Question Noob Researching VR flight sim build

Hey all, I've been reading a lot of posts here over the past few days. I had considered the DOF reality systems, but I can't justify the cost, especially after shipping/etc to the US. I consider myself capable of learning new tricks, and while most of the concepts of building a motion rig are outside my wheelhouse, I'm nervously jumping in because I like to learn new tricks.

I'm looking to build a rig similar to @SaintFrank and @Ronan Design .... a somewhat compact 2 DOF. This will be used exclusively for VR flight sim (MSFS and IL-2), at least for the foreseeable future. I'm 300lb, 6'2", so I need to move some weight around. I'd like to keep the budget under $1500.

I've already ordered some 4040 Aluminum Extrusion and a flanged U Joint which will make mounting the seat a breeze. I also bought a Ford Explorer back seat off ebay, but I haven't picked it up yet and could cancel if it's too heavy? I was looking for a cheap ($81 in this case) but comfortable seating solution that would feel more like a small GA plane.

I had also ordered two motors from amazon (CUEI Brushed Electric Motor, 24V 250W 75r/min Low Speed High Torque Brushed Motor, Low Noise Professional Metal Brushed DC Motor for Unite, for Electric Wheelchair Modification and Repair, 22 N.m) but cancelled as I was worried I wasn't knowledgeable yet to make that decision. I read that finding 24V drivers can be difficult, but I may have misunderstood or misread the post.

I've been messing with SimCalc but it doesn't really explain anything as far as what Outputs are desirable. I found one explanation on a thread here that 300mm/s is the minimum linear travel needed (at least for racing, I suspect fs is different?) But as for the others, I don't know what Pitch/Roll efficiency is, what Pitch/Roll Force is desireable, or what Pitch/Roll torque is. I don't know why motor speed doesn't have any affect on the outputs. I guess I'm in the dark on how exactly to use this program to design my rig?

While I have some basic python and html experience, and wiring experience, I have zero experience with control boards and motor drivers (I'd never heard of a motor driver until yesterday and I still don't really know what an Arduino board does exactly). I can solder (although I'm not great at it) and do some very basic shop work. I have a friend who is a mechanic and has a 3d printer and other tools if needed.

I have two worries... getting to a point where I just am not capable of doing something, or having a poor design with motors that are too weak or improper construction where something breaks loose.

Questions I have at this point:

How do I use SimCalc to determine the motor I need? It doesn't take into consideration the weight of the system and the outputs don't mean much if anything to me.

Does motor shaft type matter? I don't know how to attach a lever to a motor shaft. Does this require custom machining?

Do mounting bolt locations/patterns matter? Some seem to be easier to mount than others. The 4040 has a plethora of options thankfully, but I don't want to get a motor that I can't do anything with.

I think that's all for now. Thanks!

Hi I am also building a 2DOF on a 24V 250W 75 RPM motor, about what I discovered :
1. attempting to build according to this guide https://www.xsimulator.net/community/threads/my-finished-2dof-project-videotutorial.16214/ is fraught with one major flaw IBT2 bridges are too weak to withstand 24V power supply of motors as above as reported by the author himself who lowered the power supply to 18.5V so as not to burn IBT2.
2) I connected 24V motors to IBT2 and despite lowering the voltage to 21.8V I burned 2 IBT2 pieces, a greater reduction is not allowed by the power supplies I bought 24V 25A for LED.
3 I am trying to get out of this problem by replacing parts in IBT2 bridges according to this thread https://www.xsimulator.net/community/threads/btn8982ta-as-a-replacement-for-bts7960.17952/ unfortunately I am waiting for a shipment from aliexpress so I can not say anything more for now, the disadvantage of this solution is the need to have the right equipment and skills to solder the circuits .
4. in your case I would go into the purchase of the controller written about in this thread https://www.xsimulator.net/community/threads/reasonably-priced-100a-motor-controllers.17638/ , I also intend to buy it but it is at a later time, as an example of use you can see this advanced simulator https://www.xsimulator.net/community/threads/keiths-6dof-wheelchair-motors.17038/
5.In general, the topic of using 24V motors turns out to be quite problematic, but I think I will be able to complete the project successfully, for testing the settings I use a power supply from a PC and supply the 24V motors with 12V, which turns out to be sufficient
6. if you are looking for a simpler project, check out this fim on youtube Roman Design on its website provides a ready-made configuration file for FlyPtMover software for MSFS2020 without which you can not dream of running 2DOF, I tested this file and it works without any problem. I decided to use 24V motors due to the fact that I am from Europe and buying on ebay.ca was too cumbersome.
5.In general, the topic of using 24V motors turns out to be quite problematic, but I think I will be able to complete the project successfully, for testing the settings I use a power supply from a PC and supply the 24V motors with 12V, which turns out to be sufficient
6. if you are looking for a simpler project, check out this fim on youtube Roman Design on its website provides a ready-made configuration file for FlyPtMover software for MSFS2020 without which you can not dream of running 2DOF, I tested this file and it works without any problem. I decided to use 24V motors due to the fact that I am from Europe and buying on ebay.ca was too cumbersome.

I don't have much experience but go ahead and ask what I know the answer to I will try to write.
Sorry for the style but I'm writing through a translator.

Much appreciated... I wish there was a written tutorial of the general concepts of this somewhere. I'm still not sure if I should be going with 24v or 12v. I've read that 24v stay cool and 12v tend to get hot. I'm assuming 24v means more power (generally), which if true would be beneficial to move the above average weight of the sim. I guess I need to do some more reading.

I'm making progress. I ran across @scruck 's build and he uses the same motors I had ordered (and cancelled). There seem to be an abundance of 24v supplies so I'm not sure what the concern is, and they're inexpensive. I do have a question however:

Scruck lists a 20A power supply. From an online calculator, the 24V 250W motor pulls less than 11A. There is a 15A version of the same power supply and it's half the price. Wouldn't that work?

The data from the motor calculator does not coincide with reality, according to all sources 24V 250W 75RPM motors have a constant current of up to 13.4A
During my tests with 24V 25A power supplies at fast movement of motors I observed voltage drops, which indicates that at the moment of changing the direction of movement the instantaneous current is greater than the declared 13.4A wanting to have peace of mind I would buy power supplies of at least 25A for each motor. You have to remember that @scrub lowered the supply voltage to 18.5V and the PWMmax paramter to only 130 which also lowered the motor power, while you need the full power of the motors to get a satisfactory effect.

https://www.aliexpress.com/item/328...p4p_id=202310260810472841285417595640051971_0

Good to know, I'll go with the 25A.

What power supply board do you plan to use IBT2+modification or 100A DC motor drive module? remember 100A DC motor drive module has only one input for power supply, I don't know so much about electrics can you connect two power supplies to one input ?

I ordered pretty much the same stuff as @scruck :

Same motors, 24V 250W, 75rpm
2x BTS7960 43A High Power Motor Driver Module/Smart Car Driver Module for Arduino Current Limit
2x ALITOVE 24V 25A 600W Power Supply Adapter SMPS Switch Mode Power Supply
2x Hall Effect Potentiometer Angle Sensor 360 ° Measuring Range 0-5V Output 5V Supply Voltage

I also ordered the motor shaft gear for the pot, but scruck's link is dead for the pot gear so I'll worry about that when I get to it. Now that I have the motor's picked out, I'm going to go back to simcalc and try to figure out the best way to attach everything. I don't intend to make mine nearly as compact as Scruck's so that should give me more flexibility. The aluminum comes in tomorrow. Fortunately with the extrusion system, I can always move things around a bit if needed.

I recently posted a new thread showing my build that is mostly inspired in Romans Designs one. I hope it can help you anf if you need something, you are welcome to write there asking for help.

Cheers!

Cool, thanks, I'll look it up.

I'm still waiting on the motors, but the parts are accumulating. I just picked up a seat from a 2nd row ford explorer. It's 45lbs which is much heavier than I was hoping for, but it was pretty cheap and like new so I'll try it. If I need to swap it out later, it should be a big deal.

I've been spending some time learning the Arduino with the 30 days in space project. I don't know how much of that stuff I'll actually need for this project but it's good to know and I'll have a better understanding of how things are working.

Apparently the motors have shipped but won't be here until January....*sigh*.

I'm pretty sure this explorer seat isn't going to work either. I don't see a way to separate the seat part from the frame... it's pretty much one big piece. What a waste of time and money. I think I'm just going to look for a used/broken cushion chair that I can saw the legs off.

My first option also was a car seat but that is very heavy. I did not buy that car seat but I picked up from my work trash bin so I didn't paid for it. Finally I returned it to the trash and install a second hand cheap and light office chair with armrests. Best option for me.

I'm hoping I can get a few bucks off it... it's almost like new. I bought a new conference-type chair (no arm rests) and unbolted the legs. So far I've attached a piece of 3/4" plywood to the bottom so I can screw it into the aluminum frame. I can look at the bright side with the motors taking so long to get here.... I don't feel like I need to rush and can take my time. I tend to get in a hurry with these things because I want the end-product so bad and end up making mistakes (like buying something that won't work).

I just wanted to check in:

Everything above the u-joint is almost done and looking real sharp. Rudder pedals are ready to attach. I haven't built platforms for the hotas or keyboard yet, but those shouldn't take long at all. The aluminum extrusion is very easy and fun to work with, although expensive. I just started the stationary platform and have ordered a short 8080 piece to use as the support column. I'll probably brace it with something in addition to corner brackets.

The 8080 will take a few weeks to get here so I've started work on the software/data/electronic side. I have SMC3 installed on the Ard and the utilities on the desktop and talking to the ard. I'm not sure what I'm supposed to be doing with this but one step at a time. Lots of reading to do. The trick is knowing what I'm supposed to be reading/doing as I have yet to find a start-to-finish manual or overview of the entire process, so-to-speak, even a broad-view version. I'm having to piece it together from snippets located in various threads and posts. If anyone knows of a good overview of the entire motion rig system and how it all works, that would be great to have. I've got most of it figured out (afaict), but I could be missing some concepts. The FAQ is very useful, but the info is scattered and seems random, instead of being organized based on a likely project timeline.

I also have SimTools v2 installed and have started reading the manual, although I haven't purchased a license yet.

My next immediate steps: continue reading the SMC3 setup thread.
How does this interact with SimTools?
How will I create/find and then attach a CTC lever to the shaft of my motors? I found a thread for this in the FAQ, I just need to decide the best option.
What size of secondary gear do I need to maximize the resolution of my potentiometer? (I already have the primary gear)
Do I need protection for the pot to prevent it from being turned beyond the stops? EDIT: (No, not on a hall pot)
Wire everything up for a table-top test run (no CTC for safety) according to a found wiring diagram using Mode 2 in SMC3.

The SMC3 Utils program is a standalone program for configuring the Arduino how it should manage the IBT2 bridges and motors connected to it. Once the motors are configured, there is no need to use it.
1.Lever mounts as of today are probably the most elegant ones shown on this page https://www.sckgaming.es/tutorial-2dof-motion/ the lever has a 6.5 cm distance between the motor axis and the pivot axis but the attached dxf files can easily be modified to suit your needs. Making the above-mentioned lever requires ordering laser cutting in aluminum, I think currently this is a widely available and inexpensive service.
2) The size of the secondary gear is a secondary matter, as long as you do not exceed the ratio of 2:1, too large sprocket on the axis of the motor shaft combined with a small sprocket on the axis of the potentiometer will cause too much deflection of the potentiometer readings. Most projects use a 1:1 ratio connection, the resolution of the potentiometer is sufficient.
3. mechanical protection against over-turning is not needed, for testing set in SMC3 Utils the Max Limits 255, Clip input - 255 this will protect against too much rotation of the motor shaft.
In general, you should run SMC3 Utils connect to Arduino,set the motor axis to the position you want to have as the start position, then set the potentiometer so that the green line positively coincides perfectly with the blue line (below is an example) then set the Max Limits and Clip input to 255, Kp to 400 and slowly increase the PWMmax when you reach 90-100 and the motor does not start it means that everything is ok, then click the Out Mode>Sine button and the motor should gently move up and down.

Mouting 1:1

That was immensely helpful.

Could you expound on the reasoning to not exceed 2:1? I have a 360° pot and just ordered a 12T secondary to pair with the 40T. That would get 300° if I only use 45° of motor travel (I think) which would use a lot of the resolution without getting close to the edge (if that's how it works? I was going to put an ohm meter on it to see how it works but the battery is dead). Will a 12T and 40T not work well with a 360 pot?

And the SMC3 is editing the code on the Ard as I make the adjustments?

The Hall sensor is rotatable 360 degrees but effective measurement is made only in the range of 180 degrees, I have checked this personally and too much rotation of the sensor axis causes exceeding the values read by the arduino and locking the motor. The standard resolution at 1:1 ratio is sufficient to build a 2DOF that works well.
SMC3 Utils does not edit the code in Arduino only sets the operating parameters for the uploaded program code.

So the code is already on the Arduino... now I run SMC3, make some adjustments, and it regenerates new code to upload/overwrite?

SMC3 Utils itself automatically saves the settings to the arduino, it does not need to be uploaded again.