Fat Shot 617 - Medium format 6x17 modular panoramic film camera

This is a film camera with modular design - cassette (film back), focusing screen, lens unit and misc accessories are detachable from the main body for customization, adjustments, movements and portability. It shoots panoramic photos on medium format (120 type) film with an image size of about 56x170 mm. Markings for 6x4.5 frames on the backing paper are used to count frames with exposures made on frames 3, 7, 11 and 15. Design inspired by the Horseman SW617.

Project is more or less finished. No updates are planned in the near future.

Later I've designed a remake of this camera - Fat Shot X. It has many improvements over this project, ability to shoot multiple formats other than 6x17 and not many compromises. Check it out too.

Features

I've tried to include every convinience into this design that seemed important for me while keeping everything exceptionally easy to print without supports. So here’s the list of features I've managed to include in this design:

• Easily detachable film back (I call it the “Cassette”) with a dark slide built in.

• Easily detachable ground glass focusing screen.

• Presice focusing with the help of the off-the-shelf M65 17-31mm helicoid adapter (focusing scale included).

• Lens cones that are swappable without any tools. Use the parametric cones and generate your own.

• Rise (13.5 mm) and fall (3 mm) movements of the lens cone for perspective corrections.

• Spring loaded plungers under both spools that keep them securely in place.

• Ratcheting mechanism on the winding knob that keep the tension on the film.

• Spring loaded pressure plate that firmly presses the film around the frame and keeps it very flat (a couple of first photos show a different story with slightly curved vertical lines - these were made on previous versions of the camera and in the most recent version the problem is fixed).

• Spring loaded film retainers on both sides that keep both feed and take-up rolls from unwinding.

• Lens guard.

• Optional cold shoe mounting points.

• Optional mechanical frame counter on the top.

• Optional handle for comfortable handling and handheld shooting.
   

What also makes it different from other similar cameras is that both spools are located behind the frame. This makes the film back much less wide and more compact overall, but of course this design makes for a FAT camera :).

Note: viewfinder pictured in some of the images is a one-off made from a door peephole. Later I've made a couple of much more accessible open source designs that you can find here: version 1, version 2.

Compatible lenses

Current design is made for a Super Angulon 90 mm f/8 in a Copal No. 0 shutter with FFD = 98.8 mm. Corresponding lens cone can be found along the rest of the files.

Other lenses with FFD between (probably) 72 mm and (also probably) 150 mm can be used but the lens cone will need to be different in length. To create custom lens cones for your lens use this project, or message me the FFD of your lens so I can generate the lens cone and upload the STLs for you.

Recent updates

2025-12-14:

• Uploaded the Fusion 360 project that allows to create parametric lens cones. See the "Compatible lenses" section for more info.

2025-12-04:

• Added a list of (theoretically) compatible lenses in the corresponding section above.

2025-11-30:

• Added pdf-s along with all svg files in case there are problems with fonts and also made small corrections to the images themselves.

2025-11-29:

• Added a ridge around the opening on the dark slide frame and a corresponding slot on the cassette to make the interface more light-proof. If you have already finished printing the previous version, these parts will need to be reprinted:

  • Cassette Bottom 

  • Cassette Top 

  • Spool Flanges Left and Right

  • Dark Slide Frame 

• Added a sloped top to the round holes in the cassette bottom where the pressure plate slots in. This should eliminate any postprocessing needed for the pressure plate to move smoothly. 

• Made the holes longer for all the screws that are used to mount the cassette top to the cassette bottom in an attempt to eliminate the need of some screw types. 

• Added an optional variant of the main body that has a flat top with no holes for cold shoe mounts. Use it if you want to modify the model yourself to add your own mounts. 

• Added an optional two part plug that covers the hole for a cold shoe mount. Print these if you are not planning on using all three mounts to cover the rest. Use M3x10 screw to secure each one in place.

• Reuploaded all files to have more consistent and overall better naming. No changes were made to the models themselves. 

• Exported the most recent version of the project.

2025-11-25:

• Made a 3D-printable toggle latch as a replacement for the off-the-shelf toggle latches that can be inconsistent in their quality and/or hard to buy. I recommend using these instead of chinese metal ones. See the "BOM" section for more info.

2025-11-14:

• Updated the information on all parameters of the springs that can be used, because I understand that it can be impossible to find the exact springs that I had. See the hardware list below.

2025-11-12:

• Uploaded a simple SVG for a movement scale and added example photos of what it should look like at the end of the description. You will need to print two and cut both to size.

2025-11-09:

• Added notches to the lens board to be able to tighten it with a lens wrench.

• Added slightly larger (101%) version of the lens board. For me this version has the best contact with the M65 thread on the helicoid adapter. 

• Added an SVG file with a focusing scale to be glued to the lens board. If you assemble the lens unit correctly it will be very accurate. Also added instructions for this at the end.

• Removed a recess in the model “617 Dark Slide Frame Front” that I've made to be able to load the film easier, in order to increase the flatness of the film, because curling turned out to be too noticeable on pictures. Film loading is already made much easier with the addition of ball bearings.

• Exported the most recent version of the project. Hope this will stay the most recent at least for a while.

2025-11-08:

• Added instructions (see below) to properly assemble the lens unit to get the perfect FFD. For this purpose I've also added an stl for a spacer that has to be scaled appropriately.

• M65 helicoid has arrived and it turned out to be 0.5 mm shorter that I expected, so I've lengthened the lens cone by the same amount and subsequently changed dimensions of guard rail and guard ring. Files for the lens cone, helicoid mockup, guard rail and guard ring are updated.

• Added optional logo on cassette top. See model “Cassette Top Lid Logo”.

2025-11-07:

• Added parts to build a lens cone for Super Angulon 75 mm f/5.6. Made just by assumption that flange focal distance is 15.7 mm shorter and every other dimension is the same.

• Uploaded a M65 Helicoid mockup that I use in place of not-yet-arrived real helicoid so everyone can use it too.

2025-11-06:

• Updated multiple parts (Cassette bottom, cassette top, dark slide frame front) to add bearings that enable steel rods to rotate freely, and it has completely eliminated the problem with film being too hard to pull through. Turns out that steel rods, being only 3 mm in diameter, create too sharp of a turn in the film path and it creates too much friction.

• Added longer and more comfortable to use bottom knobs.

2025-11-04:

• Added two variants of a handle that is mounted on the left side of the body for easier handling. “45” version of the handle is made for comfortable handheld shooting - left hand on the handle, right hand under the lens, pressing shutter lever with your thumb.

• Updated a couple of small parts to beef them up a bit. 

Videos

The film transport system has its quirks. It is a little fiddly to load a new roll as you have to push the film through, though it becomes pretty easy after a couple of tries. Here are some tips:

• Keep the paper leader folded, it will help in pushing the film around metal rods. Paper edge can catch on layer lines behind the rods. Pushing it while folded basically makes the leading edge 2+ times thicker and rounded and this helps a lot with it gliding along the uneven plastic surface.

• While pushing, press film retention flaps out of the way so the film won't get stuck under them.

Here is a video on using the Fat Shot 617 cassette - how to load a new roll, count frames and unload an exposed roll:

And here is an assembly video:

There is a mistake in the subtitles at 04:25 - those are 9.5x19 mm springs, not 7x19. Although 7x19 can be used if a larger wire thickness is chosen.

BOM

• Metal toggle latches. These latches hold film back and focusing screen tight on the camera body and enable you to swap them easily. I used ones with mounting points 20 mm apart both directions. Latches go on the camera body, catches are mounted on the other parts. You will need 8 sets of them: 4 latches are attached to the camera body, 4 cathes are mounted on the cassette and 4 more catches are used for a focusing screen. The rest 4 latches are not used.
  Here is the picture of the type that I used:
  

  

  
  It is made in China and available everywhere (Amazon, Ozon, Aliexpress), costs about 1$ a piece. Just search for “Toggle case latch”.
  
  UPDATE: these latches unfortunately can be inconsistent in quality and/or hard to get. I recommend using these 3D-printed latches instead, they are much more reliable and more comfortable to use.
  

  

• Focusing screen uses custom made 2 mm thick frosted glass 80x190 mm.

• Dark slide is 1 mm thick 70x195 mm aluminum plate with two 3 mm holes for the handle that can be drilled in place. Other opaque sheet material like ABS plastic can be used.

• 3 mm stainless steel rods 70 mm in length used as film guides (x2).

• MR63ZZ ball bearings to mount the steel rods (x4).

• Compression springs. I used ones from an assortment kit that I have.

  • Pressure plate (x4). I used 9.5x19 mm with 0.7 mm thick wire.
    Other springs can be used here:
    - ID of ≥ 5mm and OD of ≤ 11 mm.
    - Free length of ≥ 17 mm
    - Compressed length of ≤ 13 mm.
    - Wire thickness ≥ 0.6 mm.

  • Bottom knobs (x2). I used same 9.5x19 mm with 0.7 mm thick wire.
    Other springs can be used here:
    - ID of ≥ 8 mm and OD of ≤ 11 mm.
    - Free length of ≥ 17 mm
    - Compressed length of ≤ 13 mm.
    - Wire thickness ≥ 0.6 mm.

  • Film retention flaps (x2). I used 7x19 mm with 0.6 mm thick wire.
    Other springs can be used here:
    - ID of ≥ 5.8 mm and OD of ≤ 7.2 mm
    - Free length of ≥ 16 mm
    - Compressed length of ≤ 4.5 mm
    - Wire thickness of 0.5-0.7 mm.

• M65-M65 17-31 mm helicoid focusing ring. It is not present on first photos as I was still waiting for it to arrive. There is a 3D-printed spacer of the needed size in its place.

• 3/8'' to 1/4'' adapter used as a tripod mounting point.

• 1/4'' thread to cold shoe adapter used as standard shoe mounting points (x3).

• 1/4'' 10 mm long flat head screws to hold these adapters (x3).

• Heat set threaded inserts. Used as few as possible only where occasional disassembly is necessary, as those inserts can be hard to get where I live. All other screws are just screwed into undersized holes.

  • M3 : x4 (Body sides, to mount accessories)

  • M4 : x2 (Lens cone mounting)

• Screws:
  There are a couple of places where the particular head type is needed, I will point them out below. For everything else you can use either button heads (ISO 7380) or cylindrical heads (DIN 912):
  

  • M3x4 cylindrical head : x2 (Used as a mounting point for springs under film retention flaps)

  • M3x8 countersunk head : x24 (Toggle latches)

  • M3x8 : x6 (Top spool flanges) + x2 (Dark slide handle) = x8

  • M3x10 : x6 (Focusing screen) + x3 (Cold shoe mount plugs, optional) = x9

  • M3x14 :  x6 (Dark slide frame) + x2 (Handle) = x8

  • M3x16 : x2 (Cassette top) + x8 (Lens Guard) = x10

  • M3x20 : x2 (Bottom knobs) + x3 (Cassette top lid) = x5

  • M4x20 cylindrical head : x2 (Lens cone knobs)

  • M4x35 : x4 (Pressure plate). Partially threaded type should be used, because the unthreaded part acts as a guide rail for the pressure plate movement.

• Nuts:

  • M3 : x2 (Dark slide handle)

  • M4 : x8 (Pressure plate)

• Washers:

  • M4 : x2 (Lens cone mounting) + x4 (Pressure plate) = x6

  • M7 : x2 (Ratchet spring)

• Two strips 71x6 mm of 2 mm thick dense felt used to close the opening for the dark slide. These need to be glued by their sides to be able to bend away when the slide is inserted. Like this:
  

  

• Two strips 137x20 mm and 137x10 mm of the same 2 mm dense felt have to be glued to the lens unit flange to allow sliding movements up and down without light leakage. There are corresponding recesses 1.5 mm deep in the model.
  

  

General printing and assembly tips

Printing:

• Everything was designed to be printed in PETG. And although most of the parts are probably OK to print in other material, there are two parts that are designed to flex - right spool plunger and the rear cover, and I am not sure how well these parts will operate without breaking, if printed in any other plastic other than PETG.

• Stack up on filament, all the printed parts will weight about 1100g.

• There are parts that are 200 mm in length that are meant to be printed face down, so 205-210 mm print bed is the bare minimum for this build. It is probably possible to use a smaller bed but you will need to rotate parts and use a lot of supports.

• All parts are designed to be very easy to 3D print with no supports. The only exception to this is the model “617 Dark Slide Frame Front”. 

• Model is designed for 0.6 mm nozzle and many dimensions are made multiples of this. But 0.4 mm nozzle should be totally OK as modern slicers are very good at filling gaps that are not exactly equal to the line width.

• Any common layer height is passable. I've printed it at 0.25 mm. Only M65 thread for the helicoid is recommended to be printed in 0.1 mm layer height.

• "Fuzzy mask" models are not supposed to be printed, these are volumes to be used as modifiers for corresponding models in the slicer, on which you can enable "fuzzy skin" setting. This way you can mask certain surfaces and only partially cover them with fuzzy texture.

• There is one of each model in the file list. Even if there are two of the same parts or they are mirrored, I copied them anyway and named “Left” and “Right”.

• Don't print the “No mounts” variant of the body. Use it only if you want to modify the model and make your own mounts.  If you are not planning to put cold shoe mounts on top of the body and want to cover all or some of them, print the included cold should mount plugs.

Assembly:

• See exploded view to understand how it all goes together. Assemble it from bottom to top and from back to front. So, start with knobs and spring loaded plungers, then film retention flaps, cassette top, pressure plate, etc.

• Watch the video!

• In the current 3D model, the spring cradles behind the pressure plate are about 16 mm long. That’s a generous length and might be too much for proper spring compression. Unless you’re using particularly stiff springs, it’s better to add spacers there and reduce that distance. Film should be very firmly pressed against the frame. Use the model named “Spring Spacer” and scale it if necessary.

• The lens cone needs to be glued to the flange that’s screwed to the camera body. I used small dabs of CA-glue to tack it in place and then generous amount of black T7000 glue to fill all the gaps. Glue should go here:
  

  

• I recommend to cover inside surfaces of camera body and dark slide frame with black matte paint to reduce flares from bright light sources just outside of the frame. Probably not needed if you already print in matte plastic. Painting lens cone is also not necessary as it is outside of cone of light created by the lens and can only cause secondary reflections which should not be much of a problem. Paint should go here:
  

  

• The gap between the dark slide frame and the cassette can be prone to light leaks. If you notice a strip of light hitting the area between frames, or just want to play safe straight away, use an opaque glue like black T7000 between dark slide frame and the cassette, and between the cassette top and cassette bottom. Glue should go here:
  

  

Assembling the lens unit

You may notice that flange focal distance (FFD) in the model is 97 mm for SA f/8 90 mm, when datasheet says it should be 98.8 mm. This is done on purpose. These are not precisely machined parts and no 3D prints are perfect. Temperature fluctuations, the properties of the plastic, mechanical inaccuracies of the 3D printer, felt not being squished all the way, the texture on the print bed, etc. etc.— all of these introduce errors, and multiple stacked parts will accumulate those errors. For example, one of the versions that I've printed on my 3D printer, had about 1.3 mm larger FFD than in the 3D model and the remaining 0.5 mm I've added using a spacer. And in the assembly video I've got full 98.8 mm and did not even have to use a spacer at all.

Here is the way to properly print the lens unit that I recommend. This process is also shown in the assembly video.

• Print all the parts, glue the felt in place and assemble the camera. Do not screw in the lens yet.

• Attach the M65 helicoid and the lens board. Tighten them properly.

• Collapse the helicoid adapter.

• Measure the distance between the lens board and the pressure plate with a caliper or other depth gauge.

• Subtract the resulting value from datasheet FFD value (98.8 mm for SA 90). You will get the thickness of the spacer that has to be added between the lens board and the lens itself.

• If you got more than a couple of tenth of a millimeter, you can 3D print a spacer, otherwise use another material of appropriate thickness like a sheet of paper. If 3D printing, scale the thickness of the “Spacer” model accordingly in your slicer and then print it. Use the appropriate layer height to get as close as you can to the correct dimensions.

This way you should get the perfect FFD no matter the inaccuracies.

You should know that you can get away with relatively large inaccuracies here for the following reasons:

• You can overshoot your FFD by about 1.4 mm and still get acceptable focus. That is because at max aperture of f/8 for 6x17 format this lens has hyperfocal distance of ~8 m, which corresponds to ~100.2 mm distance from film to lens flange (this means that if you set a focus at 8 m at f/8, then everything will be in focus from 4 m distance to infinity). And at smaller aperture sizes the hyperfocal distance is even closer.

• On the other hand, if you undershoot your FFD, you will overshoot your infinity focus when helicoid is fully collapsed, which means you can correct it by extending the helicoid.

BUT you should try to get as close to the datasheet FFD as possible if you want to get the most accurate focusing scale on your lens board.

To place the sticker with the focusing scale correctly, you can follow these steps:

• Screw together the lens board, the helicoid, and the lens cone, and tighten them.

• Rotate the helicoid to its shortest position.

• Use the lens to position the scale where it will be the most comfortable for you to read. Make a mark on the helicoid and a corresponding mark on the lens board where you want the scale to start (the infinity mark). 

• Disassemble everything. It's just easier to work on every part separately.

• Place the index mark on the helicoid where you marked it. Use any method you want. I used a white permanent marker.

• Glue the scale with the infinity placed on the marked position and cut away the excess paper.

• Assemble the lens unit.

Here is how the lens board should look with a scale and the helicoid rotated to positions ∞, 2m and ~0.71m (MFD). Scale is printed on a sticky label using a thermal printer.

Placing the movement scale is much easier. Just place the lens unit flush with the bottom of the camera body and the lens will be exactly centered vertically. Index marks are part of the “Lens flange” model and you just have to position the sticker with these marks pointing at the “0” on the scale.

Here is how the movement scale should look.

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Let me know if I missed something.

If you decide to take on this build, please share your progress and feel free to ask questions. Surely I have not covered everything and there are a lot to figure out. I'll be happy to help.

And if you manage to finish the project, I’m of course looking forward to your feedback and sample photos.

Related links

Growing facebook group, dedicated to this project. I don’t run it, but I check in there from time to time.

My telegram. Feel free to contact me if you have questions.

And here are my other designs that can be used with this camera:

• Optional frame counter 3D model on printables

• 3D-printable latch

• Universal wide angle viewfinder v1

• Universal wide angle viewfinder v2 (recommended)

• Parametric lens cones