- My design must be able to be 3D printed using pieces that people can get from Instructables by winning free prints. This means no prints can exceed the 3"x3"x3" bounding box that Instructables has set for free prints.
- The design must have moving pieces.
- The design must be packed for printing in such a way that no more than 3 prints are used to complete all the pieces.
Here's how the design breaks down:
The very bottom piece will be specified in the flexible rubber material. This pad snaps into the base piece and gives the whole assembly a non-slip surface to sit on. The base is hollow with holes for the rubber pad on the bottom, holes for screws to secure the lid on the top, and one hole in the back for a panel mount switch. The batteries for the LEDs will be housed in the base, as well as anything else you choose to hide there.
Bolted to the base is the lid, which includes the supports for the barrel. The thicker support on the right has a pass thru for wires running from the LEDs to the battery, and a counter-bored hole for the axle. The left support has two straight holes, the upper for the larger gear, the lower is where the lower gear and handle meet. The axle in the right hand support has a hole through the middle where the wires for the LEDs will pass through.
The large gear on top is fixed to the barrel while it spins free in the support. It has a 1.5" pitch diameter, 48 pitch (72 teeth), and a pressure angle of 20º. The lower gear spins free in the support and is attached to the handle. It has a pitch diameter of .25", 48 pitch (12 teeth), and a pressure angle of 20º. The gear ratio is 6:1 from the cranker's perspective (6 turns of the handle would turn the barrel once).
The barrel is 2" long and has a plate part way up that allows 5mm or smaller LEDs to poke through. There is also a bolt, thru hole to attach a PCB to the underside. There are no LEDs directly behind the symbol to help cast a sharper silhouette. The black cap on the bottom of the barrel allows access to the LEDs using a twist lock design. The two nubs on the cap engage two matching slots on the barrel. The boss that holds the axle on the right also has a pass thru hole for the LED wires.
To meet the requirement I set of not using more than three prints I stacked the small components in the empty space inside of the bounding box made by the pad, base, and lid. The printer will simply fill in with support material between pieces. When the support material is removed the pieces will come free and then can be assembled. I managed to get all the pieces into 2 prints, with the second print being the barrel by itself.
The whole thing will be put together using glue and a four #8 screws. The assembly is designed so that even when it is glued together you still have access to everything in case there is an electrical failure.
I did the design and modeling in CATIA V5 (The colors in the pictures are only so you can see the different parts in the model, the final product will be painted). Attached below are two .zip files with the CATIA files."Bat Signal" has the assembly in it's proper configuration, "For Print" has the stacked configurations for printing along with the .stl files. The .stl files are attached separately as well for anyone with their own printer. If you need a different file type let me know and I'll do my utmost to convert the files for you. I'll be sending out for the first print with in a couple days and the second as soon as I earn another print. Once I receive them I may tweak the design if necessary, so you may want to contact me to make sure the .stl's are up to date. If you want to know the moment I finish assembling the final build, complete with circuit, make sure to subscribe. Thanks for reading to the end of that wall of text, please feel free to comment or ask questions.
Na na na na na na na na Batman!
You asked for it, ok not really, just JerryBYong but that's semantics, and it's here: A barrel with the Dark Knight style logo. There's a picture above and .stl file below.
Both prints are in the queue for printing at Instructables. As soon as they arrive I'll post pictures here and a guide for the construction of the LED circuit and general assembly.
Thanks for all the comments and constructive feedback, keep it coming.
The pieces, or most of them, arrived today! They all turned out better than I could have hoped for. The fact that the rubbery bottom pad turned out perfectly plus the fact that nothing broke during the separation and cleaning or shipping is awesome. Unfortunately the piece with the small gear didn't make it into the box. I'm not sure if it broke or just got lost in the processes but I can see where it was printed. Regardless everything will go together except the handle and I'll be posting a guide to the circuit and assembly soon. I've attached a couple of pictures of the pieces below.
The build for the Mk. I is complete and documented. Check it out HERE.