Showroom 2DOF Build

Hello,

I'm in sim-racing since the mid 90s and even as I have a static rig so far I'm following the motion topic for a while now. While at the moment (at least in the sim racing area) most people tend to actuator based motion systems (like SFX-100) there are other people with different requirements. In my case: budget, space, noise.

Some years ago I was able to test the motion seat from SimuKit at the SimRacing Expo and instantly felt in love with it. Since that I wanted to build my own system but well... life kicks in from time to time. However I'm now back at the topic and I'm planning to release the project under the Creative-Commons-License incl. BOM, source files, build instructions etc. as there are so much different builds out there that it was really hard to find a starting point.

As this is my first build I would really appreciate your input and thoughts on it to improve the build. The main goal for me is a clean design, easy to get components and of course: the pricing point. Roughly said I'm at around 400EUR with this build at the moment. The price of one SFX-100 actuator which is not bad I guess.

Base components:

• 4040 and 4080 aluminium extrusions
• 5mm thick connection plates for the universal joint and the bass shaker mounts
• 24V 250W 75RPM wheelchair motors which have a rated torque of 36Nm
• Electronics: TBD

I've entered the base data in SimCalc but I'm a little bit lost on the results, would also be nice if someone can have a look at it.

As pictures are more worth than thousand words here is a rough overview of my plans so far. As said I would appreciate some input if this is a good base or if you would change something:

Nice design. It is almost the same as I did. Maybe you will find something useful in my post.
https://www.xsimulator.net/community/threads/simlab-gt2-to-2dof-conversion.13948/

Nice compact design
Actuator noise is also a concern for my next build , my 2dof build with wheelchair motors is silent, so good choise on that topic.
Budget will be a challenge , arduino and ibt-2 driver is the way to go to keep cost down ,imo
goodluck with the build.

Thanks for the link. TBH: Your build inspired me to finally start with mine. You've done amazing work, thanks for the help it gave me.

I ordered some parts already and while I'm waiting I've started with the design of some 3D printed parts. I will go with the IBT-2 first till I made a final decision on the motor drivers. Any recommendations beside a sabertooth board (which is clearly out of budget at the moment)?

Best,

Ben

I have one 100A in my project box but have not tested it yet. Back in the day it was cheaper. IBT-2 are cheap but are hit or. miss. Good to start and later upgrade.
https://www.xsimulator.net/community/threads/reasonably-priced-100a-motor-controllers.17638/

Hello,
I just want to give an update on this project. It took a while till the ordered parts got delivered but most is there now. Still waiting for the motors but they should be delivered in the next two days. However, I've already started with the build and created some parts with my 3D printer:



Most important part as I don't want to create an electric chair. :-D



I've added some 3D printed housings to the backsides. On the left I have put in the power connector, on the right side I plan to put in the USB connector and some Cinch connectors for the bass shakers.



As I'm currently using the IBT_2 I've created some mounts with fans:



...and finally have soldered a simple board with a mounted Arduino Nano and a step down converter to convert the 24V to 12V for the fans.

I'm currently strugeling a little bit with the electrics as I've read a lot of people using Fuses (at the moment I only have a 10A fuse on the 230V connector) and diodes to protect the motors (I guess a flyback diode is meant but I wonder if the IBT_2 has not included a diode?).

That's the current state. Comments welcome.

Best,

Ben

I have fused the motors with ordinary fuses like (and they have already protected my motors ):
https://www.aliexpress.com/item/32873374711.html
https://www.aliexpress.com/item/1005005478264389.html


Also you will need to lower the voltage for IBT drivers on power supplies, if they have the pot. If you will use 24v the flyback voltage will kill them.
Besides you will need a diode to avoid power supply tripping. I am using one power supply and has newer tripped. I have used https://www.aliexpress.com/item/1005003153563182.html and mount it against metal so that it gets cooled.

For fan controller you can use also something more advance like https://www.aliexpress.com/item/4000413575282.html

I also used KBPC5010 diodes, stucking dissipators on them. They do help reducing/eliminating power supply tripping

Oh, I didn't recognized this. First of all is there a way to place some kind of a flyback diode on the motor outputs? If not, what is the best voltage to use them? I've read something about 18,5V? I guess I need to exchange my power supplies then.

I've understood it in a way that this is only needed when running both motors on one power supply? I use two, so is this still needed?

Thanks for the help,

Ben

Diodes rectifiers allow current to only flow in one direction, so, not going back to the power supply. That energy has to be handled by the diode, if it’s higher than it can handles it gets hot then eventually burn. That's why I use dissipators on diodes, they help dissipate heat

Well to be honest diodes are cheap and I am sure you have some heatsink lying around. You can use one bridge rectifying diode to protect both power supplies from tripping. Follow my pictures from my post.

You can not use diodes on the motor. Also adding fuses to the motors are cheap, easy and worth it.

Regarding power supplies I always use Meanwell one they have pots and are reliable. I do not trust no name china one.
I think I have 20 volts or something but IBT drivers are so so. If you are heavy then you will be looking for an alternative sooner or later.
The alternative to IBT I have listed to you already few posts above where they say that are good.

Hey,

short status update. I've added KBPC5010 rectifier diodes and some car fuses. Thanks @iLLuac4, you convinced me to do it. I also will put the 100A motor driver on my list as it seems like I will not have much fun with the IBT-2s.



Beside of that I've finished the connectors on the right side which include the USB connector and Cinch connectors for the bass shakers:



Additionally I've exchanged the power supplies to some which I can regulate voltage wise. Also the motors arrived today. Will be an interesting weekend!

Best,

Ben