Question DOF Output not working with more than one axis assigned

I've almost finished building my rig and sure enough I bump into a very strange problem.

I opened simtools a couple of days ago after finally finishing my 2Dof rig. Everything was working as expected using the SMC3 code and instuctions - using Dof output, the motors would work together with pitch and roll just as anticipated:

SMC3 code and instuctions: https://www.xsimulator.net/communit...3dof-motor-driver-and-windows-utilities.4957/

A mechanical problem meant that I didn't get to do any more that night. I've now come back to simtools to find that it wasn't working as before: Dof Output works when I have one axis (screenshot 1). But when a second axis is selected (screenshot 2), the motors do nothing aside from set to the center position at the start.

I should say at this point that SMC3 utility is working as expected and so does axis testing.

Things got really weird when I finally got it moving (screenshot 4): I know these setting arn't going to work properly. However I show them just because it was the only config which moved the rig. It's so hard to describe what this config actually did but I will try anyway: Moving the Roll to the left made one motor move, then moving pitch in the same direction made the other motor move. Pitch only moved when Roll was off-center.

Basically both motors will not operate at the same time (like they did a few days ago)

Does anyone have a clue what is going on?

Thank you for the quick reply Noorbeast

I have already tried that combination. It gives no movement. It's like the Uno isn't able to communicate with both motor drivers at the same time.

SMC3 is closed - is there any way to test two motors at the same time with SMC3?

Is it perhaps that the Arduino doesn't have enough 5v power to be able to send all the output signals to 4 MM's at once? It was definetely working with both motors the other day, and no wiring has been changed, though the right sensor has been remounted - they are 180 hall pots.

It works fine in game but only if one axis (motor ) is assigned a dof. Assigning 2 axis (both motors) it just stays centered - the motors kind of 'jiggle' in the deadzone due to the worm drive, but they don't actually attempt to move position. SMC3 seems fine, I don't really see how anythings wrong - moving each motor manually works as expected. It also does the 'motion' sample just fine.

In output testing, dragging a second axis bar does nothing unitl the first has stopped it's movement. So the problem seems to be bandwidth/comport related. The arduino seems to be queuing the command for the oppsosite motor, instead of running it simultaneously.

I've tried older versions of SMC3 (and code).
Tried usb2 usb3
Uninstall/reinstall comm port.
Set languages to English US
disabled anti virus/ firewall

Is there any more information I can give you to help?

May i need a fanout buffer?

(((EDIT: this was not the problem. My wheelchair motors weren't grounded likes most wiper motors. )))

Ok I've found the problem. It's the ground isolation problem. Turns out the motor body is connected to 'ground' current. This then short circuits to the other motor across the frame. So the jiggling of the motors was, I think, the short circuit protection of the MMs rapidly turning on/off.

If I disconnect the pushrods, the path is broken and the motors work fine, together, as expected... YAY!!

Now I just need to take the motors apart, and make sure all the internals are isolated from their case. From what I've found on the forums, one of the brushes will be connected to the case, and I need to cut that connection, and attach my 'ground' going to the MM's, directly to the brush. A continuity test is a good idea afterwards.

Ok,

That isn't the problem, it just happend to start working at that point. I tested the motors and had a good look at the insides. The body of the motors aren't connected to ground - that theory is out the window. The rig was working with the pushrods attached too, briefly...

It was working fine for about 10-15 mins in output testing, then I set up Rfactor2. I installed the plug-in, patched the game, set up limits, and... it stopped working - output testing has stopped working too. Back to stage one - I can only use one motor again. I have taken off the pushrods (which seemed to be the fix last time) and nope. The wiring hasn't been touched throughout this whole thing. I really don't know what to do now. I'm going to take a look in my PC bios - maybe there's something weird on the USB

I can click on axis testing and control a motor by itself - this always works. The motors work very well, and reliably, aside from when they're being driven from DOF testing, or in game motion. I can run each one perfectly in SMC3utility at full power and load. I've been through my fair share of bad MM's but it really does look like these 4 are in good shape.

When I install a plugin, where does it actually install?

I've replaced the arduino - makes no difference.

At the moment, it looks the most likely thing is some kind of usb problem with my computer. I have a laptop I can use - I really, really hope it works because I'm running out of options.

Sorted!!!

The motor drivers were hooked up to a 3.3v pin on the power supply. I checked the datasheet for the motoshield and I interpreted that it would work on 3.3v - and it did, however when 4 MM's are connected to the same 3.3v pin, the voltage must drop a bit and fall under the threshold.

I plugged them directly into the arduino 5v instead and now I am happy it has solved the problem.

Long story short - don't try to power MM's with 3.3v.