How to open a Minox camera

How to open a Minox camera

There are hardly any instructions on how to open a Minox camera. I had to figure most of it out for myself and would like to share my experiences with you here.

Opening a Minox can be a nightmare if you don’t know exactly what you’re doing. It is easy to irreparably damage sensitive parts such as the shutter blades or make it impossible to assemble the camera. There is also the risk of accidentally changing settings or damaging the complicated internal mechanism.

How to use this guide

In order to service or repair the camera, you have to remove various housing parts. It took me a lot of research, time and Minox cameras to learn how to do it. Since it’s not obvious how to open an 8×11 Minox and there’s a lot you can do wrong, I wrote a comprehensive guide here to make it easier for you.

I have arranged the chapters in the same order as you would proceed when disassembling the camera.

Everywhere, I mention the purpose (Why?) for dismantling the relevant part of the housing. In addition, you will find the housing parts that must be dismantled beforehand so that the current dismantling can be carried out at all.

Please read my Legal Disclaimer before proceeding with how to open Minox camera.

The housing parts of a Minox camera

 

How to open a Minox camera
Minox A housing: 1 cap (top part), 2 bottom part, 3 front cover, 4 control panel

Remove the cap

Difficulty level

Simple

Risks

Scratching the cover if you slip with the screwdriver.

For what reason?

  • Required for the later opening of the control panel.
  • You can remove resin from the escapement if you don’t have to remove the control panel anyway.
  • However, you must always remove the control panel to oil the escapement bearings.

How?

  1. Open the film compartment and pull it all the way open.
  2. Loosen the 2 screws on the head side. Since space is limited in length, use a screwdriver bit. A short bit adapter can help apply more torque.
How to open the cap
Open the minox cap with a screw driver
  • Remove cap. You can now simply pull back he cap.
View on the escapement with the cap removed

Hints

  • The screw heads are sealed with a black lacquer that you have to scrape out of the slot with a scriber.
  • Since there isn’t enough space for a screwdriver, use a screwdriver bit. If a screw is too tight, you can turn the bit with pliers or use a bit adapter as shown in the photo above.

Remove the bottom part

Difficulty level

Medium

Risks

Overstretching of the blade springs.
Scratching the film chamber when loosening the starhead screw.

For what reason?

• To remove the front cover
• To remove the control panel
• To remove the back

Note: It is not necessary to remove the cap first.

How?

Dismantling

  1. Be sure to press the trigger first so that the shutter blades are free.
    This releases the shutter blades from the locking pins so they can move freely with the lower part in the blade guide. If the shutter is cocked, pulling the lower part would put unnecessary strain on the blade tension springs.
  2. Open the film compartment
  3. Unscrew the locking screw above the starhead screw a few turns
How to open the star screw
Housing with starhead screw (1) an locking screw (2)
Homemade screwdriver for starhead screw
How to open the star screw
Loosened starhead screw
  • Turn the starhead screw until it protrudes at least 3 turns. I recommend a special key for this purpose. You can make it from a scalpel by contour grinding. The screw has 3 slots so that you can reach the next slot after turning it 60°. Use the key to turn the screw until you reach the next slot and so on.
  • Turn the camera over and carefully pull off the lower part until the slot between the lower part and the control panel is approximately. 3 to 4 mm large.
How to identify the spring hooking arm
Spring hooking arm in housing
  • Through the slit you can now see part of the toothed copper spring hooking arm on the left.
    • Insert a thin screwdriver along the spring hooking arm as far as possible towards the lower end of the housing. Then carefully use the tip of the screwdriver to lever the spring hooking arm downwards by approximately 1 mm until you hear a quiet click.
      The following two pictures show a look inside the housing for a better understanding.
    Fastening of spring hooking arm in housing
    Spring hooking arm attached to housing. Move hook upwards (red arrow) to detach. 1: Housing attachment point (see picture below)

     

    Attachment point for spring hooking arm in bottom part
  • Now the spring hooking arm is detached from the lower part and you can completely remove the lower part without the spring hooking arm moving.
    If the spring hooking arm moves, it is still connected to the lower part. Then stop pulling immediately and first loosen the connection as described above.
    Attention: The spring hooking arm can be completely pulled out with the housing’s lower part. However, the highly sensitive shutter blades are then completely removed from their guide. They then hang freely on the spring hooking arm and can easily be damaged. It is therefore better to detach the spring hooking arm from the lower housing part beforehand. However, if the hook cannot be released in the manner described above, there is no other option but to pull out the hook together with the blades and the lower part of the housing completely.

  • After removing the bottom part, we see the spring hooking arm with the springs and blades protruding from the body of the Minox:

    How to open a Minox camera

    In the picture below left you can clearly see the guides for the blades. On the right the other end of the blades with the recesses for the release pins seen in the lens window:

    Reassembly of the bottom part

    1. Back and front cover must be assembled first.
    2. At the same time, push in the spring hooking arm and insert the blades into the blade guide. The best way to do this is to clamp the camera vertically in a vice so that you have both hands free.
    3. Place the lower housing part on the guide rails and push it all the way on so that the spring hooking arm engages in the lower part.
    4. Screw the starhead screw back in.
      Check: The lower part must not be able to be pulled out further than is necessary for tensioning (otherwise screw the starhed screw in further) and it must be easy to move (otherwise loosen the starhead screw slightly)
    5. Tighten the locking screw otherwise the protruding screw will hit the lower part when the camera is pushed together.

    Do not forget steps 4 and 5. If the locking screw is not screwed back in completely, the camera will jam when it is pushed together. If you forget to screw the starhead screw back in properly, you will pull the lower part off completely with a jerk during the first cocking of the shutter, damaging both the blades and their tension springs.

    Remove front cover

    Please read our Legal Disclaimer before proceeding.

    Difficulty level

    Medium

    For what reason?

    • To clean the viewfinder
    • To clean the filters
    • To clean the lens and the lens cover
    • To fix problems with defective shutter blades

    The front cover is held in place by a screw on the left below the viewfinder. Loosen the screw (with a 1.2 mm screwdriver) and pull the cover downwards.
    Note: Be careful not to lose the tiny screw.
    The filter unit is loosely attached to the slider under the front cover. The driver ensures that every time the camera is pushed together, the filter is pushed away from the lens.

    How to open the front cover
    Minox A front cover: 1 lens cover, 2 viewfinder, 3 yellow/green filter, 4 filter slider, 5 driver for filter reset

    Now you have access to the viewfinder, the filter unit and the blade guide:

    How to open the front cover
    Minox A front without cover
    How to open the front cover
    Minox BL front without cover

    Remove the control panel

    Difficulty level

    Difficult

    Risks

    The distance dial and image counter disc can fall out, which may require complex readjustment of the lens and the film feeding mechanism.

    For what reason?

    • Remove resin and oil of the escapement mechanism
    • Grease the spring hooking arm
    • Grease the guide surfaces on the housing to pull the camera apart
    • Set the coupling between distance dial and lens
    • Set the image counter
    • Set negative distance

    How?

    Dismantling

    1. The cap must be removed first.
    2. Set the shutter speed to ½ s because this time is set automatically when the control panel is removed. Otherwise the shutter speed dial will be positioned incorrectly when it is mounted later.
    3. Set the distance to infinity as a precaution in case the distance dial falls out.
    4. Loosen the screw on the upper part of the control panel.
    How to open the control panel
    Minox control panel locking screw
    • Now comes the hardest part.
    How to open the control panel
    Lift control panel

    After loosening the screws you are ready to lift the control panel at the top. At the bottom of the control panel there is a tab that reaches into the camera body and secures it from being lifted. Now fix the distance dial with one finger and lift the upper end of the control panel with your other hand. As soon as the control panel is far enough above the distance dial, carefully push the control panel backwards until it slides out of the tab and remove it. The distance dial must be kept in place at all times!

    Caution: When the control panel is removed, the distance dial and the image counter disc can slip and fall out of the housing when moving the spring hooking arm. Inserting and adjusting this unit is complex, so always press with one finger when operating the spring hooking arm to cock the shutter.

    Reassembly

    1. Push the spring hooking arm all the way in.
    2. Position the image counter disk correctly. Check with the control panel in place, see chapter Image Counter.
    3. Set the shutter speed to ½ s.
    4. Slide on the control panel at the bottom tab, leaving enough space at the top to avoid touching the distance dial.
    5. Adjust the distance dial with tweezers until the control panel can slide over it.
    6. Carefully press the control panel down over the distance dial and adjust both correctly.
    7. Press the control panel down.
    8. Screw in both screws

    Remove the back cover

    Difficulty level

    Simple

    Risks

    • Viewfinder can be spotted
    • Pressure plate can be damaged

    For what reason?

    • Adjust distance setting, set lens to infinity
    • Clean the pressure plate
    • Clean viewfinder
    • Adjust the pressure plate
    • Measure shutter speeds with conventional method
      Read here my reflective Minox specific method without dismantling the camera

    Preconditions

    • Bottom part is removed

    How?

    Dismantling

    How to open the back cover
    Back cover
    1. Loosen the two screws.
    2. Remove cover.
    How to open the back cover
    Back without cover
    • Remove pressure plate.
    Back without pressure plate
    • Remove the viewfinder glass cover.

    Reassembly

    Reassembly is done in reverse order.

    Summary on how to open a Minox camera

    Knowing how to open a Minox camera is a prerequisite for being able to carry out repairs. I hope this has been described in sufficient detail here. You can now start to repair your Minox.

    Nevertheless, something may be missing or unclear. In this case, please use the comment function at the end of the article.

    Back to Minox repair

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