Lens plates question

[karavelov]

Hello,

I am designing for myself a little 6.5 x 9 folding field camera. What lens plate standards are there that are smaller than 9 x 9 cm (3,5 inch square - the dimensions of the front standard I am planning)?

If there is an interest I could publish my CAD drawings of the camera - it has some limited movements - no back swing and shift.

Thanks is advance.

luben

 

[Ole]

There's the "Baby Technika" boards - I don't know exactly how Big they are. Same with the "Baby Speed Graphic", which is a far simpler board to make!

Or in "classic" 6.5x9cm, the Voigtländer Bergheils had lens mounting through a really neat bayonet lock, with no board at all!

 

[Steve Smith]

If there is an interest I could publish my CAD drawings of the camera - it has some limited movements - no back swing and shift.

I would be interested in seeing your CAD drawings if you didn't mind sharing them.

Steve.

 

[karavelov]

Thanks Ole,

I have found some lens board dimensions here:

http://www.skgrimes.com/lensboards/index.htm

Baby technika boards are too little - 63.5 mm for my design. Ideal dimensions are Horseman VHR 80x80 but are too complicated to produce at home. So may be I will go with "Graphic A" wood boards - 3.3" (83mm) square that are not so complicated.

Steve,

Attached is the image of the plans. It is intended to fold in 11x11 cm square. Compressed bellows are 3 cm thick, so folded it will be 6cm without the back. Max bellows extension will be 18 cm. I am planing to make a plate holders back because it is most simple and I have a some plate holders, sheet film inserts for them and ground glass.

I am open for suggestions

Best regards

luben

P.S. Later I will upload somewhere .dxf files and post a link.

 

[Curt]

Try making a board for a Busch C 2x3, the hole have extremely tight tolerances and the fit must be perfect.

 

[karavelov]

No Curt,
It seems too complicated for my skills and equipment. The metal parts of the camera will be cut and folded from 2mm aluminum sheets - it will be done very precisely (computer controlled mill) but Bush C plate needs a metal press, making custom steel martix on lathe etc.

 

[blubellows]

Busch C are really fairly simple

I have made many boards for the Busch C out of different materials - Alum., model aircraft plywood, hardboard, even thick paper in a pinch. They are really fairly simple. Cut 6 cm x 6 cm square, locate center, drill hole to fit lens or flange, drill corner holes, sand round the corners. I have only wood shop tools. But, because you can make the board to your own specs., I would leave it square, nix the corner holes, and use a sliding lock to mount.
On the C I use the most I modified it with slide locks for easy lens changes, it also has a tilting back that has sliding locks for 23 roll flim back, also uncovered wood, a very pretty little camera.

 

[argus]

Luben,

So you are one of those guys that takes the time to make drawings of his camera building projects ;-)

Are you sure you want back rise&fall?
It will account for some of the rigidity problems most of us encounter. Better is to have a rotating point at the bottom of the back standard and the long gliders to control tilt.

I never had rise&fall on the back standard of my cameras and never missed it. You can easily counter a possible fall movement on the back with a front movement.

What I do use a lot are back tilts and swings and occasionally shift. I just added them to the 8x10 project I'm currently building.
If you want, I can make plans of if but I won't promise that you will see them before Christmas. The camera though... I want to have it ready by next weekend ;-)

G

 

[Steve Smith]

So you are one of those guys that takes the time to make drawings of his camera building projects ;-)

I never make plans for anything but I do like to look at other peoples designs for ideas I can steal... I mean incorporate.

I get told off at work for building a piece of test equipment then not having any design documentation for it and then have to create the drawings and diagrams after it is built!

I have only ever built one fairly rudimemtary 5x4" camera and I am always looking out for plans which have the geometry right for folding up neatly. My camera does not fold up and is a bit bulky for carrying.


Steve.

 

[karavelov]

Hello,

Yes blubellows, Busch C boards are quite simple - I have taken a part of the front standard for the board. Anyway, it is too small - the whole of my front is planned to be a little more than 6x6cm. And I do not like quite the four screws mount to the front.

About the plans drawing. Thanks for your suggestions. I know that back fall/rise is not so useful movements as swing/shift. It was added in order to make the camera fold with exactly 3 cm compressed bellows - the other option was to move the back 3 cm backward - 3cm out of the camera which I think will harm more the camera rigidity. This will also limit the front movements.

I think also for adding back swing but I am not satisfied with 1 central point for swing and shift - this will compromise the back stability in my regards. May be I will go with 2 points swing only design. Argus, I will be happy to see pictures of your camera when it is finished.

There are 2 reasons for the drawings. The first is that drawing it I could simulate folding and different movements - so I could be sure what the camera could do before constructing it. In this way I have found and corrected some not so obvious errors in the design. For example see the attached image. In green are possible movements and you see that back tilt gliders are long enough to not limit tilt when the back is in normal fall/rise position. It will limit it if the back is risen to the max possible but I had to make compromise in order the fold it compact - without gliders that stick out of the box dimensions

The other reason is that I have to make CAD files for the saw/mill on which a friend of mine works.

Thanks for sharing your experience

luben

P.S. You could download the .dxf drawing from here:
Dead Link Removed