btrettel's Nerf blogI am developing a Nerf gun purely for test purposes. My main goal is to get consistent performance. I am using a few methods to do this: regulated pressure, reducing the effect of the speed of opening the trigger valve by piloting my QEV with another smaller QEV (that is in turn piloted by a […]
Comparing valves for compressed gases can be difficult for several reasons. Even if you are familiar with how valve performance is specified, you can easily make mistakes. Valve performance is specified in several different sloppy and confusing ways, almost always in non-metric units. The worst part is that valve performance can be specified in obvious […]
I’ve started organizing my writings and thoughts on Nerf ballistics into a set of notes (link corrected). Readers of my blog might be interested. For the moment my notes are very rough and incomplete. I’ll update the PDF as I make changes. I’d appreciate any feedback, especially corrections and ideas. Edit (2012-10-02): I’ve removed the […]
I previously wrote about how to estimate the expansion diameter of latex tubing, but I made no measurements to verify that the formula I suggested, where is the unexpanded inner diameter of the tube and is the unexpanded tube wall thickness, was accurate. Back in 2010, I made some measurements for tests that were aborted […]
Check out this interesting project by PVC Arsenal 17. For those who were wondering, I’m still alive, but I am kept extremely busy with school work. Two grad. classes (one mech. eng., the other applied math), two advanced undergrad. classes (one math, the other mech. eng.), and the senior design course will keep you busy! […]
When a Nerfer wants to increase the pressure of a bladder, they generally turn to “banding,” the layering of rubber bands on the bladder. I came into this hobby from the similar water gun hobby, and I’ve often wondered why this method is so prevalent in Nerf but not water guns. It’s not that layering […]
Back in 2006 I had an idea to improve a pneumatic Nerf gun my brother made. This Nerf gun had a semi-auto valve. At the time I was interested in semi-auto Nerf guns, but I saw the valve as a more daunting task than an advancement system. Like my brother, I started focusing on only […]
When drawing up homemade pneumatic Nerf guns in a CAD program, I used to wonder how deep a fitting would go in. Eventually I learned that technical drawings from McMaster-Carr and many other places offer this information in the listed “thread engagement”. See the drawing from McMaster-Carr below. Click on the image to view the […]