Graflex 3 1/4 x 4 1/4 to 4x5 graflok adapter plate

This is a design for a simple adapter to convert the very portable 3 ¼ x 4 ¼ Graflex SLR cameras to be able to shoot with common graflok backs and attachments alongside cropped 4x5 sheet film.
 

Additional Materials Needed:

• Adhesive flannel for sealing the space between the camera and adapter
• 7x m2 x 4 screws
• 2x m2 x 6 screws
• 9x m2 nuts
• 1mm thick light seal foam (optional)
• Longer m2 screws for pulling in m2 nuts into slots carefully (optional)

The most important part of all is the graflok back from a crown or speed graphic.

Printing Tips:

I printed all of my parts in Atomic Carbon Fiber PETG filament. It is very opaque and strong. I would recommend using 3-4 perimeters and 30+% infill with this filament on these parts in order to ensure that things are light tight as well as strong.

Original Back Removal:

The first part is to remove the original slotted Graphic back. This requires the removal of the whole back itself. Some of the screws you have to remove will be hidden by the slotted back and may only be accessible by rotating the slotted back at a non-locking angle. 

Remove the following eight screws:

Once those have been removed, remove the two screws on the left and right sides of the bracket, then carefully remove the bracket from the main camera body. 

Flip the bracket over and remove these four hidden screws on the slotted holder.

Remove the remaining screws that hold in the slotted holders.

and finally remove the 14 screws that hold in the main part of the slotted back. Save these screws for the installation of the adapter plate.

Adapter Plate Prep and Install:

For light sealing, use the adhesive felt on the flat side around the film area. DO NOT use camera seal foam. The flannel will provide a light seal as well as smooth rotation whereas the foam will create a TON of friction. 

On the opposite side you are free to use the 1mm light seal foam mentioned to create more of a seal on the light trap that seats inside the metal Graflok back. I would recommend this for the thinner 1.3mm adapter.

Once you have applied your seals, Poke holes in the material at each of the screw holes. When finished, you can begin to attach the adapter to the main bracket.

1. Align the adapter plate with the screw holes on the bracket. Screw in all 14 screws. You may need to squeeze the back and plate together a bit due to the felt. 
2. Reseat the bracket back on the camera body. Remember to have the button for the rotation on the right rear side of the camera.
3. Screw in the two left and right screws for the bracket.
4. Screw in the four top corner screws and the two outer bottom screws. The inner two are no longer accessible due to the large adapter.
5. Seat the graflok back on the adapter, use longer screws to pull the nuts into their slots on the rear of the adapter, then seat in the m2x4 screws into their places. The back is now secured to the camera.

Ground Glass Calibration:

The process of adding the new back has offset the film plane. You will need to manually recalibrate the ground glass. Chances are you will have to raise it quite a bit, but that is what my ground glass riser I have included is for. 

Remove the original ground glass mounting hardware from the camera by removing the four screws on each side. you will attach the hardware to the new riser with two m2x6 screws and nuts at the thicker side and two m2x4 screws and nuts at the thinner side. The thick side seats towards the lens. 

Calibration with my riser is the same as calibrating the original camera. Loosen the screws to adjust, then tighten to set. The riser is held in place by the hood clamping down on it.

NOTES:

The thinner version of the adapter will flex if you pull at the corners (however why would you do this…) that will cause a light leak unless you mitigate this with additional light sealing. This version also gives a bit more wiggle room for hitting infinity on the stock lens.

The thicker adapter is nearly solid at 30% infill. This version still hits infinity on my camera with the stock lens. Overall this version was much easier to calibrate alongside my riser I include in these files. 

My riser is meant to adapt to the hardware that I have in my personal 3x4. I believe that all the parts are stock. If you run into any issues or have hardware that is incompatible please shoot me a message so we can talk. I would like to make this as universal as possible.