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Building a 4DOF from the SK3 kit provided by Simukit

Discussion in 'Commercial Simulators and Peripherie' started by stargazer, Jul 19, 2018.

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  1. momoclic

    momoclic Active Member

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    Hello,
    In this tutorial I explain how to correctly mount a crank handle system.
    If you do not respect this assembly, the right and left movements will be dissymmetrical.
    In your case the problem is not complex to solve.

    https://www.xsimulator.net/communit...lator-building-tutorial-3dof-heave-axis.9249/
    • Like Like x 1
  2. stargazer

    stargazer Member

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    Hi @momoclic
    Sorry but I don't understand this. The kit from Simukit already have the cranks and motor shaft drilled for attachment. All that I had to do was connecting them together. What else is there for me to do?
    The kit would have to make sure that everything is correct and symmetrical as you have mentioned, correct?
  3. momoclic

    momoclic Active Member

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  4. stargazer

    stargazer Member

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    Hi @momoclic
    I am not sure if I followed your thought. Are you talking about the problem whee my motor axis1a (the front most motor) sag over time and spun backward? This problem happened way before I added the fourth motor for traction loss. Are you thinking that the traction loss motor (axis4a) is causing a problem for the motor on axis1a? If yes then how does it do it?
  5. momoclic

    momoclic Active Member

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    The idea is to add a bracket that will serve as a pivot point to the end of the connecting rod:


    upload_2018-9-24_15-37-47.png

    In order to comply with this rule:

    Angle de rotation = Angle of rotation
    Bielle = Connecting rod
    Manivelle = Crank handle

    [​IMG]

    Only method that guarantees the symmetry of the movements.
  6. stargazer

    stargazer Member

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    @momoclic I guess you are concerned that the traction loss (use motor axis4a) doesn't have symmetrical movement around the center. This is not related to the motor on axis1a that always sags and spins backward.

    I am uploading a diagram of how I built my traction loss if it could help someone else.
    MotionPlatformDiagram.jpg

    I didn't work out the math but from my experimental measurement this gives me about +/- 20 degree so that is good enough for me. So far I don't have any problem with this motor (axis4a).

    My problem is with the front motor on axis1a which sags and spins backward over time. Given it enough time it just spins backward continuously. It is a pretty scary situation when it does it. It did it to me several times and it did it to my daughter once and, fortunately, I was in the room to shut it down right away. Otherwise I don't know what would have happened. @yobuddy think this is a motor problem. I just wish to hear from Simukit if they know what the problem is and how to fix it.
  7. yobuddy

    yobuddy Well-Known Member Staff Member Moderator SimAxe Beta Tester SimTools Developer Gold Contributor

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    @stargazer,
    I would replace the pot connected to axis1a.
    And / or look for a loose connection to the pot on axis1a.

    If the pot were to come unconnected, the system would think the current location is wrong and try to fix it by moving the axis.
    Unfortunately, since the pot is not connected it will just keep spinning.
    This is my best guess as to what is happening anyway.

    Take care!
    yobuddy
  8. stargazer

    stargazer Member

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    I did that already @yobuddy . The pot axis1a motor today is actually one from another known good motor. I tried rewiring twice already on that pot too. The only thing I have not done is replacing that motor.

    Right now I am running with axis1a output limit to 85%. This helps to prevent the spinning to the back problem and allow me to enjoy riding the rig a bit. But it bugs me a great deal that I dont know what could be wrong with it.
  9. momoclic

    momoclic Active Member

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    I'm sorry, for that you have to contact Symukit, I don't know these engines...

    On the other hand I insist you do the same number of degrees on the right and on the left but the plate does not move the same distance on each side.
    The movements of the connecting rod have a very complex kinematics. It is not a question of calculation but of geometry ;-)
    It is the only solution that ensures correct travel !


    upload_2018-9-25_0-3-58.png

    In addition, if you move the pivot point (red) to the front of the triangle you will increase the sensations. :)

    upload_2018-9-25_0-37-19.png
    As you can see in the image, the center of the triangle moves by multiplying the feeling tenfold.
    And the end of the connecting rod moves +/- 60° by +/- 4.5".
  10. stargazer

    stargazer Member

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    @momoclic, thank you for that suggestion. I am all for increasing the sensation :)

    If I move my lazy suzan toward the top of the triangle then I will need to build some wheel support on the back of the cockpit platform, otherwise nothing will move. This will be another new project for me. The reason that I was able to get this far was because I was unemployed the last few months. Now that I am about to go back to work next week, I doubt very much that I will be able to get anything done anymore. Working on this project gave me nothing but admiration for other builders. Such dedication and resourceful they all are. Before I started this project did read your tutorial and I found that simukit sk3 kit is actually very close to your idea. I am glad to have met you here finally. I would have consulted with you on some of the ideas for building the rig if I had known you from before.
  11. momoclic

    momoclic Active Member

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    Thank you and I hope you will quickly find the solution to this engine problem.
    It's no coincidence, Simukit it's well inspired by many of my ideas.
    The forums are great, they are in Belgium, I am in France, you are in the USA, the Web reduces the world :)


    Good luck getting back to work ;-)
  12. stargazer

    stargazer Member

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    Hi all

    It was a great coincident that the day I received my motion kit was also the day I got laid off from work. So in the last two months I was able to spend a good deal of time building the rig. Now that I am about to go back to work and probably don't have time to work on it anymore, I like to share some concluding remarks with the hope that it could help to improve the built for somebody.

    First I like to express my heart fell thank you to a lot of people on this forum who had helped me. Without them I would not have made it. So thank you @jjanu , @axenic, @noorbeast , @yobuddy , @RiftFlyer , @momoclic , @Wanegain . you guys rock!!!

    Here is the picture of my final built.
    20180926_004834.jpg 20180921_231815.jpg

    I am very satisfied with the performance of this rig. It took me a while to learn how to tune it right but once it is done I can feel every little movement of my car or airplane. I found that for motion simulation a little go a long way. For example the traction loss movement I only have to set at 40% out of a 100% and it already gives me a nice drift feeling as the car race around the curb.

    In terms of cost the whole thing costs me about $4500 (monitors and stands included). It is not cheap but compared to all the available 4dof commercially available I think this price is not bad at all. If you are an experienced builder may be you can source most of the parts from eBay for less but for a beginner builder like me, I would recommend buying the kit instead.

    If you follow my built thread from the start you must have seen a number of issues that I have encountered. Some were from my inexperience but some can be avoided if Simukit would readjust their design a little bit. It is still a great kit that can help you to get started though. Simukit is also working on adding traction loss to their kit so in the future you don't have to build it yourself.

    There are enhancements that I am making to the rig. One is adding a buttkicker unit to the seat. The other is to add vr. For the vr I would like to wait a bit for something that offer good resolution and motion cancellation. But this is something I would like to get into soon as so many people are having great experience with it.

    Once again thank you to all who have shared ideas and helped me with the built. And good luck to all who are inspired to build their own simulators.

    Take care.
    • Like Like x 5
  13. axenic

    axenic Member

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    That is an amazing setup you have build here ! Congratz !:thumbs


    For the VR part : the motion cancellation is already supported within steamVR with this amazing plugin :https://github.com/matzman666/OpenVR-AdvancedSettings

    I used it on a daily basis within PCars, Assetto Corsa and Elite Dangerous.
    However, if you can wait, I fully support the idea of waiting for a good resolution enhanced headset. This will require a beast of a GPU, but VR is the way to go !
    • Agree Agree x 2
  14. jjanu

    jjanu LiveForSim Gold Contributor

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    Hi Stargazer, I love your build. I'm glad that all your latest efforts paid off! Based on a similar build to mine it's interesting to see the original solutions that you've implemented to come up with your own results. Congrats. I especially like the way you've added the T16000 hotas to your rig. I'm planning to do the same for flight sim and ED. This Thrustmaster model seems to be a strong option. I would have liked the Warthog but can't afford to get one.

    After a busy summer I recently finalized my latest tweaks and came up with some visuals available in my thread.

    Check it out:
    https://www.xsimulator.net/communit...th-simukits-solution.11465/page-3#post-164012

    Cheers mate!
    Last edited: Oct 20, 2018
  15. Stephen Borick

    Stephen Borick New Member Gold Contributor

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    I've been considering the same SimUKit build... all I can say is, WOW, what an ordeal. But it all appears to have been worth it in the end.

    I'm thankful that you took the time to post everything, the good along with the bad. It's made me think a bit longer as to which route I will take, go all out with the SimUKit SK3 (which states it includes the reinforcements springs mobile platter and preparation of the evolution in version 3.1) and the 400W kit , or possibly save some headaches by purchasing the DOFReality, which is pre-wired and ready to go.

    Hummm... maybe a combination of kits. DOFReality's P2 to P3 upgrade kit (which includes the extra motor, frame parts and an upgraded control power box) along with SimUKits 400w 3 DOF kit and SK3 kit. This would provide the motor and parts for a yaw setup and a bit more "plug and play". Might be the way to go.
  16. stargazer

    stargazer Member

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    Hi Stephen,
    The nice thing about building with a kit like Simukit is that you got to learn a lot about motion simulation. You may save some money but you must spend a fair bit of time working on it. If you don't have time then a platform like that of DOFReality is a good one for the price. You may also get support from them with simtools config and tunning which I found took a fair bit of time if you have to do it yourself.
    Good luck with your build.
  17. Stephen Borick

    Stephen Borick New Member Gold Contributor

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    Hey @stargazer, appreciate the good words.
    I'm retired and have plenty of time on my hands. Even so, I'm thinking a Frankenstein build of the two might just be the way to go as it could reduce the headaches.
    Before I make a final decision I'm going to put together an actual cost of the two systems melded together without duplicating parts(I'll need to price the parts separately on Simukit rather than just purchasing everything in a bundled kit). I really want that heave effect for flight along with yaw for both flight and traction loss.
    At any rate I find I have more fun putting things together, like my motorized recumbent trike, my N1, a 150" screen that drops and then rises into a soffit in the living room using a garage door opener.
    Whichever way I decide to go, I'll post here on xsimulator, you never know who it may help... like your post helping me. CHEERS
  18. stargazer

    stargazer Member

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    Hi Stephen
    In that case you will actually have fun building it and learning a whole lot about motion simulation. Twenty years ago when my friend at CAE took me into his lab in Montreal and let me tried his simulator. I was totally awe struck by how real it felt. So when I saw people building their own simulator I can't helped it but to build one for myself. It was a lot of work and there was time when I wished I just bought a ready made one instead, so that I could enjoy the flying right away. Instead of toiling with the motors and electrical connections. At the end when it finally worked I am just happy that all the effort was not wasted. I showed the finished product back to my old friend at CAE and he was totally impressed too. Not that it came any close to his $20 million simulator. But that he didn't expect that one can do so much for less than $8-10k.

    So good luck with your build. Please let me know so that i can follow your progress when you have started it.
  19. stargazer

    stargazer Member

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    Hi all,

    Just an update: the platform continues to perform well with many friends came over to try it. I have recently bought the Oculus Rift S to get into VR. So far I have been enjoying flying with it as it gives me a good sense of depth compared to the triple screen setup.

    My problem is with the roller coaster game, No Limits 2. Within a minute or two of trying it out, I felt a strong sense of dizziness and nausea. To the point that I have to take off the VR and run for the bath room. It took several hours for me to regain my sense of well being. I wonder if any body else also got this problem???

    I have two VR setups at home, both run on core I9, 32GB and RTX2080. I didn't feel as sick with the VR that has no motion. I was able to complete a roller coaster run with that one. The VR with motion was the one that almost killed me. Would someone know why this is so?

    Thanks,
  20. noorbeast

    noorbeast VR - The Next Generation Staff Member Moderator

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    Some people are more susceptible than others to VR sickness, particularly when starting out.

    But my guess is that your motion profile is not as refined as it needs to be for VR, hence your brain gets conflicting cues from what it expects.

    With motion and VR less is more, you need to tune the motion profile for speed and precision, not large axis movements.