Telescopic Pole Twist-Lock Mechanism

thingiverse

****************************************** Telescopic-Pole Twist-Lock Mechanism ****************************************** ** Easy-building : The marriage of 3D printing with Off-the-Shelf. ** This item allows us take standard low-cost steel tubing, available at many DIY stores, and create the far more useful adjustable pole. When hidden on the inside of two tubes, this mechanism gives us a neat telescopic assembly, which can be shortened or extended as needed. The pole is simply adjusted using a quick twisting action to unlock and lock. The mechanism works by using a single nut and bolt to move a wedge in or out of an expanding collar. While I have been using these adjustable poles for photography, lighting and backdrops etc, they have many other applications. That said, these poles should not be used in any critical situation, since both the tubing and mechanism are not particularly strong. ** 3D Printed Items ** 1 x Internal Expander, for 25mm (1") tubing 1 x Internal Expander, for 19mm (3/4") tubing 2 x Wedges, taking M5 hex bolts 1 x End Gap Cover, for 19mm and 25mm tubing ** Other Items Needed ** Length of 25mm (1") steel tubing Length of 19mm (3/4") steel tubing Steel hex bolt and nut, M5 size with thread length 30mm to 40mm Double-sided (carpet) tape The double sided tape is to help prevent the smaller expander from sliding inside the 19mm tube. While it could be kept in place with some drilling, cutting or denting, I'm trying to keep the tooling used down to a minimum. 4 small 10mm x 10mm squares of tape are to be placed on the outside of the 19mm expander. 4 small 5mm x 5mm squares of tape can be used to secure the end gap covers. Glue could be used instead of tape, so long as care is taken where the glue is placed. ** The 3D Printing ** All the 3D items were printed with a brim and 50% cycloid infill. Although I used PLA myself, PETG is expected to work well too. I printed the smaller wedges at 0.12mm layer height, upright with the hexagonal hole at the top, so there was no overhang. The End Gap Covers were also printed at 0.12mm layer height, and printed horizontally. To give a good surface for these covers, they were lifted just off the print surface by 1mm and supports then switched on. Both the Internal Expanders were printed at 0.20mm layer height and printed with supports. Print these on their sides to ensure that there are no layer ridges on the internal cone shapes. This allow the wedge cone shape to slide inside the expander rather than catching on any layers. ** Assembly ** Place the bolt in one of the wedges and put this in the 19mm Expander. Add the other expander, wedge and nut. Place the End Gap Cover on the 19mm tube. Place the 4 pieces of 10mm x 10mm tape on the outside of the 19mm expander, between the ribs. Push this assembly into the 19mm tube so that the smaller expander is in all the way. Then hand tighten to get the tape to grip. Unscrew a little, then push into the 25mm tube. Tighten again to ensure the 19mm expander is attached really well. Test that the locking mechanism works as expected. Since you want to keep the 19mm expander in the 19mm tube, always unlock before trying to extend. Add a little more tape to the end of the 25mm tube and push the End Gap Cover over the 25mm tube. All ready to use. If force is applied to the expanders when they're not in a tube, they can be split in half. This is not an issue at all, because the expanders will be kept in place by the steel tubing when assembled, and the mechanism can still be assembled and work, with these expanders being split.