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Need suggestions for a flight simulator. 1

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cplatt

Student
Nov 28, 2020
3

Hello and thank you for looking 😀.  I have loved flight simulators for 50 years and finally tried to build one myself.  I have come up with one thats basically an upright hemisphere mounted on omni-directional wheeled frame for support.  Unfortunately I cant come up with a method of simulator movement that doesn't have significant drawbacks.  I am only asking for maybe a couple of ideas that maybe I haven't considered.

 

Five considered solutions and their pros and cons:

     1. The best idea that worked reasonably well was to use two pneumatic cylinders to move the sphere as shown in the jpeg. The pros were this solution was incredibly inexpensive and reliable. The cons were, due compressibility of air , I could never get really accurate and precise movement and always had to have a noisy air compressor around. The 34 in stroke of the cylinders also leads the project to have a much greater footprint than the actual sphere.

     2.  Second idea was to mount the sphere on the top of three Mechanum wheels- like an upside down ball balancing robot. Pros would be great accuracy and speed. This is the solution invariably done by others. Cons are Mechanum wheels and their corresponding stepper motors breakdown and overheat often. The load is approximately 500 lbs. Also expensive solution.

     3. Third idea was to use worm gear winches and cables in some arrangement. A set of 8 winches at cardinal points to pull the sphere around seems feasible and inexpensive. Cons again probably reliability. This is what we might try next.

     4. Fourth idea replace pneumatic cylinders with electro-mechanical cylinders or use some other type of EM mechanics. This is very, very expensive for the stroke needed ( 34 in.)

     5.  Finally maybe a weight shifting mechanism...similar to a “Sphero” robot. I feel that the weight be too onerous and passenger compartment gets in the way.

 

Thank you again and happy holidays.

 
 https://files.engineering.com/getfile.aspx?folder=bc620be7-8036-4033-ad50-4d75a32eca88&file=20201128_102009.jpg
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You could eliminate a lot of the cons of pneumatic actuators by replacing them with hydraulics. Additional benefits are that you would rapidly achieve an enviable level of expertise in the toxicity of, and best ways to clean up spills of, different types of hydraulic fluid.

Could you reduce your actuator stroke using a cable and pulley arrangement? You'd need to use two cables with each actuator to make it work in both directions.

A.
 
Forgot to add hydraulic...leaving that out due to the dangerous nature of 1,000 to 3,000 PSI running around. Thank you, the reduction of stroke length suggestion is really helpful but sadly would still not help with the accuracy and precision of pneumatics...
 
Thanks Greg for the reply. The system of course has a neg feedback loop for the pneumatic cylinders...good to a 100th of a mm. Problem is air is a compressible gas. In other words it acts like a giant spring. Try moving a load on the end of a spring around. It is very difficult. The gas could be changed to nitrogen which is non-compressible gas and that would help but totally unfeasible for a project like this. Pneumatics are so dang cheap but so hard to use for any thing.
 
Nitrogen is not non compressible. I design suspensions, I am fairly familaiar with the idea of springs. While I don't believe 1/100 mm is achievable, I doubt that is a requirement of the setup. Sounds like you need a better feedback system.

Cheers

Greg Locock


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