argus C3 Rangefinder Film Camera Owner’s Manual

Argus Model C3
SERVICE GUIDE

C-3 SHUTTER AND RELATED PARTS

00406
00407
00408
00409
00410
00411
14151| SHUTTER ESCAPEMENT (New Style)
1st Gear
2nd Gear
Scar Gear
Pallet
Frame Assembly
Screw, Frame
SHUTTER ASSEMBLY, WITH HARD RUBBER BLADES
---|---|---
21| 412| Plate, Shutter Front
22| 413| Blade, Shutter
23| 414| Plate, Inner Shutter
24| 415| Ring, Shutter Control
25| 90057| Screw, Shutter Mounting
26| 416| Screw, Shutter Plate
| 417| Base Plate Assembly
| 418| Spring, Shutter
| 114860| SHUTTER ASSEMBLY, WITH
| | METAL BLADES
| 14523| Plate, Shutter Front
| 14520| Blade, Shutter (Metal)
| 14522| Plate, Inner Shutter
| 14364| Shutter Control Ring & Pin Assembly
| 14166| Screw, Shutter Place
| 14363| Base. Plate Assembly
| 14528| Spring, Shutter
| 14275| Shutter Mounting Screw ( Long)
| 90059| Shutter Mounting Screw (Short )
| | LINKAGE ASSEMBLY
27| 14203| Link, Wire
28| 14200| Lever, Triangular
29| 14201| Bearing, Stud
30| 14199| Screw, Speed Adjuster
31| 14198| Adjuster, Shutter Speed
32| 14197| Spring, Linkage
33| 14196| Pin.
| 14814| CAM FOLLOWER
| 14819| SHUTTER. COCKING LEVER
| 14215| Set Screw

The Argus C-3, Fig. 2, is a good example of a 35mm camera using a built-in behind-the-lens shutter. In theArgusC-3, almost q third of the volume of the camera body is used to house the shutter mechanism. The result of the Argus design is a shutter that is inexpensive to manufacture, easy to service, and quite dependable — three factors which contributed to making the Argus C-3 one of the most popular 35mm cameras ever designed.

The Argus C-3 has two controls in addition to the setting ever and the release button. One of these controls — the SPEED KNOB–operates a cam to determine the amount of retard, Fig.3.

The other control permits “bulb” operation –just turn the knurled release button from “I” (instantaneous)to “B” (bulb), Fig. 4.
Notice that the speed knob, Fig. 3, contains the number calibrations 4 through 8. The particular Argus C-3 illustrated is called the “Matchmatic,” a name that refers to the unique method of calibrating the shutter speeds and the f/stops. Other Argus C-3 models are calibrated in the conventional fractions of a second. The numbers on the Matchmatic speed knob refer to the following shutter speeds:
8 — 1/300 second
7 — 1/125 second
6 — 1/60 second
5 — 1/30 second
4 — 1/10 second.

REMOVING THE FRONT PLATE IN THE ARGUS C-3
The front plate assemblies of the various Argus C-3 cameras vary only slightly. In the older models, the setting lever is held by a set screw. Just loosen the setscrew and unscrew the setting lever in a counterclockwise direction.
But the setting lever setscrew is eliminated in the later models — such as the camera illustrated. Instead, a JAM NUT –located immediately under the setting lever, Fig. 5 — holds the setting lever in place. The setting lever post (on the main lever, as you’ll see in a moment) has a left-hand thread. So moving the setting lever counterclockwise to cock the shutter binds the jam nut and the setting lever more tightly against one another.

Hold the newer-style setting lever stationary with your fingers and turn the jam nut counterclockwise with a thin-headed wrench — you are now moving the jam nut away from the setting lever. Then, unscrew the setting lever from its post by turning it in a clockwise direction –and, after removing the setting lever, turn off the jam nut in the same direction.
CAUTION: Do not remove the Argus C-3 speed knob during the front plate disassembly — the speed knob remains in place on the front plate. In Mathematics, the speed knob retaining screw is covered by the cemented calibration plate. But in other models, the screw is visible — and there’s always a temptation to remove an exposed screw. The speed cam — which controls the movement of the retard section — is attached to the back side of the speed knob. So by removing the screw, you lose the timing between the speed knob and the speed cam. You can, however, see the proper speed cam timing in figures 7 and 8.
Five or six screws (the number depending on the model) retain the front plate to the camera body. These screws are underneath the leatherette covering the front plate, as indicated by the arrows in figure 3. So carefully lift the leatherette at the four corners of the front plate with your bench knife — try to avoid tearing or sharply creasing the leatherette.

VARIATIONS ON THE ESCAPEMENT RETARD

Another screw is located at the bottom center of the front plate — as indicated by the dashed arrow in figure 3. And, in some models, there is a sixth screw adjacent to the rangefinder window. You can reach the lower screw without completely re-moving the leatherette –either lift the bottom of the leatherette or cut the leatherette as indicated by the dashed arrow, Fig. 3. Make your cut very carefully with the sharp point of your bench knife — when you later recement the leatherette, the cut will be almost undetectable.
If the sixth retaining screw is used, you can cut the leatherette by the rangefinder window, Fig. 6. Remove all off, the flat-headed screws which hold the front plate. Then, carefully lift off the front plate — be careful you don’t drop out the CAM FOLLOWER which remains with the front plate, Fig. 7.

CAUTION:
The front lens for the eyepiece may be loose once you’ve removed the front plate. If so, lift out the lens to prevent loss or damage –the lens sits in the round cavity to the right of the rangefinder assembly, Fig. 10.
Figure 7 shows the inside of the front plate –here, you can see the speed cam and the cam follower. The pin on the cam follower fits into the hole in the BELL CRANK (in the lower right-hand corner of the camera body, Fig. 9). The bell crank is part of the linkage between the speed cam and the speed escapement, also pointed out in figure 9.

SHUTTER SET TO 1/300 SECOND (“8” ON MATHEMATICS)

SHUTTER SET TO 1/10 SECOND (“4” ON MATHEMATICS)
You’ll notice that the cam follower is at its highest position when the camera is set to the fastest shutter speed (1/300 second), Fig. 7. And the cam follower is at its lowest position when the shutter is set to the slowest shutter speed (1/10second), Fig. 8.

OPERATION OF THE ARGUS C-3 SHUTTER

The main lever in the Argus C-3 is multiple cams, Fig. 9. The SHUTTLECOCK and a long phosphor bronze ribbon — the SHUTTLECOCK RIBBON — connect the ma in lever to the tension-type mainspring.

To cock the shutter, rotate the main lever in a counterclockwise direction with your finger — as shown in figure 10. The main lever is then latched in the cocked position by the lower end of the RELEASE PLUNGER, Fig. 11.

Depressing the release button pushes the release plunger down to free the main lever. Now, the mainspring pulls the shuttlecock from left to right, causing the main lever to rotate in a clockwise

direction. The shuttlecock assembly, during its release travel, contacts a lug on the blade operating ring to open the shutter blades — you’ll be able to see the action of the shuttlecock more clearly after we remove the shutter blade assembly. A spring on the blade operating ring, not yet visible, then closes the shutter blades.
Since you’ve removed the front plate — and, along with it, the speed cam and the cam follower — the shutter now delivers the fastest speed (1/300 second). The reason is that the bell cranks spring, Fig . 11:holds the bell cranks all the way in the counterclockwise direction.
Setting slower shutter speeds pushes the bell crank in a clockwise direction — the speed cam pushes the cam follower down, and the cam follower in turn rotates the bell crank. Notice in figure 11 that a long WIRE LINK connects the bell crank to the RETARD LEVER in the speed escapement.
In its present position — 1/300 second — the retard lever holds the first gear segment (in the speed escapement) away from the lobe at the bottom of the main lever. But as you select slower speeds, the bell crank pulls the retard lever away from the first gear segment. The first gear segment then turns clockwise, under its own spring tension, as simulated in figure 12 — now, the pin (on the first gear segment) is in the position to intercept the lobe (on the main lever) during the release cycle.
So the position of the bell crank determines the position of the retard lever and the retard lever decides how far the.

The first gear segment rotates in a clockwise direction. The farther the first gear segment moves clockwise, the longer it remains in contact with the main lever lobe during the release cycle — and the slower the resulting shutter speed.
The bell crank pivots on an eccentric bearing which provides an adjustment point for the shutter speeds. You’ll adjust the shutter speeds after replacing the front plate — a hole through the front plate allows you to reach the eccentric bearing, as you’ll see a little later.
You can see that the ArgusC-3 retard system is quite unlike anything examined in previous systems. But the most unusual part of the whole design is the time at which the retard is introduced. In other shutters we’ve discussed, the blades open fully before the speed escapement slows down the main lever — the escapement then holds the blades fully open for the required length of time. Yet in the Argus C-3, the main lever strikes the first gear segment just as the blades start to open. So the retard is introduced during the blade-opening time –the slower the shutter speed, the more slowly the blades open.
The position of the pin on the first gear segment at the slowest shutter speed is critical — careful observation now will help you in adjusting the escapement during reassembly. That is, the speed escapement has a sliding adjustment — after loosening the two screws shown in figure 13, you can slide the complete escapement to adjust its position. Referring to figure 13, here’s the timing you should note:

With the first gear segment in the slowest-speed position and the main lever in the cocked position, the lobe on the main lever should contact the pin on the first gear segment — but, at the same time, complete rotation of the main lever must be possible without interference from the first gear segment. To obtain the “bulb” action, rotate the release button until its “B” calibration aligns with the index dot on the camera body. Turning the release button to “B” rotates the release plunger to the position shown in figure 14. Now, when you release the shutter, the blades open to the full-open position –but the flatted

end of the release plunger catches the upper lug on the main lever, Fig: 15. Consequently, the main lever is arrested before the shuttlecock has moved far enough for the shutter blades to close. When you let up on the release button, the release plunger frees the main lever –so the main lever completes its rotation and the shuttlecock moves past the lug on the blade. operating ring.

DISASSEMBLY OF THE ARGUS C-3 SHUTTER

Remove the shutter blade assembly by taking out the three screws shown in figure 16. Now, on the back of the assembly, you can see the spring-loaded blade operating ring lug that is engaged by the shuttlecock assembly to open the blades, Fig. 17.

The shuttlecock is also clearly visible at this time, Fig. 18. During the cocking cycle, the pivoting action of the spring-loaded SHUTTLECOCK LATCH, Fig. 18, allows the latch to bypass the blade operating ring lug –but on the release cycle, the shuttle-cock latch engages the lug and drives the blades to the open position.

Now, disconnect the wire link from the retard lever. Remove the two screws shown in figure 19 and lift out the entire speed escapement.
Disconnect the two tension springs — the bell crank spring and the mainspring –from the post on the camera body, Fig. 19. Remove the main lever by taking out the screw through its threaded post, Fig. 19.

To remove the release plunger, first take out the setscrew at the end of the camera body, Fig. 20 — but be careful: a spring and a ball detent remain inside the cavity. The ball detent acts on the rotating part of the release plunger assembly, holding it in either the “I” or the “B” position; and the setscrew you just removed determines the amount of spring tension on the detent. You can now remove the spring and the ball detent from the setscrew cavity.
Remove the brass pin screw at the front of the camera, Fig. 19, and lift out the release plunger. A release plunger is a complete unit which does not require further disassembly.”
As we mentioned earlier, the bel I crank pivots on an eccentric bearing. The eccentric bearing is pointed out in figure 21; the screw, also seen in figure 21, both holds the adjustment of the eccentric bearing and retain the bell crank. To take out the bell crank, remove the screw and the eccentric bearing. Now, lift out the bell crank and the wire link — you’ll have to adjust the eccentric bearing on reassembly to time the shutter speeds.

You will rarely have to disassemble the camera any further than we have just done — at least to service the shutter. The disassembly and adjustment of the rangefinder pointed out in figure 19, are covered in a later lesson — avoid disturbing the rangefinder at this time.

REASSEMBLY OF THE ARGUS C-3 SHUTTER

Replace the bell crank and the wire. link as one assembly. Then, seat the eccentric bearing and replace the retaining screw — make sure the eccentric shoulder on the bearing passes through the hole in the bell crank. While tightening the screw, check to assure that the bell crank pivots freely. Insert the release plunger assembly through its hole at the top of the camera — the elongated slot in the release plunger (which receives the brass pin screw) must be to the front of the camera. Then, replace the brass pin screw from the front of the camera. The release plunger should now rotate freely between the “B” and “I” positions — remember, the ball detent and spring hold the release plunger at either setting. Place first the ball detent, and then the spring, into the cavity at the end of the camera body. Then, tighten the setscrew until you feel the two solid “click-stop” positions of the release plunge. r. Before replacing the main lever and shuttlecock assembly, examine the joint between the shuttlecock ribbon and the main lever, Fig. 22. You can see that the shuttlecock ribbon is soldered within a slot in the body of the main lever. Replacing a broken shuttlecock ribbon is one of your more common repairs in the Argus C-3.

Handle the shuttlecock ribbon very carefully as you lower the main lever into position. Accidentally placing a kink in the shuttlecock ribbon could cause the metal to fail during the shutter operation. When the assembly is fully seated, replace the main lever retaining screw and hook the end of the mainspring over its post. Test the movement of the main lever by cocking and releasing the shutter several times.
Hook the end Of the bell crank spring over the post on the camera body. Now, cock the shutter and seat the speed escapement in position. Make sure that both the main lever lobe and the retard lever (with its hole end down) are to the right of the stud on the first gear segment. Then, replace the two strews holding the speed escapement. Before tightening the two screws, adjust the speed escapement to the position shown in figure 13. Then,.tighten the two screws to hold the adjustment. Check your adjustment by cocking and releasing the shutter several times — the stud on the first gear segment must not slip past the main lever lobe as you cock the shutter. When you’re sure the retard position is correct, hook the end of the wire link to the hole in the retard lever.
As you seat the shutter blade assembly, make sure the stud on the blade operating ring is toward the top of the camera. Then, replace the three retaining screws — the long screw goes to the bottom of the shutter blade assembly.

ADJUSTMENTS ON THE ARGUS C-3 MAIN LEVER

We mentioned earlier that the main lever is multiple cams. Actually, the main lever is in three separate parts — and the relationships of these parts to one another may require adjustment on reassembly. The two screws provided at the front of the main lever, Fig. 23, hold the sections of the main lever together as one piece –but by loosening the screws, you can reposition each part of the main lever.

The three sections of the main lever are the main BODY which secures the shuttlecock ribbon, Fig. 22; the RELEASE CAM which engages the release plunger and the pin on the first gear segment, Fig. 23; and the SYNC CAM which closes the internal sync contacts, Fig. 23. To adjust the release cam, you must loosen both of the screws shown in figure 23. But to adjust the sync cam, just loosen the one screw indicated by the dashed arrow.
First, let’s check the adjustment of the release cam. Cock the shutter and set the release plunger to “bulb.” Now, release the shutter and hold the release button depressed — the shutter blades should remain fully open. But if the release cam is out of adjustment, the shutter blades either will fail to remain open on the “bulb,” or will open only part way.
Say, for example, that the shutter blades remain partially open on the “bulb” — this means that the main lever is blocked by the release plunger before rotating far enough to allow full blade opening.
The correction is to continue holding the shutter open on the “bulb” and loosen the two screws, Fig. 23 — loosening the screws allows the body of the main lever to turn separately from the release cam. Now, while the release cam remains held by the release plunger, allow the body of the main lever to rotate slowly (clockwise) until the blades are fully open –then, retighten the screws. As the body of the main lever turns clockwise, the shuttle-, cock ribbon moves farther to the right — and that allows the shuttlecock to open the blades the additional amount.
The other symptom of maladjustment is that the blades open and close before the release cam is arrested by the release plunger. Consequently, the shutter delivers an instantaneous speed when set to “bulb.” The correction is to loosen the two ‘screws and turn the body of the main lever counterclockwise in relation to the release cam.
Once you’ve adjusted the release cam at “bulb,” you can check the timing of the sync cam. Since only one of the two screws in figure 23 holds the sync cam, adjusting the flash sync doesn’t disturb the release cam adjustment.
Compared to some of the other shutters you’ve studied, the operation of the Argus C-3 flash sync is quite simple. Locate the lug on the sync cam in figure 23 — as the main lever revolves in the release (clockwise) direction, this lug strikes the movable sync contact. The sync cam lug then pushes the movable sync contact against the fixed sync contact to fire the flash.
By loosening the sync cam screw, Fig. 23, you can move the sync cam to change the time at which the flash is fired. Here, you have a wide adjustment range –by just turning the sync cam, you can change the sync delay all the way from “F” sync to “X” sync.
Most Argus C-3s are set for “F” sync –that is, the contacts close to fire the flash just before the shutter blades start to open. The actual delay is then the time it takes for the blades to reach the full-open position. But if your customer wants you to convert his Argus C-3 to “X” sync for electronic flash, all you have to do is turn the sync cam until the contacts close when. the blades reach the full-open position.

REPLACING THE FRONT PLATE AND ADJUSTING

THE SHUTTER SPEEDS IN THE ARGUS C-3
When either the speed escapement or the bell crank has been removed, you must readjust the shutter speeds. Strip back the leatherette from the lower right- hand corner of the front plate to reveal the inspection disc, Fig. 24. By removing the inspection disc, you can reach the eccentric bearing on the bell crank.

Set the speed cam at the highest speed (for ease of alignment) and fit the cam follower in position, Fig. 7. Now, seat the front plate on the camera body –you can work through the inspection hole in the front plate to fit the cam follower pin into the bell crank hole. Then, replace the screws holding the front plate — the long screw, if there is one, goes beside the rangefinder window. Depress the release button to make sure the shutter is in the released position. Now, replace the setting lever — remember, the setscrew type has a right-hand thread, while the jam-nut type has a left-hand thread. If you’re installing the setscrew-type, turn the setting lever clockwise as far as it will go. Then, back off the setting lever until it points to 10:30 o’clock, Fig. 25, and tighten the setscrew.
But if you’re installing the jam-nut type, first screw on the jam nut in a counterclockwise direction as far as it wil4 go. Then, turn the setting lever all the way down to the jam nut. Back off the setting lever to 10:30 o’clock, Fig. 25. While holding the setting lever in position, use a thin-headed wrench to turn the jam nut clockwise –until the jam nut is tight against the underside of the setting lever.

You can now make a fairly accurate adjustment of the speeds by just listening to the retardaction. At the fastest shutter speed, there should be no retard action — and there should be just a trace of retard at the next-to-the-highest speed. Cock the shutter and set the speed knob to the fastest speed (1/300 second). Now, while restraining the setting lever to slow down the main lever’s rotation, push the release button. As you allow the main lever to run slowly through its cycle, listen for the sound of the retard. If you can detect retard engagement at 1/300 second, you must adjust the eccentric bearing. working. through the inspection hole in the front plate, loosen the bell crank screw, and turn the eccentric bearing. Set the eccentric bearing so you can hear no retard action at the fastest speed, and just a trace of retard at the next-to-the-highest speed.
But if you can’t get enough adjustment out .of the eccentric bearing, you may have to bend the wire in ink to change its effective length. Shortening the wire link provides less retard, and lengthening the wire link provides more retard. Bending the wire link is a rough adjustment for the shutter speeds — you can then make fine adjustments by turning the bell crank lever eccentric.
When you’re sure, everything is working properly, recement the leatherette. PI iobond, a rubber-based cement, works well for this purpose. Apply a thin film of Pliobond to both surfaces –the camera body and the back of the leatherette — and allow the cement to dry until it is tacky. Be sure your cement is applied. evenly — “lumps” of excessive cement can damage certain types of leatherette. Then, press the leatherette to the camera body.

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