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X-SIM 360° 2DOF Motion Flight Pit with Arduino for DCS World

Discussion in 'DIY Motion Simulator Building Q&A / FAQ' started by apointner, Aug 12, 2015.

  1. apointner

    apointner Siddhartha

    Joined:
    Aug 16, 2014
    Messages:
    64
    Location:
    N 48° 9'0.88" E 12° 5'45.84"
    Balance:
    356Coins
    Ratings:
    +11 / 3 / -0
    My Motion Simulator:
    3DOF, DC motor, Arduino, Motion platform
    Hello all!

    i´ve builded a 360° 3 DOF (bank/roll/heave axis) Motion Simulator Pit for DCS World with Arduino / Sabertooth and HTC Vive.
    Take a look:
    Carrier launch and some Aerobatics with VR in DCS World:



    :popcorn

    Load Test with 80kg and full rates:



    first things first: Thanks to the Motion Cancelling Tool "OpenVR Input" from Maxman666,
    VR tracking and alignment works like a charme with the HTC Vive (Pro).

    Customer riding the Simulator:
    https://drive.google.com/open?id=1EuEQIgN5V6ZDv2TSNpF5A5mr8iqRAGF3


    And here old vid with only one Axis 360°!
    NOP mit VR (Visitor flight via Track Replay)
    https://adobe.ly/2N4eBrM

    Aerobatics Fun (Motion Controller works now quit fast and precise)
    https://adobe.ly/2Mthm4P

    First Vid of Belt-tension System (WIP)
    https://drive.google.com/open?id=1EjWV2XVJd15zkLaol0C9RC04WvdRZoSp

    I'm flying in DCS World mostly together with a Virtual Wing (vJaBoG32).

    And because many peaple ask: This is not a funny roller coaster :-D
    The main goal is to reach a perfect Situation Awarness (SA) for mill. Missions.
    E.g. if you are doing Bombruns, Night OPs, Dogfights or Aerobatics it´s very easy to get disorientated.
    In a real Airplane you have many little helps to stay orientated (like g-Forces, wind, noise, vibrations, ...).
    In a PC-Simulation you don´t have these helps, but i want to have them!
    And this is the reason for 360° 3DOF - you simply feel you´re flying inverted - even if you are in fog hole!
    However this is not realistic...in a real Fighterjet you mostly have positive Gs (heave or Z Axis).
    Everythings else like Yaw, Sway, Surge forces are tiny effects in realtion to the huge possitive Gs (assumed your are doing millitary or aerobatic flights).
    Since no one can simulate constant Heave (not even 2Gs), I go for the 360° option, cause i have a perfect simulation of the Aircraft postion at least and therefor a better SA.
    Thougt i was very surprised how realistic the 2DOF feels - in VR a constant pitch Up feels like +2.5G and a sudden pitch almost feels like Zero G. But i have to admid, in a 70° to 120° Rollangle (levelflight) it dosn´t feel realistic at all , cause it´s like a 1G sideslip.
    Therefor i´m building a seatbelt fastener to simulate heave (constant G pos).
    And this works very good! Although only the belt buckle is tightened by a cable, the pressure is distributed very cleanly on shoulders, chest, thighs and buttocks.
    You can hardly feel that in reality a pull in the middle is the source of the Gs.
    Each G is clearly noticeable, even fast rashes during take off.
    At max. Gs i almost lose the air, although the objective pressure on the body is only a fraction of the real Gs.
    Unbelievable that such a small thing can have such an effect!

    But why not a 6DOF MotionSim?
    Even a Stewart hexa can´t do constant rolls, loops, Pitch Ups, invert, or just stay in the correct bank angle.
    Particularly with VR you feel every false Degree between Real Life Angles and InGame Angles. OnSet cuing dosn´t work good for me, cause my Eyes tell me: Right, i´m rolling 47° right, so why it feels like 20°!?
    This brakes immersion and SA, to me at least.
    However i use the Pitch and Roll Axis to simulate certain g-forces like slip and horizontal velocity.
    Example:
    On a Carrier Launch the Jetpilot feels +0.9 G velocity. I can simulate this 1:1 via pitch up with ~80°.
    Same thing with Carrier Landings: 2.6G decelerate...ok i can only simulate -1G deceleration with pitch down 90°.
    Both things a scary and exhausting even with just 1G!
    And this is maybe the most important part why 360° 2DOF:
    It is scary like RL flying! My first real life loop scared me in the same way this simulator did !
    Not to mention how scary LowLevel Flight suddenly becomes - same like real even if Gs are far away!
    But having a blast when going vertical and doing a Split-S? You bet!
    Actually I do (or do not) make the same mistakes both in the simulator and real life, so this biest is a great teacher to me.
    But in the End of the Day it is exhausting - this simulator gives you a
    small clue what real fighterpilots must accomplish. With motion sim you will never win a MP Dogfight again :cry: !
    So this is nothing you could ever get with +/-30° and OnSet cueing *ggg

    Some Datas:
    The Pit-Basket (Rollaxis: weight: 160kg + 100kg me), Pitch Axis (90kg) and Mainframe (120kg).
    Material is steel 40x40x4mm, Round tube 140mm/4mm. Size is now 240cm x 220x 250cm
    No Chance to do this width Polulu JRK.
    Some shooping list:
    - 3x Arduino Uno R3
    https://store.arduino.cc/arduino-uno-rev3

    - 2x Hallsensor (360° endless)
    https://www.megatron.de/produkte/we...halleffekt-absolutwertgeber-serie-mab25a.html

    - 2x Sabertooth 2x60 + 1x Sabertooth 2x15
    https://www.dimensionengineering.com/products/sabertooth2x60

    - 4x 12V / 45AH Car Batterie in parallel for 2x 24V Power source + 2x 12V 2AH for Belt Tension

    - 2x 24V 800W DC Brushed Motor with high ratio gearbox:
    Rated 60A and 120Nm (peak about 250Nm) with max. 65 RPM under load.
    - 1x 24V 500W DC Brushed Motor with planetary high ratio gearbox:
    Rated 40A and 60Nm (peak about 80Nm) with max. 85 RPM under load.

    This one i use for the roll axis.
    https://www.transtecno.com/en-en/ge.../12v-24v-dc/helical-bevel-dc-gear-motor-ecmb/
    And this for Pitch:
    https://www.transtecno.com/en-en/ge...v-24v-dc/helical-in-line-dc-gear-motors-ecmg/

    Some Frame specs:
    Pitch Axis shaft drive: d=80mm ; t=10mm; l=1200mm
    Roll Axis shaft drive: d=60mm ; t=20mm; l= 300mm
    Gears- and Accurators shaft drive: d=25mm (minimum!)
    Pitch Axis frame round tube: d=140mm ; t=4mm (minimum!)
    Main- and Roll Axis frame L-Profil: 40mm x 40mm x 4mm (better would be 30x30x4mm square profil!)

    The Warthog is now damped by adjustable motorcycle handlebar dampers...very nice feeling, soft as butter and still a lot of resistance, much closer to reality, ideal for rotorheads, I can only recommend (thx to Bergison for the ingenious idea). With a strong damper setting you also have a trim system!

    Safety things: Rollbar in AcesII Seat, Relay Power Switch, Fast Fuse, AC Mainswitch, Mech. Pitlook, 5-point seat-belt, ...
    Important Funstuff: IBEAM Bodyshaker + Subwoofer + Surround System,


    I use this values to get the Bank rate out of DCS:

    local pitch, bank, yaw = LoGetADIPitchBankYaw()
    local vel = LoGetVerticalVelocity()

    Pitch Problem:
    If you pitch up a Aircraft 90° the Bankaxis flips suddenly to 180° and the Pitch Axis inverts after the 90°.
    This is the same behavior as the artificial horizont instrument in the aircraft doas.

    With this Export.lua for DCS World you can counter this Effect!
    https://drive.google.com/open?id=1aEOugM5Z3pzPwALsnRIgLk-S1ZP7Obx0

    You can make forward / backward / inverted loops as you like,
    For example, you can cancel the climb at 80° PitchUp,
    You can even roll up at 90° pitch,
    You can go up to 5 degrees off the track through the vertical,

    And it works! Have Fun!



    Safety and security

    With 360°, 200kg Basket and 230V AC even small mistakes can end deadly.
    - So include a separate, super sensitive FI switch directly in front of the rotary grinder between the main power line.
    I have not experienced any unwanted offs or voltage fluctuations so far.

    - Emergency stop switch: To switch off the 24V current I built a power relay between the accurators and the battery. From the pit a 12V control signal goes over two signal lines to the relays. If the control signal is cut by the stop switch, the power relays disconnect the 24V load current.

    - Roll bar and basket: Worst case would be if an axle, bearing or drive mount breaks while your flying invertet. So install a stable basket which protects your head from any impact!

    - Heavy duty anchor: I have installed 12 of them in the floor and walls to keep the Simulator in place.

    - Emergency brake system: Via wireless con. and a self-sufficient battery I control two 25mm bolts on a linear motor, which drill into the walls
    and frames. This stops any movement. Why wireless? How do you want to release the brake if the axle or signal cable tears apart?

    - Helmet, 5 point belt and alarm button are mandatory. Installing HTC Vive in a pilot's helmet works just as well!

    - Emergency lighting is really good in case of AC Power loose.

    - Uses ONLY tested rotary unions that are really designed for 230V (up to 700V peak)!
    An extremely fast fuse + FI switch is important.

    VR with Motion
    Basically all VR glasses track absolute. I.e. if your plane rolls with 45°, then the 45° real cockpit angles add up with the 45° angles of the InGame View.
    So optical it looks as if you are flying at a 90° angle. This leads to motion sickness. But there is a solution called motion cancelling. This means that an App simply subtract the e.g. 45° RL angle again. Motion cancelling works in 2x 360° only with the HTC Vive and min. two Lighthouse Stations!


    Monitor-Pit.jpg 12V-DC-120Nm-Mördermotor.jpg Saber-Arduino.jpg

    Attached Files:

    • Like Like x 1
    Last edited: Apr 1, 2019
  2. noorbeast

    noorbeast VR - The Next Generation Staff Member Moderator

    Joined:
    Jul 13, 2014
    Messages:
    12,881
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    98,331Coins
    Ratings:
    +8,224 / 40 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
  3. apointner

    apointner Siddhartha

    Joined:
    Aug 16, 2014
    Messages:
    64
    Location:
    N 48° 9'0.88" E 12° 5'45.84"
    Balance:
    356Coins
    Ratings:
    +11 / 3 / -0
    My Motion Simulator:
    3DOF, DC motor, Arduino, Motion platform
    Thanks a lot! But it seems that dontcarefilmer didn´t manage to get a full 360° with LFS :(
  4. noorbeast

    noorbeast VR - The Next Generation Staff Member Moderator

    Joined:
    Jul 13, 2014
    Messages:
    12,881
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    98,331Coins
    Ratings:
    +8,224 / 40 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    Not 360° with LFS but as I read the code notes it allows for positions 0-360 degrees, so well worth a try with a flight sim like DCS, FSX or P3D.
  5. RacingMat

    RacingMat Well-Known Member Gold Contributor

    Joined:
    Feb 22, 2013
    Messages:
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    Marseille - FRANCE
    Balance:
    18,098Coins
    Ratings:
    +1,848 / 16 / -2
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Last edited: Oct 21, 2015
  6. apointner

    apointner Siddhartha

    Joined:
    Aug 16, 2014
    Messages:
    64
    Location:
    N 48° 9'0.88" E 12° 5'45.84"
    Balance:
    356Coins
    Ratings:
    +11 / 3 / -0
    My Motion Simulator:
    3DOF, DC motor, Arduino, Motion platform
    Thanks a lot! I contacted him, but he didn´t build a 360° SimPit :(
    Last edited: Aug 14, 2015
  7. dance77

    dance77 New Member

    Joined:
    Sep 17, 2015
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    Balance:
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    Ratings:
    +0 / 0 / -0
    My Motion Simulator:
    2DOF, SCN6
    good flight sim!!
    thank you!
  8. RacingMat

    RacingMat Well-Known Member Gold Contributor

    Joined:
    Feb 22, 2013
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    18,098Coins
    Ratings:
    +1,848 / 16 / -2
    My Motion Simulator:
    2DOF, DC motor, Arduino
    maybe this could help?
  9. mgill4bu

    mgill4bu Member

    Joined:
    Mar 13, 2015
    Messages:
    36
    Balance:
    105Coins
    Ratings:
    +9 / 0 / -0
    My Motion Simulator:
    2DOF, 3DOF, DC motor, Arduino, JRK, Joyrider
    How do you like using the sabertooth for the controller? Any pros or cons?
  10. apointner

    apointner Siddhartha

    Joined:
    Aug 16, 2014
    Messages:
    64
    Location:
    N 48° 9'0.88" E 12° 5'45.84"
    Balance:
    356Coins
    Ratings:
    +11 / 3 / -0
    My Motion Simulator:
    3DOF, DC motor, Arduino, Motion platform
    Sabertooth 2x60 is really great. Handle 190A on 12VDC for 1 second! If current is such high for longer, the controller just throttle down for a few seconds, that´s it. You can not overheat or overpower the Controller and the Options in the DEscripte Software tool is just amazing esp. with the Kangaroo motion controller (but no 360° endless option with kangaroo!). Also the support is good. This thing just works - whatever! But it´s expensive. And more then 900W eff. output, you won´t squeeze out - not even with 24VDC.
  11. apointner

    apointner Siddhartha

    Joined:
    Aug 16, 2014
    Messages:
    64
    Location:
    N 48° 9'0.88" E 12° 5'45.84"
    Balance:
    356Coins
    Ratings:
    +11 / 3 / -0
    My Motion Simulator:
    3DOF, DC motor, Arduino, Motion platform
    Pitch Problem sloved!
    In DCS when you pitch up the Aircraft 90° the Bankaxis flips suddenly to 180° and the Pitch Axis moves inveted over 90°.
    This is the same behavior as the artificial horizont instrument in the aircraft doas.

    With this Export.lua for DCS World you can counter this Effekt!
    https://drive.google.com/open?id=1aEOug ... -S1ZP7Obx0

    You can make forward / backward / inverted loops as you like,
    For example, you can cancel the climb at 80° PitchUp,
    You can even roll up at 90° pitch,
    You can go up to 5 degrees off the track through the vertical,
    Some small stutters and jumps are still there, but i hope "someone" solves this :)

    And it works! Have Fun!