Showroom 3DOF Sim and VR adventures

I first found this place early in 2015 (I think through a silentchill video?) and immediately decided a motion sim was something I needed in my life. I was already playing a lot of Assetto Corsa in VR and adding some motion seemed like a necessary step to complete the experience.

I guess I should start with showing the finished product:



..and here's how I got there

I already had a "GT Extreme" cockpit from Next Level racing which seemed like a good base to start from. Here it is being used by a friend of mine, using the DK2.




At about this time Valve was showing off room-scale VR, which I also immediately decided was something I needed. But unfortunately I lacked the space in my house for both a motion sim and room-scale VR. At the time I was doing some fairly major renovations on my house, so the decision was made to extend these plans to removing some walls accommodate both room-scale VR and a motion sim.

This wall's gotta go:






Because we were deleting a wall that was supporting the floor upstairs, we had to double up on the beams you see here:






Done! Insert motion sim here:



That's an old 50" Samsung 1080p plasma on the wall there. I took a guess at the height it would need to be for the motion sim, ended up being spot on.

At the other side of the room is my main gaming rig and room-scale VR area. My Vive showed up the day after launch day, which was about a week after the renovations were completed! Ended up with a play space of 4m x 3m. Here's me looking dumb, but having the time of my life:




With the renovations completed I could finally commence work on the motion sim itself. I didn't really have any firm plans, but I had done a lot of reading here and had a reasonable idea of what I needed to do. I had briefly entertained the idea of building a 6DOF, but considering this was all new to me I thought I would start with 2DOF + traction loss. I scribbled a vague drawing, took some measurements and ordered a bunch of steel to get it started.

My plan was to start at the top basing it from the existing GT Extreme frame (though somewhat modified), then work down through the middle and bottom layers.

The standard seat on the GT Extreme was not going to cut it. Luckily I had a spare Racetech 4009W seat from my real-life race car which would work perfectly. I reused the seat slider from the GT Extreme, but hacked off the old mounts and made my own to suit the Racetech.







With the basic ergonomics done for the top section I could start building the frame that would carry it. Most of this is built with 30mm SHS with 1.6mm walls. There's about 60 metres in total.






These 2 pieces just bolt together




Next step was to find the COG of the whole top section to decide where it should pivot from. I did this using an old piece of roll cage tubing, with me sat in it:




With the COG found I could add a cross brace, with the centre being the pivot point.




Next came the middle section. Did the basic outline:




Using 3 x 200W 12VDC motors with 25:1 ratio from Motion Dynamics. They go somewhere here:




Put a cross brace in the middle section to match the top section. This will carry the bottom of the uni joint.





Lazy susan bearing at the front of the mid section:




Next came the bottom section. I wanted 150mm of traction loss movement in either direction, with some margin.




It all moves on some little wheels. They run on some quite thing 0.7mm steel, but underneath these runs they are packed out with extra lengths of 30mm SHS to take the weight.




Underneath are some adjustable feet with a nylon base. I couldn't find any rubber ones that were big/strong enough. The nylon on the tiles is a bit slippery, so it does move around a bit under operation.




Next came the motor mounts. I made these mounts bolt on rather than weld in case I needed to move to bigger motors. As it turns out these motors are more than sufficient.






Next came the uni joint. A friend of mine donated a tailshaft from a Datsun 260Z which he also installed a new uni joint into for me. I wasn't sure how high it needed to be, so I bolted it together, put it in the vice and took some measurements.



Ready to be welded in






Checking the alignment and tacking in:




Safe to say it is now "stuck"




Painted black! I've held the top section level here using cable ties to start working out the control arms.




Using M12x1.75 male spherical rod ends with left and right threads, and half nuts.




My motor shafts have 45mm CTC arms, with option for 65mm CTC. I have stuck with 45mm which is working great.




Misalignment spacers made using some old furniture legs which just happened to be the perfect size.




End of a control arm with half nut welded on.




Control arms done




Panhard rod for traction loss. Shaft here is set for 150mm CTC, but has several options in 25mm increments.




Mounting the Moto Monsters, heat sinks and fans. The heatsinks are hacked up CPU heatsinks from old IBM servers. Not that pretty, but are effective.










First power up, success!




The power supplies are actually in a different room to motion sim. I did this in order to cut down on noise in this room. They're also pretty ugly so I'd rather not have to look at them. I am using 12v 69A power supplies, again from old IBM servers. 4 of them. This makes a total output of 276A, which is a huge overkill, but may be necessary for my future plans.

Before:



After:



Mounted together with some extra cooling




This is in the attic in my garage, directly above where the motion sim is.




Cabling runs down some slotted duct and through a wall plate into the room with the motion sim



Note only the an Ethernet cable is run in this pic. The cable for the actual motors is run in 4mm^2.



I decided to put a new circuit in the house to run this, which again is overkill. But in this process I installed an EDMI MK10A meter to monitor the power usage. At a later date I'll do some analysis of the power usage which might be interesting to some.

Now to finish off the top section. This is the Fanatec Clubsport Handbrake.




This is the Ram Mount which will hold the Oculus Rift CV1 positional sensor. This has 1" rubberised aluminium balls. Super strong and deals with vibrations well.




Mount for the control box:




Mount for the Ram Mount which will hold the keyboard / mouse:




Painted:




Test fit:




First time all bolted together




Wiring time. Using SMC in the Arduino:






For feedback I am using precision 10K pots mounted on some bent steel sheet, with 12mm to 6mm couplings:




Red LED strip lighting mounted everywhere so it's obvious when it's turned on and you shouldn't go near it. It also looks cool



The control box has On/Off/Emergency Stop, a volt meter, and a pot to do motion scaling. I didn't really get a good result from the motion scaling, so I leave this pot disconnected for now.




PC specs are i7 3770K @ 4.2GHz, 16GB, Asus Strix 980Ti. This PC is currently sharing duties between the motion sim and main battlestation on the other side of the room. Eventually I will leave this PC here permanently and build a new PC for the other side of the room.




I'm using a Ram Mount X-grip that is intended for tablets to hold the wireless keyboard / mouse. I like this solution because it can quickly be attached or removed, and can stay in place for games that require keyboard commands (eg. ETS2).






And since I'm running out of space for images on this post, I'll continue on another one...

Here's some more of the finished product:






















Meet "Spaten", my helper during the project. He seems pretty proud of his work.




Check out some of my crappy driving on it:

great job! that's so cool!
the axises can adjust to be better feedback feeling.

Thanks . Metal fabrication is definitely not my profession, but I do have some experience from building my real-life race cars. I do my best to keep things neat and tidy.

My apologies! Living FTTH life here, I sometimes forget what it used to be like. I'll change them to thumbnails.

Done. My pic-heavy posts should be a bit easier to deal with now

Something else that's worth pointing out is, that from conception to actually completing this I never had to post on this forum or ask for any help. All of my questions were already on here, answered. I believe this is a strong testament to the quality of the documentation that has been put together on xsimulator. Well done, thank you all very much.

Great job, clean and well done, congratulations.

My motion project went about like yours. Most of my questions had already been answered. Knowing which parts to buy was nice also. I didn't have to buy multiples of stuff i didn't need.

Well documented man, Very well done. Guys like Us who document every little thing and post pics with mini explanations helps Immensely for the new guys. Ive heard many positive comments as well from this posting style. Keep it up.

This is very true. Though I did end up buying FOURTEEN moto monsters before I had 3 which looked like they might work. And I've changed 2 more since finishing it because they were having issues. It all seems to be going well now though. I don't think I'll use MMs on my next build.

With these sorta things I try to think of the type of build threads that I like to read. I try to show small details because that's the kind of thing from other's builds that has helped me and given me ideas.

Has anyone else been having tracking issues with the latest Oculus drivers (ASW)? Note my tracking camera is firmly mounted on the rig.

Tried it yesterday for the first time since the update and it randomly moves the head position to about roof level, then sometimes it jumps down the bottom of the seat. Really weird, and very frustrating. Same behaviour in both Assetto Corsa and Dirt Rally. Prior to the update the tracking has been flawless, never a single issue.

I used a camera gimbal to fix my tracking issues. With Aerofly2, I had to enable the pitch part of the gimbal, but thought it was just something to do with the program , had forgotten about the update.

Yeah it's just weird that it's only just started doing it now. Last time I used it was a couple of weeks ago (been working away). Tracking has been perfect up to this point, and now every 1-30secs it does some ridiculous vertical shift. The only thing different is new Oculus drivers.

I'll experiment with different USB ports, see what happens.

Have you recently experienced new tracking issues too?

Yes, forgot about the update so did not blame it, just thought it was the new game. Only had a issue in pitch as the gimbal was enable in Roll, as I originally did not have a issue with pitch. Have enabled both axises of the gimbal now and pitch tracking issues are gone. Not saying that is certainly your problem, but...

What an awesome build.
It would easily pass for a commercial Sim such is the quality of your work.

I really enjoyed seeing that come together in the pictures. Thank you for sharing.

So I shuffled some USB ports around, which prompted quite a lot of driver reinstallation.

Unfortunately the issue remains.

Can anyone suggest a cost-effective gimbal to try?

Great job i am amazed how well you build everything! - I think this one is exactly what i want to build 3 DOF ( for playing CMR Dirt)
i want to purchase the same stuff as your DC motors ,Moto Monsters, Arduino,etc and please give me advice for power supply something from ebay may be just to do work properly - and need scheme or little bit more explanation for the electronics how to connect them and how they exactly work - what exactly software i need how to setup .Found this 12vdc motor looks same as yours 12v dc 25:1 ratio if they are ,please let me know and i will order them
cause i can`t upload link to ebay here you can put this in ebay search bar and see it " GEAR MOTOR 12 VOLT GREAT FOR SAWMILL/CRAB POT PULL/FEED 150/160 rpm 25:1 ratio "