C-mount extender

thingiverse

C-mount extension tubes of different lengths. <h4>Update 08/2018</h4> * Corrected thread pitch of outer thread (0.75mm corrected to 0.794mm=1/32"). * Increased tolerance on thread diameter (0.2mm instead of 0.1mm for each thread). * Reduced model resolution to lower file size. <h4>Printing</h4> Because threads are fine, a layer height of 0.15mm or smaller is recommended. Accuracy must be high for smooth operation. Over-extrusion should be avoided at all costs. If threads don't fit, adjust slicer parameters (XY scaling factor and "Surface inset" or "Horizontal size compensation"). Be aware that re-scaling affects inner and outer thread differently. Nominal diameters are 25.2mm (outer) and 24.74mm (inner). Average of both is 25mm (exact: 24.97mm), with a difference of 0.5mm. If measured average doesn't match 25mm, adjust XY scaling factor. If measured difference doesn't match, adjust "Surface inset". <h4>Notes</h4> * Models have high resolution, which may cause slicer errors. Simplify3D does not see model errors, while KISSlicer does (but results are fine anyway). * Small tube length changes can be made by scaling along Z in the slicer. Threads won't fit if change is too big; spacers might be a better solution for larger changes. Spacers can also be scaled along Z. * 5mm extender has thin wall between inner and outer thread, making it mechanically weaker than longer tubes. Be careful with heavy lenses; light may shine through the thin wall section. Thin wall is caused by 60° overhang instead of 90°, making part printable without support. * Painting inside of tubes with black matte color reduces stray light. Don't paint threads; normal wall paint works well for this. * Material can rub off threads, especially when first used. Prevent debris from landing on lens or image sensor by applying oil or grease to threads.