3 ms·
Oh man! Who would have known my undergraduate capstone project would be so relevant? To improve accuracy of Nerf Blasters, we realized that barrel rifling had
by mikeknoop 13y ago
Oh man! Who would have known my undergraduate capstone project would be so relevant?
To improve accuracy of Nerf Blasters, we realized that barrel rifling had little effect. So we took a different approach.
Prototype: http://zpr.io/PphB.png http://zpr.io/PphB.png
High-speed footage of added rotation: http://www.youtube.com/watch?v=87Y0A6IMJM8&list=SP0FF1657C0B08FAB8&index=15 http://www.youtube.com/watch?v=87Y0A6IMJM8&list=SP0FF1657C0B...
(all videos: http://www.youtube.com/playlist?list=PL0FF1657C0B08FAB8 http://www.youtube.com/playlist?list=PL0FF1657C0B08FAB8)
PPT report: http://mikeknoop.com/upload/MAE4980CapstonePresentation.pptx http://mikeknoop.com/upload/MAE4980CapstonePresentation.pptx
Major problem is fishtailing. Adding too much rotation and the darts just aren't rigid enough to hold a solid spiral.
In the end, adding 4 degrees per flywheel off the horizontal gave the best rotation vs. consistency (the darts held about 1500-1800RPM). There are already Nerf Blasters in production that use flywheels, so it's not hard to imagine introducing a small tilt.
We didn't do hardly the statistical analysis from OP but our numbers:
Distance
+4.6 ft. (14%)
Accuracy Standard Deviation
-2.3 ft. (40%)
- DanBC 13y ago> Major problem is fishtailing. Adding too much rotation and the darts just aren't rigid enough to hold a solid spiral. Would adding a cocktail stick to the dart help? Or is modifying darts not acceptable?
- mikeknoop 13y agoAdding weights to the tip helps dramatically, even without rotation. There is a small hole in the tip of streamline darts which you can push metal BBs into to achieve this out-of-the-box. However one of our design requirements was not to modify the darts because it was disallowed for safety concerns from another student-org of mine: http://muzombies.org http://muzombies.org
- rickdale 13y agoDude, thats awesome. I think its funny as hell that you're irrelevant capstone project would be hn relevant and awesome that you are here to see it.