1. Do not share user accounts! Any account that is shared by another person will be blocked and closed. This means: we will close not only the account that is shared, but also the main account of the user who uses another person's account. We have the ability to detect account sharing, so please do not try to cheat the system. This action will take place on 04/18/2023. Read all forum rules.
    Dismiss Notice
  2. For downloading SimTools plugins you need a Download Package. Get it with virtual coins that you receive for forum activity or Buy Download Package - We have a zero Spam tolerance so read our forum rules first.

    Buy Now a Download Plan!
  3. Do not try to cheat our system and do not post an unnecessary amount of useless posts only to earn credits here. We have a zero spam tolerance policy and this will cause a ban of your user account. Otherwise we wish you a pleasant stay here! Read the forum rules
  4. We have a few rules which you need to read and accept before posting anything here! Following these rules will keep the forum clean and your stay pleasant. Do not follow these rules can lead to permanent exclusion from this website: Read the forum rules.
    Are you a company? Read our company rules

8020 2DOF Stage 1 add on

Discussion in 'DIY Motion Simulator Projects' started by principiamacb, Feb 25, 2017.

  1. Gadget999

    Gadget999 Well-Known Member

    Joined:
    Dec 27, 2015
    Messages:
    1,886
    Location:
    London
    Balance:
    11,543Coins
    Ratings:
    +453 / 9 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino, 6DOF
    can anything be done to run it on the leonardo usb interface - may just need a little wiring done
  2. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Quite likely. It uses an optical encoder and a motor that are standard parts avalible to buy and all the wiring is all out in the open. Just depends on the specs I suppose although electronics aren't my strong point. I'll have to do more research.
  3. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
  4. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    After almost a year since the original plan to build a 2dof and started collecting parts I'm into the last stages of the build. The original idea was to build an add on similar to the simexperience stage 1 however it's going to end up looking more like a cxc not though planning but that's just how it's ended up.
    • Friendly Friendly x 1
  5. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
  6. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    20171210_193843.jpg
    • Like Like x 2
  7. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    I ended up ditching the power supplies as nether worked properly. Unfortunately because I bought them so long ago I couldn't really return them. I've found this on a few of the components I've been buying. This seams to be what to expect when buying used/cheap stuff. The mm's were hopeless and I had to return the first battery I bought because it didn't work. It was only from the local scrappy though so I've swapped it for a good one now and everythings working.
    • Like Like x 1
  8. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Just one question. With the JRKs could someone explain what "Max Current exceeded? "

    In the JRK documentation it sounds like it's there to protect the jrk and the motors or is it to stop the psu shutting down from the jrk trying to draw too much power?
  9. Zed

    Zed VR Simming w/Reverb Gold Contributor

    Joined:
    Apr 4, 2017
    Messages:
    1,044
    Location:
    USA
    Balance:
    5,828Coins
    Ratings:
    +1,042 / 4 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    In the JRK configuration utility, you can limit the current the JRKs can deliver before tripping out. I don’t remember what the max value is that you can set but you can also set it to unlimited (0.00) where the JRKs won’t trip at all on overcurrent. The H-bridge that’s used does self-limit the current to about 50-55 amps though. It’s a built-in protect but also leaves damage in the bridge chip over time due to localized heating in the chips from the current.

    The reason the limit is there is probably multiple reasons but the heat dissipation of the bridge chip is limited by the small board area and it can protect the 12v12 itself. But like any fuse or circuit breaker, it can protect multiple things in the circuit. They are rated at 12 volts and 12 amps but with proper heat sinking you can go much higher. I disable the current limit in my JRKs and use fuses rated at 40 amps.
    • Agree Agree x 2
    • Informative Informative x 1
  10. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    OK, thanks for the help.

    So I'll set a limit until I'm happy everything is running OK then I'll set it to unlimited.
  11. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    I was using a Factal Design gaming case that was great but didn't really fit into my plans as I'm putting the pc underneath the rig.

    I had a Silverline htpc case in the garage that wasn't being used and is the right design, only problem is its not big enough to fit my evo 212 cooler and the case fans aren't really enough. What to do?

    CUT SOME HOLES!

    20171211_190336.jpg

    It's not particularly neat but it won't be seen and it'll do the job.

    Now to cut some holes for 2 140mm fans.
  12. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    All ready for testing. Looks pretty messy at the moment but all works!
    20171212_213328.jpg

    20171212_213348.jpg
    • Like Like x 4
  13. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    The plan was to get it finished completely then take photos however that's not happened yet.

    The rig has been working for a few months without any real issues apart from backlash in the gearboxes. I can tell i'm loosing a lot of fidelity and its so loud its keeping the rest of the family awake at night.

    So, what to do?

    1, Leave it as it is.

    2, Change to 25-1 gearboxes so I can run shorter arms to get rid of some of the backlash.

    3, build some actuators.

    Ive decided to build some short actuators especially as ive not seen any on the forum for a 2dof (please link me to a thread if there is one!). I've ordered some 200mm 1610 ball screws. They should be here in a few weeks. Im thinking of a similar design to the existing designs for 6 dof, just shorter.

    Im planning on using my existing 180w motors at least for the time being and also my jrks.

    Ive read up on all the threads of actuator builds on the forum but if anyone's got thoughts on any specific issues I might have with shorter actuators im all ears.

    Anyway, here's some up to date photos.

    20180304_180232.jpg 20180304_180031.jpg 20180304_180308.jpg 20180304_180321.jpg

    Attached Files:

    • Like Like x 2
  14. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
  15. Zed

    Zed VR Simming w/Reverb Gold Contributor

    Joined:
    Apr 4, 2017
    Messages:
    1,044
    Location:
    USA
    Balance:
    5,828Coins
    Ratings:
    +1,042 / 4 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    That’s a 10k 3 turn pot. Are you going to gear it? If you direct connect it and have 90 degrees of throw on your motors you will get only 1/12 of the resistance change which will be 1/12 of 5 volts worth of feedback. The JRKs do a good job of scaling but I’d bet that’s too low of a change to work well.

    Most here will probably recommend Hall sensors since many models of those don’t have stops and won’t be damaged by overruns of travel. Resistive elements and windings can also wear out over time.
    • Agree Agree x 1
  16. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Thanks for the reply

    I'm already using 120deg hall sensors on my setup at the moment. They work well.

    These are for the actuators I'm building. I'm going to use a rack and pinion system so was looking for a 3 turn pot.

    Attached Files:

  17. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Or 3 turn hall sensor if I can find one.
  18. Zed

    Zed VR Simming w/Reverb Gold Contributor

    Joined:
    Apr 4, 2017
    Messages:
    1,044
    Location:
    USA
    Balance:
    5,828Coins
    Ratings:
    +1,042 / 4 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    Ah. There is no provision that I know of in the JRK controllers to sort out multiturns on a Hall sensor. I think your only solution would be to gear the Hall sensor so three turns becomes 120 degrees if you kept using the sensors that you have, or do something else that can handle multiple turns and potentially ambiguous positioning. Or go with a multiturn pot.

    Resistance elements are going to spend a lot of time around the middle position in these rigs but have lots of movement around that point. That can wear out the resistance elements fairly quickly which can lead to loss of feedback runaways. The JRK has provision to detect when feedback pots open and can stop the motor control and take power off the motor to help prevent damage. If you go with the wire-wound pots, I'd definitely use that connector and set that trap in the JRK configuration.
    • Informative Informative x 2
  19. principiamacb

    principiamacb Member

    Joined:
    Nov 18, 2016
    Messages:
    60
    Location:
    United Kingdom
    Balance:
    128Coins
    Ratings:
    +28 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Thanks, that's really helpful. Ill keep all of that in mind.