camera repair · Photography

Nikon LENS SERIES E Zoom 36~72mm 1:3.5 – Reassembly

An interesting lens that I bought with a tired Nikon FM2.

Originally released in 1982 with the Nikon EM model as an economical range of lenses for a mature photographers. This lens design is intended to provide you with three lens functions in one package; a macro, a prime and a zoom. Matched with the EM, this made for a very useful kit.

But, what I have here in my hand needs some servicing. The glass is clear. After a check to see how the sliders and helicoid work, I find them very stiff, Especially the zoom, so I decided to disassemble, clean and reassemble.

To support me I found another blog showing how the parts were disassembled, including some original drawings.

So I started. I took it all apart. Except for the elements in their mountings. Now to put it all back together.

The Aperture Subassembly

This was the last part out, so I started here, then I discovered that the aperture blades were oily.

After disassembling the aperture subassembly, without disassembling the actual blade subassembly, I soaked the components in isopropyl alcohol to remove the oil and then used canned air to blow the parts clean.

Then I began my reassembly. First these two parts.

Then the retaining ring.

The the lens subassembly.

Turn it upside down. And drop the lens element in place; flat side down.

Finally, the retaining ring.

The Zoom Tube Subassembly

This subassembly took a couple of iterations to get the sequence correct.

I start with the front extension tube.

Place the aperture subassembly inside the tube.

I place the copper leaf springs in their pockets and drop some lube on the peak.

Then slide the zoom helicoid over the springs, noting the orientation marking.

Assemble the screws and nut blocks.

The Focal Length

The focal length scale tube is mounted to tube assembly, after extending the tube to its full length.

The Mounting Face

This is straight forward, making sure to catch the actuators for the aperture.

Once the sub assembly is done, put a cover so you can stand the lens.

The Focusing Ring

The outer focusing ring is in good shape even if there are a few nicks. However, the rubber grip is in good condition.

Position the focus stop.

The inner half of the helicoid looks good, after cleaning.

The infinite focus needs to be set before the focus ring is locked down.

camera repair · Photography

Mamiya M645 1000s – Light Seals

Some time ago I purchased a kit of seals for my Mamiya from an online shop located in Folkestone, England. The kit has enough seal material for two cameras. And, the kit comes with a short, pointed bamboo stick to push the seals it place (don’t use this stick to clean off the old seals, which I describe later in this blog).

two sheets of camera seals in the kit; on the left (showing the foam side, being the front of the seal) is the set for the door, on the right (showing the paper side that covers the sticky, being the back) is the set for the body.
There are three places the camera body that use seals; between the door and the body, the stop surface for the mirror, and the seat for roll film insert.

the door
The model that I am going to repair is a Mamiya M645 1000s, which was manufactured between 1976 and 1990. Not sure of the actual manufacturing date my camera, but I would guess it is from the late 1980’s. So after (at least) 30 years the seals have pretty much decomposed to a sticky, gooey mess. In the photo you can see that some trash has attached itself to the seal in the lower right hand corner.

the body
The channel for the door in the body is also a gooey mess. Here you can see the shutter window in the body. Don’t touch.

I used a non-acetone nail polis remover to soften the seals. Then, using a bamboo bbq skewer (don’t use the skewer supplied in the kit), I gently scrape the seals off the surfaces.

trimmed skewer (see the shadow)
For some of the areas I trimmed the end of skewer to give me a broad enough point to push up the sticky side of the old seal from the surface in the camera as I slid the end of the skewer along the surfaces where the seals are mounted.

If the point is too “pointy”, it will break off. If it is too broad, it will not fit against the bottom of the seal mounting surfces.

Be gentle as you slide the skewer along the surface, but be firm. After the removal of the seal, clean any residue using the nail polish remover.

cleaned door seal surfaces

the hinge areas on both the door and the body

the channel for the door in the body
The cleaning took about 30 minutes, using 20 cotton tipped sicks and about 10 skewers.

door with new seals

I put the door seals on first. Then I attached the seals in the body.

To keep the sticky side of the seal from attaching to the side walls of the channels, I gently stretch the seal and use the stick in the kit to place the seal on the bottom of the channel.

The whole job took me about an hour, just for the door. I didn’t replace any of the other seals because they still are holding their shape.

If you have questions, send a comment.