2DOF DCS Motion Pit

This is a really creative approach. Just add two friends with 2 arms each, and you have a full 6 DOF rig. And I am sure they are able to simulate quite realistic plane crashes.

Well, the amount of rotation is not meant for simulating the actual inclination of the plane, but the acceleration.
And I can confirm that the 10 degrees of my rig are quite amazing when I am wearing my VR headset.
Besides, the plugins of the two flight simulations I am using (FSX and Aerofly FS 2) not just provide values for the roll and pitch angles, but additionally for the roll and pitch acceleration(!). By using these values you get the impression to roll / pitch a bit further with every new stick movement.

Maybe I can use something from this controller

actually, true story, i went to Patong a few months ago, which is the big tourist area of where i live, and a couple of local guys had a computer with a rift (DK2 days) and a plywood platform suspended on chains. they were playing an oculus roller coaster demo for tourists and the 2 guys would push and pull the platform around by hand to simulate motion. i wish i'd have got a video of Thai VR in action, priceless!

good to know. thanks. are you doing much 'extreme' flying? i know FSXers tend to like cruising around in passenger jets.

First test with the motors



It was a quick and dirty test run this morning with only 12v 10A psu - so half speed and the 10A are just a Little about the idle current but bigger psu is here, test it this evening.

But, they move and everything seems to work . Next thing is the mechanical part


Ps: yes they are loud , Especially the clicking of the gear - I have to investigate what's the problem

I have a question

Would you recommend to use a capacitor behind the PSU (secondary circuit) to "cut" the current peaks?
Thought about something like 50v 1F capacitor parallel to the boards/ motors

@steveh2112: I have written you a PM, because I guess we should not expand this discussion in @Intruder's building thread. Here it seems kind of off topic.

i think i officially joined the club (or at least filed my application) to the mosim club. i ordered motors, PSU, arduino board and MonsterMoto shield motor controller and will be building my 2DOF tilting chair based on this thread
https://www.xsimulator.net/communit...3dof-motor-driver-and-windows-utilities.4957/

it will take a few weeks for all the stuff to arrive from china and australia (motor from here
https://www.motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque.html )
so i'm starting on the chair platform now.

i know there are a few other people building similar designs for use with DCS so i think this is going to be fun.

That's great Steve! Wish you good luck with building!

Back to my question with the capacitor ?! Any ideas?

And another question appears:
What's about galvanic isolation? If I burn my H-bridge and all went totally wrong ... 24v through USB in my pc ? Not a good situation. How do you guys save you from such a problem?

It's me again... what to do against burning H-bridges...

This "42 amps " bridges don't like my motors. When I testet the force and the current went high (max 20A from the PSU) the motor stopped and the PSU went to short circuit shut off . I know they get hot, so I used thermal compound for the heat sink and an active cooler. But it went to death in seconds under force.
Next test - new H-bridge, no force , just free turning with high rpm ... maybe 10 turns, then the same as above.

Conclusion: I need other bridges that can stand at least 20 amps continuously at 24v ...

Are there any good ones? I heard about the sabertooth?!

I was using the IBT-2 bridges.

The MM are only 12V I thought?! I need 24

Thanks! They say the IBT-2 have Heat and over current protection? Is that correct? Mine seems to be absolutely dead! Maybe I will upgrade to the sabertooth 60/120 ... not so cheap but maybe necessary

Hi Intruder,
here is a link to pictures of my motor control with galvanic isolation:

https://www.xsimulator.net/communit...lica-with-wheelchair-motors.7905/#post-111078

Your motors seem to have a electric brake, did you connect it correctly?
20A at 24V for a unloaded motor indicate that the brake is active (approximately 3.5A is normal without load).
The brakes should have 12V or 24V to unlock.

Oh forgot to say it, I removed them before, was thinking about using them for stabilizing the neutral position, but they take another load of amperes and I fear it get to slow for fast little movements?!

The brakes from my wheelchair motors have only 24V 0.5A each. You can take a separate small power supply.
It's not a good idea to take the same supply for motors and brakes, because if the PSU is too weak it will cut off shortly at current peaks and every time the brakes go in.

About the IBT-2 bridges:
I'm not very satisfied with them. I've killed three of them when i adjusted the SMC3 parameters. If you turn for example the Ki factor a bit too high and the motor begins to oscillate they immediately blow up.
With SimTools they work until now, but i also think about upgrading to sabertooth, but i think the 60/120A are too big. I use slow car fuses with 15A for each motor, so the average current for each motor should not be higher than round about 20A.

Ok so I am not the only IBT killer here

My motors seems to be really strong, the 20A was reached with a fast direction change from right to left (PSU gone to overload shut down)

I ordered the 60 amp sabertooth, if I kill a 30A one then 99€ are to hell, so 50€ more end I am "save"

Do you use a car battery or a capacitor parallel in your circuit?

My PSU has 24V 106A, so i don't need a battery in parallel (It hasn't shut off until now). In my opinion a capacitor in parallel makes no sense because there are allready enough of them inside the PSU.
I'm not shure but you will need a battery connected to the sabertooth.

The high current with a direction change is very short and the overcurrent protection of a PSU is very fast. If you would have a average current over 20A (=480Watt), your motors would get very hot.

Ok, that makes sense. Did you order a Kangaroo expansion board also ? Then you can dispense with the arduino and the SMC3 software.

Thanks for your reply!
Oh boy, that is a huge PSU !
So you mean I generally will need car batteries for the sabertooth ?

And I didn't ordered the kangaroo, I saw this diagram in the Smc3-sabertooth thread:


Would you recommend a kangaroo? And what does it do? ( not just jumping around I think )