Showroom Smitty's Rotary Servo 6DOF build (Complete!)

Hi, yep I think I have it all worked out. Won’t really know for sure until it’s built. Basically the one thing I had wrong was the angle setting on the thanos should be 180, I had put in what my rig was going to use. But flypt will handle the endpoints.

another buddy build! Are you making two of them?

Thanks for the reply. Good to hear because the Thanos is what I am going to be using.

Eventually we will make another but we are gonna do 1 as a prototype first. He is doing the building(welding cutting, grinding, etc..). I will be doing the programming/computer work.

Look forward to the completion of your build.. It is looking amazing. Wish you guys had more time to dedicate. I do hate waiting for updates to awesome things.

A few more pics. We finished building the other 2 servo cabinets. I found that a couple sets of spark plug wire markers work great for tagging all the cables! Much nicer than labelmaker stickers.

also started to draw in some fans for wind simulation. Using 24v seaflo 4” fans. (24v because that’s what the ffb joystick is using) Now that the frames are almost done welding, the mount tab for these will probably be the last extra thing before paint.

I like that rack, plenty of space for proper cable management!!!

A little more progress.. I took home one of the bases to finally start mounting some servos.


Meanwhile at the shop we did the first “motion test”!!

Started cutting the main crank arms. Also got the wind fans programmed and running. Details on that are at: https://www.xsimulator.net/communit...-wind-arduino-sketch.14425/page-3#post-237340

Huge update!!!
got the arms machined, broached, tapped and slotted. This was the piece needed to finally assemble!

I wasted no time getting the upper frame mounted. Some final adjustments in flypt and it was going thru motions.

Still have lots of wiring to do, so most things are just zip tied in for now. Joystick mounting parts are the last thing needing machining so the only game I can test now is NoLimits rollercoaster. After getting motion compensation centered, we took it for its first ride!! So amazing!!

Fun to watch the details unfolding. Looking forward to a video

Cleaned up the area to take a nice picture!
I’ve been able to try some driving games like AC, and dirt rally 2, both work great. Need to make some joystick parts yet.

Took some videos today! Here's the first one

I figured i should make a post here about some of the tuning issues i had and how they got resolved. I got some help in the other threads and discord.

This is how it was:


It's just a slow 5sec +/-100mm heave loop.

I got the complete AASD manual from http://cnctechproductions.com/files/AASD-china.pdf - Its quite a bit longer than other versions floating around on the interwebs.

First, i put the e-stop to Kill Power and ran Fn018 on some of the motors one at a time. This makes them wiggle a bit and reports back the inertia it finds. This number is then entered into Pn257. Default was 1.00, i have it at 3.00 now.

Then since there are no PIDs on these drives, i found the 'stiffness profile' in PN259- it is a bunch of presets that change a few settings together based on how mechanically rigid everything is. Default was profile #4, i put it down to #3. Also make sure Pn258 is set to 1 so that it uses the profiles.

After testing that, it looked pretty good but still had a wiggle. Pn110 adjusts the smoothing filter time in ms. I used the app phyphox which records accelerations (and can output flypt player files!) and put it on the seat. Here's the results from changing that:


Finally i did the same with Pn113 feedforward. I didnt see as much change as Pn110 but settled on 40.

And here's the final result:

Rig #2 coming to life!

200mm, they are big bars of 2024 aluminum. i also put tap holes in at 180mm and 160mm in case i had made some grave calculation error and it wasnt strong enough to lift us. thankfully it is!

Beautiful rig mate !!!! What is the cost of the 6 servomotor + reductor ? Have you calculate the failover threshold of your rig ? (are the feet far enough apart?) What is the diameter of the circle that contains the six feet on the floor ?

the cg of the cockpit with me in it at full heave is 1200mm from the floor, so i made the base feet on a 1200mm circle. the front foot is a little further out because pitch moves more than anything else. It cant move much at 1200mm though, at normal midpoint ride height the cg is 1000mm. even with some violent motions it hasnt moved yet. The base weighs about the same as cockpit+rider, it's 1/4" plate and 3/16" wall square tubing (steel). i havent felt the need to lag it to the floor but i think one of my buddies plans to.

servos & gearboxes came from aliexpress, looks like they are both a lot cheaper than when i bought them 1.5 years ago
servos https://www.aliexpress.us/item/2251832657924811.html
gearbox https://www.aliexpress.us/item/2251832781256249.html

so.. it appears I’m going to need to lag this thing to the floor:


Not sure if it’s been creeping up or happened in one move, since I use it with vr goggles on. But it’s definitely 6” forward from where it was!

The force feedback is phenomenal! I discuss finding it in post 21 but having used it now for a few months, no joystick or pedal with a spring can come close. It's so nice to feel the stick go from floppy on the ground to stiff at cruise. And turning elevator trim relieves the pressure by moving the center point just like a real plane. You can adjust friction, dampening, inertia, and force to make every aircraft feel different.

The only thing it could be compared to is the hardware from Brunner, which is twice as expensive and uses a closed-source control program. They also don't offer a stick, just a yoke and pedals. VPForce units use windows-standard DirectInput for FFB communication just like the old Microsoft Sidewinders.

There still is no website, but https://vpforcecontrols.com takes you to the discord where you can get on the waitlist to order a complete turnkey joystick. It's currently a 1-man operation so the wait is pretty long (over 6 months!) You can then just pop on any of the fancy grips from Thrustmaster, WinWing or Virpil.

But, if you just order the DIY kits, which are 2 motors and the bare usb board, they will ship in just a few days! For us DIY types, there are many designs being passed around on the discord, most are pulley-belt designs but I really like the gearboxes i used on them. They are the same type, just smaller, of the ones i used on the 6 main axes so there's no backlash and as a bonus they match! He also has larger motors available, so if your application requires more grunt like pedals you can get that too. Currently, DIY is the only way to do pedals.

The forces are incredible though. The config software lets you set up maximum effect forces, counterbalancing, and compensating forces so that no matter what you have on top, it can be adjusted to move effortlessly and stay where you put it. The work he did on eliminating the stepper motor "steps" is amazing.



Using it with MSFS currently requires another program, XPForce, for the telemetry where you can set up profiles for all the different planes and helis. For quick adjustments I made a little box to use the 2 pot inputs on the usb board (you can change the function they do)