Adding 2DOF (Seat Shaker) to Aluminum Rig

I'm finally jumping in on a seat shaker upgrade for my existing simulator and I know all the members here will help me be successful.

A little background on me, I'm an engineer in the USA and I have had a working racing rig for about a year now. I always plan on doing Iracing or dirt rally, but I think I enjoy designing and building more then actually using my rig. I started with a full pvc setup and quickly moved to a 80/20 aluminum rig. I have some designs on GrabCAD (Search for Extruded Aluminum Sim Racing Cockpit) and I will be updating the rig there as I go.

Currently I am running
Small MIGE OSW with Fanatec BMW rim and accuforce QD
Fanatec CS3 pedals
Fanatec Shifter
Fanatec E-Brake
Tripple 28" monitors
I7 PC with GTX1080
4x Aurora Shakers one on each corner.
Oculus Rift CV1 (Some people cant handle the rift so I like to keep the rig setup for both, But I love the rift)

Parts I Have already sourced for my upgrade
2x 50:1 motors from PWSAW on ebay
2x 600W server power supplies
6 point cheap racing harness from ebay
double flange u-joint for the chair
misc hardware, rod ends and rods
saber-tooth 2 x 32A
multiple arduino micro-controllers
potentiometers
2x Marine Fans for simulated wind
4x dayton shakers for seat, pedals and shifter

I design everything in CAD and usually have a fully assembled model before beginning to build the real thing.

some challenges that I see ahead are
software configuration with all of my software playing together (Fanaleds, EKSimManager, simtools, SimVibe, OSW etc.)
Power Draw, I would like to keep my system to a household outlet (15A at 120V in my case)
establishing the correct angles for the chair motion
cramming all of the components into my extremely compact rig

Here are a couple of photos of my rig as it sits now, I will try to keep updates rolling in.

Here are some screenshots from my cad software to give some ideas on where I am at with the design. I have to keep everything in the existing frame space which is 60" long and 27" wide to the outside not including monitors. I fold the monitors in when not in use.

I know everyone suggests going with the motors mounted behind the seat and long rods connected at the top rear of the seat for the best leverage, but I'm really going for a compact design. I did purchase the 50:1 motors and according to my calculations at 10degrees of swing the should be able to rattle my teeth right out of my head.

That brings me to my first question for the group, how much angle of swing should a seat shaker have? I have designed my platform so that the pitch and roll angles achieved are identical and I was planning on about 10 degrees total swing both directions, It seems like very little to me though. My current design allows for 9 degrees on each side for a total of 18 degrees before I start crashing. I was going to limit the throw of the motor to achieve the 10 degree total swing though.

Right now I'm not able to move the motors to the front of the seat due to the control box in the center of the rig being too wide. The pc sits at the back of the rig and is just narrow enough to get the motors with pots squeezed in. I could drop the last damper and gain 3", but I wouldn't want to do that unless I had an alternative support method.

You said you run 80 degrees at 50mm ctc, what kind of seat angle does that equate to?

On my design +- 33 degrees at 60mm ctc is +- 5 degree seat pitch. What I'm trying to gather is what everyone runs for max pitch and roll, then I can work the numbers backwards.

I printed the prototype motor control arm last night. I did a quick test fit and everything looks really good.
I printed the part 100% fill with PLA and its really beefy, it will be plenty strong to test motion with an empty chair.

hopeful I can get both motors mounted in the next couple days and start playing with position and linkage length.

I didn't get as far as I would have liked tonight, but I was able to get the motors ready for mounting to the rig. I still need to design a bracket to hold the potentiometer. Originally I was going to mount off the single bolt at the bottom of the motor with a Z bracket, but I decided to tap the two mounting holes in the gearbox (you can see the bolts sticking out of them in the picture) for a simple L bracket. I will be 3D printing the pot mounts, hopefully I can find a design that has very stable rotational rigidity, but will still allow for wobble in the pot.



I also started reassembling my wheel motor, but then I realized that I still have a couple of plates that need to be made before I can fully complete it. I threw a picture in to show what it looks like mostly disassembled. The big blue part is a high speed slip ring so that the USB connection for my Fanatec wheel is fully contained in the QD. I ended up going this route because my kids kept going down and rotating the wheel a billion times in one direction eventually wrapping the coiled usb cable so tight it was all but destroyed. Also its very cool to be able to pull your wheel off with no usb cable dangling, whenever I show people that along with infinite rotation they look at me like I'm breaking the laws of physics or something.



I updated my grabcad projects with the current status of this design.
I f you want to see more detail on any of the parts I'm using, jump on grabcad and download the 3d model. You can even view the file right in your browser on grabcad, no need for cad software or cad experience.

https://grabcad.com/library/aluminum-racing-simulator-r2-01-1

I printed the prototype pot bracket and did a test fit, hopefully it will have enough flexibility to allow for the off axis wobble that is inevitable in these gear motors.
I'm happy with the results, so I will clean up the design a little and print a left and right set at 100% fill. These will not be replaced with metal so I will probably print a couple of sets to have in case I have a runaway motor.







Unfortunately my 3d printer died on me and get to spend part of the day determining why. its a Monoprice ultimate which just a re-branded Wanhao duplicator 6, which is a redesign of the Ultimaker. Its been a very good and reliable tool and once you have a 3d printer you start to understand how it can be worked into your toolbox. Ive printed a lot of prototype parts and brackets which saves me the time of building things twice in steel and aluminum.



I will have to put the motion project to bed for a while though, I really need to focus on the steering wheel assembly and finish up the last few brackets.

some info on the parts
Motors are from PGSAW on ebay, 50:1 Gearboxes 75/80 RPM, $99.99 +18.99 shipping to USA. he only has the 25:1 motors listed now, but they may be available by request.
Motor side mounting plates are 1/4" aluminum custom made
Shaft adapter clamp is 1/5" aluminum custom made
The lever is 1/2" thick solid PLA, this will be replaced by aluminum once the correct CTC is determined
The POT bracket is solid PLA, this will stay a 3d printed part on the finished design.
the POT is from McMaster Carr, 7436K73 $14.32 each 5K, this will be replaced by a hall-effect sensor.
the Swivel rod end is from McMaster Carr, 6960T71 $9.92 Each.

The finished system will be using a Sabertooth controller, so here is where I need recommendations from the community. Can anyone recommend a proven Hall-Effect sensor, preferably from a source like Digi-Key?

Another quick thought I had was to build another pivot assembly at the back of the simulator and use a second linkage to get the pivot as far back as possible for motor leverage. It would be a much more complicated system but if its needed after testing I will design something.

Made a lot of progress today, I was able to finish up the few brackets I needed for the steering wheel assembly. sorry if the pictures are not great, I was working in a dark area and iphones suck in the dark.



I had most of the brackets made at a machine shop, i did make the simple plates in the middle. Also to save on cost I had the machine shop drill pilot holes and I drilled to the correct size and tapped all of the holes myself. I hit the parts with an orbital sander using 220 grit to remove all of the scratches and machining marks.

I would have liked to notch a double wide piece of aluminum extrusion, but I just don't have the tools to do it accurately so I had to fabricate my own out of two single sticks. The reason I had to go with double wide was because the connectors for the MIGE servo motor sticks out too far, the double extrusion allows enough clearance for the connectors.



I added custom plates to the top and bottom of main mounting extrusions for strength and aligment.



I then added the front plate which will be the dashboard when you sit in the simulator. Notice there is a flange mounted bearing that adds support for the stealing shaft. the bearing us mounted to the front plate.



Next I mounted the middle tablet bracket, due to a slight error in my design there are two screws that are inaccessible once the shaft clamp is installed so unfortunately to remove the middle tablet requires a lot of disassembly. After the tablet and bracket were mounted I installed my custom shaft clamp adapter. This plate adapts the shaft clamp to the Accuforce QD assembly

I spoke with the customer service group at SimXperence and the Accuforce no longer ships with a slip ring and instead utilizes a USB tether. I was able to get a pcb assembly from them, but they no longer sell them so if you want to go this route you will probably have to get creative. I have designed a custom PCB to replace the existing one in the future. eventually I will add a Fanatec Formula 1 Rim to the collection.




Here is the Accuforece QD mounted to my custom adapter plate.



Here are the two side tablets installed, the front plates are 1/8" aluminum and the rear plates are 1/4" aluminum. the rear plates are supported so there is no wobble or flex from the tablets.



Next I had to solder 4 wires for the Accuforce QD. I am only using 4 out of the 6 connections because i am using the QD as a usb pass-through connection.



with all of my connections completed I hooked power up to the tablets and did a quick test.


the tablets are running EK Sim, I will eventually build a few custom screens for buttons and data on both the left and right tablet. the middle tablet will only be for guages and will not be used for touch control. Its not as good as a real button box, but I really like the look of the screens, and it will be easy to customize to each game.

I then fired up a Faneleds and plugged in the my BMW GT Wheel to check for errors.



In he sim cockpit I will view the middle tablet through the top of the GT wheel. I'm pretty happy with the results.

Here is a view from the backside, you can see the angle brackets attached to the tablet plates, they are rock solid




I did a quick weight on the scale and the whole assembly is over 50 pounds. it is extremely rigid and I know that even with the power of the MIGE OSW there will be no flex.

I have all of my pictures in dropbox, so if you want to see all of the pictures at once go here
https://www.dropbox.com/sh/tug5yhcugcdjryx/AABLO8316AIqkBhNAPs9BoCxa?dl=0

I will also put the link in my signature

heu you use touch screen as buttonbox ??

The software is called SLI MAX Manager Pro from EKSim Racing.
It is relatively cheap, but not free (each device requires a license $10 US for first device and $2 for each additional device) and requires wifi.
You have to run the software in the background on your simulator PC and then it sends game telemetry data to the other devices, in my case android tablets.
There is an app for android devices and it includes a few sample dashboards and a button box layout. you can build more and have as much or as little as you want on the display.

you can get more information here.

http://www.eksimracing.com/sliemu-sli-pro-emulator-for-android/


It works well, however when you have the same telemetry like RPM on each of the three tablets there is a difference in update time so you get lag. It seems to be more of a problem with the center tablet which is the least powerful.

Thank you very much for all this information, I will dig all this because I have 2 tablets that do not serve me and eventually can use them as dash it can be excellent.
The direct compatibility of android is a plus.

merci beaucoup pour tout ces renseignements, je vais creuser tout ça, car j'ai 2 tablettes qui ne me servent pas et eventuellement pouvoir les utiliser comme dash ça peut être excellent.
la compatibilité directe d'android est un plus.

I have been using my 3D printer to build test brackets, I Print them at 100% fill with PLA and I embed hex nuts in the prints for more strength when mounting.
Here is a bracket for a attaching a swivel rod. The final part will be a simple aluminum plate, but because I 3d printed it I had to really strengthen the parts. I print up until the nut is about to be covered and then drop the nut right in and the printer prints right over the top of it.

I was able to get the monitor/steering rack support re-installed, I changed the angle supports in the front from 45 degree extrusions to an adjustable pivot. this gives me more support near the monitors and will allow for the required space to add transducers to the front of the frame.



I also re-installed the steering wheel rack, it was a challenge being that it weighs 50+ lbs and it has to be lined up just right to slide into the t-nuts. it feels good, but I will probably raise the monitor a little and move the wheel closer to the monitor to give my arms a little breathing room. I wont make any changes until I get the seat and motion setup assembled though, i want to make sure the seat is in the correct position for the controls and balance.

I installed the gear motors on the rig. I don't like the location and I have a plan to get more leverage if needed, but for now I think they will be acceptable for testing. I didn't install the pots yet and I won't until I get everything to start playing with my sabertooth controller.





I had temporarily mounted the u-joint and seat base, but I had to remove it and re-install so here are some pictures of how how it works.
The U-joint is a double flange assembly off of Ebay, I actually found a thread here that talked about a seller that had 4 available (military surplus) so I grabbed one knowing it would be easier then welding my own.



I had to add a plate to get the height of the chair base back to where it was before when it was fix mounted



This is the custom chair base, you can see all of the t-nuts already installed and waiting for the mounting plate to be attached. you can see the finished 3D printed part from my earlier post.
My seat rails fit the outside extrusions exactly and install with 4 bolts, hopefully that will be enough to survive motion without destroying the seat.



Here is the mounting plate installed, the reason it is so large is that two transducers will attach to the underside and vibrate the seat directly the 4 holes in the middle are for the u-joint to be mounted from the underside.



Here is the mounted U-joint



And ready to install in the frame



Here it is sitting in its final location while



And finally installing the screws to hold everything in place, this was a real challenge. Also getting everything lined up as best I could. I used Button Head Cap Screws which I use just about everywhere on my rig. I like the finished look of them, but they can't be torqued as tight as socket head cap screws or hex bolts so I will probably change these eventually.



The last thing I did was installed the linkages from the motors to the seat base.







When looking at the rig from the back the linkages have a lot of angle, too much in my opinion and I fear that there will be too much stress on the motor shaft. Also my gear motors have about 1-2 degrees of play and it is really noticeable when I grab the platform and wiggle it from side to side. I hope it won't be that noticeable when I'm actually racing. all in all I'm happy with the results for the first shot at it, once I'm able to actually test the motor performance I will decide if I want to change the design.

Here is a quick video of the platform being moved manually (me standing on it and shifting my weight around). Ignore the music in the background, my kids were watching some Disney movie at the time.

Lovin the build so far Hoddem. Keep it up.

Strange i was under the assumption you couldn't back drive the 50's.....Interesting.


And the Tick of play in the motor is 100% normal. Ideally you have a very small rearward weight biased pivot point which keeps that tick of play in a spot where you'll never feel it in motion.

I was under the same impression,
I ordered the motors from PGSAW on ebay and they are hand marked 50:1. Also under no load at 12V they spin at almost exactly 75 rpm so that leads me to believe they are indeed 50:1.
I weight 200lbs so by standing on the seat base I can really put some force on the motor, but I was able to turn them by hand with a little grunting (using a 60mm ctc shaft).