For making this model, you will need the following: 1. A 3d printer or you can always ask someone to print the parts for you. 2. A heat gun/hair dryer to do some fun fittings. 3. A rubber band of correct size and tension (once you make the model, you will be able to find the right one for it). 4. Last but not least, zeal! Here’s what I have used: https://c5.staticflickr.com/9/8138/29809808076_c26fa83324_b.jpg For the 3d printed parts, few of the parts will have to be printed multiple times (or multiple at one time) so here is the list of parts that you need to print: X1 Base X1 Crossbow Body X1 Gear 1 X2 Gear 2 X1 Release Hold Pin X1 Release X1 Support Left X1 Support Right X2 Updown gear X4 Wheel cap X4 Wheel X2 Wing Assembling them together should be pretty simple and hence I did not put up an instruction for it. Once you have put on the four wheels, heat up the four wheel caps enough so that the caps are slightly soft but not too hot to get deformed (please don’t let kids do this). Once it is soft, put on the wheel cap on the portion protruding out from the wheel. Once the caps cool down, it will have a (to some degree) permanent fit and won’t come off. Heat gun will need to be used for release pin too. The release pin will need to go through either one of the holes at the rear portion of the crossbow body, then through the release pin and out through the other hole. When the release pin is slightly protruding out from the other hole, heat it up enough so that it is soft and slightly press it (using something since it will be hot!) against the crossbow body to seal it off. See, it is fun setting up the model :) I have tried to keep the model as easy to print as possible but there is quite a significate bridging that needs to be done by the printer while printing the crossbow body. You have been warned! I have made the parts to accommodate the tolerance of my printer so prints from other printers may or may not print well enough so slight adjustments using heat gun and hobby grade knife might be needed. Alongside, some of the parts like the Updown gear is meant to be snug fitted so that the crossbow body doesn’t fall down on its weight. Loading the crossbow should be very straight forward: 1. Aim using the gears (or manually if you feeling lazy). 2. Pull the rubber and have it rest on the small protruding shape near the release. 3. Load your NERF dart 4. FIRE! (using the release…duh!) Here is the link to the video of the crossbow in action: https://www.youtube.com/watch?v=Iasy4pHdnd8 As mentioned before, this is my first 3D printable model so there might be some mistakes and I do apologize for those. I would love to get your feedback on what needs to be fixed and how the model can be improved further. Hope you liked it 