Flipper Robot. This is a 150g combat robot. I'm attaching the .STEP file as well for those who want to edit.
Very simple build that doesn't require many extra tools. Wedges can be printed or cut out of a sturdy material. 0.5mm Titanium is ideal. But Plexi/Acrylic also work as well. Printed wedges work fine if you're just flipping things around the house. There are two styles of top plates also, flat plate version or thicker angled prints
Assembly tricks: I used a lighter and heated the nails when inserting them into the printed arms. This creates a tight fit and keeps them from backing out. Otherwise a drop of superglue keeps them in the arms. The holes in the body and the hole in the lifter linkage should a loose fit for the nails so they can rotate freely. The nail spacers are put on the nail to keep the servo linkage from moving too much laterally on the nail.
I use a paper clip to attach the flipper to the servo arm and cut off the excess after its bent.
The lego hub has tolerances to printed easily on my printer and be a snug fit, but attaching a tighter tolerance version incase you need it.
You can use #4 Plastite screws for everything (to save on buying parts). But I use #3 for the top brace and top panels and #4s to attach the wedges to the arms.
1qty 2" Brad Nail
2qty 3/4" or 1" Brad Nail (https://amzn.to/2JvT7mE)
Small Zip Ties
4-20 Plastite Screws (https://amzn.to/2Q5UFWI)
3-24 Plastite Screws (https://amzn.to/2AInL9z)
Wheels: Lego 24x14 Tire (https://amzn.to/2yLfDUd)
Flipper Servo: TurnigyTGY-306G-HV
I use the Turnigy but it's often out of stock. Here are other variations to look for that will also work. KST DS215MG V3, ES9256 HV, KST X12-508, PTK 9495MG-D
Drive Motors: N20 Micro Gearmotor 30:1 or 1000rpm (https://amzn.to/2JsTwpA )
ESC: Endbots DESC or Budget DESC :https://www.endbots.com/collections/products/products/endbots-desc?variant=5580585992221
RX: Your choice the Endbots DESC comes with a Spektrum receiver.
TX: Your choice. I use a Spektrum DX6 (https://amzn.to/2qk8RQA)
Battery: Nano-tech 300mah 2S Lipo Pack (https://hobbyking.com/en_us/turnigy-nano-tech-300mah-2s-45-90c-lipo-pack.html)
Note: Any micro servo will work, but you'll be limited on flipping power. For that reason I prefer the Turnigy linked above, but you can build with a cheaper servo to test first.
You can buy these wheels to save weight if needed. Although the lego wheels work great and are much cheaper
SC-2110p ProComp (http://www.132slotcar.us/store/product_info.php?products_id=4523)
Printed with esun PLA Pro https://amzn.to/2DbbSLP
However, printing the entire thing out of Markforged Onyx is ideal.