6 DOF Stewart platform prototype

[NulEnMath]

Hi,
I'm French I try to build my Servo platform .
I've already cut the platform in plastic.
Now I want to place the servo .
In the code you say that the position each pi/3 but you don't explain how it is.
Is there a drawing that explain hte position of each servo ?

Regards,

[StephenB]

Actually I use 400k baud , USB or UDP so the transmission speed is not a problem.
My goal is to drive my small platform with a software that is not a game , that why x-sim is not really interesting because all the formula are in the computer instead the arduino.
Sorry about that ...

Having the calculations done by a computer is actually the best way to go! In a simulator, there is always a computer present. So why not make use of it? The computer has much, much more resources to do everything. And with a user interface, nothing has to be hard-coded into a microcontroller. The Arduino will also have more "free time", so your data transfer speed can be improved.

The delay we have can be neglected. The biggest delay is caused by the data filtering/smoothing that X-Sim performs. But without any filtering, the results wouldn't be too good. We only had a bit of trouble with Flight Simulator X, the data rate was really slow there for some reason, probably a problem with the game plugin, not X-Sim.
But overall the total delay is: extracting the values from the game, filtering them, converting them, sending them over UDP to our program, calculating the output values, sending these with serial over usb (standard 9600 baud rate), receiving them with the arduino and then moving the motors. This cycle happens at 50 Hz. The total delay is actually really impressive. If we use our smartphone app, using wifi (that adds another small delay to the cycle), the platform moves nearly instantly when the phone is rotated.

[StephenB]

Hi,
I'm French I try to build my Servo platform .
I've already cut the platform in plastic.
Now I want to place the servo .
In the code you say that the position each pi/3 but you don't explain how it is.
Is there a drawing that explain hte position of each servo ?

Regards,

Can you explain, what code do you mean?
Maybe you are talking about the project by FullMotionDynamics, their system is completely different than our system, although it "looks" similar.

[zerax]

Hi StephenB,
I don't remember where I found the files.

I remember where you found the file, since it is I who created the pdf file. Small world...
The original source: https://forums.robertsspaceindustries.c ... -chairs/p1

@tronicgr
Are you selling AMC1280USB controllers.

[maximum]

servo_min, servo_max,
servo_mult

error servo_min
servo_max
servo_multi

()???????

[StephenB]

servo_min, servo_max,
servo_mult

error servo_min
servo_max
servo_multi

()???????

As I have already said, the code you found is not created by us. You are confusing our project with the project by FullMotionDynamics, their system is completely different than our system, although it "looks" similar.

[Mertensbart20]

Hallo StephenB,

Nice looking project, as a teacher (elektormechanica, elektrische sturingen) I am very impressed with your work. I have build a 2-DOF simulator last schoolyear which you can find here:

viewtopic.php?f=37&t=335

From what school are you? I am from Belgium and teaching in the Provinciale Secundaire School Diepenbeek (in the middle of Limburg). Should you want some help, please let me * I use a PLC tho drive the simulator but an arduino is also very interesting. But since I must use PLC's arduino was not an option.

My simulator is working very well now (better than in de the videos that are now online) and this year we are adding a yaw-movement (the whole construction will be placed on a "draaikrans" an thus the simulator will be able to turn infinitely which is best for the data provided by for instance Dirt 2).I will soon open up a new project on this site and provide details about the add-on. So in the end I will have a working 3DOF-simulator. It will not be as realistic as a 6DOF but looking from an arcade-perspective it will be a lot of fun (and the movements will feel realistic). Should you live in the neighbourhood you are always free to come over and have a ride

Keep up the good work and if I can help just let me *
Bart

[StephenB]

Hallo StephenB,

Nice looking project, as a teacher (elektormechanica, elektrische sturingen) I am very impressed with your work. I have build a 2-DOF simulator last schoolyear which you can find here:

http://www.x-sim.de/forum/viewtopic.php?f=37&t=335

From what school are you? I am from Belgium and teaching in the Provinciale Secundaire School Diepenbeek (in the middle of Limburg). Should you want some help, please let me * I use a PLC tho drive the simulator but an arduino is also very interesting. But since I must use PLC's arduino was not an option.

My simulator is working very well now (better than in de the videos that are now online) and this year we are adding a yaw-movement (the whole construction will be placed on a "draaikrans" an thus the simulator will be able to turn infinitely which is best for the data provided by for instance Dirt 2).I will soon open up a new project on this site and provide details about the add-on. So in the end I will have a working 3DOF-simulator. It will not be as realistic as a 6DOF but looking from an arcade-perspective it will be a lot of fun (and the movements will feel realistic). Should you live in the neighbourhood you are always free to come over and have a ride

Keep up the good work and if I can help just let me *
Bart

Thanks
We made this project during the last year of our education at VTI Waregem. This was our final project (GIP). Now we have started our studies at the university of Ghent.
Well we could choose whatever project we'd like to make, we weren't assigned a specific project. We had the freedom to choose whatever project we wanted (this is a very good system by the way, every school should allow this), so we had to choose by ourself how we were going to solve all the technical problems. Using a PLC wasn't really a good option for us because we believe those are meant for automation and industrial use. We were also much more familiar with microcontrollers. But because we didn't want to spend more time on designing our own microcontroller board, we chose to use Arduino to keep it simple.

Our project is finished now, it is how we wanted it to be. We did not have to go further and build a real simulator. We were able to demonstrate how a system like this works and how we built it, without spending a lot of money.

Thanks for the offer to try out your simulator, but unfortunately we're not living that close to Diepenbeek
Best of luck with your project!
Stephen

[emiel]

Really impressive job!
I want to build this platform which can actually be used for a child (50kg)
Does someone know which kind of actuators I should order at eg Conrad.com?
Or tips what the minimum requirements are?
I want to have precise motion and compatible with Arduino.
So looking forward to realize this in 2015!
Thanks!
Emiel

[tronicgr]

Really impressive job!
I want to build this platform which can actually be used for a child (50kg)
Does someone know which kind of actuators I should order at eg Conrad.com?
Or tips what the minimum requirements are?
I want to have precise motion and compatible with Arduino.
So looking forward to realize this in 2015!
Thanks!
Emiel

The only actuators I see at Conrad are these:
http://www.conrad.com/ce/en/product/192657/Drive-System-Europe-12V-Linear-Actuator-100mm-Stroke-150N-45mms?ref=searchDetail

They are a little slow, but for 100mm it will take 2 seconds to fully extend. You will need motor drives as well, Sabertooth I suppose that can handle 24V for the motors.

Take care of the rating of these motors, with six of them you will be able to handle 50kg, but not more. Make a very light "cockpit".

Thanks
Thanos