Treehouse Elevator or Dumbwaiter

thingiverse

My kids wanted to take things up and down their treehouse constantly, and instead of watching them climb a ladder with heavy buckets (they really were carrying rocks), I started building a solution. The dumbwaiter is now installed on our treehouse, but its design makes it suitable for any venue where 3/4 inch EMT conduit won't be an eyesore. The "car" part of the system is still under development and will likely evolve further. Right now, it's made from plywood with PVC (I believe 1 inch) on the rails. There are potential improvements to be made in the future to enhance the car itself. Also, pulling the ball chain (even with its approximately 4:1 mechanical advantage) can still be a bit challenging for young kids, so I plan to add a crank at some point. I designed and printed a crank arm (see attached STL file), which has greatly improved the system and now even our two-year-old can easily bring things up and down. Print Settings: Printer: QIDI Tech I Rafts: No Supports: Yes Resolution: 0.2mm Infill: 35% or more Notes: Support is only required in a few pieces, but it should be fairly obvious where they're needed. Remember that this will need to withstand some abuse, so use at least three perimeters and decent infill. Installation: Printing the system is relatively easy. Assembling everything can be less straightforward, though. The set is designed to be flexible for various mounting options, which means none of them are particularly convenient. Here's a basic overview of how it works: First, you need to create the two horizontal surfaces where the brackets will mount. Then determine the length of your vertical pieces of conduit. Since they need to be continuous, you're probably limited to 10 feet. Next, attach the brackets to the horizontal surfaces. The screws go in diagonally, so I included drill templates that you can print to guide a 1/8 inch bit for pilot holes. It's helpful to build the car first to define the spacing between the conduit rails. The rails are secured to the brackets with zip ties. Once the rails are done, size the horizontal conduit at the top to be long enough to span the brackets and the ball chain cog and guide. Pictures show how the parts are installed on the top piece of conduit. The bushings and chain cog are secured to the conduit by drilling a hole in the correct place and putting a #8 screw through it. The car is connected to the car via a rope (I used paracord) that passes through the provided holes in the bushings. The routing, number of bushings, knots, etc., will depend on your specific situation. #6 ball chain is used to drive the cog. Installation involves wrapping the chain around the cog and then sliding the guide over it. The pictures are useful for understanding this process. I also split open one ball and spliced the chain so that it was continuous without having a connector in the loop. How It Was Designed I designed this system using SolidWorks.