The 3rd DOF

Hello all,

I'm gathering parts and equipment to start a 2DOF build inspired by Roman
Design with a few tweaks, more to follow on that. I'll be using a wood frame to save on initial cost with the idea that if it works in wood it can be upgrade to metal later.

Looking to the future though, with primarily flight sims in mind, which would be the best 3rd DOF to add? Surge, heave, traction loss, or yaw? Thoughts on implementation? further upgrade?

I have seen traction loss on a wood rig, no big deal, I can envision surge fairly easily, but not both without the rig getting too tall. But does traction loss add that much value for flight sims? Would just surge be better?

Lots of questions, would love to hear some thoughts from those with more experience.

For flying, I rather don't see the point of adding additional axes in a typical 2DOF, if anything it's more like building a 3DOF in a completely different layout and with more powerful engines like here
https://www.xsimulator.net/community/threads/my-3-dof-with-heave.18449/

Write more about what you are going to buy/do according to Roman Design, I also built initially according to this design and a few things I had to change heavily to be satisfied.
Basic question what voltage supply 12V or 24V and what power of motors?

I'll be using a pair of these guys

GEAR MOTOR 12 VOLT GREAT FOR SAWMILL/CRAB POT PULL/FEED/SIMULATOR 75-80RPM 50:1

So far these seem to be the best bang for the buck. Not sure what my lever arm solution for the hollow shafts will be. Welding seems unlikely so I'm leaning towards the Shimano pedal crank arm

Powered by battery for ease of set up and because I have one.

U-joint already procured from amazon

World American 2-2-479R Flange Yoke (DL-FY-1310-PDM2.7500 FFC1.3750) x2
Spicer SVL 15-153X U-Joint Kit x1

It cost a little less than the 4 pillow blocks and 2 pins

Arduino with electro cookie
IBT2 x2

Not sure yet whether I will try Roman's magnet and hall sensor set up or regular potentiometers.

Engines OK , U-Joint OK
As for potentiometers, however, I suggest using hall sensors, as in this project
https://www.xsimulator.net/community/threads/my-finished-2dof-project-videotutorial.16214/

You just need to figure out how to attach/gear the sensors to the motor shaft.
You can find ideas on this channel https://www.youtube.com/@DMAX_DIY

My advice IBT2 bridges are of poor quality, if you happen that one breaks then do not buy another one just buy this one
https://www.xsimulator.net/community/threads/reasonably-priced-100a-motor-controllers.17638/

I myself have changed IBT2 for the bridge 100A and I am very satisfied, the motor stopped buzzing, they work more smoothly, there is no phenomenon of "shooting" the position of the arm at fast movements, which happened with IBT-2


Another question will you fly in MSFS 2020 or DCS ?
And will you be using FlyPTmover or Simtools ?

Undecided as far as software, but I understand FlyPT is more suited to flight sims.

I'll be starting out flying IL-2 Sturmovik since I already have it. Moving on to DCS later.

Good info about the 100A bridge, I hadn't seen that before. More expensive but if I read correctly, you can run 2 motors with one 2 channel bridge?

Yes 100A bridge supports 2 motors.
It costs a lot but I spent the same amount on 8 defective IBT2
If you have some more time I will have another 60A bridge for testing in a few days https://tiny.pl/dk46t
I will test it how it works.
FlyPTmover is a super program for flying , well and it supports software motion correction when you fly in VR, there are several good setting profiles for it.
My platform (still under reconstruction )

Hello, for my part the IBT2 bridges work very well, to preserve them I lowered my power supply from 24 to 21 Volt. I also went with a 2 DOF copied from Ronan (these plans and layout were a great help to me). My 2 dof for example:

https://www.xsimulator.net/community/threads/my-2-dof-fs2020.18543/#post-249454

I don't feel the need to switch to 3 Dofs for the airplane simulation, for the car race on the other hand it would be a plus