Parametric lens cone for Fat Shot X

Important updates

• 2026-04-21:

  • Updated the structure of the file list. Parts that are common for all lens cones are now in a separate folder.

• 2025-03-01:

  • Fixed errors that appeared on certain offset operations when using FFD < 96 mm. Uploaded the most recent project version.

• 2025-02-15:

  • Uploaded new version of the Fusion 360 project and updated the assembly guide. I've been made aware that M65 helicoid has M65x1 thread (1 mm pitch) and M77 helicoid has M77x0.75 thread (0.75 mm pitch). So I've made the thread pitch parametric and dependent on the thread size.

  • Updated the instructions for correcting errors in the FFD after 3D-printing the cone (section 5.5 of the assembly guide).

  • Moved the lens cone assembly guide to this project.  I feel it just makes sense to keep it here.

Summary

This is a Fusion 360 project that you can edit to generate the lens cone for your specific lens to use with the Fat Shot X film camera:

I don't have the exact compatibility list for different lenses, but the range of values that you can enter without any errors is pretty large and should cover most of lenses from focal distance of 75 mm up to probably 250-300 mm. The main reason for incompatibility for many lenses will not be their FFDs but rather the size of their elements, specifically the diameter of front and rear attachments.

BOM

• Heat set inserts:

  • M3x5x5 - x18

• Screws (ISO 7380, button head):

  • M3x8 - x10

  • M3x16 - x8

• Screws (DIN933, hexagonal head):

  • M4x25 - x2

• Washers:

  • M4 - x2

• 2 mm hard felt (300 g/m^2 or denser) - around the size of an A5 sheet.

• Shoelace eyelets - x2. Used as strap attachment rings. 

How to use

If you don't have Fusion 360 or you encounter problems with using this project, please feel free to contact me and I will generate the models for your lens.

Open the project, click "Modify", then "Change parameters" and enter values for these parameters in the "Expression" field. The values describe the lens itself and allow for some additional adjustments.

Detailed description of each parameter, their limits and all the information needed to build the lens cone can be found in the document "Fat Shot X Lens Cone Assembly Guide"  that is located in the "Instructions" folder in the file list of the main project.

Pre-generated files

In the file list you can also find the files for the lens cones that I was asked to generate by different people that couldn't do it by themselves for different reasons. If you find your lens here, you can use these instead of generating your own. You'll need the folders named "Common files" and "Additional parts" and all the files from the folder that corresponds to your lens.