Showroom 3 DOF racing sim

I appreciate your reply and would like to say I haven't been random choosing values and saying "this is what will work". I have read those those posts in the links you provided many times and have a good understanding of PID loops (even before starting this project). I got to those values after trail and error over that past 6 months or so and have admittedly changed things on the fly so as to see how a specific parameter may affect how things perform. If you see something that is totally out of whack, I definitely appreciate you or anyone questioning why that was chosen or even making recommendations.

As for the Fpwm, it was my understanding that the lower the frequency, the higher the effective torque delivery and subsequently the cooler the drivers are by reducing switching transitions. I hadn't seen in those initial guides that 25 kHz was the recommended "set it and forget" figure.

In any case, I took your advice and started from scratch again. Below is the bare bones start having added just enough PWMmax to get the motor to move:

As you can see I am back to the question I've asked before; why isn't the the target received (dark blue) not reaching the target sent (light blue)? Since I am at square one basically, is this something to do with the SMC3 code in the arduino? The reason I am hung up on this, is because I don't get much movement at all from motors 1 and 2 whereas motor 3 (the one that the received value reaches the sent) moves a noticeable amount.

If you are using 3 motors on one arduino, the 3rd pwm has less resolution so it may be making bigger steps compared to tbe other two

We're all good. Like I said before, I appreciate you trying to help and understand the difficulty of doing so remotely and not in real time. Every setup is different whether it be the geometry or equipment or configuration.

They are hall effect sensors and they are being driven at a ratio of 1:2.5. I feel like this is something to do with the code though because the moment I click and command for movement, the sent and received signals don't match/diverge like seen in the screenshot. I have ordered another arduino though and will load SMC3 on it and swap out to see if maybe it's something to do with the .ino file or the arduino itself.

I have tried lowering and raising the pwm of motors 1 & 2 but that doesn't affect any change in this issue.

Well I figured out what was causing the problem and I admit it was totally my fault. When I started this a few years ago and was bench testing the motor driver and the motor, I enabled the "pot_scaling" in the SMC3 code:

I don't remember why I enabled that but I do vaguely remember back then doing so. Commenting that back out gives me the full received target that is sent (matching light and dark blue lines) for both motors 1 and 2 now. It is laid out what it does here AND in full caps says don't do it unless a POT is attached:

Since nothing was terminated to A5, my guess is it must default to 50% which is what I was experiencing. Turns out this setting doesn't get applied to motor 3. I am so embarrassed and feel quite stupid. I am sorry for asking for help on what turned out to be a problem I caused.

Glad you found the issue NickD, been watching your thread.

I'm in the process of building my first 2DoF and still learning what is feasible.

Wish I would have seen your thread before starting my build as I like your IBT-2 set up. I did not know this configuration was possible. When reading the Arduino can run three motors, makes sense. Didn't realize you can run six IBT-2's for the three motors.

One question I have, could the IBT-2's at any time handle full 24DVC motor builds without flyback protection and not get burned out? When running 12 volt motors, does the flyback not burn the IBT-2's due to the extra voltage overhead?

I didn't plan on 4 IBT's for my build so would have to create another control box to house the additional IBT-2's. May have to do that if issues arise on mine.

The one thing for your set up I would suggest are Zener diodes for the power lines to your motors to prevent flyback. Really cool layout to take the stress off a single IBT-2.

Really like your build and glad you stuck with the project. You're in the home stretch now!

Just got mine up and running and tuned with SCM2, I'm the wheelchair build in this section.

How funny it is you ask and mention the flyback because tonight I got to actually run WRC 10, (my favorite rally game) and play around with some settings, and I am getting some shutdowns after a few minutes of gameplay. I believe you are 100% right I need that protection as it seems to be cutting out my power supplies.

As for the IBT-2's, I know they can handle 24 V but apparently if you are running at 24V, the IBT-2s are much more sensitive to "spikes" during heavy transitions. If your PSUs have a voltage adjustment screw, you can back them down slightly to 21V or 22V. This was mentioned by noorbeast in earlier posts.

I have been able to start playing around in Simtools and doing so in WRC 10 (YAY ) but ran into shutdown problems after only a few minutes of gameplay (BOO ). Below is my current axis assignment:

Here is the filtering I added to the sway:

And these are my current Min/Max tuning:

I have been changing this little by little to tune it in but it is hard when I can't run the motion rig for more than a couple of minutes before shutdown. I will add a flyback diode or capacitors across the motor terminals as Garrett suggested and hope this keeps the shutdowns from happening. I also tuned a bit more in SMC3 and reduced my pwmmax in hopes that there wasn't clipping happening in the background.

Ultimately, I think my rig is too heavy for my motors and I could probably get away with swapping out my gearboxes with 60:1 instead of my current 50:1. Don't really want to spend that but I found some that total to $100 (but doubles on checkout due to tariff fees): https://www.alibaba.com/product-detail/Flange-Ratio-5-7-5-10_1601038313125.html?spm=a2706.products_search.normal_offer.8.53c367afpy1H3r&selectedCarrierCode=SEMI_MANAGED_ECONOMIC@@ECONOMY&priceId=0acaa57a6b4d442da7f29e0907ffb370. I also could do with a MUCH lighter seat too, but again don't want to spend the money when I already bought one...