https://www.youtube.com/watch?v=gVVSuHa_Wu0&feature=youtu.be Reading about the contest in the 3D printing Facebook group, I decided to make this Nerf Dart Compatible Launcher. As told in the rules the design must be an original design and not something you had laying around or used before, so I started designing in 123Ddesign. Because the rules said that functionality, the percentage of 3D printed parts vs off the shelf parts and feasibility to print are taking into account, I decided that the riffle had to be as much as possible 3D printed with as less as possible other materials. This killed a lot of my ideas, because they were more complex or needed electronics, like motor drivers, microcontrollers, servo's, etc, to work. This is how I tried to come up with a mostly mechanical operated rifle that would function as good as possible. It's a pitty I couldn't get around the two DC motors and therefore the batteries. Otherwise it would have been a blow gun. :-) The idea of making it a large rifle (72CM tall) was born in a toys store. The manager there told me that all the children are looking for the biggest Nerf guns and rifles they can find. They cost you up to $ 150,00 to $ 300,00 to buy, so my goal was set to build a rifle like that. I choose the A.R. style rifle look and started designing. A gun as big as this print would easily cost up to $ 200,00 but now you can print it and get the parts to make it for about $ 40,00. I hope that a lot of parents, teachers, and specially children, will build this blaster and have a lot of fun with it. It's a great project for parents to do with their kids, so make your kids day and print it :-) P.S. The thing is to large to get the drawing on YouMagine correct. Therefore there are pictures as well to show how it should look when it is assembled. I tried to get it right, but I couldn't get my parts that far from the buildplate in YouMagine. Everyone joining this contest... I wish you all the luck there is. May the best design win !!! UPDATE !!! (23-09 - 04:36 AM) I added a magazine for 7 rounds 13x72mm Nerf so the blaster is now a semi automatic riffle. https://www.youtube.com/watch?v=gVVSuHa_Wu0 https://www.youtube.com/watch?v=GJLC--HXSaY