Making Bag Bellows for MPP monorail

Terrywoodenpic

Terrywoodenpic

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Terry
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MPP Bag Bellows Project



I have just completed making a bag bellows for my renovated MPP monorail.
As I did not have spare bellows frames I had to make my own out of Ash to match the standard square bellows.



  1. Outer view of frame showing construction from two layers of laminated 1.8mm x 24mm ash, with relieved areas for the locking slides. The inner shape was cut out after completion.

  2. Inner view showing added light trap
  3. Retainer made from 6mm x 0.8mm brass strip.
    bb3.jpg~original
  4. Detail of corner relief. To ensure flat holding surface to hold vinyl. And screw holes.

  5. Detail of position of retainer on painted frame.
  6. Cut Vinyl/PVC sheets ready for glueing assembly.
  7. Glueing frames. The larger frame was used to glue and fix the the first end. The smaller second frame was constructed so as to be removable from inside the finished bag after fixing the second end.
Continued.......
 
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  1. End assembled and ready for for glueing up.
  2. Final stages of glueing. Masking tape was used for positioning and for taping joints.
    PVA glue was used. This proved to make a stronger joint than the material. However it was necessary to etch/clean the pvc, first with Acetone then with meths. to ensure the glue fully wetted the plastic surface. (neither when used alone achieved a full adhesion)

  3. Finished and folded bag.

  4. Attached to the camera in neutral position.

  5. Full front fall and back rise.


I also made the brass lens board to mount the Yashinon 127mm 4.7 lens and lens cover scavenged from a Polaroid 220 camera. I will use this in combination with a Graphic (singer) 120 film back.

MPP monorail lens-boards have a 2mm return lip, I created this by soldering a 2x2mm brass strip around the inside of the the 2mm plate. The back of the board has been finished matt black.
 
Reckon you might get (even) more interest in this if moved to F&C, Terry!

For me, pics 2, 3 and 6 in post 1 and pic 1 in post 2 aren't showing up... but it might be TP as it's been a bit weird today!
 
Reckon you might get (even) more interest in this if moved to F&C, Terry!

Nice work from what I can see... For me, pics 2, 3 and 6 in post 1 and pic 1 in post 2 aren't showing up... but it might be TP as it's been a bit weird today...
 
ChrisR said:
Reckon you might get (even) more interest in this if moved to F&C, Terry!

Nice work from what I can see... For me, pics 2, 3 and 6 in post 1 and pic 1 in post 2 aren't showing up... but it might be TP as it's been a bit weird today...
Click to expand...
The pictures are showing on my devices, so I do not know what the problem might be

If a mod would like to move the thread it might be a good idea, as it would be easier for people to find.
 
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stevelmx5 said:
Thanks for the pictures and explanation Terry. I'm going to making a bag bellows for my lasercut 4x5 field camera so it's good to have detailed pictures from yours to help me;

https://www.talkphotography.co.uk/threads/lasercut-acrylic-4x5-field-camera.636352/

Cheers
Steve
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Hope it is of some use.... MPP make rectangular bag bellows whilst most others use elongated hexagons. I have used both sorts professionally and do not have a preference. But rectangular ones are far easier to glue up accurately.

finished overall accuracy in wood is not difficult to achieve with hand tools to within 0.5 mm. Squareness is only a problem if you do not take care and make accurate drawings, and jigs.

I do not have the benefit of a laser cutter, so have had to uses normal joinery tools. Including hand thicknessing the ash to 1.8mm And shaping the brass reliefs.
 
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Repeat post, sorry!
 
As bag bellows have no card inserts in the folds, like standard bellows, the folding style is entirely optional and does not constrain them in use. however how you do it can help to avoid obstructions in the light path. This is an alternative I have settled on, as it reduces that possibility when using little extension.

 
ChrisR said:
Reckon you might get (even) more interest in this if moved to F&C, Terry!

Nice work from what I can see... For me, pics 2, 3 and 6 in post 1 and pic 1 in post 2 aren't showing up... but it might be TP as it's been a bit weird today...
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Terry I can't see any of your pictures on this thread.
 
Coyon said:
Terry I can't see any of your pictures on this thread.
Click to expand...
You are right. They have been there for a while, so I don' t know what the problem is.
I will try to investigate tomorrow.

if you click in the crosses you are taken to the shots....
 
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Coyon said:
Not really I'm afraid- endless painful hour-glassing for me.
Chrome browser on fibre for what it's worth.

Photobucket is the work of Satan mind you.
Click to expand...
I will relink them in new posts tomorrow.
 
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