DIY 2DOF Motion Simulator – Inspired by Mantis FS2

I’ve been dismantling the setup bit by bit to rule things out. Checked wiring, tested with Describe, measured outputs… everything points to the logic being fine but still no voltage at the motor terminals.

I’ve already opened a ticket with RobotShop and I’m waiting for their guidance before rebuilding everything again — don’t want to put it all back together only to find out the driver is faulty.

In the meantime, if anyone has ideas for extra tests or has run into the same issue, I’d really appreciate it. Also, does anyone know if there’s a way to manually drive the motors directly from Describe, just to confirm output

Possibly under the 'custom test' panel?

I think that’s the right place, but I don’t really understand that feature. I’m going to wait for the response from Robotshop/Dimension Engineering to see the next steps—maybe they’ll send me clear instructions for testing.

In the meantime, I’ll keep building the setup. Yesterday I finished the U-joint supports, and now I just need to cut off the excess.

Also, I have two IBT-2 drivers that I bought at the beginning of the project, so I’ll consider moving forward with them if the Sabertooth issue isn’t resolved.

This is whats the Dimension's team responses:

Hello,
What is your DIP setting? And which serial protocol are you using from Arduino?
If you are using a PSU (and not a battery) for the 24V, did you activate the Sabertooth power inputs by installing power resistors, as instructed in the documentation?
Thank you

I answered already, but I'm not sure what they mean with activate the sabertooth power inputs... I use the 100w 6ohm resistors for brackes, but I assume that they are talking about another thing... I'll post the new response when they do it

100w 6r resistors are fine but you need 2 in parallel for each power output. In describe you need to ensure voltage clamp is turned on for the feature to work. I leave settings as auto.

The first time I tested the motors with the Sabertooth and Arduino I didn’t use resistors and it worked just fine. I don’t understand why I should connect them now — does the Sabertooth have some kind of safety mechanism?

In another application I didn't use resistors and didn't have any problems but I'm sure it depends on the PSU you are using and if it has protection. While the rig works fine I can often hear a clicking noise coming from the PSU during fast direction changes - probably some kind of back voltage protection. I don't get the clicking noise when I use resistors to dissipate back voltage. Will likely prolong the life of the psu

I'll continue the project with the IBT drivers in the meantime, I'm waiting for robotshop answer and guidance for the sabertooth.

@early_m, could you give me more details about how do you assembly this part? do you use some kind of extensor? how is the upside attached to the structure?

The bottom is just a bolted connection using M10 nuts either side of the rod end. I had spacers manufactured for the top with an M8 bolt straight into a t nut

ok, but both of the rod ends are M10?