2 DOF Seat Mover Build Thread

Today I want to start sharing my 2 DOF Seat Mover Project with you.
My main goal in writing this thread is to reach out to you guys as I hope some of you will follow along and help me out on my little journey into the DIY Motion Sim World. Because their are still a ton of things that confuse me right now that you can hopefully guide me through as a community!

I stumbled across the NextLevel Motion Plattform V3 a few months ago and gave up on it as soon as I saw the price for it. But after having a closer look at it and reading through many build threads here, I figured maybe I'll be able to build one myself. I soon realised: this is not going to be as easy as it looks by reading some of the very successful builds on this site. After struggeling with the basic questions of life like:
"Do I really need this?", "Can I really justify this in front of my girlfriend?" , "I might end up screwing things up if I build it myself so I'd better of buying the commercial one."
I finally decided: "No, you are not gonna get past this! You WILL build one yourself! Both for cost reasons as well as self-esteem reasons."
(Yes... I admit it. I just wanted to survive my girlfriend's rage so I went for the least dangerous option here.)

After recovering from all the blows and bruises I could only move my feet a little and started making a sketch in 3D to get a basic feel for how I wanna mount things and where and to get an overall feel for the space needed.
Because I want to integrate it into my current rig without having to expand its overall size my goal is to keep it as compact as possible.

This is my current setup:

An originally Playseat-based custom rig with modified G27 shifter, modified G27 pedals, DIY handbrake and my greatest pride and joy: my accuforce v2 with the ADAM LZ Steering Wheel.

(Don't ask how I got it past her.)

With that out of the way and with you having a basic idea of my setup let's get straight into the pre-construction phase:

The basic design is inspired by @pipis2015 's 2DOF compact seat mover
The base measures 400 x 490 x 50 mm.
My plan is to put the two motors and the connecting rods in the FRONT of the seat.
Most seatmovers i have seen have mounted them in the back but the NLR v3 also does mount them in the front. I figure, this will give me a better and more direct feedback - considering in a real car you sit closer to the front suspension then the rear one and any motions "start" from the front.
Also it would allow me to position the u-joint (red) further back and therefore closer to the actual center of mass.
Have a look at these two pictures:



I also blocked out the position of the other components:
green = motors
blue = electronic's box (arduino and motomonster with fan)
orange = power supply

The connecting rods are sized the same as @pipis2015 's (60mm x 20mm x 5mm).
I also checked if they could potentially turn 360 degrees and adjusted the placement of the motors.
I also read in various threads that the connetction rods from motor to seat base should be an 90 degree angle if the seat is perfectly horizontal. In theory it is right now, but of course this depends on the size of the resulting u-joint I can grab.

Right now I have a friend reach out to a local machining shop for the steel plates. I hope to get them within a few weeks. In the meantime I will look out for wiper motors, the u-joint and for ordering the electronic parts.

I will keep you updated as soon as I made progress.
Thanks for reading so far and I hope you continue to follow along!

Looking forward to seeing progress on the build.....

Hi @FoxHound.92, what you have so far looks really nice.
About the motors: Since you are planning a compact seat mover, wiper motors are probably too weak. I would look for wheel chair motors instead, like these here:
https://www.ebay.de/itm/Antriebsmot...510307?hash=item2a9c654a63:g:jnYAAOSwEWtZrUN4

Good luck with your build,
Markus

Hello Markus, thank you for your recommondation! I will have a look into it. I'm currently in the middle of making my parts list so there could not have been a better time to point that out!
Would this require different electronic componentss then Arduino R3 + MotoMonster since they are 22v instead of 12v or is fine anyway?

Yes, as far as I know the MotoMonster shield only supports up to 16V, right?
The recommendation that you can find in multiple threads of this forum is the Sabertooth 2x32 (or 2x64, depending on the needed current):
https://www.dimensionengineering.com/products/sabertooth2x32

I also wondered about the 22V of the motors. Most wheel chair motors I saw are designed for 24V.

@MarkusB I found those on ebay:
https://www.ebay.de/itm/24V-Gleichs...-Torantrieb-Fenster-Grill-Motor-/200517678680

May they work? Btw, I will use a Sabertooth 2x32 after reading through several threads.

Well, actually I am not a motor expert. I used these motors. With the 1:25 gear box, the max torque is 20 Nm, which is ok for a shoulder mount, but turned out to be too weak for a compact design. That was the reason why I added an additional chain gear (see here). At the moment I am doing a re-design, and in this context I will switch to wheel chair motors.

@noorbeast uses the same motors from MotionDynamics, but with a 1:60 gear box instead of 1:25, and from what I read they are more than strong enough for his compact design.
The motors you mentioned have a max torque of 30 Nm. Maybe they are ok if the lever is short enough, but I am nor sure.
Maybe someone else can comment on this?

Thank you very much @noorbeast for linking me to Sim Calc. I thought I can skip it but I should have looked at it before.
After finishing my project I will make sure to write a Do's and Dont's List Guide for planning and building a motion sim.

According to SimCalc I get 99.7 % both Pitch and Roll efficiency with this motors and given the rough values I remembered for my design (talking about +- 2cm of margin).
So - after checking it 3 times to make sure I my inputs were correct -
I should be good to go with these kind of motors.

After a few months without any progress on my build due to life - I'm back to continuing my 2DOF!

RECAP:
While having the steel plates machined by a friends friend took its time, so I did the same with ordering all the components and slowly gathered everything required for the build.

I took a few photos of everything I have right now:


There are still a few things I need to tackle before I can assemble everything:
1) Come up with a solution for attaching the lever to the motor transmission axle + combining it to the potentiometers.
My idea for this is to make a steel cube with a cutout to fit the transmission axle and welding the lever onto it. The axle has a 5mm thread which I will use to somehow connect the axle to the potentiometer.
But maybe you have a better solution for me?

2) Wire and test the electronic components.
I already have a wiring plan and basically know how to wire everything but I will need help with the software setup & how to run a test routine.

3) Clean the steel plates and paint them to make them look neat.
Self explanatory. One thing I need to do before painting is drilling the holes for the motor mount bracket and bolting everything together.

I hope to continue the project a bit faster now and hope I will figure everything out with your help + searching the existing forums.
That's it for now.
Stay tuned!

I'm slowly making progress as the winter season is coming around

So this is what I have so far:


I painted the steel plates, bolted everything together, came up with a solution for the CTC lever attachment and wired everything up.
For the electronics housing I simply used one of these standard issue electronic boxes made of plastic. On the housings roof there is a fan for cooling the boards.

Right now I'm waiting for a long USB-cable to arrive to connect the arduino board to the PC as I have the plattform beneath my current rig until I could test it out.

My biggest concern are the motor axle attachments for the CTC lever:



I was not able to find the correct fittings for the motor axle's shaft so I ended up with ebay couplings without a tooth or anything. They need to be secured with 2 screws only but at least I didn't need to weld anything (because I can't.).
They are secured by flattening the axle on two opposite sides and only 2 4mm screws. They seem to fit really tight and I had to use a hammer to slide them fully onto the axle.
Fingers crossed that it will hold up...


For the potentiometer attachment I simply used a strong metal wire bent between two opposite screws which fits the u-shaped axle of the potentiometer perfectly.

I hope to be able to connect everything to the PC within the next week.
I'm excited if my build will work!

@noorbeast
To be honest I haven't checked if these motors need ground isolation. I opend one up and was heavily confused as it looked way different from the example in the forums tutorial so I didn't mess with it. Can somebody enlight me why I actually need ground isolation for and if I can damage the other electronic components by trying to operate it anyway?

Finally making progress:

It is moving!
All thanks to this great community!

Unfortunately I damaged the brushes on one motoras I opened it up to check for ground isolation:

So that's the bad news.
The good ones are: I don't need to do it!

I hope the new motor arrives until tomorrow so that I can finish version 0.9 of my seat mover over the weekend.

Hey hey hey!!!!
I found your thread!
Nice to see you've got it going, now I'm gonna start at the top and see how it all began.

Cheers, and congrats on getting it in motion!
I'm looking forward to watching your progress.

Progress update:

While waiting for the new motor to arrive I build an electronics housing:




I also added the new motor but was not able to really continue testing in SMC3 except for a short 5 min test and everything worked but the new motor is twitching the more I power it up end ultimately ends up out of range.

Seems a bit strange. I'll have to sort this out on Sunday when I can continue actual testing.

I wonder if maybe the pot is bad?

So far it is looking good but at this point not working well

I have some issues which I suppose are caused by the potentiometers that I need to sort out before "real world testing".

When the rig has to move upwards I get a stuttering motion instead of a smooth movement. I'm puzzled at the moment but hopefully will work something out throughout the day.

I really appreciate all the help you guys give me and hope to be able to give it back someday to the community.

Here is the first testdrive of my 2DOF.

At the moment I start fiddeling with the basic settings to better understand the different forces.
In the video I use only surge and sway both at 40%. As my rig is not self centering very good on "roll" / sway movements I set the washout filtering option. appearantly 50 was a bit to high and felt a little numb.

Worth mentioning is both my motors got pretty hot and within my 15min testdrive I had 2 power shutdowns on heavy braking. (0:50 min)

I'm happy to report my seat mover has been working great in its second iteration (v1 had some flaws I will point out in my "final post").

Due to the help of this community I can enjoy the latest Dirt Rally 2.0.
In the Video above you can see it in action.

The sabertooth is great! Make sure to get some resitors for your specific setup as well if you haven't already.
You can get more information about it in the sabertooths documentation.

Also worth to mention: it stays cool no matter what! I don't even have to actively cool it with a fan.
But if I know I'm going to do a longer session I turn it on anyway.

UPDATE FOR V2

Motors: MOTIONDYNAMICS Worm Drive Motors 24V 200W, 180RPM, 20Nm
PSU: SKYRC Extreme PSU 1200W 24V 50A (model seems not available anymore)
Control Unit: updated design using an old psu casing

Sabertooth 2x32: added 2x 1Ohm resistors

updated Axle shaft levers: switched to M8 ball joints
Might be worth noticing that I added an additional support rod end connector (the large nut thing) as I felt the M8 rods were a bit too weak. Choose M10 if you wanna fell better

Nice work on the control unit.
How did you attach the XT60/90 to the 3D printed holder? Can you post some more pictures of it?