Low cost 2DOF/3DOF/6DOF motion simulator - DOF REALITY

Rest of settings are standard as from 3dof H3 P3 presets

Just thought I would provide a little info on a problem I had recently with my DofReality P3 rig.

I few days ago I noticed my right hand motor wasnt moving. Pulled up SMC3 and the motor trace was showing as attached.

After some swpping around of connectors etc to isolate the fault and discussions with Igor, the problem was traced (hopefully) to the motor driver BTS7960.

Fortunately I was able to locate a place in Malaysia where I could buy Arduino stuff and was able to have a replacement motor driver posted to me.

Fitted the BTS and tested the rig and all is well again.

Thanks to Igor for helping me troubleshoot my problem.

Mxcobra, Vegas DCS A10C flyer here. Im getting ready to purchase the DOF REALITY P2. Now that you have had it for a while do you have any helpful info on Pros/Cons ?. Do you have slack issues with the bigger motors.?Suggestions for a light comfy seat? Basic feelings about system?

Hi Lasvideo

I think some of my earlier posts summarise the pro's and cons of the DofReality system but simplistically speaking, you are getting a lot for your money. Its far from perfect but it's still very good and great fun to play. I honestly think 2 dof for flying is never going to be perfect and with the somewhat limited movement of the axis, you are only ever going to get a feel for the sesation of flying.
The DofReality rig doesnt do a great job of simulating forward/backwards motion (surge) and up/down motion (heave), they just endup feeling like pitch. For the racng sim that I do, the 2/3 degrees of freedom is great, but for flight, I'm not sure.

Thats only my opinion of course.

The rig itself is functional, in so much, it does what it is supposed to do but there is play in the system. There is a little slop in the worm drives which translate to areas in motion that isnt controlled by the software and you can clearly see that when you view the trace through SMC3.
The DofReality rig is very sensitive to balance. You have to get all you rig balanced on the universal joint otherwise the motors will struggle.

If space is an issue for you, the rig is very compact. Roughly speaking the wides part of the rig is the seat width and as for length the rig is about as long as you sat with your legs streched out.

But again, it really is great value for what you get. Go for the more powerful motors if you can. Has to be better in the long run.

Andy

Thanks Andy. Thats what I needed to hear. $2000 for a retired guy on a fixed income is a lot. And I love what the Jetseat does for $200. But for that big sum of money Im not sure that I wouldnt suffer from buyer remorse once the initial thrill subsides. Flying the hog in DCS in my current rig is a blast. Maybe thats good enough...all things considered.

Lasvideo,

I do hope i have not ruined your dreams but also hope that I've saved you from a questionable investment.

Honestly, buy a Oculus Rift or HTC Vive instead. I think that would make the huge difference in flight sims.

Andy

LOL! I appreciate your candor. FYI I have had a Vive for the past year for room scale stuff and a Rift dedicated to flight. Every time I enter DCS its another thrilling adventure. Thats enough for the time being...

Wow. Great.

Then perhaps motion may be very immersive. From what I read, motion works really well with VR.
Im waiting until the next gen with better visuals.

Im not sure if this applies in Malaysia, but on Black Friday the Rift goes on sale for $350. I would encourage ALL aviators that love the experience to do themselves a favor. Next gen maybe as much as 2 years away. Would you postpone eating cake and ice cream for 2 years just because they dont have chocolate yet. I am dead serious here. You have no idea what your missing (unless however you HAVE tried VR).

I did purchase the Rift DK2 but didnt get on with it.

Everything was just that bit to difficult to work without messing about. One minute Assetto Corsa would work fine, the next minute it wouldnt and you had to spend time trying to problem solve.

My biggest problem with the rift however was personal. My left eye isnt great due to a detached retina so whenever I wanted to view and respond to a command that was viewed in the left display I had to take the headset off, take out the lenses and peer through the holes at the very small display on the screen, then put the lenses back in and put the VR helmet back on. I was never able to make an additional screen work so I could just remove the headset and view a screen.

I'm sure it's all a lot easier now but it does deter me from jumping in with both feet again.

As for a 2 year wait, I'm not sure. That Pimax 4k looks impressive and the 8k helmet on kickstarter looks really interesting however I suspect those kits will probably be a repeat of the Rift DK experience previously.

Hi all,
I've got my 2DOF Reality Motion Simulator running with simtools, flying with DCS 2.1 flight sim. I've followed Ravens help on the DCS forums, and am using the latest export.lua to help with some unwanted motion.

The issue I am having is the rig has these small (step like) jerky motion when making smooth motion on the flight stick (both pitch and roll). I've tried changing the axis force percentages. Noorbeast thinks it may be a plugin issue.

Here is a video of the behavior

Any ideas on how to fix this jerky motion for DCS 2.1?

I know this thread has been moved over onto another part but I wanted to comment from a DofReality point of view from a driving simulator point of view.

I had that similar sort of jerky motion with my P3 rig until I got the moving part of the rig more ballanced over the universal joint.

This rig seems to be very easily affected with the rig out of balance. To be fair, DofReality do stress that everything needs to be balanced and attachments are added. To have my rig close to evenly ballanced I had to redrill my seat rail, wheel mount and pedal mount quite a long way over to the right before that jerky motion was reduced (wouldnt say eliminated however).

Unfortunately, as you get the rig closer to being nicely ballanced, the slop in the worm drives start to be more apparent. It is worth having a little weight forward just to reduce that slack.

Andy

Thanks Andy for the input. I think you may be on to something. I tested both motors with the SMC3Utils based on DOF Reality guidance, and one of the motors is giving the jerky motion when trying to match the sine wave test. It also happens to be the motor with the extra weigh on that side (HOTAS and gear box). Will see what they come back with, just sent them my results.

Curious, how did you get your rig in balance, trail and error, or did you weigh everything before doing all the drilling and resetting?

It was pretty much trial and error.

I disconnected both of the threaded bar control arms and sat in the seat (being held in place by two friends). And was able to feel where the most weight was.

For the seat mounting, I redrilled the two fixed seat rails (the rails with the three mounting holes), I think it was about 10mm. I also slotted those three mounting holes on each end of the seat mounting rails which allowed a level of fine adjustment.
My racing pedals are on 20/20 aluminium extrusion which allows me to move my pedals from side to side.
That just left the steering wheel mounting plate which I drilled out additional mounting holes allowing me to have a number of position options.

So with all that I was able to check balance and adjust side to side balance. It really surprised me how far out of balance my rig was and how much shift to the right my rig needed to be to feel light.

Front to back balance is by repositioning via the three mounting holes where the UJ attaches to the spine of the rig with some fine adjustment with the seat sliders.

You can feel when the rig is balanced because you get a lot more free play at the worm drives. That can be reduced by adding a little weight front to back.

Looking at the trace on SMC3 the green line still doesnt follow the blue line but it's not far off.

Its worth also noting that with the adjustment made to the rigs balance, it now struggles to move if I'm not in the seat but works fine if I am in the seat.

My friend had an alternative approach with side to side balance. He weighed his shifter (which is offset) and added an additional corresponding weight to the other side of the rig. It worked fine for him but I didnt like that approach.

Is there on "official" way to align potentiometers on this rig? Had to disassemble traction loss motor completely and now is time to put it back together.

Why i diassembled it is a topic for half a book, maybe on that topic later.

Ok, sorry for that, i had powered hub where the control box was connected and kept power to controllers on all the time. Old in-n-out trick with usb-cables resetted controllers and i got movement on motor to align it with the pot by turning pot a little bit one way or other.

Lets try this after a long-ish pause.

I would also love to know if there is a 'proper' way to set the pots.

I seem to lose control of my motors (particularly with the rh pitch /roll motor pot) far to often and have to mess around for far too long to get everything working again (SMC3 is my friend). The motor has 'driven hard over' so many times one of my threaded bar control arms is actually bent.

I really want to hear the story for the disassembly. Probably been there as well.

Changing the subject completely.

Those of you with a 3Dof rig (and perhaps if you are a little heavier than ideal) please check your traction loss rollers.

The 5 rollers supplied by DofReality (2 at the front and three at the back) are not really fit for purpose. They are wardrobe door rollers and not designed to take a lot of load.



I had some new rollers made from nylon and replaced the existing ones. I used nylon because there was some available and the material is quick and easy to machine and doesnt need lubricating. Aluminium would also be good but some oil or grease between the roller and the axle would be needed.



Rollers are (sorry Americans, this is in metric) 27mm outside diameter 12.5mm thick with a 5.2mm hole through the center.

It's a bit of a bitch pulling out the existing rollers and pressing back in the new rollers but once refitted, and after a few weeks trial, I have to say it's a complete success.



You will notice, in the third photo, the roller is rubbing a little against the side of the cutout. The roller width could be reduced a little but keep the width at the hole 12.5mm. Something like the diagram below:

Hope this helps guys

Andy