Project Nimitz: An Immersive Flight Experience

System Diagram (Click for hi-res diagram)

Nimitz is an ongoing hardware and software project to provide immersive flight simulator experiences at an affordable price in a home computer setting.

See It: Watch Nimitz in action in this Tomcat Landing Video.

Read About It: Read the original Nimitz Spec from January 2019.

Stream It: Charles flies as callsign “Rocky” on Twitch stream “MoFVFS”.

Project Components

The Core: The heart of Nimitz is an Alienware Aurora R8 with an Intel i7-9700k CPU, 32MB RAM and an Nvidia RTX 2070 GPU. No GPU upgrades are possible due to power supply limitations - and the specific difficulty of installing a beefier power supply in an R8.

The Seat: Equally critical to Nimitz is the seat - the Volair Sim Flight Cockpit. This solution provides mounting for all controls as well as three 1080p monitors arranged side-by-side for a wide field of view. The seat itself is adjustable for different heights and has a space to mount the Buttkicker haptic unit - see the blog post for instructions.

Additional components are discussed in detail, categorized below.

Visual and Spatial Awareness Components

The VR Option - HTC Vive: One way to get visuals is with the HTC Vive; the RTX 2070 GPU puts out enough pixels to run DCS World or X-Plane 11 simulations at 60Hz stereoscopic, as long as you keep to lower detail modes. The Vive controllers aren’t a factor - it’s better to stick with the HOTAS controls.

The IR Option - Triple Monitors and TrackIR: A more common scenario is to watch the action on the three mounted monitors up front, which are software-wired together into a single 5760x1080 surface using Nvidia Surround, a mode supported natively on both DCS World and X-Plane 11. Head-tracking is accomplished using a NaturalPoint TrackIR5, with the receiver mounted above the central monitor, and a TrackClip Pro transmitter mounted to the headset.

A potential add-on for the future, suggested by StingTV’s Home VR Cockpit Tour, is a side-mounted trackball that can be easily indexed and used for mouse movements and clicking, even when in VR.

Philips Hue Lighting: An additional level of visual ambiance comes from two floor-mounted Philips Hue Play light bars that project onto the wall behind the monitors. When in non-VR mode, these lights use Hue Sync to sample the dominant colors being displayed on the three monitors, setting the lights to those colors. Flying at sunset, for instance, will light up the walls in a golden tone, whereas flying in blue sky will light the walls blue.

Audio and Haptic Components

The Rumble Seat: A ButtKicker Gamer2 unit turns low-frequency sound into rumble effects. The Volair Sim seat has a mounting point for the rumble device. However, it’s not quite as simple as plugging it into the sound card. Here’s why.

Getting the Right FX: There are two problems to solve about rumble. The first is splitting the audio signal to keep a stereo audio signal for headphones while also piping it to the transducer - which is a problem with the Aurora series due to its Alienware Audio software. The second problem is isolating out just the signals you want to be translated into rumble, and not just every effect that happens to have a low-frequency component (think about someone calling you over the radio, and it shaking your seat in time to their voice. Creepy.)

Both problems can be solved through the application of inexpensive hardware plus software: a tiny USB external sound card (buy two - I’ll explain why in a moment), and software called SimShaker for Aviators that exports just key game events as rumble sounds. This guide on 476vFighterGroup was an excellent reference to show how to configure the USB sound card and SimShaker for Aviators together to get a great effect.

Clean Up the Sound with a Second USB: A second USB sound card isn’t a must-have, but it is a significant quality-of-life improvement for audio. The Aurora R8’s onboard sound card suffers from significant electromagnetic interference, which gets worse at high CPU/GPU usage - like during a flight sim. Noticeable audio artifacts are heard when plugged into the front audio jacks. The solution - a second USB sound card. The interference is completely eliminated with an $8 purchase.

Headphones - The TFlight USAFs: Audio output and microphone input are provided by the Thrustmaster T-Flight US Air Force Edition headset. It features an adjustable boom microphone, on-headset volume control, and an easy place to attach the TrackIR Pro Clip. Audio quality is excellent and the cups provide decent sound isolation; since it’s only simulated jet/prop noise, true active noise canceling isn’t necessary.

VoiceAttack, VIACOM Pro, and SRS: To provide additional utility during flight without the need for more switches, Nimitz uses VoiceAttack voice command software with the VAICOM Pro addon for DCS World, including the Chatter pack for immersion and the AIRIO add-on for hands-free voice control of Jester, the AI-controlled RIO. When flying in multiplayer servers in DCS World, Nimitz uses SimpleRadioStandalone - SRS to tie voice communication into DCS’s radio simulation.

Controller and Avionics Components

Warthog HOTAS: At the heart of all military - and some civil - flight simming is the HOTAS: short for Hands-On Throttle And Stick, it refers to the stick and throttle combination that provides the range of motion needed for all the stick-and-throttle work a pilot needs to do to fly, as well as enough switches to make common auxiliary controls (flaps, gear and brakes, weapons, radar, radio) easy to reach and available to muscle memory.

The HOTAS journey has gone from the inexpensive Thrustmaster T-Flight, to the more featured T.16000m HOTAS, finally settling on the expensive but very sturdy Thrustmaster Warthog HOTAS. Considered the Cadillac of recreational sim sticks, the Warthog provides smooth motion and configurable switchology. Equally importantly, the Warthog controls are mountable directly on the Volair Sim Flight Cockpit, which provides a non-slip way to engage with the controls, rather than simply placing them on a desk.

The original A-10 modeled stick is useful for many aircraft, but Nimitz uses two optional replacement sticks depending on the aircraft: for the F/A-18C Hornet and AV-8B Harrier, Nimitz uses the TM F/A-18C Hornet HOTAS Add-On Grip, and for the F-14B Tomcat, the Virpil VPC VFX Grip - although this last one didn’t play well on the Thrustmaster base, and required buying a Virpil WarBRD base instead.

CH Rudder Pedals: One of the longest-serving components of the Nimitz journey, which started years ago in early flight-simming days, the CH Pro Pedals provide rudder control and nosewheel steering with differential toe braking. Often overlooked, a good set of rudder pedals is key to immersion - and necessary when upgrading to the Warthog HOTAS, as it has no rudder input ability, whereas the T-Flight and T.16000m have rudder-like controls on the throttle quadrant.

Saitek Pro Flight Yoke System: A fully separate yoke and throttle quadrant are available on Nimitz, mounted away from the Military controls, but available without having to remove or move anything. The Saitek Pro Flight Yoke System provides the more civil-friendly yoke controls for pitch and roll, along with a three-axis throttle quadrant for throttle, mixture and prop pitch controls. Switches abound and one of the most useful accessories comes standard - a digital clock right on the face of the yoke that can be run alternatively as a stopwatch.

Saitek Avionics Panels: For further immersion in the civil flight world, Nimitz has three Saitek panels mounted above and to either side of the yoke: the Saitek Switch Panel, the Multi Panel, and the Radio Panel. Nimitz is only set up to use these in civilian flight sim, but this intriguing post on the DCS Forums suggests they can be used for military sims as well.

Cougar MFDs: Experimentation has been done with attaching the Thrustmaster Cougar MFDs for easy interfacing with military craft that use MFD panels (F/A-18C, AV-8B, upcoming F-16), but space considerations, inability to use accurately in VR, and USB overload (see below) has made continued usage impractical. These have been removed from Nimitz.

⚠️ Caution - USB Overload: Without an externally-powered USB hub, the Saitek units do not function. Nimitz has one such powered USB hub attached on the back of the yoke that powers all the Saitek components. In this configuration, no further high-draw USB items can be added to Nimitz without starving power. Starved power causes the Aurora R6 to fail to post on boot with no diagnostic information available. In this case, unhook the main connector for the USB hub and the system should boot again. Similar steps have to be taken when booting after a BIOS upgrade.

The Future of Nimitz

There are a number of possibilities for expansion on Nimitz, each exploring different potential for immersion:

Enhanced VR Fidelity: Current resolution in VR for Nimitz is 1080×1200 in each eye with a field-of-view of 110°.

VR Hands and Haptics: Infrared/ToF depth tracking of fingers or the use of haptic gloves could provide a way to flip virtual switches without the need for mouse and keyboard, or physical switches.

Switch Panel Buildouts: A variety of switch panels could be purchased or built to further remove the need for keyboard/mouse activation of inflight switches. Often these panels are airframe specific, so builds must either be made generic or panels made removable for switching out.

Movement Platforms: Mounting Nimitz on a moving platform can provide physical feedback in a whole new way. Affordability is still an issue, but six degrees-of-freedom (6DOF) units like GForceFactory’s Edge 6DOF are beginning to approach levels of consumer affordability.

External Reprojection: Traditional ‘sim dome’ multiprojector curved setups are now almost fully obsolete thanks to VR. However, if the IR+Monitor option is still going to be useful in future, an upgrade to the Hue lighting system could be a projector that reprojects areas beyond the screens onto a wall beyond the unit, in order to give an even wider peripheral field of view.

Wingman/RIO Station: A second Nimitz unit - or a modified, simpler flight sim portable unit - could be paired up with Nimitz to provide multi-crew capabilities in the same room.

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