Modular Yoke/Spreader Bar

thingiverse

This is a modular assembly that can be customized into various yokes, spreader bars, or simply cuffs. It's still somewhat under development, but I've had limited time to work on it, so I decided to upload what I have for feedback when I finally get some free time. There are only a few components, but most of them have multiple configurations that have been exported as individual STL files. Here is a quick overview of each component: * Cuff Body, End - This is the primary body for a cuff that attaches to the end of an assembly; it has one connection point. * Cuff Body, Middle - This is the main body for a cuff that's placed in the middle of an assembly; it features two opposite connection points. * Cuff Loop - This is the other half of a cuff and can be paired with either style of cuff bodies. * Bar - This bar connects two cuff bodies together. One end is male, while the other is female, allowing multiple bars to be connected if longer lengths are desired. * Link - This piece joins the female end of a bar or cuff body to another female end of a bar or cuff body. * Cuff Hook Point - This can slip over an open cuff for securing or anchoring the assembly. To create a traditional yoke, you would need to print two end cuff bodies, one middle cuff body, three cuff loops, two bars, and two links. The file names list the diameter of the cuffs and overall length of the bars in inches; diameters with an "R" suffix have a reversed swing. You can use these parts without necessarily printing them, but if you're like me and having the bottom layer texture on the top side drives you crazy, you may want to consider using them. The actual diameter will be slightly larger than indicated due to the two parallel 0.5-inch lines with R1.5-inch semi-circles on each end. The height of all parts is 1.380 inches and the width of cuffs and bars is 0.500 inches for reference. This assembly fits comfortably on the popular Ender 3/5 beds (the 12-inch bar is tight but still fits on a 235x235mm bed). It also uses M4 hardware, specifically M4x30mm bolts. To lock the cuffs in place, I used some clevis pins; as long as they're placed on the bottom side, users can't reach them. You can print your own clevis pins or pick up a variety pack at Harbor Freight. For more exact lengths like the ones shown, you can order 1-7/16-inch length pins from McMaster, part 97245A245, which are available in packs of 25 for under $9. I printed this assembly using standard PLA and found it to be reasonably rigid with a 30% infill and a 1.2mm shell. However, I'm mostly concerned about the longer bars due to their increased leverage potential, which could lead to breakage. Make sure your prints come out dimensionally accurate before assembling anything. This assembly requires little to no post-processing beyond cleaning up support mesh and trueing hole sizes. The fitment on hardware is tight to minimize looseness or wobble between parts. Any feedback you can provide would be greatly appreciated; I'm trying to see if it's possible to design a model that doesn't require any hardware, but I still haven't completed designing or printing one yet.