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Miniature Speed Graphic questions

 
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bretpim



Joined: 01 Sep 2018
Posts: 16
Location: Ottawa, ON, Canada

PostPosted: Sat Feb 23, 2019 4:38 pm    Post subject: Miniature Speed Graphic questions Reply with quote

I inherited my father's Miniature Speed Graphic and have since acquired a second one (for parts although I think both are nearly complete)

I have some questions

1) The serial numbers are 356858 and 376314, which according to this thread means I have models produced in 1945-6 and 1946 respectively. Is this correct?

2) Both models do not have a flash contact on the curtain for the second largest aperture (opening 'A' in manual). I also cannot see a place where a contact had ever been attached. Did this curtain opening not have a flash contact?

3) Both lenses are Graflex Optar 101mm. On one of the lenses the exposure time dial is hard to move and feels like something is scraping. I have applied some fine oil and light grease which has helped but the problem still persists somewhat. In particular it is very hard to move the dial to 400.

4) Could someone please point me to instructions for checking and adjusting the focal plane shutter timings and tensions.

thanks
brett
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45PSS



Joined: 28 Sep 2001
Posts: 3750
Location: Mid Peninsula, Ca.

PostPosted: Sat Feb 23, 2019 8:51 pm    Post subject: Reply with quote

Due to a computer failure I lost all my serial number info. A list of numbers dated on this site was compiled and shared with several members. A google search for Graflex serial numbers gives several hits and some are the list that was made.
1. 356858 - likely 1945; 376314 - 1st quarter 1946.
2. The Miniature Speed is built like a Anniversary Speed and the instruction and repair manuals for the Anniversary can be used for the Miniature.
I'm not willing to disassemble mine to find out.
http://www.southbristolviews.com/pics/Graphic/manual-pdf/Anniversary.pdf
http://www.southbristolviews.com/pics/Graphic/manual-pdf/AnniversaryService1.pdf
3. The factory service manual for the Graphex shutters is here:
http://www.southbristolviews.com/pics/Graphic/manual-pdf/GraphexShutterService.pdf
It can be used to service Rapax shutters as well as there are minor differences and both were made by Wollensak. The 101mm Optar is in a #1 shutter and its assembly instructions are out of order. The instructions for the #2 and #3 shutters are in order and can be used for the #1 by skipping the steps for parts not used in the #1. The Graflex came in 3 versions, no flash sync, full flash sync, X flash sync only. The manual is for the full flash sync.
Speeds in all makes of shutters are controlled by the cocking spring and delay timing for speeds of 1 second to 1/100-1/125 with a booster spring for higher speeds. Most shutters are hard to turn to their top speed in a released state and virtually impossible in a cocked state.

The Graflex Focal Plane Shutter has two requirements: 1) With the tension at its lowest setting, the curtain at O it should close and lock when released. Locked being the wind key will not turn against the wind arrow; 2). with the tension at its highest setting the curtain should wind to the smallest aperture.
The common failure of the FPS is the grease in the roller bushings has dried out and the tensioning spring has weakened.
Instructions for servicing FPS is downloadable here: https://drive.google.com/file/d/0B1sPJkp-MdghRkRId1EwT0dpNkk/view?usp=sharing
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Dan Fromm



Joined: 14 May 2001
Posts: 2038
Location: New Jersey

PostPosted: Sun Feb 24, 2019 3:34 pm    Post subject: Reply with quote

S/n 356858 was part of a batch of Miniature Speed Graphic serial numbers assigned 8/22/45. The next batch was assigned 10/24/45.

376314 was in a batch assigned 12/28/45. The next batch was assigned 1/9/46. The batch after that was assigned 3/8/46.

There's no guarantee that the serial numbers were used in the order assigned.
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bretpim



Joined: 01 Sep 2018
Posts: 16
Location: Ottawa, ON, Canada

PostPosted: Tue Feb 26, 2019 12:19 am    Post subject: Reply with quote

Thanks for this info. The FPS servicing instructions are just what I need.

With regards to the flash contacts, there are 4 flash contacts on the curtain, one for each of the openings: O, B, C, D. But no flash contact for the A opening. This is true for both cameras and neither seems to ever have had a flash contact for the A opening. Is this the full flash sync or X flash sync?
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45PSS



Joined: 28 Sep 2001
Posts: 3750
Location: Mid Peninsula, Ca.

PostPosted: Tue Feb 26, 2019 12:31 am    Post subject: Reply with quote

FP (focal plane) flash bulbs are the only light source usable with a focal plane shutter. FP Flash Bulbs have a 55 to 60 millisecond usable light burn time and the aperture openings take 45 to 55 milliseconds to traverse the film plane on a correctly functioning shutter. Standard M type flash bulbs have a 15 to 20 millisecond usable light burn time. Flash Bulbs take 15 to 17 milliseconds to reach usable light output from power applied/flash contacts closed.

Use 1/30 second or slower for flash bulbs.
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45PSS



Joined: 28 Sep 2001
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Location: Mid Peninsula, Ca.

PostPosted: Wed Feb 27, 2019 12:57 am    Post subject: Reply with quote

I have a parts body (incomplete) with curtain, there is no flash trigger stripon the A aperture. Don't know why Graflex did that.
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bretpim



Joined: 01 Sep 2018
Posts: 16
Location: Ottawa, ON, Canada

PostPosted: Wed Mar 06, 2019 10:40 pm    Post subject: Reply with quote

45PSS wrote:
I have a parts body (incomplete) with curtain, there is no flash trigger stripon the A aperture. Don't know why Graflex did that.


OK, it seems this is normal then. Thanks
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bretpim



Joined: 01 Sep 2018
Posts: 16
Location: Ottawa, ON, Canada

PostPosted: Sun Mar 31, 2019 9:02 pm    Post subject: Reply with quote

45PSS wrote:
The Graflex Focal Plane Shutter has two requirements: 1) With the tension at its lowest setting, the curtain at O it should close and lock when released. Locked being the wind key will not turn against the wind arrow; 2). with the tension at its highest setting the curtain should wind to the smallest aperture.


I have cleaned all the parts and regreased the gears and bushings

I have two questions:

1) When I am setting the spring tension, I have two tensions which satisfy your two criteria quoted above. Should I use the weaker or stronger of the two?

2) When I turn the curtain to the "O" aperture, in one of my cameras the top of the gap is 1cm and the other is 2.4 cm (see picture below). When I think about it It seems it should be fine as long as for the "A", "B", "C" and "D" apertures:

- before the exposure, there is no light gap
- the aperture passes completely over the film area
- after the exposure there is no light gap

And for the "O" aperture, the film area is completely exposed when the curtain is locked to this position.

The flash sync contact is placed on curtain relative to the aperture, not relative to the curtain's position before or after exposure. So I think it is all OK, but I wanted to ask about it in case I am not seeing something important.

[img] https://www.dropbox.com/s/x64elmqq9qv28ea/IMG_0894.JPG?dl=0 [/img]


[img] https://www.dropbox.com/s/ew93aaagf90ylu6/IMG_0893.JPG?dl=0 [/img]


thanks
brett
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45PSS



Joined: 28 Sep 2001
Posts: 3750
Location: Mid Peninsula, Ca.

PostPosted: Sun Mar 31, 2019 11:18 pm    Post subject: Reply with quote

I usually use the lowest tension at which the curtain closes from O with the camera in any position. With the camera in portrait position the curtain may not close as it does in landscape position. Higher tension usually causes low speeds to be fast with little to no change on the higher speeds.


There is a roller just above and just below the film gate opening. Apertures A,B,C and D when wound to the aperture the bottom stay should be about 1/4 inch above the top guide roller, when released and the release held in the release position the top aperture stay should be about 1/4 inch below the lower guide roller. Closer than 3/16 inch will leak light fogging the film.

I find most cameras top aperture stay at O to be between what your pictures show by about the width of the aperture stay. The position of the A,B,C,D apertures at the wound to and released positions are more important with the B or C aperture the most reliant on the start position of the top roller initial position.

Graflex Corp.cameras were laid out with an engineers rule. ALL Measurements are in inch,tenths, hundredths, thousands of an inch. 1 inch=25.4 millimeters.
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