Another … back … again

Man, I really am going back to the beginning … seven years ago I got my first Mamiya Six.

I did some exterior cleaning … internal view/rangefinder cleaning … got knob … then I put it on the “collection” shelf.

Ok, so I decided to pull it off the shelf and take another look at it. Figure I should check out this flash delay mechanism on top of the shutter … hmm, not much to it but not the easiest thing to understand.

Two screws to take of the cover .

Hmm … no comment.

Things move but I am still not sure what it is supposed to do … oh well, put the cover back.

One of the things in my reassessing is that the shutter is not working at lower speeds. Back when I first got this camera I did not have the knowledge to understand how this shutter worked so I just could not fix it … now thanks to https://learncamerarepair.com/ I now know.

The NKS-Tokio shutter is a Gauthier type shutter.

Ok, so opening it up … unscrew some stuff on the front.

Firing the shutter I can see that the star wheel is not engaging the pallet smoothly.

I noted the spring that pushes the shutter was not sitting right under it’s shouldered screw thus impeding its tension. I took that apart and seated the spring correctly.

Ok, so now the slow speed escapement needed to be removed and cleaned.

This is when I found that the pallet lever was not attached properly, so I took it apart, cleaned it and secured it back on.

Now it engages the star wheel without sticking.

Put it all back together … fiddle with the positioning … now I have the slow speeds back to expected levels.

When I got this camera I knew that there was a missing part.

One of the spool securing knobs was missing. Lucky for me a friend made me a new one

I finished the knob on my Unimat with exception of the knurling.

One mis-step and you’re filed !!

Ok, so I’ma testing the TKS shutter on my Frank Six to see how off they are … hey its old and tired … most of the speeds are within 1/4 stop, except for 1/10s which is too fast.

The shutter on this camera is a Gauthier Prontor type copy. From what I have learned about these leaf shutters there are certain speeds that engage a pallet and retard, on this shutter the 1/10s is the fastest one that engages both, so that means some lever is not being engaged.

OK, the first thing to do is …

Get down to the speed cam.

The pallet and retard mechanism is really what we are hunting for.

Lets take a closer look underneath

Ok so some arrows to point the way … I fired the shutter and noted what moved.

Ok, so putting the speed cam back on I fired the shutter and watched those points that engage it at the different speeds … especially below and above 1/10s.

OK, so the cam setting for 1/10s sits on the noted post on the cam … and I noticed that it does not travel very far to keep the timing.

So I filed a bit off … checked the speed … filed a bit more off, and then suddenly I got 1/10s !!!

This is one of the things noted in the National Camera Course material … sometimes you have to physically modify the cam to get the speed correct.

Pronto, pronto … Prontor.

Ok, so I got an Agfa Isolette with the bunch of folders from Goodwill. This camera was really cheap … so this has now become a test subject … or should I say an experience building project. Since joining the Learn Camera Repair FaceBook group, I have worked further into the restorations that have have done, particularly the shutter … scientia potentia est … knowledge is power.

I tore down this shutter to individual components, cleaning them, and then tried to put it all back in WORKING order … well, it was a chore … appears I have taken this apart about five times.

What did I learn?

1. Camera Repair tech’s deserve the money they charge.
2. Read repair course lesson 7.
3. You never have enough hands.

So lets take a look at a Gauthier based Prontor-S shutter.

Note: if the metal parts look nice and clean it is because I took these images after I cleaned it … and sorry about the different colour temp of light as I added an additional illumination but it is warm white.

Another Note: to really finish off the blades you should put a bit of Moly on them … Molybdenum Disulfide (MoS2) powder.

First you need to get the front element ring cap thing off.

Set focus to infinity. Loosen the three tiny grub screws, then remove the ring. Mark the front elements position to the focus mark … or just collimate later.

Unscrew front element

Unscrew rear element.

Turn half-head lock screw

Unscrew inner notched securing ring.

Take off cover plate.

Full off speed cam ring.

The printed speeds point to the shutter setting lever.

Take a real good look at the movement of the levers and also how the tension springs are located … I have a closeup image later in the program.

Setting/main lever on top … speeds escapement … delay timer escapement … release lever … bunch of other levers.

So lets go … take apart to reveal shutter blades … layered

aperture | shutter | everything else

Flip over – turn the aperture dial to reveal the four screws … mark the position of the long one

Hold the bottom, and pivot out with the flash port at base and pull off

Clean blades (those are my fingerprints before I  cleaned up the blades … I really should not be handling them that way) and other things

Note the orientation/position of the blades.

Flip over.

Remove little tension spring on the bottom, one end of it anchors to the shutter ring and the other to the long screw that was removed from the back.

At 1 o’clock you can see the leaf lever engaging the pin on the shutter ring. Remove the cover thing. You will need to disengage the leaf lever from the pin.

Flip over

Remove the five screws+washers

Now you can clean up the ring and other surfaces.

Put the ring back on and remember to attach the leaf lever.

To take off self timer escapement, note the positioning of the large spring and pop it off the left side. Underneath there is an arm that catches the escapement that you will have to release, then turn self timer lever to align the  curved cutout notch

To take off speed escapement you have to cock the shutter to reveal a black screw … the second screw is the tall one.

Off to the ultrasonic cleaner … and a tiny dab of watch oil on the pins afterwards.

You can take this entire part into a cleaning bath … or if you are really ambitious you can take it all apart. I have done it but I did not take any pictures of it … and I really do not want to do it again just to show you.

At this point you really want to take good look at how all the levers are positioned, how they move, and most importantly how the springs are anchored … draw a spring map of what you can see.

Some tips from the experience:

Go slow and start with the topmost items (you really don’t have a choice about that).

One by one take one item off (well sometimes one becomes many) and note any springs that come with it … look at where the spring would be anchored

The shutter cocking arm main lever has a loaded main spring, when you try to pull it off it will pop !!! It is revolved once, so remember to do that when you put it back. I lifted it, almost off the post, with the spring attached and revolved it once (while keeping the leaf lever out of the way). Note one end of the main spring is anchored on a brass slotted washer, the slotted part rests on the bottom. Repair course lesson 7 has a trick using a wire string which looks easier than what I did.

You can start putting everything back together … but if you really really really, and I mean really, want to take the aperture apart you can continue on.

Turn aperture ring to open it up.

On the cover plate mark it where the flash socket is in relation to it.

Remove the two screws.

Tip: temporarily put it the plate back on so you get used to its position … note that it sits without much movement if all the holes line up.

Take of the plate

Now you will see the aperture blades … do not feel bad if you feel like running away at this point, cause it’s gonna get worse.

Flip it over and let the blades drop out as one whole unit.

Here it it semi unfolded.

Look at how the blades overlap, which looks like a nightmare … its not that bad.

Take a really close look at the position of the pins on the top and bottom … they are slightly different. You will need to know this when you put it back. This image is of the bottom … you can see a slight difference to the image above

Separate the blades and clean them

Two screws hold the aperture plate on and also the aperture lever. When you remove the two screws the lever behind will fall off from the rear.

Now putting the aperture blades back together is the reason why this is a #$%@ pain in the ass …. though the more you do it the easier it gets … by the time you have done this a hunderd times it should be easy.

I noticed that all the blades were not cut the same … I could not figure out why, and most importantly if they had a major affect if they where not put into a correct order. I just put them in whatever order and it appeared to have no affect.

One way is to use the cover plate. Flip it over to the side that the blades would contact. Put the blades in the holes but leave them hanging outward with a weight in the middle … I did not take an image of this, but this site has a picture of what I mean: Prontor aperture blade assembly Then start pushing the blades towards the center one by one making sure to overlap them.

Once they are centered you can then place the bottom section on top of it … make sure the pins of the blades appear stay in the holes. Put the screws back in but not completely tightened. Open and close the aperture to see if the blade pins have fit properly.

Well if you made this far … you are doing pretty good.