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

Well, let us start from the beginning, why: traction motor had too much slack. Chair would move 5cm+ with motor standing still and pushrod in the middle hole. So that is a lot of slack.

So fault number one was the woodruff key on the axle holding the actuator lever. Groove in the axle was way too wide. Solutkon for that was to drill a hole and tap it in the lever where it goes over axle. And then with a file do a flat section where the bolt would meet the axle.

That done most of the slack was gone. But there still was a bit, maybe 1cm+ but a lot stiffer slack.
That slack was inside the motor. The axle connection to the cog connecting to worm-gear was loose. I disassemled the motor and pulled the axle-cog-assembly out. Removed the pot-drive-connector and triangular piece that was the root of the problem. Then with sandpaper polished axle end and inside of the cog and with silver, brazed them together for good.
The slack is gone.

On the other side, the motor internals are fantastic. 2 ball bearings, steel shaft, brass drive cog, steel worm-drive, good grease. Motor quality is very good.


Pot alignment, how i did it.
If you disassembled the motor, put the shaft with cog in about the right position when in rest and middle. Pots middle position is when the flat part is in line with the pot wires. Then put everything together but leave the motor side on axle-pot connector loose. Then connect motor to controller and check motor rotation. If it rotates, just a little turn the pot to stop it, either direction. Then with very little turns of pot, drive the motor to middle position. Tighten the pot-axle-connector and you are done.

https://pekkakaukalo.kuvat.fi/kuvat/dof/

Just a few pictures there. And a video showing the worst part on slack.

That was a lot of slack.

Was it like that from the beginning?

The slack from the woodruff key was from the beginning. When i fixed that i found more slack inside the motor and fixed that too. Now only slack is from cog and worm screw, like 2mm from the end of the actuator lever.

Glad you have it resolved.

I have the p3 rig which uses the mpre powerful motors and all my free play seems to be in the worm drive. Don't think there is a lot I can do to make it bettter.

I toyed with the idea of replacing the motors with gearboxes for linear actuators. I spoke to Igor at DofReality and he said the only actuators that could be installed without major upgrade were just far too expensive.

Guess I'll live with a little slack.

Andy

Mostly finished assembly of my new P3. The default Pitch Roll and Sway were completely wrong. I figured it out (I think) and have Asseto Corsica working well, but Project Card 2 (UDP) is completely wrong. Is it common for different games to be so backwards in motion?

Also, I am not sure how to test and balance the rig. I know its important, but I don't have anyone that could spot me with the motors disconnected. How can I tell how out of balance I am?

Also the mounting bolt head that attaches the frame base (part that doesn't move) to the sway/yaw traction loss motor, seems too tall. The unit wobbles on the head of that bolt (the four corners of the base are higher up). Should there be feet/levelers on the bottom of each corner of the traction loss base?

srt8driver,
Regarding:
"Also the mounting bolt head that attaches the frame base (part that doesn't move) to the sway/yaw traction loss motor, seems too tall. The unit wobbles on the head of that bolt (the four corners of the base are higher up). Should there be feet/levelers on the bottom of each corner of the traction loss base?"

If I understand what you are saying, you are talking about the moving frame pivot point locating into the bearing which is welded onto the lower fixed frame. It is an interference fit and you need to push the upper frame into the lower frame until the upper frame sits on the rollers.

Regarding:
"Mostly finished assembly of my new P3. The default Pitch Roll and Sway were completely wrong. I figured it out (I think) and have Asseto Corsica working well, but Project Card 2 (UDP) is completely wrong. Is it common for different games to be so backwards in motion?"

As Norbeast said, you will need to set up profiles for each sim. Within the Axis Assignments screen, at the left of each Axis row there is a checkbox called DIR. Select that next to the axis that seems to be going in the wrong direction. On my P3 rig I have all three axis checked for DOF1, axis 1 checked for DOF 2, all 3 axis checked for DOF3 and axis 2 checked for DOF4 and DOF5

As for balancing the rig, there is no real easy way of doing it other than getting some friends to help. I was able to get it close based on seeing restricted movement looking at the traces when viewing SMC3 however I was only able to get it right when I had friends helping me.
I disconnected the control arms and sat in the seat with friends holding me upright. My friends were able to tell me where the weight was and what difference it made if I shifted my weight. With that knowledge I was able to get out, adjust the balance forward to back and side to side. Forward to back is quite easy because there are three positions where the universal joint can mount to the moving frame and then fine adjustment with seat rails (assuming you have seat rails).
But it's the side to side balance that is a lot more difficult and time consuming. I had to elongate and slot the seat mounting square section steel so I could push my seat over to the right. That wasn't enough for me and I then had to re-drill where those seat mounting box section drill to the long frame. That pushed my seat even further to the right. I then slid my pedal box over to the right (my pedals are mounted onto aluminium extrusion giving me the ability to independently adjust each pedal left to right) and then had to re-drill the wheel mounting plate to push my wheel over to the right. I can add some photos if my explanation is confusing.

I slotted the two sets of 3 holes at each end of the seat mounts and also re-drilled the two mounting holes circled in red. I think I moved aprox 10mm.

With all those changes I was able to get the balance close enough.

You know its about right when, with you sat in the seat the whole upper frame will rock side to side with very little weight shift. Once you have the side to side, you can then adjust front to back so there is a little weight over the front of the rig as suggested by Norbeast.

Axis is swapped in project cars 2, i cant figure out to fix it. Anyone can make a motion profile?
Thanks!

Peter

I also have problem with roll and pitch wrong, i can change it so it works right in game engine and press save with the game name in game list.
But when i start the game axis is still wrong?
I can´t see how to make a motion profile?! i dont understand the guide, is there a youtube video with that?

Output test in GameEngine use default profile for testing, pls disable all DOF in game profile.

Add only Pitch on Axis1 and Axis2 with default settings, run game - if pitch inverted - use DIR checkbox on both Axis, If Pitch make tilt on side, use DIR on one of the axis.

Noorbeast posted:
"For roll one Dir should be checked and the other unchecked. For pitch, surge and heave on a 2DOF both will be set the same."

Strangely enough, for my DofReality P3 rig its the exact opposite.For roll, both Dir is checked however for Pitch, only 1 Dir is checked.

I guess you just play around until it feels right.

Andy

It doesn't surprise me if one is wired incorrectly, but it works so I'm not gonna complain too much.

The joy that is DofReality

Andy

Though useful to know things are behaving mechanically, be aware that you often don't even want to bother with roll /pitch. If you're in VR, roll/sec and pitch/sec are often more effective. If available these tend to be mapped to extra1 and extra2. In Aerofly FS2 Roll doesn't even work.

The wiring is connected correctly, nothing in the wires should be changed. This is the specificity of the components used.

ohh what's that? and you know the release date?