Grafmatic 4x5; Red Dot Indicator

[spacegoose]

I recently loaded a Grafmatic and don't recall if it's normal for the red dot indicator to be on, on the initial loading?

I set the dial to 1, pressed in the lever and pulled the cartridge out, pushed the dark slide in to release the septums, filled them with film, seated them in the cartridge, closed the slide and pushed the cartridge back into the Grafmatic.

The dial is still on 1 and the red dot indicator is on. Is that normal? It seems like it might be, but I'm not sure.

Thanks for any info!

[spacegoose]

To answer my own question - it seems red dot on initial loading of Grafmatic is not correct.

I neglected to push in the tab (fig 4) inside and at the top of the cartridge. I decided to double check this after watching and reading here:

https://www.photrio.com/forum/thread...roblem.177633/
https://www.graflex.org/speed-graphic/grafmatic/

When I opened the cartridge in my dark bag, the septums popped up as normal and I could feel that tab was extended, I pushed it back up. I assume the red dot went off then. It was still off when was I done checking and out of the dark bag.

When I had loaded the Grafmatic initially, I did spin the dial a few times after I was done, to see if that might make the dot go away (it didn't), so I'm not sure if that spinning of the dial might have extended the tab, or if it was just extended when I loaded the Grafmatic initially (I'm guessing the latter).

I'm also unsure if initial loading with tab extended might have damaged the septums. Hoping not!

Thanks!

[Corran]

I've noticed this for years. Personally it doesn't bother me, and reminds me that if the red dot is there when set to "1" then I've loaded film into the Grafmatic. This is helpful for me as I have about 10 Grafmatics now and I keep a variety of films loaded for quick access.

[sharktooth]

This is an interesting and timely question. I have a Grafmatic sitting on my workbench that needs to be tested, so I went and tried to reproduce this scenario.

If you pull out the module when the red dot is exposed, the inner septum remains in the main body of the holder (since it's being advanced to the back). You could load film in the other 5 remaining septums, but not the one still in the main body of the holder. The red dot will be covered, however, when you push the module back into the main body.

I couldn't reproduce your scenario where the red dot was exposed after film loading. The red dot is exposed when you pull out the dark slide. It gets covered when you push the module/cartridge back into the main body. Since you have to pull out the module/cartridge to load film, the red dot should always be covered when you push the module/cartridge back into the main body. This seems entirely logical.

Maybe my Grafmatic is a newer design, it has CAT NO. 1268 noted on it. I suspect that either your model is an older design, or it has some sort of operating defect. Try functioning it without film. See if the red dot gets covered when pushing the module/cartridge back into the main body.

[spacegoose]

I've noticed this for years. Personally it doesn't bother me, and reminds me that if the red dot is there when set to "1" then I've loaded film into the Grafmatic. This is helpful for me as I have about 10 Grafmatics now and I keep a variety of films loaded for quick access.

Interesting. Are you saying you load the septums without pushing the tab (see fig 4) up into the body, as I had neglected to do?

Does the red dot ever go off for you? I wonder what this might do to the septums, or if the inside tab eventually goes up on its own?

[spacegoose]

This is an interesting and timely question. I have a Grafmatic sitting on my workbench that needs to be tested, so I went and tried to reproduce this scenario.

If you pull out the module when the red dot is exposed, the inner septum remains in the main body of the holder (since it's being advanced to the back). You could load film in the other 5 remaining septums, but not the one still in the main body of the holder. The red dot will be covered, however, when you push the module back into the main body.

I couldn't reproduce your scenario where the red dot was exposed after film loading. The red dot is exposed when you pull out the dark slide. It gets covered when you push the module/cartridge back into the main body. Since you have to pull out the module/cartridge to load film, the red dot should always be covered when you push the module/cartridge back into the main body. This seems entirely logical.

Maybe my Grafmatic is a newer design, it has CAT NO. 1268 noted on it. I suspect that either your model is an older design, or it has some sort of operating defect. Try functioning it without film. See if the red dot gets covered when pushing the module/cartridge back into the main body.

Thanks for testing this out ... were you also keeping the inner tab in mind? I was referencing the one in fig 4 (attached).

Attachment 245158

[sharktooth]

O.K., I've figured out how this system works, and how you can get the red dot.

I didn't know what you were talking about with the tab, but after looking more closely, I can now see it, and explain how it works.

The tab is closer to the center than in the diagram you linked to. The tab has a small lip that is about the same height as one septum thickness. This tab acts as a cocking lever for the red dot cover and the counter mechanism. The red dot cover is released by a small pin that protrudes from the back of the cartridge. The pin gets pushed in (released) when it goes into a chamfered groove in the main body.

When the pin is released, the cover for the red dot is still in place, since the bottom septum prevents the tab from moving. When you pull the darkslide all the way out, the internal springs push all 6 septums up higher, and now the tab can move forward, thus releasing the red dot cover to expose it.

When you advance the sheets, you pull the entire cartridge out, and the top septum now drops to the bottom. When you push the cartridge back in, that bottom septum now pushes the tab back as the cartridge is fully back in the main body. This cocks the system again, and covers up the red dot and moves the film counter.

Here's how things can get screwed up:

1) If you pull out the cartridge, remove all the septums, and then push the cartridge back in, the tab will be released and the red dot will be shown. At this point, there is nothing in the cartridge that will push the tab back to the cocked position. If you now try to put septums back in, they will sit on top of the lip on the tab, and you might end up damaging some septums, or the holder. You would have to manually push that tab back before you install the septums.

2) You need to install all 6 septums. The system only works properly if there are 6 septums in place. For example, if you only have 5, there is not enough thickness in the film pack to drive the tab back to the cocked position. As in the first case, you need to manually push that tab back to the cocked position before installing all 6 septums.

If your counter isn't working, it's likely that the tab is out and you'll have to manually push it back to the cocked position.

I guess the bottom line is to only remove the septums for film loading, and don't cycle the mechanism without all 6 septums in place.

[sharktooth]

Here are some pictures for reference.


Opened for septum loading with film sheets


Tab in the cocked position. This is where it should be when loading film in septums


Tab in extended position. It shouldn't be out like this when loading film. Push it back in.


Release pin for red dot cover. Not released.


Release pin pushed in, so red dot is exposed.


Chamfered groove in main body the pushes in the release pin.

[sharktooth]

Checked some of my other Grafmatics today, and found one where the tab would just pop back out again when you pushed it in. The release pin on the back side was stuck in the depressed position, so I decided to take things apart to see if I could fix it.

There are 6 screws that hold the back cover in place. Once the cover is removed, you can see the mechanism. The tab and red dot cover are the same piece. The pin is held in a round boss. The pin itself has two diameters, a small diameter (that you can see), and a large diameter that rides in the boss. There is a spring under the pin that keeps it popped up. When the Grafmatic is in the normal state, the pin is pushed down in the boss. Dirt and corrosion caused the pin to get stuck in the boss. I had to use a little Liquid Wrench, and some pliers to pull it out. I cleaned it up, and lightly sanded the surface, and now it moves up and down freely, as intended.

Here are some pictures to show how this works:

1)
In this picture you can see the keyhole slot in the Tab/Red dot cover. When the pin is pushed in, the Tab is pushed out to the narrow end of the keyhole slot. The red dot is exposed.

2)
In this picture the pin is up, and the Tab/Red dot cover is in the cocked position. The large end of the keyhole slot is engaged with the large diameter of the pin. The red dot is covered.

3)
This picture shows the pin. It has a large diameter and a small diameter. It is held up by a spring in the boss. The large diameter of the pin engages with the large hole in then end of the keyhole slot. The small diameter of the pin engages with the narrow section of the keyholes slot.

4)
In this picture I've shifted the Tab/Red dot cover out of the way so you can see the pin stuck down in the boss, before I pulled it out to clean it up.

5)
This picture again shows the boss with the Tab/Red dot cover moved out of the way.


I must say that I'm really impressed with the design and construction of these Grafmatic backs. They truly are ingenious devices.