The Bronica ETR series were 6×4.5 film SLR medium format cameras manufactured by Zenza Bronica in Japan from 1976 to 2004. The series consisted of the original ETR (January 1976), the ETRC (October 1977), the ETRS (January 1979), the ETR-C (January 1979), modified ETRS (July 1982), and the ETRSi (October 1989) (Gonzalez, 2016). Production of the ETRSi ended in December 2004; full technical support for the ETRSi ended seven years later, in December 2011.
The ETRSi incorporated a number of changes over the preceding ETRS, namely improvements in the focusing screens, shutter speed dial, and in sound and light-deadening material in the interior of the camera (Gonzalez, 2016). One other relevant change was the enlargement of the battery cover over that of the ETRS (#2912) to that of the SQ-A (#1912) (Gonzalez, 2016).
The battery cover in place on the bottom of the Bronica ETRSi
As is often the case, various parts of such a camera system can go missing – the eyepiece, the winding lever, the battery cover, and so forth. In the case of the battery cover, replacements are hard to find. The only other (efficient) way to obtain a replacement battery cover would be to buy a broken ETRSi camera body. Though this is useful from a long-term repair perspective, it is not entirely feasible if just the battery cover is needed. The intent here was to create a 3D model of a ETRSi battery cover in order to allow for 3D printing of replacements.
FreeCAD screenshot of battery cover 3D model
Using the original part as a guide, I constructed a 3D model using FreeCAD. I decided to keep it close to the original part in terms of design. That said, the grip/groove pattern was changed slightly, in order to make it easier to shift over. Because of the lack of a finish on the replacement battery cover, it is easier to remove from the camera body, as compared to the original battery cover (due to the rougher, as opposed to smooth, surface finish).
The part was test printed by Sculpteo (Paris, France). The total cost, with shipping, ended up being €6.00 (~$9.00 CAD; ~$7.25 USD).
The materials and related characteristics were:
Process: Multijet Fusion
Material: Nylon PA12 (Black)
Original (bottom) and replacement (top) battery cover
The part can be downloaded from Thingiverse.
Gonzalez, D. (2016). Bronica medium format cameras. Retrieved from http://bronica.org/start/bronica-medium-format-cameras.html