Zimmspeed NPRC Chassis1.0

thingiverse

This is the first release of the ZimmSpeed NPRC Drag Racing chassis. The goal with the project is to make a community driven NPRC Drag Racing chassis for people who want to make their own chassis based on the popular Team Associated B6 platform. The design prioritizes simplicity for the home builder, minimum special tools, and where printed structural parts are used, they are through bolted as to put the parts in compression. All parts are designed to be able to be printed by a common Ender 3. All parts can be cut from a single 300x400x3mm sheet of carbon fiber. This build requires either the Team Associated Builder's Support Kit, or a donor B6 buggy. The templates support the use of any variant of the B6 from the B6 original to the current B6.4. They will all work with this design. Tools needed. 1.5mm hex wrench 2 mm hex wrench 3mm and 4mm Tungston Carbide Drill Bits (https://amzn.to/42xRrQH) Flush Cut Router Bits (https://amzn.to/3VL2C6d) 90 degree countersink (FYI, metric bolts use a 90 degree countersink, which is different than an imperal 82 degree bit) https://amzn.to/41hwWGZ A common woodworking router A drill press A 3.0mm suspension arm reamer Diamond jig/scroll saw blade. (https://www.homedepot.com/p/DIABLO-3-in-Diamond-Grit-Hard-Tile-Jigsaw-Blade-DJT150DG/313114955) Parts needed: 300x400x3mm Carbon Fiber Sheet (https://amzn.to/42AKZs5) Various 3mm flat head screws up to 30mm in length. (https://amzn.to/3ny20Ve and https://amzn.to/3HSzQLw) Countersink Washer in your desired color (https://amzn.to/3pfejpD) 3mm lock nuts (https://amzn.to/3LIfs0M) 10mm standoff (option, but steering is better https://amzn.to/44zueQ1) Super Glue (CA) Traxxas 2336A turnbuckle for wheelie bar (https://amzn.to/3nIraQW) Body Mount posts. Printing of Template Files Template files are used for test fitting, and ultimately cutting. The chassis has 2 sections, since it is too long to fit on the build plate of an Ender 3. Print the front and rear separately, and connect with the connector file. Printing the templates can be done with any cheap filament and infill percentage does not matter. All templates are true to size, meaning they are all 3mm thick, like the carbon fiber sheet. This allows for test fitting if desired. However, once you are ready to cut with the router, I recommend you use your slicing software (I use Cura) to scale the thickness to 6mm to allow for enough room for the flush cut bearing bit to ride along. Cutting of Carbon Fiber Place a layer of masking tape on the entire surface of the carbon fiber sheet to be cut. Trace each template out on the sheet with as little waste as possible. Once that is done, you can rough cut the pieces with the diamond jig saw blade. The more accurately you rough cut, the easier the routing will be. Be sure to wear the proper PPE, as carbon fiber dust is not healthy. After the parts are rough cut, super glue the template down to the masking tape on the carbon fiber sheet. Allow the glue to dry. Then use the router with the flush cut bit to do the final cut. Drilling of Carbon Fiber After cutting, use a drill press to drill out the holes following the template as a hole guide. Tip for cutting holes is to set the depth of the drill press to allow the bit to drill to just pierce the other side of the carbon fiber sheet, the flip it over, then drill all the way through. The holes turn out cleaner that way. Then for the holes you need countersunk, use the drill press to set the correct depth to get the correct countersink depth. Tip is to go very slow, else the bit will chatter leaving an uneven hole. Printing of structural parts. The printing of structural parts should be done with PETG or ABS. I have designed the parts to be through bolted to minimize the reduced strength along layer lines. All parts are designed to be printed with no supports. Please note the print orientation of the bulkhead, as that part orientation is critical for strength. The bulkhead uses 1.5mm holes, so due to printer tolerances, the holes generally come out just under 1.5mm, so the suspension arm pins will not fit. Use a 3.0mm suspension arm reamer to make the holes perfect for proper and free arm movement. Use washers on the head and nut side to better distribute load. Assembly. Assemble as pictured. Pay close attention to the steering section. The transmission is raised a total of 10mm, so add 10mm to the length of the B6 fasteners in the manual for fastener lengths. For the front floating body mount requires a 3/32" hole be drilled into the caster block to hold the mount in place. Good luck everyone. I hope to clean up these instructions to be more complete in the future, but was excited to get this initial version out on the street to share with everyone. Please comment with what you find works, and doesn't work. We can make this into a very agile platform making updates on the fly if we all work together. If anyone builds this and it's successful, and if you wouldn't mind, throw a couple bucks my way via tip. I spent a lot of time and money buying parts I wound up not using, unnecessary tools, and lots of wasted filament before I finally got it down to what you see here. Looking back at it, it does look simple, but it did take time to get to this point. Thanks!