6 DOF with 360 Roll and Pitch

yeah, exactly... well done Sir, this is the point. It ain't straight forward. I will have to build my own plugin. In the end its all math that references to the ring axis but it isn't going to be easy.

In relation to the inversion. This is an issue but I can tell you now if you take off, pull an 80 degree climb you are on your back. Doing 5, 360 degree rolls, as you climb will be awesome and realistic.

What I am NOT going to do is reference the games position of aircraft. The Gimbal will reference the forces applied to the pilot. This is where it gets complicated.

I may not be able to do what I really want to do. It all depends on what can be done in the export.lua file.

At the top of a cuban 8, everything gets light. You're upside down but you fell weightless and that is why you can't tell up from down. Then after you have hit the rudder and the aircraft points down, you begin to yank back on the stick and pull pitch up Gs. So what does the gimbal do during this time?

I have not completely worked that out yet but I think it is something like this. It will pitch up pitch up as you climb but as your air speed drops and your weight reduces the gimbal will bring you down to the neutral position while in the headset it is telling you you are on your back. Then as you have done the turn and the Gs start it will tip you forward.

The Gimbal cannot increase your experience of Gs. 1G is its maximum, but it can align that G with the resultant direction of the pilot experiences. Your head Mounted display will fill in the hole, because you can't see your real position. All you see is the horizon reference changing.

Will that work? well we will see won't we. Remember, its a simulation. Not the real thing. That's a completely different budget.

Love the passion. Good luck.

Wow. It is an incredible project. Good luck.

Designing Carbon Fibre rings

Well this was harder than I thought ( probably not the last time I am going to say that! )

CF has great tensile strength, not that great compression strength but here I am asking for the rings to be able to have forces if two planes.

Yeah I have to design for max load in one orientation and max load at 90 degrees to that orientation. So its all about bending moments and area moment and lots of physics. Sooo much easier if I was to do this with mandrel bent box tube steel. But then it would look as agricultural as F#$%.... and who wants to make that.

With Carbon fibre Tension is good
The design will use an outer light weight weave for cosmetic appeal.
Reinforcement right underneath of uni-directional wide tape with supporting verticals coming into the central plain.
All the strength comes from the ring wanting to either;
1. Collapse the weight of the ring down and pushing the side out
or with the weight on the bottom
2. Collapse the ring down in the bottom centre pulling the sides in (like standing on plank of wood)

The answer is to use the outer skin in high tension like the metal rings on a wine barrel and support them with verticals on the inside.

I needed to remove a scection of the inner skin to allow me to;
1. Mould the damn thing up, I have to get the stuff in there.
2. Lay wire and the like,
3. It will filled with foam and laminated to add strength and rigidity.

This is a small video snapshot with the other little mind stimulating CAD shapes I used to do mass calculations and just to get me realising where the forces a really were.



Horizontal stiffening next
This is just the vertical forces, now I have to add structures to resist the strain when the ring is parallel to the ground.

That is a whole different discussion. And it also means laying up CF weave in different direction and good quality bonding agents or adding a strange vacuum bagging techniques...which I only mildly want to think about right now.

Motor decision almost done
I have sourced the motors to purchase from china. I am getting a test sample sent to me, and the servos I need to drive the motion of the rings.

Some serious turning force
After some calculations (and more estimation than I like to admit) I now know the Torque I need to apply to the rings to produce 250 degrees per second roll and pitch, with 120 degrees for deceleration to stationary.

So if you're rolling at 260 degrees a second, I am giving 120 degrees from full speed rotation to totally stopped.

Who can figure it out?
Anyone wanna guess how much Torque in N.m of any other force x distance that is required for this with a 100kg person and 35kgs of motors under them and all that other junk?

Its not a small force.

Lets see who gets close.

Unless I missed something, not enough information. Since highest torque will be overcoming inertia during acceleration and deceleration need to know ring diameters, their weight, and the distribution of all the weight within each ring. Also need to know its efficiency e.g. what you expect to loose in friction.

How much information does someone need to guess? If you don't like to guess then I won't force you to guess. For the rest of you, take a risk at being wrong and shout out a figure.... But only if it pleases you to do so.

If you read the post you would see that I have already calculated the torque. The only element I estimated was the distribution of mass of the person and equipment like motors at their respective radius from the turning point.

And Noorbeat, that page doesn't apply to anything I am doing with the rings.

Like I said, read my post and you will see what the it is referring to. The rotation of 360 continuous rotating rings.

Yes you are missing something. I am not moving something at a linear speed I moving it at an angular velocity. Its a rotating mass. There is no linear motion in any of the work done on this so far. Even my reply to you stated this.

I am not talking about the stewart platform, or pushing connecting rods. This is the Gimbal part of the design. I am sorry if I had not made that clear

Hey @GusBiz! I’m interested in your project so I’ll play along if that’s what it takes for you to continue sharing it with us.

Without over studying it, roll and pitch torque is probably different, but I’ll guess 200ft. lbs.

But I’ll probably be as close as you will in trying to guess the total amount of soybeans in this jar from this incomplete viewpoint.

See that wasn't that hard... believe it or not you were 4% off from my calculations.

I had it at 260N.m which is 191 ft.lbs

Which was of course still an estimation because the weight distribution over the radius is pretty hard to figure out but I took a resultant weight to be 53 kgs at about 73 cms out from centre. Considering most of the mass is at the centre and the motors (35kgs) are at about 65cms radius. The rings don't weight much. Put it this way the core material is only 2.9kgs per ring, probably 2-3kgs in fibre and resin, and I haven't calculated the Bearing housing, and aluminium joining sections yet ( rings are build in two halves for transportation purposes), but those numbers are for the entire ring so its the weight at the end that matters.

Like I said this will take more experimentation than math. Yes I will build one and turn it with more and more weight till it breaks.

My response to your challenge.
This is how I would calculate the soybean. I assume the bowl is round-ish. I use the top as an indication of depth, (round bowl, round depth). I take the top of the bowl shows what a count of a layer of beans looks like and I know from my approximation of the depth of bowl how many bean layers I can fit in this. I would probably model it in CAD because it s a good way to do math in a visual format. What is my guess? I couldn't be ass-ed counting them in the picture... but that was my point! Do it, only if you want to.

Great come back... made me think

I don't have anything witty to say.But All i can say is this thing will be flipping awesome cannot wait to see it all done I want to have a go!!!! Good luck

Jimmy,

your only a 90 minute flight away. When its done your welcome to come over to try it.

Good Luck @GusBiz its a cool big project and I hope you can get it built sooner rather than later Don't dwell on math too much its totally over rated

Yeah, the diameter of the jar isn’t much to go on but it’s about the only thing to use to attempt to estimate its depth by. Glad you didn’t try to come up with an actual total though since you have as much information as I do.

I didn’t use cad software to calculate how much torque my guess should be I used a thought experiment instead. My weight is around 200lbs so I visualized myself standing on the end of a 1 foot lever that is parallel with the ground. A 1 foot lever would create a 2 foot diameter circle when rotated so its circumference would be 6.3 feet of movement. You stated you wanted its rotation to stop in 120 degrees so that would be 33.3% of 6.3 feet or 2.1 feet. Converted to linear movement that would be lifting my 200lbs 2.1 feet to stop the rotation. I assumed the majority of mass would be close to the center of rotation so I thought that would probably be enough torque to do the job. Of course, if the majority of mass were nearer to the rings it would take a lot more torque.

That sounds fantastic would love to come check it out when its done. And have look around Melbourne cheers

One sample Motor purchased.

200W DC 24 V 20:1 spur gear ratio.

Also have a figure to size it correctly.
(yes it looks like Iron man but thats only because my wife wanted me to change the colors to look like that, I kept it because it looked cool)

Hope you pull it off man. That looks mighty impressive.