Anyone out there running the Sabertooth/Kangaroo combo?

I originally built my 2DOF system using JRKs as I liked the all-in-one design aspect of them over something like an Arduino/Motor driver combo, but was later tempted by the idea of the autotuning feature of the Kangaroo x2 used in conjunction with the Sabertooth drivers as PID tuning is such an important part of good motion and motor life. I pulled the trigger on buying one set to play with as I was looking at building a linear actuator style 6 DOF system. I did some bare component testing and managed to finally get things working after moving to a newer software release (the Describe software from Dimension engineering, earlier version didn't seem to like the Kangaroos that much). I then swapped out the JRKs on my 2 DOF system just to see how the new controllers would work and after a lot of fiddling I finally got the autotune feature to work and did some test drives and was pleasantly surprised. One of my motors used to thermally shut down after driving for a while and they were both quite hot to the touch. With the new controllers and PID settings there were just warm at most, so I was pretty happy with my choice.

Fast forward several months and I finally started building my 6 DOF. I have actuators mostly built with "production" metal parts instead of my early plastic prototypes now and wanted to see how they responded, so I hooked up my Sabertooth/Kangaroo combo and tried to get it to run the autotune feature, but I'm having nothing but problems. When trying to run the autotune function from the Describe software, I'm getting either a "no feedback" error or a "limit switch tripped while tuning" error. Based on their knowledgebase articles, they suggest shielded cables for the limit switches and potentially extra pull-up resistors on the encoder. I ordered some shielded cable, but what I'm struggling to figure out is why it worked fine before and is only a problem now. My limit switch wires are a fair deal longer now that I'm trying to test on a fully built part compared to my earlier tests, but I'm not seeing anything in the software that would indicate the problems it is having. Has anyone else used this combo and can offer some advice? It seems like a really nice system once it's all up and running, but it's pretty dang finicky getting it there.

Did some more playing with it over the weekend and past couple of days and think I figured out some of the problems. One of them was likely the serial rate settings between the Sabertooth and the Kangaroo. The Sabertooth was expecting 19200 baud (or something like that), and I think the Kangaroo was set to 9600 still, so part of the "no feedback" error was the motor wasn't moving to begin with, so it had no feedback to detect. I rewired things with shielded cable as well and it ran a full autotune fine, so we'll just see how it goes. I've got all 6 actuators built up with wires now, so just waiting on some tubes to get back from the chrome shop before I can actually assemble something that looks like a rig.

I have been considering a transition to Kangaroo/Sabertooth recently due to not making much progress on my drift axis with SMC. So I don't have experience but want to see how your stuff works out. Hopefully, someone who has been successful will add to this thread. I think I am in a similar place and want more info on what works for you.

I have been running a two axis gear motor system for a couple of years. It's refined to a point where it works well doesn't overheat and rarely cuts out. I decided to add a traction control axis with a lead screw and oversized motor to get experience before taking on a 4 axis or 6 axis system. What I have found is that the SMC is not up to the task for a few reasons. The end result is that I can move the axis but it keeps crapping out on quick direction changes. I am using a Hall effect transducer as a multi turn encoder but this is really difficult with the analog only input of the SMC. It works but tends to drift. I think I can get it working but I don't think I want to deal with it on a more complex system. Quadrature encoders are a must but that will not happen on a Uno.

So I may invest in a a set of these to see if I can get something to at least work.

I got my 6DOF all wired up for initial testing last night and so far things are looking fairly promising. The main issue I have at the moment is that the CH340 based serial to USB converters I bought for them don't seem to want to work anymore for some reason, so I have some FTDI based ones on the way that will hopefully show up today. I have a spare FTDI based dongle I've been using in the meantime to program each controller one at a time, but I can't run them all at once yet. That being said, 4 out of my 6 actuators ran the autotune with no issues. One of them is throwing a limit switch error that I'm still trying to figure out. I'm not sure if I just have a flaky switch, faulty wiring, or I did notice that one of plates I built my actuator with was actually running into the frame and bending a corner, so it might have been overloading something. The other actuator gave me a "soft limit" error, which is a current limit thing. It feels odd since all the others worked okay, so I'm going to have to check that Sabertooth and see what the limit is actually set at. Unless the rig is really in a bind I can't imagine it would have pulled full current to shut it down, and since the other ones ran the autotune okay it seems unlikely it would be bound up.

Fiddled with it some more the other night and the one actuator that threw the soft limit error retuned fine. I did notice when trying to plug in my motors that the material they use for their terminals is about as thin as paper and easily bends/cracks. Wondering if maybe I just had a bad connection that caused the soft limit error. I re-terminated all of the motors with new terminals just to be on the safe side.

Also fought with the one actuator giving me limit switch errors some more last night. I tried swapping limit switches first to no avail, then just replaced all the wiring between them and the Kangaroos as well and still saw errors. I was running out of ideas so I just tried moving the cable further from my power supplier and that seemed to finally be the trick. I'm not sure how only that actuator was consistently erroring out as all the others have their cables similarly close to their respective power supplies, but maybe that supply is just extra noisy. Still a little strange since I'm using shielded cabling as well, but if it works, it works. Next step will be checking the output of FlyPT Mover to make sure it's talking nice to the Kangaroos and then I think I'm in business.