Jump to content

Sign in to follow this  
David Gibson

Motion Platform MK2 (added Traction Loss) WARNING LOTS OF PICTURES

Recommended Posts

Building a motion platform was the biggest influence on my choice to get into Sim Racing. While I am still very much a rookie in racing I have found it to be a great deal of fun. This motion platform really enhances this.

My original platform incorporated only two axis, which allowed for pitch and roll. This latest platform allows pitch roll and traction loss (the rear end slides out from underneath you in a turn).

I dressed this one up a bit more than the last. It pretty much has the same top sled (for the seat, monitor, controllers, etc) with a slight change in the metal work. Sorry that I could not get better pictures, the contraption is located in a back corner of my shop so there is little room to move around it.








Here are a few pictures of the mechanical bits:

Motive power is provided by three winch motors, the cheap 2000lbs types which connect to a ball hitch to pull ATVs and boats around. They are 12v 90w motors with 400:1 mechanical advantage. The output speed is 10RPM. The traction loss winch was modded by removing the final gear and connecting the lever to the next to last which gives the winch a mechanical advantage of 100:1 but a faster speed of 40RPM. I still need to do some wire management.



Electricity is provided by two HP 700GB 700watt server power supplies that I found on Ebay for 15.00 each. They are easily modified to provide 56 Amps.

The drawback to these power supplies is that they do not have internal fans and must have some type of cooling or they go into thermal shutdown. I remedied this issue by making my own fan housings and adding 80mm fans to each unit.





The entire rig is built in three layers, the base layer is a torsion box built with 3/4" cabinet grade birch plywood.





The middle layer is the traction loss platform. The front pivot is a 12" lazy susan bearing from a hardware store. It is mounted under a sub platform of plywood to make it easier to mount to the upper platform. The rear movement is provided by an array of in-line skate wheels spread out to better support the weight of the platform and driver. I used my CNC router to create the plywood mounts. Note that the layout allows the wheels to move in an arc from the pivot point.





Since the platform went a bit...wonky....one day and spilled me out onto the concrete floor (google "No Limits Roller Coaster Simulator), lol; my wife insisted that I put seat belts on the platform. And to be honest while racing it really does seem to help. I had planned on adding a spring mount for the shoulder straps to help simulate tightening when I brake but I found the snug fit is comfortable without further tightening.



I did change the original upper platform a little bit by moving the front upright supports from 90 degrees to an angle matching the front. This gave me more leg room.


The center pivot is from some type of large delivery type truck. I purchased it from a scrap yard for 5.00.


And of course a driving video. Please note that I did mention that I was a rookie and I really need to work on my cornering wink

It is noisy with the winch motors but eventually I will put a housing around and over them to reduce the noise. I am usually using headphones while driving so the noise is not noticeable anyway.

I am a very big guy (with what my wife calls "layers of dormant muscle"), 6'4" @ 350lbs and this platform bounces me around with little effort. biggrin

Share this post

Link to post
Share on other sites

That looks really cool. I watched the vid, but really impressed with your build progress pics. Thanks for posting.


Share this post

Link to post
Share on other sites

Very, very cool propnut. I have a simxperience GS-4 6DOF which simulates sustained g forces from braking, cornering, acceleration, suspension movement etc. It really adds another dimension to the experience.

Seriously impressive that you built that yourself. Are you using x-sim?

Thanks for sharing BTW. thumbsup

Share this post

Link to post
Share on other sites

Ah, my own pit....close to being a usable kit, it had to be deconstructed during a small re-model and holding my daughters wedding in our house before Christmas. Storage of extra furniture/tools/books at my house is like putting 10 lbs of crap in a 5 lb poke....unfortunately my office is the 5 lb sack.

Actually have even more ideas and thing-a-mabobs to use when I do slap it back together. A spare Logitech 5.1 sound system, a new-ish android tablet for a telemetry display, made me a new set of cushions, etc.

I was looking at A-10 plans since the wide side consoles could make switching from race-sim to flight-sim a possibility. I'm hoping springtime will have more time to get back into my build.

Later, Derek

Share this post

Link to post
Share on other sites

Thank you gents.

Darren, I am using Simtools software. It is free and very easy to work with. More here: XSimulator.net

David: biggrin

Derek, sorry to hear that, hopefully it will be in use again soon.

I added some controllers today to my pit, it is starting to look....busy smile

I wanted a sequential shifter mounted near the wheel but the aftermarket units are a bit expensive. So I modified an old hydraulic controls joystick that I had laying around the shop into a sequential shifter...it was a very easy controller to make. The E-Brake unit is a left over short throw gas spring and potentiometer. I cut the framework out on the CNC. But units are connected to the button box via telephone cables. I wanted plugs that had a positive lock, I hate the PS2 plugs that Fanatec uses; they work themselves loose after a while. The button box has 28 inputs (including the six position rotary) and two analog inputs.

The controller inside the box is a Teensy++2.0 micro controller configured using GenericHID software. It will do up to eight axis' and an unlimited number of buttons with big enough matrix's but I am using the easy to wire 32 inputs (no matrix needed) and only three of the analog inputs. The controller is 10bit so I get 1024 steps on each axis so it is pretty precise.

The handle for the sequential shifter is a chunk of aluminum that I had laying around, a few minutes with the lathe helped to to look a little more like a real shifter knob.





Share this post

Link to post
Share on other sites

This thing is pretty much done now. I might add a cover for the motors, electronics but perhaps not. Depends on how I feel smile

Added the other two TVs today. The LCDs are 32" 1920x1080 running eyefinity. Although I do not see an advantage over TrackIR using this setup it does look pretty cool, lol.



Share this post

Link to post
Share on other sites

Very cool! I bet it was throwing you around at Norisring today...damn bumpy track...lol.

Share this post

Link to post
Share on other sites


Finished the mancave in the new house and installed the motion pit. Did a few upgrades including a single 4k monitor and an enclosure to, somewhat, reduce the gear noise. 




Share this post

Link to post
Share on other sites

Goddamn David.  I'm speechless. Having this kind of thing with something you bought is amazing enough, but building the whole thing from scratch is just mind blowing.  Real professional looking and a labour of love.  Kudos to you my friend.  Probably the best home built rig i've ever seen.

Thanks for sharing and taking the time to post an update. :)

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this