Instax SQ1 LF lens mod

Summary

This is a Fusion 360 project that allows you to generate the lens cone for your LF lens and mount it onto an Instax SQ1 instant camera, converting it into a manual instant camera with actually good optics.

Big thanks to Georgiy from https://master-lynx.ru/ (Youtube, Printables) for the inspiration, ideas and for the invaluable info on the internal workings of this camera that I've gathered from his work on Instax cameras (his Lynxstax series).

WARNING #1: This is a model that you have to generate yourself by modifying the "FFD" parameter inside the Fusion 360 project and by exporting the files you need! STLs in the file list are there only as an example, generated for the lens with FFD = 88.6 mm. If you don't have access to Fusion 360 or for some other reason are not able to do it, but you have the exact FFD of your lens, reach me and I'll generate the models for you.

Compatible FFD range is around 75 to 150 mm. "No shoe" variant can be made even shorter, down to about FFD = 55 mm.

WARNING #2: There is a 320 V capacitor inside that powers the flash! You better stay away from it if you don't know what you are doing.

Required materials

In addition to the Instax SQ1 camera and the lens you will need:

• Glue, 2-part epoxy or a thin double-sided tape to glue the 3D printed lens flange to the original plastic. Double-sided tape worked really well, because it's a less permanent solution and the 3D printed part can be easily removed if needed, but still strong enough to be handles without care.

• M65-M65 17-31 helicoid adapter

• Shoe mount that screws into the 1/4'' thread.

• 2 mm self adhesive light seal foam.

• 4x M3x5x5 heat set inserts

• 4x M3x8 screws

Conversion

I won't be making a thorough illustrated step by step guide for this like I did for my Fat Shot X project, but I will list the steps that I took for my particular conversion that you can follow:

1. Open the Fusion 360 project, click "Modify", then "Modify parameters" and enter the FFD of your lens.

2. Export the Lens Flange, Lens Cone and Lens Board parts. Use either normal Lens Cone, or the "No shoe" variant.

3. 3D Print the parts.

   1. Optinally, add the Fuzzy Volume STL as a modifier for the Lens Cone part in the slicer and add fuzzy skin to it to apply it only where the parts intersect. This is just for the aesthetics.

      

4. Prepare the 3D printed parts:

   1. Install heat set inserts into the Lens Flange.

   2. Cut 10-15mm wide strip of light seal foam and glue it around the Lens Flange as shown in the picture to the right.

   3. Cut the rectangular section in the foam to give some room for the plastic tab on the camera.

   4. Cover the inside surfaces of the Lens Flange and Lens Cone parts with matte paint. Avoid painting the threads!

5. Disassemble the camera.

6. Discharge the flash capacitor!

7. Remove the original lens unit.

8. Desolder and remove the on-off switch, motherboard, flash and capacitor. Leave the original button if you want to use it.

9. Optionally, find some thicker wires. The next steps will use signal wires for power transfer and this is generally not OK because of the voltage drop and increased heating. I decided to leave it as it is because the wires are short and carry the current for very short periods of time, but I do not recommend it.

10. Wire the motor directly to the battery terminals. To switch it, use the original button or add you own. This will be the development button that starts the cycle. Be careful to not reverse the polarity of the motor or you will destroy the plastic gears inside. Ask me how I know.

    

11. There are two yellow wires that come from under the motor. Solder these parallel to the button (so it can also switch the motor on). These wires come from the micro switch that is held pressed by a cam gear until the development cycle finishes. This will allow you to hold the development button just for a couple of seconds until this micro switch catches and the cycle will finish by itself.

12. Optionally, add another switch that cuts the power to the whole system. I've installed it in place of the original flash.

13. Glue the 3D printed Lens Flange to the empty space where the original lens unit was. Apply glue or double-sided tape to the surfaces shown in the picture to the right. Shown in the picture below is my progress at this point. Don't worry about leaving the gaps not exactly light tight. The light seal foam around the Lens Flange part should keep the inside volume of the camera completely dark anyway.

    

14. Assemble the camera.

15. Attach the Lens Cone to the Lens Flange using 4x M3x8 screws.

16. Prepare the lens:

    1. Print the focusing scale and attach it to the lens board.

    2. Mount the lens on the lens board.

    3. Screw the lens board to the M65 helicoid.

    4. Make an index mark on the helicoid in its collapsed position opposite to the infinity mark on the focusing scale.

17. Attach the M65 helicoid with the lens to the Lens Cone part.

18. Check the whole assembly for light leaks in a complete darkness with a bright flashlight. Pay attention to these places as they can cause problems:

    1. Hole for the original LED.

    2. Hole for the original flash.

    3. Space between the lens shutter and the Lens Board part.

    4. Space around the Lens Flange part.

Additional projects

These can also come in handy: