DIY 3DOF two-seater

Me and a friend are currently building a motion platform that is meant to resemble the cockpit of a Cessna 172 and carries two seats. This makes everything quite heavy so we needed powerful motors (1kW each) and an additional pneumatic weight counterbalance.

The motors are already moving. Here is a video where we just tested the servos with the jog buttons of the controller. The simulation software and most of the controls are also working. I made my first flight, yesterday, but still without the rig moving. So the next step would be to connect everything together.
For this, I have some questions:

• I browsed the forum a bit looking for software that does the motion cueing and found FlyPT Mover. I think it should do what we need. But I'm struggeling a bit with the documentation. The latest version is from 2021 and says it supports X-Plane 11. We have XP12. Is that also supported?
• Our Servos have step/dir command inputs. I've found the motion4sim controller. Can you recommend it or is there something simpler? The feature list says it could do its own motion cueing algorithms which I think we don't need as this is already done by FlyPT mover.
• I'd like to have some safety features implemented such as soft limits for the drive axes themselves plus some additional limits. For example we could crash into the ceiling or hit the stops of our counterbalance cylinders even though the servo drives/spindles are within limits. Is that possible?

Thanks for your help
Nicolas

The forum seems to dislike the Youtube link. Please go to YT and type "/shorts/RrBwNnA-AY8" to watch it.

Next try: Video
I think the link was supressed because I had less than 3 posts. I got a message displayd that this is a limitation to avoid spam.

Ah, I just found out that there is already a 3DOF rig defined in FlyPT Mover:

This is exactly what I need. Don't know why I haven't discovered it earlier. Thanks @Attyla.pl

"I'd like to have some safety features implemented such as soft limits for the drive axes themselves plus some additional limits. For example we could crash into the ceiling or hit the stops of our counterbalance cylinders even though the servo drives/spindles are within limits. Is that possible?"

FlyPTmover has a very good mechanism for safety/limiting the movements of the actuators, just enter in the RIGS fitr I have highlighted in red and even the highest values that the simulation will generate will be effectively limited to safe limits, of course the values I have shown fit only exactly to my 2DOF rotational configuration, everyone has to set them accordingly to the movement platform they have.
I fly DCS on a daily basis , believe me what happens to the aircraft after being shot down is like riding a willowy bull , the filter effectively reduces this and allows my 2DOF to survive these difficult moments.

Ah thanks, that's good to know. Our counterbalance cylinders only have 300mm stroke while the ball screws have 500. Reason is, we built it from spare parts we had left over. If properly used and the limits properly configured this would allow us to vertically heave 300mm while still being able to roll at the topmost position.

But I have to admit that I'm currently a bit overwhelmed by the vast amount of features inside FlyPT mover. I have to learn and try out everything step by step. For now, I simply limit the position range to 300mm to be on the safe side.

I downloaded XP12 demo version, plugind from XP11 works with XP12 version without any problem

I confirm FlyPTmover can scare you with the number of options , load the Roman Rig MSFS.Mover profile from the pic I attached in the FlyPTmover thread , I rely on it and it is quite pleasant to fly. Previewing someone else's profile makes it easier to understand the design of the program, always remember that in the program everything is configurable .
Do not forget to enter the correct dimensions of the platform in the appropriate tabs

Today we made great progress. We are only an inch away from a fully functional simulator. We got the homing procedure running with the sim4motion controller.The problem was inverted signals for the home switches, the direction of the servos ond the online switch. Now the axes are homing and move to the center position when activating the online switch. We can move all axes with the "Test" tab in the dashboard software.
We were also successful with PlyPTMover. I have loaded an example pose and rig module from one of the example files. With the input disconnected but the pose connected to the rig and the viewer I can move the sliders for heave, pitch and roll and the rig in the viewer moves. With the input connected we also get data from XPlane.
There's only one thing that doesn't work, so far. In the output module I can see the values changing.

I have set the output string according to the manual of the controller. It tells me to use 24 bit values, 3 bytes per axis. So the center position is ~8,000,000 or hex 7FFFFF which is 127.255.255 in decimal bytes.
It took us a long time to figure out which serial port to use. And of course you can't connect the Dashboard application and FlyPT Mover to the same port at the same time. But we finally managed it to connect. At least it displays that it should. The connect button counts up from 0% to 100% and turns red and says "disconnect".
But unfortunatelly, nothing happens. When I move the test sliders or apply input from Xplane I can see the numbers counting up and down (for example 128..129... and so on instead of 127) but the motors don't move a single step. The controller LCD display stays at "wait data" and "R R R".

Any idea what's wrong?

Aaahhhhh! It was to hot for my brain. 3 times 6 is 18 and not 24.
The output string is supposed to be 24 bytes = 8 times 3 bytes. And the controller probably doesn't display any error message or at least a single hint that it's receiving faulty data.

Yeah! Success, at least partially. We managed to connect XPlane, FlyPT Mover and the Motion4Sim controller.
see Video
There are still some small nuisances. Auto-connect doesn't work. We have to connect the XPLane source manually after starting XPlane. This is not easy because the simulator window opens in front of all other windows and we have to use alt-tab to get access to FlyPtMover.
And we have to tune the filters. When the motors have to move at high speed the whole rig shakes violently.

Autoconnect or do you do according to the scheme: ?
1. select the source
2. mark V in the appropriate box (see attachment )
3. save the mover profile

When you reload the profile it should automatically connect to XP12

Upload your mover profile.

Autoconnect works if we start FlyPT Mover after XPLane is already running. But it doesn't if we start the Mover first. The border around the "V connect" turns green immediately and the text changes to "disconnect". But the numbers are all "0" even after starting XPlane.

I suspect that the UDP protocol is actually bi-directional and the Mover has to send something to wake up the communication. That wakeup message is lost if XPlane is not running and it simply doesn't send anything back after being started.

LYDNLP filter values you need to choose for your motion

Some more pictures:

Next thing on the to-do list is installing all the covering and panelling. I hope we can make a video of the whole thing runing.