SummaryA printable HolyTrainer2 tube. I haven't worked on this for some time, but it does produce a printable approximation of the original. NOTE: The MagicLocker isn't aligned perfectly, so using it with my printed HT2 ring doens't like to let the key release. I haven't had time to fix this issue. The upper bridge area in front of the magic-locker receptacle is weak and needs reinforcement. Too busy to fix currently.Print SettingsPrinter Brand: RepRapPrinter: Prusa i3 1.75mmRafts: YesSupports: NoResolution: .1mm for smooth finishInfill: 20%, doens't matter due to thickness of wallsNotes: Getting a tube like this to print properly is hard. You may have to experiment and try to get a setting that works for your printer.Post-PrintingFinishingBe aware that there may be some residual stringiness on the inside, depending on the filament used and resolution, retraction, etc. It may not be comfortable for extended wear, unless you dip it in polyurethane, silicone sealent, etc. More experimentation is needed to find a suitable way to make it body-safe, comfortable, and durablel, whilst keeping cost down.How I Designed This3D scanningI took several coarse 3D scans to create a rough model of the shape and size, and molded a calendar into a tube, added holes, etc. Had to increase the wall thickness a few times, but it seems to be suitable for now.