6 dof

Goals: Creating a flight sim capable of the following:

• Pitch
• Yaw
• Full 360* Roll
• Heave
• Surge
• Sway

Bonus goal: Works with racing.
Bonus goal: Create an immersive and responsive rig that absolutely blows my sense of reality away.

I will come back later hopefully within 24 hours, and start posting some designs. I am posting a picture that I saw on wikipedia; this will be my reference template, but I might make changes to motor locations and frame.

Project Concerns: Motors and controllers. I'm thinking (with my limited knowledge) I will use Brushless DC motors, uncertain about controllers. Will probably need to ask for help in this section.
Project Concerns: Will complexity end up reducing the performance? Is 6 dof possible with full 360* roll?

This sums up my thoughts and mental notes.

hello and welcome @itaaronc !

you've choosen an ambitious project! congrats!!

As you're a beginner, here are some advices that mayu be useful as many have stopped before their 6dof achievement

- you may start with a scaled down model to test your hardware and code. This would allow you to learn Simtools, hardware wiring, soldering and coding and/or tuning

- you should estimate your costs and budget before starting real scale building
yours
Mat

Thanks @noorbeast @RacingMat, I will definitely build a model first before attempting a full scale build. I'm working on a 3d model right now, before I even think about a build process. Actually, now that I've mentioned modeling, will I need to have a perfectly balanced center of mass? If so would I need to factor in the center of mass to include a person? Just a thought that has been nagging me as I design this.

@RacingMat and @noorbeast Been working on my drawing. I have probably an elementary understanding of motors at best so there are a few hang ups. For example. I have drawn a motor/accuator pushing along the y axis to simulate surge, and the object being moved sits on a rail to be slid forward and backward. I have another motor/accuator pushing along the z axis for pitch, the problem is, as surge moves forward, it would pull on the accuator for pitch, and as it moves back, it once again moves the accuator. Are there ways to address this with fittings or do I need to change the design?

Here is my progress. Dimensions are not right and some things are even just sloppy. But its meant to be more of a visual aid anyhow.

Isolate the axis, so think about a multi story building. The top floor houses your seat, pedals, wheel and the roll/pitch axis. Then the floor underneath that controls surge. The floor under that floor then controls sway. That's is for a 4dof simulator, a 6dof would be a little more complex and require out of the square thinking.

In your case you can leave the pitch axis on a frame that controls roll, with surge being a separate frame that pushes the main frame.

As shown in this professionally drawn CAD model:
I use MS paint for all my modeling needs but it is somewhat limited as a CAD tool in like, everything.



Whilst the idea will not be in your best interests to copy it will at least give you an idea on how to separate layers of axis. Some axis can be combined with others to make more compact frames. it all comes down to your mechanical imagination but most importantly, your budget. If this is going to be home built and you don't have a huge budget I would forgo full 360 roll.

Don't forget that your electrical connections will need to spin around. Imagine holding a shoe by its laces, now spin that shoe around 30 times. What happens to the laces? They turn into a crumpled mess. Doing that to wiring will be 10 times worse. One way around this problem is to pre coil a length of wire that is far longer than you would normally require but even that only helps for a bout 15 turns in either direction. Next comes rotary couplers, which will be the most expensive part of the sim as they need to have many connections and also heavy duty. I'm sure there are other solutions but I'm not aware of them.

With the current cost of things these days I'm not sure what you want from the sim is attainable. I would seriously recommend building a 4 dof sim first or at least something simpler than what you currently want. Then you will have the skills and knowledge to proceed with something more ambitious.

@noorbeast, I'm kind of hoping this will make an estimate easier. I could very well just make a tiny model.

@Alexey, Lol i try to make it look all professional, but ms paint did the same task so much better and probably in a hundredth of the time too. I know you say I should avoid that frame by frame method but I have been doing exactly that.

I'm feeling you both about the complexity. I am out of my element. But I'm still determined to try. So ill take it slow and keep thinking of different ways about it and what happens happens. As far as price... we shall see.

@itaaronc : you haven't told us what is your approximate budget: if not, we cannot really help you choosing between alternatives...

My budget is about 5k USD. Not including peripherals or frame.

Could I use something like slip rings, to transfer current?

I was thinking maybe a slightly modified Stewart Platform would work better. Would only require 1 slip ring for the peripherals.

Go hard or go home . But seriously, its challenging (and costly) enough for most to build a working stewart platform, let alone a modified version with a 360 roll component. I like many would recommend for your first sim something simpler (Ie. 2dof seatmover) so you get a grasp on the complexities/cost of building a working sim which can support a large mass in motion, but it is your money and time so all the best. Just for information SimTools does not support 360+ degree sims, or the math for a true stewart platform.

@SeatTime Yeah I thought that I had read that elsewhere on the forum. The creator of this video was able to get his model to 360* rotation. Http://www.xsimulator.net/community/faq/prototype-360°-full-rotation-motion-simulator.113/
I dont imply that I am that talented, and its best to assume for now that I have no talents. I'm going to build a prototype and play with it for some time. It might be possible that I end up deciding to go with a seat mover solution, but only when I can prove to myself that what I really want isn't in my best interest (too expensive, too difficult, etc). Btw what do you mean by a true stewart platform?