3 DOF in Wood

Hi all,
I started the journey of building my own 3 DOF sim rig about a year ago.

Due to work and other family matters, I had to postpone my plans until later this year.

Finally, a few months ago, I committed myself to start my build in 2023, especially after seeing the build from @flipflop (https://www.xsimulator.net/community/threads/my-diy-3dof-wood-built-motion-simulator.17645).

Last year I bought all the electronics, 3 wheelchair motors (24v), Arduino uno clones, IBT 2, 3 power supplies and 3 hall sensors.

I followed a part of the BOM shown at https://www.sckgaming.es/tutorial-2dof-motion/

I built the testing bench with some leftover wood from another project and wired a 2 DOF:



After some problems that were solved with some forum posts and the videos from D Max (https://www.youtube.com/@DMAX_DIY) I started to build the rig frame.

Since I don't have any metal tooling I decided to build the sim rig in wood, so I went with (15 mm) sheets and some timber (30x60 mm and 50x50 mm - the 3x2's that I see much in this site wasn't available in the places I looked for - I'm in Portugal, don't know if that measurement is much in use around here).

@flipflop was fantastic in his help and was able to provide the measures that he used to build its rig. Starting with that information I adapted to the tooling that I've (I have a small manual saw and an electric jigsaw) and came up with this:





The seat from Sparco was an offer and it's an old seat from a classic rally driver who could not use the seat anymore (FIA no longer accepts this model).

As you can see, I have a very old Logitech wheel that comes with some s**y pedals, hope to invest in these later (especially the pedals).

So, this is the top frame, 140x60 plywood sheet with 30x60 mm timber. These pieces are held together with a lot of screws



I then started to work on the middle or lower frame (3DOF or 2 DOF), so, once again, following flipflop inspiration, I created a wood tower with a 20 cm height to hold the universal joint.

This is screwed to a wood sandwich composed of the top layer, plus 2 plywood sheets with a matrix of 15 screws.

The middle frame has the same dimensions as the top layer but the wood around it is 50x50 mm, I chose this wider wood to support the pressure of the 2 motors.







To discover where to place the joint, I followed a video from D Max () and, although the seat plus the wood are heavy, I can move them around with just a finger.

I'm now building a box to concentrate all the electronics.

Initial plans:

Real life (I know the power supplies are not in the correct order, but I don't have any more wire terminals to fix the wire length and fix this, hope to have some time to go the shop this weekend):



The fans are not mounted, yet, because I need to buy the electric circuit to reduce the voltage from 24v to 12v).

I'm trying to find where to place the motors (maybe somewhere beneath the pedals), and hope to do some real tests during the weekend.

For the 3rd degree of freedom, I will still have to buy a plywood sheet or something similar on where to hold the 3rd motor.

Any feedback is welcome.

LP

Hi,
already running some tests before moving the rig to its final place

I still have to buy a plywood sheet to support the 3rd DOF for traction loss, but I'm ready to start testing.



I'm trying to use the included Live For Speed to test the rig.
1 AM and I'm reading the documentation for SimTools and trying to understand how the axis mapping work

At first, I thought there was a 1 to 1 relation between columns and motors.
One Axis was one DOF, so, at this moment I have 2 motors, I would configure Axis1a to the left motor and invert the direction, and Axis2a to the right motor, but it seems that this is more complex than I thought, at least, looking at some examples, I see people with 2 DOF configuring more than "2 columns"

Happy new year !!!!

Well, I reinstalled LFS in the root directory (before, it was inside Program Files), installed Sim Tools 2, set the Axis Assignments to:





And I got it working

I don't know why version 3 wasn't working for me, I set the same settings as I did here, even on the test area, the rig would not move (I will check this later).

Now, my daughter is having fun playing LFS.



Now I have a TO-DO list of things to improve:

- Push the motors further inside the frame so that the arms align to the top frame, this will allow me to reduce the width of the rig (allowing me to move the rig from the cold garage to a warmer office ) and reduce the wobble every time there is a big movement
- Install the 3rd motor to get the traction loss effect
- Fine-tune the settings to improve the all-around feeling
- And if I'm still driving this in 6 months, get better pedals


I would to thank this community in xsimulator for sharing so much information, simtools for making this possible, and all the people that contributed to the SMC3 code. Also, a big thank you to @noorbeast, @Frantik, d-max on youtube and @flipflop for all their advice and knowledge sharing.

Awesome work. well done. It's such a good feeling when it suddenly comes to life.
I think I said, "Its Alive!" when my rig jumped to life for the first time

You do know, the best is yet to come. get that traction loss motor working and you wont stop smiling. Enjoy!
Automobalista 2 and Assetto Corsa. fantastic fun.

I have to thank you for your model and your advice to make the frame, since I had your "template", it was much easier for me to avoid guessing the measurements , when I have a final build and will model this into a 3D sketch with full measurements, with the proper credits to you, of course. If you don't mind, of course

I still have to reduce the width of of the frame in the motor area, I didn't understood why you did it, until I setup the motors and a saw a 8 mm rod bending like rubber .

Cannot wait for the traction loss, I think my motor controller backups are broken, at least they would only make my motors go up, never down (3 of them, a bit strange), still have to test that again.

When mine started moving, I was less polite, and less inspiring .

Well cannot thank you enough for your work and patience with a new fellow rig builder, hope to see you in a race in a near future.

Just added the 3rd DOF, traction lost and it's fantastic.



Just run several laps in Imola and in SPA and it's great and it was simpler than I thought, my front wheel was replaced by two metal Ls screwed to a sheet of plywood and the motor was placed on the middle of the bottom frame.

Another sheet of plywood was used and block of wood was used as an anchor, ideally, the sheet of plywood should be the same as the one used on the front,but I had these two pieces from an IKEA project and it worked .

@flipflop one again I used one of your ideas (I was going to use a lazy Susan), you are the main source of the ideas in this project, kudos to you. BTW: the power supplies are working great, at least, until now, I had zero problems.

Regarding the simtools V3, it was my fault, I didn't notice that the configuration of the axis is different from the V2, what was on the rows, now goes into the columns

Thank you all (it's 2:45 am and I'm going to bed with a smile on my face)

Fantastic work. Well done. It's such good fun when it all comes together.
It's surprising how much of a difference traction loss makes.
Unfortunately, I've been banned from driving for around 6weeks due to having to have a total hip replacement earlier this week. Very much in recovering right now.
Looking forward to getting back on the road ASAP.

I hope you have a fast recovery and get back racing soon.

Thanks again for all your ideas and advices