Water Bottle Rocket Launch Base and Guide Rail

thingiverse

Launch base with mounting holes and rail which simply push fit together. Print as many as you need for the desired height. Sized for an Ender 3. Obviously based on a 40 x 40 mm extrusion and I think most people just use those. This is a cheaper option that's easier to work with (if you have a 3D printer). Included is a pin that fits into the grooves and has a curved mounting section that easily sticks to a 2 litre drinks bottle with double sided tape. Hope this helps someone, enjoy!