Screw threaded telescopic platform (40mm, 5 segments)

thingiverse

#### Screw Threaded Telescopic Platform, 40mm Deep, 5 Segment Version This version stands at 40mm tall when fully closed and 150mm tall when fully unscrewed. It's a concentric series of threaded rings, each captive within the next ring out. The rings can be screwed up or down between two end stops positioned such that all of the rings line up with each other to form a disk, or screwed up so that each extends above the ring directly outside of it to form a taller, cone-like structure. Because these rings need to be fully captive, 3D printing offers the easiest approach to creating this type of structure as all of the rings can be created at the same time in their final position. This avoids having to fit/attach one of the end-stops following creation as separate pieces with subsequent assembly. Note: The 3D models are set-up to print with the upper surface flat on the print bed, giving a better surface for adhesion but should be remembered if it becomes necessary to apply force to free up the rings; the rings screw out of the face that was printed downwards. The point of this is to create an object that can be used to support things in the way that a pile of books might be used, but with a fully variable height (within its limits). This would have applications in DIY or modeling to temporarily support something in the correct position while glue sets. I should mention that I don't know what the maximum load that these objects could support is, and it's likely to vary with print quality and the specific plastic used. However, the versions that I have printed in PLA have all been able to support my entire body weight so they are not inherently fragile. Note: Plastics used in 3D printing (such as PLA) can fail suddenly by shattering so I would recommend considering the consequences of sudden failure in any application, and if heavy weights are to be supported then the printed object should probably first be tested with a considerably heavier weight prior to its use. A smaller version of this object exists as an option for verifying the capabilities of a printer to create this type of object without wasting too much plastic on failed prints. Ideally each ring should be as close fitting as practical, but obviously if too close then the whole set of rings becomes one solid lump of waste plastic. This is largely down to the clearance between rings (horizontal gap between the rings) designed into the 3D models, and the clearance that should be used will depend on the printer being used. To deal with this, I have included 5 models for each version, each with a different clearance between the rings. The thread faces overhang and it's generally better to print overhangs with low layer heights. I have been printing these with a 0.1mm layer height. Other details from the file names are that "S" is followed by the number of segments, and "H" is followed by the number of millimeters that represent the height of the base units. I have included optional end cap models for these 40mm versions. They are designed to press-fit together and into the ring structures and give a flatter upper surface to the central ring. #### Related Items * Screw Threaded Telescopic Platform (20mm, 4 and 5 segment versions) * Screw Threaded Telescopic Platform (30mm, 5 segment version) * Screw Threaded Telescopic Platform (30mm, 6 segment version) * Screw Threaded Telescopic Platform (40mm, 6 segment version) * Screw Threaded Telescopic Platform (40mm, 7 segment version) #### Update (22nd September 2019) I received a comment from th008 suggesting that these would be easier to print if the clearance between the rings was larger where they form contacts the build plate. This would avoid any 'elephants foot' effect from gluing the adjacent rings together and make them easier to print. It took some thought to work out how to do that without having to re-do the design from the start, but I figured that out and have now made that change. Specifically, where the form contacts the print bed the clearances between the rings is not 0.4mm wider, with that extra clearance tapering back to the normal profile within the first 2.5 mm in height. This change did indeed make these much easier to print reliably.