Board Thread:General Nerf discussion/@comment-30628894-20161219154814/@comment-27035444-20170128014115

Elliottw wrote: Time for an electrical engineering lesson. The stock Stryfe has a 4x1 battery box. That means there are 4 standard alkalines in series - 1.5v + 1.5v + 1.5v + 1.5v for a total of 6 volts. But the maximum current in that arrangement is limited to the max output of any single battery, which is about 2 amps for off-the-shelf alkalines.

Sidebar: Voltage determines how fast a motor will spin. Amperage (aka current) determines how hard it will spin. When you apply that to Nerf flywheels, these two factors work together. The voltage determines the dart's velocity (aka FPS), and the amperage plays two roles; how hard the flywheels push the dart through the cage, and how quickly the flywheels come back up to speed after a dart is fired.

What typically happens in a stock Nerf blaster is the motors bring the flywheel up to speed, then the energy stored up in the flywheel (aka the angular momentum) is transferred to the dart as it passes through the cage. The dart gets accelerated up to speed, as the flywheels slow down. The stock motors are so wimpy they're not actually "pushing" the dart through the cage, it's the momentum of the flywheels that's doing most of the work.

Flash forward. I reconfigured the battery box in my Stryfe to a 2x2 configuration. Two sets in series, and both of those sets in parallel. When you wire batteries in parallel, the voltage stays the same, but the current doubles. And I'm using IMRs. That's (3.7v + 3.7v) and (3.7v + 3.7v) for a total of 7.4 volts at twice the current. Then I replaced the stock motors with Honey Badgers, which run at 35,000 RPM. I believe the stock Stryfe motors run at 12,000, so that's three times as fast, or thereabouts. Plus I upgraded all the wiring to thicker wire (aka heavier "gauge") so it can deliver the extra current more effectively.

Sidebar: The gauge of wire, or its thickness, determines how much power (aka wattage) a wire can deliver. Much like plumbing, a bigger pipe can deliver more water. A bigger wire can deliver more power. Gauge has an inverted scale. The smaller the gauge, the bigger the wire. For instance, 16 gauge is bigger than 18 gauge wire. When you get down to 4 gauge wire, it's almost as thick as your pinkie finger.

The Honey Badgers have several advantages over the stock motors. Not only are they faster, they are made of heavier gauge wire and can draw up to 10 amps of power if they need to. If you were paying attention, that's five times more current than those wimpy alkalines can provide. So, not only are they spinning 3 times faster, they can come back up to speed 5 times faster than stock motors, if the current is available from the batteries.

These high output IMRs that I've been using can deliver as much as 5 amps of power. That's 2.5 times as much as standard alkalines. Plus I've got that 2x2 battery box. So it really provides 10 amps of instantaneous power, which is perfect for a motor that wants 10 amps !

I've pontificated enough tonight. It's really a combination of motors, RPMs, batteries, voltage, and current. All I can say is I found a perfect perfect balance. IMRs in a 2x2 battery box with Honey Badgers and 18 gauge wiring in a Stryfe. Priceless. This makes more sense to me now, thanks.

How many feet flat and how many feet angled would you think your Stryfe flings foam at?