DIY Gseat with wheelchair motors

Hello forum,

Its been a little bit since my last post so I figured it was that time again. I have here for you perusal a DIY Gseat based off the Bergison Gseat (first place I saw this design). It uses 4 electric wheelchair motors, 4 IBT-2 (BTS7960) motor controllers, 2 Arduino Unos and 4 hall effect potentiometers (180 deg). While being mostly constructed of wood it is very solid... and heavy. So heavy that I believe it would crush my 3 DOF if I tried to put it on there. For that reason I am considering turning it into a seat mover by adding a U joint and 2 more motors for pitch and roll.

One of the best parts of this design is the fact the motors that move the seat flaps also retract/ slacken the 5 point harness. One other change I made from my original plans is on the backrest flaps. At first I intended to make their resting position completely flat but after some consideration I realized in that position there would be no braking force felt. I changed the resting position to be about 20 deg forward from flat.

First video, I have just about everything wrong here as I explain in the video. Also I started this build to try and use the wiper motors that I initially used on my 2 DOF motion sim. They are being used as the backrest motors:


Video 2 I get the paddles set in their correct position and start on the electronics:


In Build video 3 I start building the bottom of the seat and start on the lower motor mounts:


The fourth video goes over the challenges of mounting the lower motors and all the connecting apparatus that goes along with it. I have also slightly changed the lower frame:


In part 5 I finally get the seat working. One of the biggest hurdles was figuring out how to modify the SMC3 software to allow what I needed since my motors were flipped and I wanted to limit more of the range but I got it all figured out and "kinda" working:

Even though I have it working you can certainly tell the potentiometer mounts were not working so I decided to learn 3d modeling in blender so I could make pulleys. This is the first attempt at that:


I ran into some issues with my 3D printer and the first iteration of the pulley design. I redesign the mount, after I fixed my printer of course, and describe how it will work on the motion sim:


The Gseat is working now without any potentiometer issues! I go over the design flaw in my previous pulley system (Dont ask my why I thought rubber bands were going to work, I dont wanna talk about it) and discuss the issues with the backrest motors and hanger/drum system. There is too much play throughout the entire system plus the wiper motors are just not very strong... I contemplate replacing the wiper motors with 2 more wheelchair motors...:


I decided to rebuild the Gseat to see what it could do with 4 wheelchair motors. Its not completed yet but Im almost there:


It is finally here!! I mounted the 5 point harness and tested it in NoLimits 2 and I was not that impressed. The rollercoaster sims lend themselves more to the full frame motion sims and this just kinda felt weird and disappointing:

I did not have high hopes for this seat as my brain is so conditioned to pitch and roll and just generally move around more. I had that in mind as I started to hook up the crappy little wheel that I dug out of the VERY back of the closet. I was just going to do a quick test on my laptop in Live for Speed since I know that rollercoaster sims dont really give you a good idea of how a sim will work in a driving game. I was not prepared for the power of this chair. It is definitely a much more enjoyable experience!

I continue the Gseat build by first getting my spare wheel (G27) and VR headset (Oculus CV-1) and connect the Gseat to my secondary computer (not my laptop). It was doing well but after about 10 min it felt like my lower spine was compressed 3 inches!!! I also noticed I was sliding down the seat towards the pedals. I addressed this design flaw my raising the front of the seat and leaving the back of the seat where it was. This makes the seat into more of an "L" shape that will prevent both the spine crushing sensation and the rider from sliding down the seat. I also started to add the side panels and start looking into upholstering the Gseat paddles.

Good to see more gseats around!
I highly recommend building some bolster into the back paddles so you get force on the sides of your ribs rather than just the back. Check out my build in the signature for an example.

I certainly will check out your build. You get pretty good force from these 24v wheelchair motors so I have not felt it dire to add previously. I am going to be disassembling one of the wheelchair chairs for its upholstery and will be adding lots of padding to the chair. Thanks for stopping by and checking it out.

Oh man, I didnt know you were THAT guy! I love your Gseat! Your design and Bergisons were the two leading designs I was thinking about but the Bergison design was easier to implement. I will definitely look into adding side bolsters like you did in the first part of your build and I might create a formed seat as you did. How much does your seat weigh, roughly? Mine is very heavy, I would guess 120 lbs or so. I want to get the weigh down but I dont believe the heavy servo motor (the 50kg ones on amazon, not stepper motors) will give the same feel.

Thanks for the kind words!
The seat is pretty heavy, something like 50 lbs or so. Not 120 for sure. The fiberglass seat was surprisingly easy, just a lot of simple work. I recommend it.

I dont have my g seat setup right now as I want to redesign it to fit with a larger variety of bodies. I have found that as you get better performance it doesn't carry over from one person to another as well.


Your demo video was great. Its fun to see others exploring the same ideas I've obsessed over. Its too bad we are all so spread out. It would be amazing to get together and try these things out more and exchange ideas.

I couldn't agree more. I want to try other people's rigs because small settings adjustments or design tweaks can mean a significant difference in feel, especially in VR.