remove the blade-operating ring, take out the rear flange as previously described. Remove the ball bearings and the spacers, Fig. 2. You can then drop out the blade-operating ring.

REPLACING THE SHUTTER BLADES
1. Turn the blade-operating ring to the opened position as shown in Fig. 10. It’s easier to find the opened position if you have scribed the housing as previously described.
2. Seat the first shutter blade as shown in Fig. 10. The slot in the shutter blade fits over the pin on the blade-operating ring; the round hole in the shutter blade fits over the pin on the shutter housing.
3. Replace the next four shutter blades in counterclockwise rotation.
4. That leaves one shutter blade –the cover blade. Seat the cover blade on top of the first blade you installed. The position shown in Fig. 10 is the position for both the first blade and the cover blade.
5. Make sure that all six shutter blades are seated over their two pins, Fig. 9. Also check the position of the bounce spring, Fig. 8. With the mechanism plate removed, the bounce spring may have turned 180°. Then carefully seat the mechanism plate, Fig. 8; fit the slot in the mechanism plate (the slot by the bounce spring) over the tab on the blade-operating ring. Here’s where you need a steady hand—a tremor may knock one or more shutter blades out of place.
6. With the mechanism plate fully seated, the five screw holes align with the five screw holes in the shutter housing. Replace one or two of the screws—you can then check for proper operation. Move the tab on the blade-operating ring to close and open the shutter blades. The blade-operating ring should move freely. Plus the shutter blades should open and close evenly, thereby telling you that each shutter blade is still over its two pins. If the shutter passes the test, replace the remaining screws holding the mechanism plate.

COMPLETING THE REASSEMBLY
You scribed the diaphragm-control ring with the diaphragm leaves in the full-open position. Before you replace the diaphragm-control ring, position the diaphragm leaves—align the inner edge of each leaf with the circumference of the diaphragm-control-ring center hole. Now seat the diaphragm-control ring by matching your scribe lines.

Check by holding down the diaphragm-control ring. Then slowly turn the diaphragm-control ring in a counterclockwise direction. The diaphragm leaves should close, forming an even aperture. If a leaf pin isn’t within the slot in the mechanism plate, you’ll see an uneven aperture. In that case, return the diaphragm-control ring to the full-open position. Gently prod the errant diaphragm leaf to the open position and again test the operation.

When the diaphragm assembly works properly, replace the two screws that hold down the diaphragm-control ring, Fig. 7. Also replace the blade-operating-ring spring with its shoulder screw and the control lever with its shoulder screw, Fig. 7. Check the control lever by moving it to its different positions. The control lever should move freely. But you should feel a solid click stop at each setting.

Lightly lubricate the control-lever detent notches in the shutter housing with shutter grease. You can also put a touch of grease in the control-lever notch that hooks the mainspring. The mainspring then slides more easily as you change the shutter-speed setting.

Hook the long end of the blade-operating-ring spring within the hole in the blade-operating-ring tab, Fig. 7. Check by moving the blade-operating-ring tab to open the shutter blades. Then let go of the blade-operating-ring tab. The blade-operating-ring spring should snap the shutter blades to the closed position.

Seat the mainspring within the main lever—you can see the proper mainspring position in Fig. 6. Hook the short end of the mainspring to the inside of the small tab on the main lever. Then seat the main lever with the mainspring over the mechanism-plate post.

With the main lever fully seated, hook the long end of the mainspring to the notched tab of the control lever, Fig. 6. Also hook the end of the bounce spring over the top of the main lever, Fig. 6. Hook the short end of the blade-operating-ring spring to the mainspring as shown in Fig. 6.

Seat the release-lever spring within the release lever—the coil in the release-lever spring aligns with the two holes in the release lever (the holes that pass over the mechanism-plate post). Position the short end of the release-lever spring to the top of the release-lever tab, Fig. 6. Then seat the release lever over the mechanism-plate post, Fig. 6—make sure the post passes through the coil of the release-lever spring.

With the release lever seated, pull the long end of the release-lever spring in a clockwise direction--hook the spring end within the hole in the mechanism plate, Fig. 6. You can now check the operation. Push down the release lever. The lower end of the main lever should move up and over the blade-operating-ring tab. When you push the release lever far enough to free the main lever, the shutter should release—the main lever should swing in a counterclockwise direction, opening the shutter blades. The shutter blades should snap closed when the main lever clears the tab on the blade-operating ring.

Make sure the release lever returns fully to its released position. When you allow the release lever to return after the release cycle, the tip of the release lever should push the upper end of the main lever up and out of its way. The tip of the release lever then passes under the end of the main lever—even if you allow the release lever to return slowly. If the release lever can’t get by the main lever, the release-lever spring may be too weak.

Also check the operation of the bounce spring. The bounce spring should move down—away from the blade-operating-ring tab—as the main lever pulls the blade-operating ring to open the shutter blades. When the main lever finishes its movement and allows the shutter blades to close, the bounce spring should move into the path of the blade-operating-ring tab. The bounce-prevention spring now prevents the blade-operating ring from bouncing open.

Put a touch of grease on the front edge and on the sloped top of the release-lever tab (the tab that comes against the end of the main lever). Also put a little grease on the left-hand edge of the control-lever tab (the tab that operates the time and bulb levers, Fig. 5). Finally, put a little grease on the right-hand face of the release-lever tab, Fig. 5. The tab comes against the cam surface of the bulb lever.

Seat the time-bulb lever assembly of the mechanism-plate post as shown in Fig. 5. Then seat the time/bulb-lever spring on top of the post. Hook the short end of the time/bulb-lever spring to the inside edge of the bulb lever, Fig. 5. Pull the long end of the time/bulb-lever spring counterclockwise and hook it to the outside edge of the time lever, Fig. 5. Check the operation at the bulb and time settings.

Lubricate the latching surface of the bulb lever and the latching surface of the time lever, Fig. 5, with shutter grease.