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Tag Archives: DIY

Some Good references for Minolta Autocord TLR Focus Level Jam / Stuck Problem repair

 

This is how the focus mechanism look like

http://www.flickr.com/photos/18067251@N04/sets/72157626869741228/with/5791030324/

If your focus knob broke, perhaps you can try this method:

http://www.flickr.com/photos/photoplastic/sets/72157594558177497/with/403607988/

 

Some tips on possible quick-fix for the focus level stuck / jam problem

Reference:

http://www.apug.org/forums/forum51/78631-minolta-autocord-broken-focus-lever.html

If you want to loosen up the focus, you can:

1) Open the back. Maybe remove one of the door hinges to remove the back completley.
2) See that black cup around the lens? It simply presses in to place. Insert two fingers, spread apart, and twist. It should release after a few tries. Lift out.
3) See that large brass piece? On its outer side, it is threaded. It is this part that moves in and out as you focus, moving the lens panel with it.
4) Well, you can’t really see the threads, but if you can drip Naphtha at the joint between the body and the brass piece, do it. An eyedropper, syrige, or draftsman’ inking pen. Lightly, let it sit, a bit more, etc. Give it a few hours. The naphtha should be able to wick in and start loosening the grease.
5) Be patient, try not to flood it. Small applications over time will be safer for other mechanisms.
6) When (if?) it loosens up, exercise it. Then drip just a few drops of light oil into the same area from the back when the focus is set to infinity (brass block pulled back into the body). The basic idea is to dissolve the old grease in the fresh oil.

I did this with my first Autocord and it still works well, 6 months later. Since then I have completely disassembled the mechanism for cleaning on other Autocords.

Also, you’ll see two screws holding the focus scale in place, one on each side of the camera. Remove these, remove the focus scale, and you’ll have a much better hold on what remains of the focus lever. Might even be able to scab something on, superglue a block or such. With the scale out of the way, it’ll be clearer what the options are. You’ll also get a peek at the same focus mechanism and brass block. Another place to attack the old grease.

A third place to attack the old grease is from inside the viewing lens chamber. Remove the hood (4 small screws) and you’ll get another peek at the brass block.

Both of these places, be careful not to flood the camera with oil or solvent. Light, precise applications.

Great lenses, great design. I think only a Planar 2.8 will get me away from the Autocord and have me go back to a focus knob rather than the lever on the Autocord.”

 

 

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Repair Mamiya TLR Lenses

Recently my mamiya tlr 65mm lens got problem – the shutter blade won’t open at whatever speeds. I did some internet search and found some very useful information regarding repairing or fixing mamiya tlr lenses.

below is a summary of these information from various sources:

the first set of pictures are from flickr: Jones_Industries

Broken
1
2
4
3
6
5
Fixed
The second set of pictures are from soundsk
#1
#2
#3
Mamiya 65mm f/3.5 exploded view
Mamiya Service Manual 65mm Lenses
Shutter Blades cleaning
Clean and assembled, ready to shoot!!
Testing focus...
Most thankfully, soundsk also provided two exploded view of the lens, as below
photo

Mamiya Service Manual 65mm Lenses

Scans from the Mamiya Service Manual, courtesy of the very kind Jack Fisher from photo.net

 

photo

Mamiya 65mm f/3.5 exploded view

Scans from the Mamiya Service Manual, courtesy of the very kind Jack Fisher from photo.net

 

some detailed information regarding how to service / repair mamiya tlr or lenses can be found in a french blog site: http://tlr-mamiya-c.blogspot.sg/

of course, you can use google translate to make it to english

 

and lastly, an enlightening post on dpreview: http://forums.dpreview.com/forums/thread/2944339

Lessons learned from restoring old Mamiya TLR lenses
Jan 23, 2011

For the older photographers in our forum, that use or plan to use Mamiya TLR cameras and lenses. Here are my lessons learned from repairing a couple of used “chrome” Mamiya TLR lenses. The usual disclaimer, use the lessons learned at your own risk.

Zero, before you start handling the lenses wash your hands. Use a clean white towel on a well lighted table as your work area. Should a part or screw fall out it will not go far and can be seen.

First, do not remove the lens from the back plane frame, there is no need to access the lens from that side. Front and rear optical assemblies unscrew. There is no need to use a spanner wrench on the retaining clamps that secure the lens to the supporting frame.

Second, if the shutter will not cock the chances are a single screw has come loose within the shutter assembly that can be restored. This screw is located at the two O’clock position viewing the exposed taking lens shutter assembly straight on with upper rings and cam plate removed, viewing lens at 12 o’clock.

Third, if the shutter cocks but does not operate the blades when released a different screw is loose or has fallen out, that can be restored. This is located just south of the release lever mechanism. Check all screws for tightness.

Fourth, never use oil on any part of the shutter mechanism or ring assemblies or aperture assemblies.

Fifth, if the aperture blades mechanism is stuck or sticky, this can be cured using small amounts of 91% isopropyl rubbing alcohol applied with a damp Q-tip. To access the aperture internal assembly, This will require unscrewing the rear optical assembly. Work the mechanism manually using the aperture selector arm, do not touch the blades with your fingers and use another Q-tip to remove excess and any grime. Do not use oil. Be sure to remove any lint left behind by the Q-tips prior to reassembly.

Sixth, if the shutter ring is sticky or the clicks indents are not “sharp”, disassemble the two rings and clean them with isopropyl alcohol. Slightly bend the metal finger on the cam plate that engages the indents on the shutter selection ring.

Seventh, screws are tiny, and can be lost in a flash. For most repairs I have done only one screw has to be removed.

Eighth, acquire the proper tools, i.e. jewelers screwdrivers, needle nose tweezers, etc. A spanner wrench designed for lenses is required (see lesson 10) to remove the optical retaining rings that hold the individual elements. If you do this be sure to note on paper which side is up, in or out facing. Do not rely on your memory.

Ninth, use ROR per the instructions to clean the optics, and do not use canned air.

Tenth, use rubbing alcohol mentioned above with your finger tips (no fingernails, just skin) in a circular motion to remove fungus clouds from optical surfaces. It may require several times to completely remove the fungus. Do not allow excess to drip anywhere. Clean with a lint free, chemical free (no anti static chemicals used in the dryer), white cotton t-shirt. Then use ROR with a t-shirt to remove any residues.

So far, I have restored two Mamiya TLR chrome shutter lenses and both are working fine now. They were a lost cause when I started. They are simple in design and easy to restore.

If you have any second thoughts I recommend taking your lens to a repair facility. But if you are a risk taker and have some common mechanical sense, my lessons learned may prove useful. Search the web for other information sources, and photographs of the lens assembly.

Good luck,

d2f