Peter's Converted 9D Vr Motion Platform

I never understand why sim manufacturers make rigs with unlimited yaw. This makes everything more complicated (sliprings, safety...) and has very little advantage for the actual simulation. I think they either don't know how motion cueing works or the want to make the machine look more attractive for spectators standing outside.

Unlimited roll and pitch angle can be useful for extreme cases like fighter jets or aerobatic flight. But rotating at a constant speed in the yaw axis makes no difference to standing still as long as you're not excentric or spin very fast so you'd feel centrifugal forces.

You nailed it, it looks cool.

Personally I'm glad it can do that and can't wait to get it to work. I've narrowed the problem down to most likely the gear box and once I replace it I'll have something really kickass.

more information is coming, but I have to do a few things before I can to this tear down.

Still working on this project! I've been spending time on the streaming side of it because aliens invaded the earth in Elite Dangerous.

The teardown and refit is coming soon and then I'll have details about the internals to share here.

I just realized i should share at least one highlight with you guys so you can see the rig in action.



Once I finished this event I started the tear down of the simstarr and it's all the way down to it's base.


I've pulled everything that is not needed to make the machine run and will replace the computers with my own for gaming and streaming. (coming soon)

where I'm still stuck is the yaw motor. I can not get it to engage no matter what I do. I'm pretty sure this is an actual broken part at this point but I'm hoping to be 100% sure before I go through the difficult process of replacing it.

I'm hoping that someone here might be able to guide me to how to test this motor, I have no idea where to start with it.

The servro is a Syntron 80cB100C-500000. I'm sharing this model number at pretty much the same time for you guys as for me. I couldn't get to this side of the motor until today.



Now that I have this perhaps I can see some info to diagnose a problem.

Narrowing it down the dangerous way.

This test was actually dangerous. If the motor had turned it would have ripped the cables off very quickly. And once the encoder cable is boroken it's very difficult to fix.

Servo motors usually don't break. The cables or connectors have a much higher probability of failure. I'd remove the motor and encoder cables from the other machine and put it in the one with the problems. If it still doesn't work I'd replace the driver. One of the possibilities is that nothing is actually damaged but the parameters in the driver have been deleted or overwritten.

This video was created to visually illustrate the issue and grab your attention. I already knew it wouldn't spin before I started.

I've gotten this far thanks to the foundation of someone else's work who actually knew what they were doing. I've been teaching myself by observing and reverse-engineering. This creates a sort of Schrödinger's mechanic situation, where I know a lot about some processes and almost nothing about others. Specifically, if something wasn't working when I got the platform, I've learned to diagnose the issue. But if it was functional when I received it, it's still a black box mystery to me.

This learning method works, I’ve already spent hours in the simulator, but my biggest gap is in terminology. I wish I had a book on the subject, but "Robotics 101" isn't the right tool for this job, and I don’t have access to the manual. That’s two paragraphs of context just to ask: What part is the driver? Are you referring to the Thanos AMC? The silver box that provides power? Or a part on top of the motor?

Once I understand what you mean, I'll check it, but I’m fairly confident the system is receiving the correct instructions. There's a digital readout that specifies how many steps each motor should take before returning to zero. The yaw motor simply isn't following these instructions.

It might be that the yaw requires something different, but the platform has four of these devices, all identical. Even though the yaw servo rotates continuously while the others move up and down, it's using the same technology to do it so I’m mostly confident the setup is correct. Still, I’m open to trying any suggestions.

Another reason I suspect a mechanical issue is that the platform spins freely even when the motor is powered on. At a minimum, the yaw should be receiving a "stop" instruction when power is applied, so I shouldn't be able to turn it manually. I think in the video above what we're seeing is the motor doing it's job correctly but the gear box under it not. I would have done the safe thing and pulled the motor to look but it won't come out and I don't have the tools to pull those four bolts right now.

I suspect once I do remove the entire unit a bolt at the bottom is what is keeping it together. either something there will be obviously missing or replacing that gear box will solve my problem.

Another update, not working but I know what's wrong now.

Ah, well done. If the "clutch", coupling, gearbox or whatever mechanical part is broken you can surely fix or replace it wihout having to troubleshot the electronics.

Just for reference... With "driver" I mean the box with the 7-segment displays on it displaying "ready" in the previous video. They can also be called "servo amplifier" or "servo controler". "Amplifier" was used when theese were really analogue amplifiers. Nowadays they are digital with software and all the motor parameters stored inside. If the motor turns only a few degrees it's a typical sign of the "number of poles" or "commutation angle offset" parameter set wrong. That's why I thought this device is to blame.

I have yaw!



I have two of these 9D platforms and stripped down the other one. It turns out that is a slightly better, or should I say refined, version of the arcade machine.

The first thing I tried was just using it's native hardware but it was flashing an error I didn't understand so I did this the three blind mice way and kept swapping out parts from the other platform until I got a mix that worked.

This was a long time coming and I'm so excited!

I'm done for the day and tomorrow I'll finish swapping out the pylons and drivers so I have a single machine that's as good as it can be and a second machine that's ready to be brought online when I have the time to figure out what the errors are.

This is an absolute success and upgrade! I've been recording it all so I should have a few episodes of this old sim for people to follow behind me and get their systems converted. I'll edit those down in the not too distant future.

Oh boy do I have a story for you today!

Remember that error message I didn't understand? I DO NOW!



At some point before I took ownership of these two 9D platforms one was treated badly. My best guess is it was damaged coming off and on the tow truck the person before me used but it's possible this was done in shipping to the states.

It wasn't possible to see this damage when the pylons were attached and the third pylon is just fine. I took the working one off a few days ago at random to make taking the egg chairs off easier and saw exactly what I expected to see.



The order of events makes me super lucky but also kept the truth of the damage from me for months.

I'm lucky because if I had started with this platform I would have given up early on. Because the other platform was working except the yaw I was able to get up to speed enough to figure this one out. Add that to me wanting to use the other pylons for aesthetic reasons and wow, everything's coming up Peter.

I've now moved all four drivers and three pylons from one platform to the other, so I have full functionality mechanically speaking.



I have to clean this one out of all unneeded wires, wipe it down of built up dirt, and I can finally starting adding my own gear back on. I should have the simstarr flying again in about a week.

The Simstarr is out of drydock and into shakedown! I would still like to increase the amount of rotation of the yaw even more but this is still a lot!



I recorded most of the tear down so episodes of "this old sim" should explain a lot of what I've done so far will come out eventually.