My first build. Another budget flightsim 2DOF rig.

The motor link doesn't show in my last post. This is the motor.

Hi there
Yes this stepping ..if that's what we call it is a pain,when going slowly in flight Sims it's awfull..just like it's not smooth almost like it's moving bit by bit and jerky..
When in hard out combat you don't notice it so much,I have 2x dayton audio tranducers and they do mask some of the stepping feeling for sure but not all of it I'm afraid.
It's almost like a resolution thing,I have 180 hall effect pots which should be fine.

Yup I removed the springs last night after getting a very hot motor on one side,in reality your asking a lot if your motors to move me and a loaded spring as well,especially in a sustained bank..
Anyway I have ordered the steering dampers from aliexpress and will try those.
Also i am experimenting with pneumatic rams and reducing valves...
See how that goes.
I'm sure that will only help the backlash issue not the cogging or stepping as we say

Yes, the slower and gentler the movement, the more noticeable the steps become. For ages I was convinced it was some sort of digital resolution thing, and perhaps it still is, but the motors are now my prime suspect. Maybe it's the toothed belt drive I have to the position sensors but I don't think so.
I've attached my FlyPT and SMC3 settings to this and if anyone wants to take a look and see if I've got something wrong then I'd be very grateful. The only slight oddity I've noticed is that any I gain at all, even just a value of 2 or 3 in SMC3 seems to cause the motors to randomly kick and twitch every few seconds so I just leave it at zero, hence the small error visible in the trace due to my weight pushing down on the motors. I have read of this behaviour elsewhere on here.

I still haven't got my force-feedback stick moved onto the rig but I had a first combat session in DCS, not online yet, just against some AIs, and it was absolutely amazing. The ROLLOVER filter in FlyPT is genius for aerobatics and dogfighting and yes, the plane shakes when the guns are fired. Such joy.

So my multi-point plan is:
1. Stop being grumpy about the stepping. It's distracting and annoying but it's not THAT bad and it's barely noticeable in combat or other 'spirited' flying. For what it's cost me so far the rig is actually really good and I'll cure the stepping eventually.
2. Try @noorbeast 's suggestion (thank you) of shortening the arms and see if any improvement in stepping is worth the loss of movement range.
3. Fit some sort of sound/haptic system, which I was going to look at anyway, to see if it masks the stepping.
4. Read up on alternative motors/actuators.

If I increase the P gain then, as you'd expect, the feedback and setpoint curves match more closely, but the motion starts to become uneven. The motor seems to pulsate at about 2Hz. It does this regardless of load. The pulsing shows quite well on the PWM curve. I don't know what's causing this. It's not like the sort of oscillation I'd expect if the P gain was too high and it's persisted through two types of motor driver and two types of position sensor.

I'm going off on a boat for a few weeks so please don't think me rude if appear to ignore any replies.

I have exact the same motors, but run with much higher KP (420) and I run with the IBT's.
What I can confirm is that even with slow movements, there is no stepping, so the issue is definitely not your motors. What voltage are you using, as I am using these engines on 19v. Maybe this is somewhat low on your side? My first build was with 12v motors and IBT's, where the IBT's got really hot, now with bigger motors and 19v... the IBT;s never get warmer than 40c where the motors are max 25C

Thanks for chiming in @Radje748 I'm away from home for the next couple of months so my project is on hold for now, but I'm feeding my motors with around 23.8 volts and I have used IBT2s before I got the Sabertooth. I guess perhaps if you can find decent ones (or just get lucky) then these drivers are great, but the ones I had hardly had time to get hot before they died, or just never worked from new, and the stepping issue was still present. There's also the fact that I tried driving my motors from a simple RC source thus bypassing all the Arduino/software/feedback stuff and they still stepped. Perhaps, in a world full of fake/cloned Arduinos and IBTs the same might apply to motors too. My setup is basically a copy of the one shown by SCK Gaming on Youtube and I notice his motors have a logo (UniteMotor) cast into the gearbox whereas mine are just plain. I can perhaps see some other small differences in the casting so who knows.... They were very cheap.
But glad to hear your motors are working for you and that there could be hope for mine. Hopefully I'll get to the bottom of it when I get home.

It eventually all will work also costed me some time and strange issues.
23.8V is somewhat High for these IBT's, when I tested them on 22-24v, they were getting very warm quickly.
Now I am running 19v, and the temp is always between 25-45C(depending on the outside temp). I also placed a fan above the IBT to cool them extra....

Happy 2024 to everyone.
I last posted here back in the summer before I disappeared off to sea for a few months. Since I've been back I've been quietly tweeking away at my rig which is proving to be surprisingly reliable given the wild thrashings it gets whenever I get shot down in DCS. I now have VR motion compensation working and have spent many hours learning how to set up FlyPT and also learning the tricks that can be used to trick the human brain into thinking there's more going on than just a little rocking in two axes. I still have the stepping issue but it's masked a bit by the addition of an HF8 haptic pad.
And the result is that I'm really liking my little rig. So much so that I just splashed out on a fancy new computer with all the latest and greatest stuff to upgrade my VR experience.
So in 2024 I'm think I'm going to look around for some alternative motors which may or may not cure my stepping issue, but also there is some backlash in the gearboxes of the current motors which I find a bit disturbing. I'm also going to look at adding a yaw axis, so the journey isn't over yet.

Hi, question did you balance the upper frame ?, I after assembling the entire upper frame including the seat , joystick and throttle , rudder I placed on the box and supported a wooden brush stick (can be any hard tube) and sitting on this I found a point where I had almost balance front back ( my wife belayed me ), thanks to this when I sit on the platform the engines do almost no work and all the power can allocate to the movement of the platform. As for the wild harrowing of the platform in DCS try the ENDYLP filter as in the attached file ( I have been testing it since yesterday and it looks promising)

I did initially design the upper frame to be balanced but of course stuff has been added, moved about, and the rig has generally evolved, and the balance has changed a little. It doesn't seem to affect the movement and the motors don't get hot. As the pivot point is well below the centre of gravity the rig is naturally unstable and will only balance at one position anyway.
As for the level of violence in a crash, well I actually like that. It makes me a little nervous of crashing. I get that quiet moment to reflect on my mistake as the ground rushes up and then all hell breaks loose.

Since my last post, I have ditched the HF8 haptic pad as it was uncomfortable to sit on and the vibrations were too simplistic to seem real. I've replaced it with some Dayton transducers playing the sim audio through an equalizer. This works much better for me. Current project is making and fitting a helicopter collective.

Tean, did you find a solution? I've got the same motors and the same problem. They step significantly (feels awful in flight) and I'm pretty sure it's a motor problem. They do this without any load at all. I started another thread on it, looking for a solution. I actually ordered different motors but wasn't paying enough attention and they are too small. Shopping around now.

Hi guys Just my 2 cents,I built my 2 dof 3 years ago using the 12v worm drive motors that many on here use.
I was never happy with the stepping and also the play in the rig from the gear meshing.
It was great for racing but not so good for flight Sims which is my go too.

Anyway In the end I got fed up with it,I sold the motors and power supplies and and purchased 2 srt80 linear actuators and servo drives with a Thanos controller.

I modified the rig a little to put a little rear weight bias to it.

The result if amazing ,like really.
Super smooth,heaps of movement if needed.
It was a bit of work but it's everything I wanted.
And I can always get an extra 2 actuators later and take it even further.

Is that the Lebois Srt80 diy kit? I could see myself going that route. Not sure I want to do that much reconfiguration though.

Jees, it's almost two years since I got into all this. Well the rig is still going. It's been surprisingly robust and reliable, refusing to fall to bits despite many hours of often spirited use. And it's generated a good number of screams from visitors as they get catapulted off an aircraft carrier in the DCS A4.
But to answer your question, alas no, I've not found a fix for the steppiness. I did a fair bit of research about it and found that even commercial rigs like Dof Reality have suffered from it.
Without wishing to ignore that @Radje748 and probably others are using these motors, or at least motors that look the same with good results, I am pretty convinced that torque ripple in the motors is the source of my little steps.
The problem is pretty minor though. I would think that in a driving game with constant ground bumps and roughness you'd never notice it. I mainly fly WW2 planes in DCS and am usually throwing them about with enough gusto that it feels fine. I've also got the bass shakers in the seat and now a Moza force feedback stick which are both kicking out vibrations and shaking that all helps to mask any steps. It's only if I go for a gentle sightseeing flight in MSFS that I really notice it. Actually I usually find the backlash in the gearboxes to be a more noticeable defect.
I do look occasionally at motors and actuators but so far I haven't seen anything cheap enough to tempt me. I'm basically happy with my rig as it is, but there's always the thought of making a 6dof....

Yes it is,great kit ,but was a fair bit of work to move the rig rearward and extend the base but hey the results are amazing,and for racing I just pull out the joystick and insert the wheel and gear change, only takes 30 seconds.

Here's some pics if your interested
All the best.

Hey @Richardamo1 . Nice job. Those actuators look the business but ooh that's big ol' pile of Euros needed.

Thanks, unfortunately I mostly fly ga... straight and level, so it feels like stair steps. I also use a FFB yoke and buttkicker, but it's not enough in my case. I would think having a higher gear ratio motor would significantly smooth it out? The ones we're using are only 5:1.

Hmmmm, I might lose sleep tonight thinking about this. I read a few other project threads with the sfx100 too. It would feel like I'm starting over from scratch pretty much, though. I'd have to redesign the whole base and would have spent a lot of money for nothing. But still worth thinking about.