Know How...

Jun 4th 2015

Know How... 146

Scramjet, Fast DIY USB Drive, and Crash Kit

Crashing is learning.

Although the show is no longer in production, you can enjoy episodes from the TWiT Archives.
Category: Help & How To

Scramjets goes hyper-freakin' sonic, SSD madness, build your own blazing fast SSD USB Drive, CNC Router, and what to do after you crash your quad.

Hyper-Freakin' Sonic!

  • We know that the US Millitary-Industrial Complex has been working on Hypersonic flight for a while. (Hypersonic = Speeds above Mach5)
  • Well, now we've got DARPA and the Military saying that we might have Hypersonic craft for the delivery of sensors, cargo, weapons and even people by 2023.
    • We've had a few test flights of varying complexity and sucess, but none of then have really indicated that Hypersonic flight is ready for prime-time

The Nasa X-43A, currently the fastest aircraft on record, was able to hit 10,617MPH

  • But it only hit that top speed for a few seconds
  • And it required a carrier aircraft and a rocket booster to get up to the speed that it's scramjet engine would work.

Let's talk about the Scramjet!

  • The Scramjet is an airbreathing engine
    • This is important, because unlike a rocket, it doesn't have to carry it's own oxidizer. It only carries it's fuel and depends on the atmosphere to give it oxygen to burn that fuel.
  • A scamjet has no moving parts... unlike an traditional turbine engine that you might find on a passenger aircraft
    • In that traditional turbine engine, A set of blades compresses air at the front of the engine and pushes that high-pressure air through the chamber
    • Fuel is added to the high-pressure air and ignited
    • The air is now hot and even higher-pressure
    • That air turns a series of turbines that provides power to the compressor blades at the front of the engine while also providing thrust out the back of the engine
  • Normal turbine engines have difficulty working above speeds of Mach 2

In a scramjet, the engine is moving through the air at supersonic speeds, which means the air will move through the engine at supersonic speeds.

  • You have a structure inside the scramjet that compresses that supersonic air, which will greatly increase it's temperature, then injects fuel.
  • The fuel will burn, creating even hotter gasses that exit out the back, providing thrust.

This process is incredibly complicated because it:

  1. Requires that the engine is already moving at supersonic speeds
  2. Needs the proper shaping of the air coming into the engine at supersonic speeds.
  3. Needs to keep the fire lit in a supersonic windstorm

Product Preview

Kinston HyperX Savage

  • This is the refresh of the Kingston KC300 SSD line that I like so much
  • 560MB/s read 530MB/s write
  • Comes with a USB 3.0 Enclosure
  • We'll be using three of these drives in an upcoming upgrade episode

But hey... there's a problem!

  • SATA Revision 3 is limited to 6GB/s -- which, once you consider encoding/unencoding, translated into about 600MB/s.
  • So most high-end SATA 3 SSDs are right at the edge of the bus' capacity.

Kingston HyperX Predator

  • This uses a M.2 card on a 4-Lane PCI-Express card
  • 1400MB/s Read // 1000MB/s Write
  • And we can get faster!
    • 2-lan gets us 1000MB/s, 4-lane gets us 2000MB/s, Gen3 gets us 4000MB/s

Now... let's get cooking on our super-fast USB 3.0 Drive!

The Control:

  • We're looking for something in the 256GB range
  1. You could get an inexpensive USB 3.0 flash drive like the PNY Turbo 256 (~ $83)
    • You'll probably see 100-150MB/s read // 20MB/s write
  2. You could get something ULTRA fast, like the Patriot 256GB Supersonic Rage 2 (~$160)
    • You'll probably see 300-350MB/s read, 200-250MB/s write

Our Build:

  • We're going to MAKE our own compact, durable, ultra-fast USB 3.0 storage device using an enclosure and a mSATA SSD. $15
  1. Sabrent USB 3.0 mSATA Enclosure
  2. Samsung 850 EVO mSATA 540MB/s // 520MB/s $100
  3. Kingston mS200 mSATA 540MB/s // 530MB/s $150

Typical USB 3.0 Flash drives will use MLC memory

  • It's good for between 3,000-5,000 PE (Program/Erase) cycles
  • SOME flash drives will use SLC (single Level Cell) and will be good for 100,000 writes This mSATA card from Kingston will do 100,000 P/E cycles before it starts to deteriorate

Crash Kit

What's in Padre's Crash Box?

  1. 2 Complete sets of Extra Props
  2. Zip Ties
  3. 2 Spare Motors (one of each rotation)
  4. 2 ESCs (Cut and Soldered)
  5. Tool kit (inc Screwdriver, dikes, pliers)
  6. 2 Extra arms (one of each color)
  7. Can of compressed air

Post-Crash Procedure

  1. Kill Power
  2. Set aside battery in a safe, burn-resistant area. Testing should be done with a fresh battery.
  3. Assess prop/structural damage
  4. Manually rotate motors, feel for binding // listen for abnormalities
  5. Blow out cans with compressed air. Look for debris.
  6. Check all electrical paths. (PDU to ESCs, ESCs to motors, ESCs to FC, FC to receiver)
  7. Power-up with props off: Test motor ESC/Motor response/rotation. -- Look for bent shafts.
  8. Props on: Hover test.
  9. Punch Out test
  10. Return to normal flight.

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