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

Steel Box Section JRK 2DOF + Possible Traction Loss

Discussion in 'DIY Motion Simulator Projects' started by Petertb, Aug 20, 2017.

  1. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    New Sim.jpg Hello chaps, I'm just starting a 2DOF motion simulator, maybe with traction loss for iRacing and AC predominantly. I've decided on a seat mover setup as I have a CV1 and I understand that the relatively small motions of a seat mover do not cause issues in VR?
    As you can probably tell, I'm not 100% sure on all of the specs of the simulator yet but I'm making this post now to welcome input so I can make more informed decisions before I get too far in!
    So far the plan is:
    • JRK12v12 Controllers
    • 12v DC Gear motors - Very hard to come by in the UK, would appreciate advice! 25:1 or 50:1?
    • I like the Battery Idea rather than going for a big power supply, any disadvantages with the battery setup?
    • If I were to include rear traction loss, would I need to mount the Rift sensor on the pivot point at the front of the rig or can it stay off it?
    I haven't even looked at the Simtools software yet, is it worth doing that before buying parts?
    Many thanks, Peter.
  2. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,460
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    144,596Coins
    Ratings:
    +10,741 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    Spend whatever time needed to research your build and wrap your head around how it all goes together.

    Generally speaking with fast and accurate small axis movement sims you won't notice the lack of motion cancellation but we also now have the option to use motion cancellation: https://www.xsimulator.net/community/threads/vr-motion-cancellation-time-to-test.10241/

    You can have a play with SimTools prior to starting your project using the demo version of Live For Speed and this 2DOF simulation program: https://www.xsimulator.net/community/faq/simulating-a-2dof-simulator.278/

    Batteries can work fine and are less sensitive to peak power spikes.
    • Agree Agree x 1
    Last edited: Aug 21, 2017
  3. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    Been a good amount of head scratching but finally I've figured out roughly what I'm going for. I've mainly been inspired by @Brett Horton's rig so it's a 2DOF + Traction loss that I've settled on. I've had some parcels arrive:
    3x Dell 2950 Server PSUs £35 for the lot
    3x JRK12v12 £275
    3x CPU heatsinks for the Jrks, definitely overkill but should look cool. £16
    3x Bournes 66395S pots £50
    Still unsure with the motors, but leaning towards ZYT90-155-12-MCP4-25:1, currently in contact with Motion Control Products UK. Anyone got anything to say about these motors?
  4. Seth2Christ

    Seth2Christ Member

    Joined:
    Apr 14, 2015
    Messages:
    54
    Location:
    France
    Balance:
    192Coins
    Ratings:
    +13 / 0 / -0
    My Motion Simulator:
    2DOF
    good luck! you will not regret it!

    Seat mover or Sim mover, I never had a problem with VR (CV2 or HTCvive)
  5. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    IMG_3169.JPG IMG_20171208_170546.jpg
    I've been a bit slow to update this but I pretty much finalised the frame design and have begun building. No real problems as of yet, still waiting on the motors - hopefully will have them by the end of next week. Once I have those I can start playing with the electronics side. Hoping to house it all in a neat sheet metal box. Not sure if I'll have the space to mount it on the rig yet.
    • Like Like x 1
  6. jaco73

    jaco73

    Balance:
    Coins
    Ratings:
    +0 / 0 / -0
    • Like Like x 1
  7. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    Just a quick update, turned and machined the shafts for the motors today (Motion control products ZYT90 155-12V 3000rpm 25:1) IMG_20171220_151125.jpg IMG_20171220_151213.jpg IMG_20171220_151301.jpg IMG_20171220_151322.jpg
    • Like Like x 2
  8. prodigy

    prodigy Burning revs

    Joined:
    Oct 27, 2013
    Messages:
    459
    Location:
    Croatia
    Balance:
    6,698Coins
    Ratings:
    +399 / 4 / -0
    My Motion Simulator:
    2DOF, 3DOF, AC motor, SCN5, JRK
    I've been a little late noticing your thread, but I see that you went with the ZYT90 motors, do you know how many amps are they drawing?

    I had these:
    90ZYT-155-12-MCP4 - 250W 5000 RPM 25:1 ratio
    Rated Voltage: 12v
    NoLoad Speed: 5000 RPM - 200 RPM with 25:1 gearbox
    Current (Peak): 23A
    Nominal Power: 250W

    And I had troubles with them and JRK's, with JRK's not being able to handle that power. AFAIK Jrks can handle around 30-35 amps with good cooling, but these motors were drawing more amps causing Jrks to produce motor driver errors and erratic / stall movements.

    I remember somebody else here had the same problems - @Avenga76 , he needed switching to 60:1 ratio boxes and slow down the motors so the JRK's could handle it.

    You can start reading from this page in his thread:
    https://www.xsimulator.net/community/threads/my-3-dof-seat-mover-gs-4-simvibe.5596/page-7

    If you end up having some JRK troubles, there are some explanations what to do, how to set up PID and similar stuff.
    • Useful Useful x 1
  9. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    Hi! Hugely useful thread there, unfortunately I hadn't read it before buying the motors! I wasn't provided with a data sheet for the specific motor I have, I found the guy advising from Motion Control Products pretty unhelpful if I'm honest. My options were quite limited on motors, I was going to get the PG saw ones but then saw these on eBay and thought I'd have a try since they're from the UK. I do have the 3000rpm version with the 25:1 box, looking at this data sheet it states that my current should be 13.5A rather than the 23A yours were.
    Capture.PNG
    If that's right or not I don't know! I'll keep my fingers crossed, @Avenga76 's thread shows that there may be some way to get it to work if I hit problems so I think I'll stick with them and see how it goes.
    Thanks a lot!
  10. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    This is going to be a big update. The sim sat at work idle for a long time as my shift patterns changed. I've made big progress over the last two weeks though.
    I decided to drop the traction loss as packaging an extra motor and lever in behind the seat was too much of a headache, also just wanted to focus on getting the seat moving.
    I first built some sturdy motor mounts from 6mm plate, had to drill a 5omm hole so they would sit flush against the motors mounting holes.
    IMG_20180918_190915.jpg
    I went through (killed) 4 Dell 2950 server PSUs when testing the motors for the first time. They'd work for about a minute and then just die with an error LED displayed. I have no idea why this happened after such success has been had by others on here. So I bought 2 12V 50A 600W LED power supplies from eBay and they have been up to the job.
    https://www.ebay.co.uk/itm/Universa...var=563174940091&_trksid=p2057872.m2749.l2649

    I bought an old AMD processor heatsink and fan to modify to cool my JRKs. I opted to mill the heatsink away to provide a relief for the soldered connections which protrude from the bottom of the board, leaving a flat surface in the middle for good contact.

    IMG_20180823_172050.jpg IMG_20180823_183245.jpg IMG_20180823_183248.jpg

    I did fail to follow the JRK setup guide the first time I tested and blew a JRK as I had not set up anything in the configurator. This has made for a useful reference PCB for wiring though :p
    Here's a quick video of my first successful test, just moving the motors individually in the JRK configurator.

    When I took the video I had the push rods mounted on the outside of the levers, I've now moved them inside to stop them conflicting. I may need to make the arms a bit shorter but I can do that anytime.

    Having finally found a power supply setup that worked I've now started to finalise the wiring. I found an old electronics box with din rail terminals already installed. I took half of them out to make space for the JRK/heatsink assembly and drilled some holes for ventilation. The DIN terminals meant that I could solder wires directly to the JRKs but still be able to unplug the potentiometers etc in case of a failure. I also have routed the motor power to and from the JRKs through the DIN terminals, I may have to change this as I've just read that the terminals I'm using are only rated for 24A. Looks tidy though! On the back of the box, I've mounted a fuse box for the power in to protect the JRKs from 30A+ and me in case something shorts. I'm going to be wiring up a panel for displaying the JRK staus and allowing quick resets from my seats thanks to @Archie 's guide.
    IMG_20180929_153909.jpg IMG-20180929-WA0002.jpg

    I think that's about it for now! I will apply for my simtools license now and press on with the last things I need to do which are:
    Finish wiring box and figure out how to wire in an E-stop (any advice appreciated)
    Mount electronics behind seat, with mount for the harness too.
    Make a mount for the pedals
    Final test run with wheel to ensure comfort
    Clean up ready for powder coat
    End (Hopefully.)
    • Like Like x 2
  11. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    As you predicted, I've hit problems! At the moment, I get motor driver errors very often, they tend to get more frequent if I continue to drive the simulator. Sometimes they even happen when the rig is motionless and just holding my weight. I've read through that thread a few times, tried different PIDs etc but haven't had any joy. Restricting the duty cycles right down doesn't help either.
    I realise my only option is to find more suitable motors or switch to a different method of motor control. I haven't read into any of the alternatives to JRKs at the moment, so any suggestions on what could handle these motors would be welcome.

    Alternatively, if anyone would be interested in giving suggestions of tweaks I could make in the JRK software to try to at least reduce these errors that'd be hugely appreciated. I'm only 65kg, so physically I'm not asking a whole lot from the motors unlike @Avenga76 said he was in his thread. Any help would be hugely appreciated!
  12. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,460
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    144,596Coins
    Ratings:
    +10,741 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    Can you please post pictures of all of your JRK settings.
  13. Petertb

    Petertb New Member Gold Contributor

    Joined:
    Jun 11, 2017
    Messages:
    9
    Location:
    Devon, UK
    Balance:
    167Coins
    Ratings:
    +5 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, JRK
    Christmas has come and gone, back to troubleshooting! I would have uploaded the JRK settings but decided that first, it'd be a good idea to read the current being drawn with a clamp meter. Just done this, with the simulator sat with the JRK config running on both motors. I just leaned back in the seat hard and read the current. It will hold about 15A no problem, however, if I lean back harder I can exceed 20A which immediately starts the motor driver errors.
    I've tried lower duty cycles:
    100 - can't move my weight, I have to lean forward to assist the motors in getting to target.
    200 - can move me just, but if I lean back hard I can exceed 20A and the motor driver errors start.
    Higher than this yields the same result.
    At this point I'm more than willing to accept that these motors are just too big in their current draw, considering that the JRKs are only rated for 16A continuous and I can exceed 20A without them even moving / changing direction.

    I've been reading up on the other options and kicked myself when I saw the prices of the Sabertooth drivers, wished I'd gone that route from the start! After the testing today I feel comfortable that the 2x32A should be capable of running these motors. I'm going to do a little more research on this forum and then pull the trigger on one. Hopefully, someone on here will be interested in two cut-price JRKs!
  14. noorbeast

    noorbeast VR Tassie Devil Staff Member Moderator Race Director

    Joined:
    Jul 13, 2014
    Messages:
    20,460
    Occupation:
    Innovative tech specialist for NGOs
    Location:
    St Helens, Tasmania, Australia
    Balance:
    144,596Coins
    Ratings:
    +10,741 / 52 / -2
    My Motion Simulator:
    3DOF, DC motor, JRK
    The old 12V12 JRKs are known to have issues with high rpm motors.