SCN6 'grindy' motion. Anyway to smooth?

nclabs "Focus to one thing at the time is the best strategy, but only if you start with a neutral ground, otherwise it's a nightmare."

This is exactly what I was doing wrong for the last couple of months. If any newbies find this thread please heed the advise. The 'throw everything at it' approach simply won't work!

Thanks noorbeast.. will do..

DaV

PS. Inserting this... completely unrelated but funny.. and presented as found.. not edited by me

Hi, sorry for the slow response. My phone was dead last nite so I couldn't capture a video. Yes there is some flex in the chassis, mostly in the YAW axis which would normally move fairly slow anyway. The ROLL axis does have some play in it as well and you make a fair point. That being said, if I were racing over a surface where the vehicle was quickly bouncing left/right the small amount of flex actually feels like the suspension on the car. In flight sims, it's normally difficult to get it bouncing as even if you are aggressive on the stick and rolling from left to right quickly because it's a slower movement. The wobble is exacerbated when the rolls axis stops suddenly (as in initializing) or there's short, quick left/right motion.

No matter what I did last nite, I still have bouncing when flying. The pitch axis is perfect but roll is the culprit. I know without a video it's difficult to explain and I will get one up here for you to see. Without me sitting in it, it almost seems like it would shake itself apart. I agree that once the bouncing motion starts, it does want to bounce more and more, making the situation worse.

If I were flying with the left wing banked way down and the sim is completely stable, and I slowly and smoothly roll the wing back to level, there is no reason for the roll axis to bounce. I am however getting bouncing because as it it appears to me, the output to the actuator is only SLIGHTLY inconsistent. So instead of being silky smooth there's almost very slight pauses, or slow downs as the axis travels. This to me is what's causing the problem.

A couple other points to consider as well.. when the axis motion was 'gravelly', it sent vibration through the chassis but the motion itself was smooth, i.e. no bouncing. I also didn't experience bouncing on the roll axis with either FS9 or FSX using the original software that came with the sim.

I did capture settings with the tuning center and played around with some ROLL values. I also played around with axis limiting and the smoothing folder, various combinations between the Game Engine and Manager profile. Nothing seemed to help much and I couldn't even get it back to 'gravelly' again. At least when it was gravelly the motion in-sim matched although as you banked you feel the grinding vibration going through the chassis. When I made the motion smooth, that's when I got the bouncing. The bouncing doesn't match in the in-sim motion which is a bigger concern. You see the wing smoothly dip but what you fell is incremental steps as it bounces and dips, bounces and dips.. etc..

So while I agree that there is some flex in the chassis, the bouncing or rocking is both a symptom and exacerbater of a root cause. I've even lowered the acceleration to zero, played with the speeds etc.. is there some way I can slow it down even more than through the GUI perhaps? I'll try loading in the plugin again to at least get back to 'gravelly' when it wasn't bouncing.

Thanks again yobuddy. I appreciate you taking the time. I'm sure we can get this sorted

Cheers,

DaV

Looking at that video, it actually seems to bounce/oscillate on any change in direction. I would investigate how much the rig is able to flex.

Have you run the actuators without a load? Ie. Disconnected from the frame.

Hey Guys, apologies for the late response.. I came down with something so I feel like #%@&. I was thinking the same thing, disconnecting the chassis from the actuator and maybe even swapping a couple actuators around. I was thinking of that and maybe lowering the COG a bit too. Hopefully tomorrow I'll get to try playing with the actuators and report back.

Happy Bunny Day!

DaV

I'm bit late to jump in, others have explained pretty much most of it.
Wanted only to say that when I first tried War Thunder game with airplanes, I've faces the same problem like @DaVinster, that crackling grinding sound. Then playing with SCN settings I've realized that high acceleration is causing that grinding feeling, like sand in the gearbox, pretty much what @nclabs said.

For racing titles, this is not that much noticeable as you have faster motions, bumps, kerbs, lots of brakes and accelerations, that's why your pCars is feeling allright, but for plane games it's a bit different. You have very smooth movements, easy elevation changes and therefore high SCN acceleration is not necessary, it's like overkill.

Have in mind that you probably won't eliminate that feeling completely, I think it's just the way those SCN's work, but you can smooth it out with slower acceleration and make it less noticeable.

Hey folks, I finally came around enough to disconnect the actuator and do some testing. See attached video. While I didn't capture the slower movement, with the acceleration turned down to ONE(!) on the axis assignments and using the smoothing and washout filters etc.. I was finally able to get somewhat usable motion. There is some flex in the chassis and some slop in the actuator and pin. The good thing about the 80/20 stuff is it's readily available. I'm going to order some brackets and whatnot to try to stiffen it a little more. The very small amount of slop in the actuator I've read somewhere that there is a re-build kit for the scn6's that should resolve that. This depends on cost and complexity. The 80/20 brackets and such should be around a hundred USD or so. The pin and ball joint is another issue and is in it's design. I may check with a local machine shop to see what can be done. It is true prodigy that this is only an issue for flying as with the quicker driving forces it's not as noticeable as you said. I'll start with the cheapest options and see what effect they have and go from there. yobuddy, noorbeast, nclabs and seatTime were in the same track in that the flex seems to be the main issue. I would have to find a happy medium where the motion will be fast enough to match the visuals with being too fast to 'rock the boat'.

Thanks all for your insights and comments!

Final question regarding the acceleration.. it would not let me save an acceleration value of zero, I had to input at least 1. I don't suppose there is a way, via .cfg file or whatnot to have a negative integer for acceleration for just my roll axis, somehow, someway? For the Scn6's the acceleration is very high and perhaps a negative number could calm them down even more?



Cheers,

DaV

From the above video the actuator seems to work like it should without a load.

Yup.. the software isn't the issue here and that's why I posted the video to show that. If anything, I was looking to the software top overcome the inherent issue with the flex. I know there must be combination that will work, just a matter of more trial end error. I have to say though even though I've only gotten close to where I'd like it, with the rift on using flyinside the effect is quite dramatic and well worth the effort

Oh and I did lower the COG a bit and it seemed to help a little.

Every little bit helps. Your rig also looks quite heavy, so for every sharp change in direction there is allot of inertia to overcome which could be effecting your SCNs tight load/speed specs.

The Rift and motion is just great - I recently put a friend on my new rig with DK2 and he nearly wet his pants - should of had the video camera running . Cannot wait for my CV1.

Just for info the SCN6 specs are below. Note the limits shown on the graph are only for driving in the horizontal axis (not vertical) so they really are not that strong. But this is not surprising seeing as they were likely not designed with Sims in mind. So for a fast change in direction the load on the actuator could be double or triple of what the moving part of the rig + occupant weighs, possibly pushing past these specifications. My recommendation for building a rig for SCNs - build light/low CG were possible.

Ya I have to look up what I have in the scn6's. I think my yaw axis has one that is "half the speed but twice the force". I'm going to figure out what is what and swap the slower/stronger one to my roll axis as that's the one with the most 'mechanical disadvantage'.

Some other good news.. I met someone who has some good lathe equipment and is going to help me machine some new parts to stiffen the frame a little.

Too bad Frex doesn't have the shock mounts for the SCn6's. They only designed them for their SCN5's, from what they told me a couple years ago..

Thx to all, it comoletely fixed my issue. In the tutorial video for the prosimu rig the guy sets acceleration on 500 (!) and that caused massive vibrations on the whole frame which my neighbour heard the whole time. Because it was too quick when the actuator jumps from one value to another. Setting it under 200 fixed it completely. All runs smooth now. Cant believe I was playing like that for three months, becaise I thought it is normal that the actuators are moving with small stuttering. In feeling there isnt much difference, but the vibrating sound is gone. And the chirping noise I reduced massively by building silentproof boxed out of rockwool around the actuators.