Cine projector spool adaptor: Super 8 to Standard 8

An adaptor to mount a "Super 8" cine film spool on a "Standard 8" projector. Note that Super 8 film has a different format for image position and sprocket hole size so this is not something you would normally want to do, unless like me you have a Standard 8 film on a Super 8 spool (I guess the original spool broke some time in the distant past and this was the only replacement that could be found).

The design uses a "pin in the spokes" arrangement to drive the spool to avoid printing a small drive pin in the normal position. The projector's drive pin is accommodated by a notch in the adaptor's hub.

The design is fully parametric and the OpenSCAD source is included, so you can modify if you need to, but it is a perfect fit straight off the printer so you should not need to unless you have some unusual spools.