Item is 18 inches in length and not intended for use by children under the age of 14.
ESPER is a Mag-Fed Top-Slide-Prime Homemade Blaster design that uses elastic cords as a replacement for traditional compression (and extension) springs. They drive a plunger with a catch surface at its tail end. The mag release and sear/trigger assemblies also use elastic cord for return.
Color/part configurator
http://captainslug.com/nerf/esper/
WARNING: This blaster MAY NOT BE SAFE FOR INDOOR PLAY. Even with the weakest string setting of 20-inches this blaster will easily shoot faster than 100+ fps. So keep this in mind as to where and when this blaster is used.
All of the parts can be printed with infill as low as 20% in PLA, but I would recommend printing in layers of 300 Micron or smaller.
Assembled Blasters and Blaster Kits are available for sale as commissioned items.
Hardware kits to allow you to assemble on you've printed yourself are restocked nearly every weekend.
All of the above are for sale on Etsy.
