I assume, that in most cases, film will already be stored on a spool. However, not everyone using Open Telecine will have an uptake reel or extra reel. For those users who are short on a reel, an open source reel was developed.
As seen in the first photo, the reel is split into two halves, each with 6 segments. The segments are connected together using a dovetail joint, with 1.5mm protruding and recessed divots to lock them together.
Each half of the film is locked together (again with divots) using concentric cylinders, with the outer most cylinder holding the initial wrap of film. There is also a small gap in outer most reel to allow for an initial film lock.
The last photo, from OpenSCAD, shows an updated version that has holes to indicate the amount of film a reel contains, starting at 25m and ending in 150m. Thus, this 8mm film reel can hold approximation 150 meters of film. By experimentation, it appears that film lenght (L in m) is functionally determined by radius of film (R in m) and radius of spool wheel (S in m), L = (6500*PI*R*R)-(6500*PI*S*S). Thus, for our S=0.03 reel, R = SQRT(L+6500*PI*0.03*0.03)/(10*SQRT(65*pi)). No additional experimentation was performed on the final reel to determine accuracy. This will be conducted for when the electronics is connected, to allow the motor to do its job in reeling up the film.
Since the Open Telecine film reel differs in thickness from a commercial reel, the motor reel connectors will also need to be updated.
This part was created by using only open source hardware and software: Ubuntu (similar to Microsoft Windows and MacOS), gimp (similar to Adobe Photoshop), blender (similar to Autodesk Maya), ReplicatorG, LibreCAD and OpenSCAD (simular to AutoCAD), and MakerBot.
I used ScanDigital transfer my 8mm to DVDs. It is such a relief to not have to think about those reels deteriorating in my closet.
ReplyDelete