High angle & Displacement 6DOF

[vicpopo]

Hi ,

What awesome movements and angles achieved ! It's a catapult !lol

And yes need to be more smoother and it looks so powerfull !!
Have fun to tune your plateform to get real motion ! Great job !

[DoctorD]

Thanks Vicpopo

I decided to have a look at how the platform responds under load. Here is a video of the heave motion (position slider controlled by mouse) with 110kg of disc weights strapped on top. Speed is limited to 50%
It handles it no problems, but there is some play in the output arms that initiate a PID 'bounce' oscillation on the way down. I'm pretty sure that if I shim the output keyway that the play will disappear, leaving the PID tuning to go.

The good thing about the test was that even with the bounce, the maximum current draw only 30% greater than compared to an unloaded platform.
http://www.youtube.com/watch?v=RJifD4zdPYs

[tronicgr]

Alrighty, I finally have some decent video to show you guys.
This is a simple clip, motion is controlled via the X-Sim plugin axis sliders (moved by me using the mouse).
I still haven't gotten around to tuning the servos and all 6 motors are running off the same wall socket (not the best practice, I know). Soon I will have them split out into 3 different sockets so you won't see voltage error pauses, like when the platform drops at the front in the heave motion in the clip.

The translational movements are a little 'ugly' at the moment because the platform geometry isn't in sync with the software plugin. Additionally, The yaw movement is only set to around 50% of it's total travel.
Max motor speed set to 83%.

Anyways, here's the video:
http://www.youtube.com/watch?v=AMBpimru3Nk


Hope to have more in the coming days...

Hey Doc! That is the biggest range of motion I've seen so far for such crank arm-rod platforms!!! Wow!! And fast too! You will need 6-point seatbelt on it for sure! Well done!


Thanks
Thanos

[TheMenace]

Very Nice Doc!
Im starting a projetc now in Brazil, and if not cause trouble , can you share some specs about all you job?
I have a CNC facilit to start manufacture some pieces and now, I designing a project.

Congratulations,
very nice job!

[billo2404]

WOW...
Fantastico lavoro, forse il miglior 6dof autocostruito di tutti, complimenti!!!
mi sembra di aver capito che hai studiato molto bene le proporzioni per ottenere i migliori risultati.
sto buttando giù un progetto anch'io, utilizzero la scheda di thanos, motori da 0,55 o 0,75 kw e ho fatto già uno schizzo per la costruzione.
Sarebbe ottimo avere se non è un problema le proporzioni del tuo progetto oppure se ti va mi piacerebbe avere da te un consiglio sulle misure che ho pensato.
Questo è un piccolo disegno, ogni suggerimento è ben accetto

Wow ...
Fantastic job, perhaps the best homemade 6dof all, congratulations!!!
I seem to have figured out that you have studied very well the aspect ratio for best results.
I'm jotting down a project I, too, will the Board of thanos, 0.55 or engines 0.75 kw and I did already a sketch for the construction.
It would be great to have if there is a problem the aspect ratio of your project, or if you like I'd get you a piece of advice on the measures that I thought.
This is a small drawing, any suggestion is welcome

[DoctorD]

Hi guys,
Apologies for the lack of posts over the last couple of months. I've been super busy with work (and have taken some time for myself).
I have, however, lately managed to put some good time into designing the user station (cockpit) and, more importantly, the visual system.

The dimensions are all subject to change (and I'll post some 3D models of the work in progress later) but here are the vital stats:
3x 1080p HD 3D short throw projectors (re-packaged seconds from BenQ. Less than half price, yay)
Image blended and warped onto a cylindrical screen (screen and projectors will move with the platform and user)
Screen size: 1200mm high x 4000mm wide (approx. 6 million usable pixels across a 220 degree horizontal FOV)

I have already done the image warping and screen design in software, all that's left is to do some ergonomic testing and I will begin building it.

Needless to say I'm getting very excited to see the whole thing finished and have friends have a go inside it.

P.S...
@billo2404 - Your geometry looks good and 0.75kw motors would produce very similar results to my system.
One suggestion, if you can reduce the upper joint spacing you will make it easier on the software for geometric alignment (if using Thanos' board). I would suggest a spacing of around 50-60mm (should still give you plenty of room for clearance).

[DoctorD]

Here are some renders of the 220 degree projection system screen I plan to build this weekend.

ScreenRender.jpg (127.39 KiB) Viewed 6652 times

ScreenInside.jpg (55.69 KiB) Viewed 6652 times

ScreenBlendandWarp.jpg (73.1 KiB) Viewed 6649 times

[DoctorD]

...and I couldn't help myself.
Here is a shot of the screen in place above the motion platform:

PlatformScreen.jpg (61.08 KiB) Viewed 6650 times

[billo2404]

@billo2404 - Your geometry looks good and 0.75kw motors would produce very similar results to my system.
One suggestion, if you can reduce the upper joint spacing you will make it easier on the software for geometric alignment (if using Thanos' board). I would suggest a spacing of around 50-60mm (should still give you plenty of room for clearance).

first of all I must compliment you for the mega screen ... with this surely your sim won't rivals
With regard to my project instead had several evolutions:
On the advice of Thanos I positioned engine levers inward and then very kindly Stevant1 user, whom I thank, has provided me with its measures and then I got based on those given that his sim behavior seems to be very good.
How to use the AMC1280USB electronics.
If you want to take a look at the latest designs I'd love to know what you think.
Can you explain what advantage would be reducing the distance between upper platform attacks?
I ask not because I doubt Council but only out of curiosity and to better understand the mechanical behavior of the system.
Here is the size of the project after the various updates

[DoctorD]

Heya Billo
The geometry in your design is excellent. You should see a good amount of movement in all directions (with plenty of power and speed).
The only reason I suggest closing in the distance between the upper mounts is so that they form more of a 'triangle' than a 'hexagon'. A triangle is geometrically easier to solve and will make the software/callibration side of things easier to tune.
i.e. you can define a plane with three points. Any more just overconstrains the plane.
...kind of like why four legged tables at restaurants always have a little rock (and why they would never have that problem if they all had three legged tables).

Here's a quick pic of where the screen is up to:

ScreenProgress.JPG (565.96 KiB) Viewed 6556 times