How to expand a 3DOF to a 4DOF using x 2 Arduino Uno R3's and 4 IBT-2 H bridges using SMC3? RESOLVED

@Rico Mortis Thanks for all that info Rico. Appreciate you taking the time to report back with your success. I'm still hoping to be able to use two motors per Arduino, as I believe that helps with data speeds. Better to have two motors per Arduino instead of 3 motors on one and 1 motor on the other. I think this can be achieved with a similar approach you took to setting up the alternative axis vs interface assignments.

@noorbeast Thanks for that info mate. Bloody confusing, but I appreciate you chiming in. It was a big day today working on the 4DOF. I'm toast tonight. The last couple of days of wiring everything up and getting everything tested in SMC3, highlighted some issues with rig alignments and balance that I've had to attack today with angle grinder and welder.

Really wanting to get this sweet and clean, but it is a hell of a lot of work. I did want to ask you about Rico's issues he had with only being able to get his 4DOF setup like his old 3DOF (three motors on one Ard) and the 4th motor to the second Ard. This to me just doesn't make sense as far as how it seems this should work in Sim Tools. You must be able to simply run two motors to each Ard. This must come down to how you write the [A<Axis1a>][B<Axis1b>] etc, in the interface settings output assignment column?

I've read somewhere on this bottomless pit of a forum, it's much better running two controllers/motors per arduino instead of three for better data transfer. My knowledge is very limited with the technical side of electronics and how this stuff actually works. Hoping to get it working like you originally advised to set it up. Should be back in testing mode by the end of tomorrow so I'll let you know if I had a win.

@noorbeast @Rico Mortis So guys', after much stuffing around today and trying the different interface axis settings recommended by you guys, I couldn't get any of them to work with my two Arduinos and 4 motors in sim tools. All worked in SMC3 as needed. I appreciate this is one of those things where there are so many possible scenarios with so many different sim platforms, versions of sim tools etc. It's one of those "one shoe doesn't fit all" situations.

So I am passing on info that may help others heading down this road, I got my 4DOF platform working with x 2 Arduino Uno R3's, x 4 IBT-2 H bridges, x 4 big worm drive 12vlt DC 180 watt motors powered by x 4 50amp PSU's. 2DOF forces on my rig include:- pitch, roll, sway, heave (with spring assist) ,and surge on the two front vertical motors. The 3rd DOF is a horizontal axis, the surge axis on the 3rd motor. A trolley rail system that carries the entire top frame fore and aft. the 4th DOF is the traction loss axis, also a horizontal axis on the 4th motor arcing the rig left to right at the rear of the platform, simulating yaw if in a flight sim, or traction loss in a vehicle.

The following interface settings were required to get the platform working in Sim Tools. (also see attached photo's of Sim Tools interface window) For Arduino 1 (the two front vertical motors) the interface input needed to be:- [A<Axis1a>][B<Axis2a>] For Arduino 2 (the two rear horizontal motors) the interface input needed to be:- [A<Axis1b>][B<Axis2b>]. This is using Sim Tools build 2.6. I got on this thing today after a big week tweaking balancing issues, alignment issues, wiring issues and today, sim tools interface issues, but it was all worth every bloody swear word produced.

Thanks for the input (ha ha get it) guys. The main thing is it's off and running. I'll post a video here of it's maiden run today in Assetto Corsa in a couple of hours. Got a lot of refining to do in sim tools now and will need to run a new tuning centre session with the new axis. You know, the usual bullshit with these type of things.

Beta testing today in game. A lot of refining to do, but the motion is incredible. A bit scary to be honest. It'll take me a while to adapt to the monitor on the rig now. Was using a static monitor on the 3DOF. I really like it.

Hi Kevinski.. appreciate your time, patience and considerable effort you have put into assisting people getting their 4DOF projects underway. I'm just setting out on this part of the journey with your awesome design of the 4DOF rig. I have completed all the "steel work" and have learned a few new tricks and skills along the way, including swearing in various languages. My "electronics" set up is with x 2 Arduino Uno R3's, 2 x Sabretooth 2x32 motor controllers, x 2 big worm drive 12vlt DC 180 watt motors and 2 smaller worm drives 12vdc 100w powered by a 750CCA 105Ah deep cycle battery and a Rossi BT-280 36Amp truck battery charger that hums at 50Hz like an old school Iron Core transformer should. Being particularly challenged by the lack of computer skills, I find this Software part confusing and concerning. Treading carefully forward I have purchased SimTools and Plugins but have come to a full stop for now.. (procrastinating). Is there a video instruction that is using the Arduino + Sabretooth + SMC3 Setups for the 4 motors? Once I get over this part then I will also be adding to the system a HF8 Haptic seat that I'm currently trying to fit under the seat cover, a Pimax 8KX VR Headset with WitMotion WT901C as its a multi-sensor device detecting acceleration, angular velocity, angle etc to make sure my VR is compensating for the Sim's movements.. maybe I have taken on more than I can chew ..

Thanks Noorbeast ... I will keep searching