Lauching finally a 3DOF (seat mover) instead 6DOF low cost dynamic simulator

Hello,
WE very rainy, so perfect to spend my time in the garage and to continue the Xdof. Now , I think you can better see and understand my special "pseudo" cardan (with easy maintenance, just 6 bearings at 2 dollars each one to change if necessary), and able to support a 3 DOF frex seat.
Concerning the sprints, I used springs bought yesterday (7 dollars for !!, coming from a old garage door), and cut in half. I begin by used only the first one, so in 2 part, but after the first test, it is enough for a children (max 50 or 60 kg), but for an adult it is too low, so I have to cut also the second one and to add it (so there will be a total of 4 short springs in parallel, able to assisted the 3 motors until 120kg, so I can eat hamburgers and fries...). To adjust the tension, very simple: a threaded rod and a simple bolt.
See you...

Hello all,
Short movie with R facto on my cheap screens installation (1 x 28" 16/9 DVI, and 2 x 19" 4/3 VGA), I can't wait my Xdof...

Hello all,

some news : Xdof adventure - Episode 33

After disassembly, panting, reassembly of the FREX cardan mechanism, I have calibrated my springs (very powerful !!!!)

see you

Hello everybody,

some news concerning my Xdoc progress:
-> the actuators for seat moving are in almost ready (one is completly assembled, and the sub-components for the 2 others are ready),
-> The arduino software is ready (I receive perfectly the data from simtools, Itried with several games as Rfactor special edition 2008, and other...). I will send a short video,
-> the electronic boards are assembled in a nice box

see you...

and now a short movie (I have not still perfectly adjust the PID, developped from scratch and not using the special arduino library, with to begin Kp=40, Ki=5, Kd=10. It will be better to adjust all that when I will sit down on the moving seat ...)



bye bye

Nice work!

You are using Rotary Encoder ky-040 right? I'm using the same encoder with interrupt routine and 33uF capacitors for DT and CLK signals.
Why exactly do you need the speed counter and periodic re-synchronization? Your rotary encoder is missing resolutions during time?
I'm using an optic sensor tcrt5000 for the initial calibration and min/max angles limitation.

Thank you Gustavo
yes I am using ky-040 (rather a chinese copy...) connected to standard digital input (without capacitor) . As I had some shift after a few minutes, I decided to resynchronise the neutral position automatically each time the axes goes from negative to positive value (so very often...). For that I am using a optical detector (do not know the reference) connected to 1 of the 2 interrupt inputs of my arduino uno (which is controlling 2 motors). I can also simply change the 180° sector used (if change of an digital input state a few second after a reset). So that allow to increase thi life duration of the motor gear.
Do you are currently building a simulator ? how many axis ? could you give me the link
bye bye from Toulouse (south of France)

Got it, I think you can try to add two capacitors for the DT and CLK and check the results, it will add stability for the encoder. This github repo has some images showing the ky-040 Switch Bounce timing:
https://github.com/Billwilliams1952/KY-040-Encoder-Library---Arduino

Yes, I'm on the beginning of a 6dof prototype: https://www.xsimulator.net/community/threads/6dof-prototype-using-small-dc-motors.12059/
So far I'm testing one motor with sensors and calibration system. I bought a 3d printer, it will arrive in 15 days, so I'll try to print some engine system for the motors/sensors/encoders, like your motor engine.
My mechanical skills sux

What H bright are you using? I bought 2 chinese monster moto shields without lucky, so'll give a try to the chinese h bridge Bts7960.

I wiil try capacitors, but just for fun as my design is already running very well with my 'multifunction' optical sensor so autocalibration of neutral + resynchro... moreover my software is detecting and counting each edge of clk and D, so my resolution is 60 per rotation instead 30.
What do you mean by "my mechanical skill sux" ? I am using chineses boards (2 channels per board, price 8 euros, don't remember the ref) namedH " bridge board with L298 similar control logic" 24v 7amp ( 50amp peak). As I am using 24v/5a motors, it is perfect...
I tried to build a cheap mechanic, so my first part of my simulator (which is just the seat moving : right-left + aft-forward + up-down) is using 3 actuators arround 100 euros each (70 for motor so the most expensive bought on the site simukit, 1 for ky040 like, 4 for optic detector, and the rest for the other mechanical parts).
Doc

Hi Oms,

Any updates? Did you try the capacitors?
My 3d printer arrived and I've been assembling and upgrading it. Do you have the 3D model of the 72 and 12 teeth engines? I would like to print the engines and try on the small motors with the ky-040, I really liked your design and the 60 resolutions using the engines.

Hello Gustavo, no great update but little by little I am now close to try the 1st part of my future simulator, so the 3dof seat mover. I am looking forward that for several months... Hope I will not be desappointed..
I have no tried capacitor but as my periodic synchro is ok to not lost the neutral position it is not a priority.
Sorry I do not have 3d model of my gear, but I know you can easly find that with sketchup (see warehouse). I can just give you some dimension if you want (but in a week when I will come back to France Toulouse, as I am currently on holidays in Spain...). By the way, what is the model/brand of your 3d printer ?

a

Hi Oms, first of all, please enjoy your vacation

Your motors engine looks really nice, so you already have all the motors and the engines working, just need to put the motors on the frame and start the tests hehe.
The 3d printer is an Anet A6 (Chinese, clone of Prusa i3), after doing some adjustments and printing some parts for the printer, the printer quality is really good, not perfect. Now that I can print anything, I really thinking about printing parts for a linear actuator, I think controlling and building the simulator with linear actuators is easier than dc motors. I will research about. Please let me know the results/tests of yours motors.

Hello Gustavo,
thank you, my holidays in Spain are nearly finished ... but I can now finish my simulator...
It is very interesting your 3D printer, I will probably buy one, that opens a lot of doors...
Concerning my current project, after a lot of thinking, I will stop this first project as soon my seat mover will be operational (so I will have 3 dof with pitch/roll/heave). I am preparing the tests, I think by the end of August... (looking forward..). Now I know that simtools runs very well, not difficult to use, and it is also easy to develop softawer on Arduino to transform simtools data to a motor position..
So I would like to continue the adventure by building a 4dof simulator with virtual reality (pitch/roll/heave/yaw is probably the most important axis to make you feel the different forces), and I think that in this case a seat mover is not very relevant. I would more design something between : &
the most compact possible, not too much expensive, but with the higher angles possibles... I agree with you when you say that it is easier to use linear actuators, but the prices is very high. I will probably instead use dc motors (24 or 48V, around 500W, and around 50 or 60 rpm), you can find on Alibaba around 100 dollars. I know now that it is easy to realize cam lever with very simple tools (a grinder and a drill).
I will reopen sketchup soon...

Waiting for news on your own project
bye bye
Patrick (Oms my last name...)

IMO after building a few different systems, there are issues in using pitch/roll/yaw to simulate forces in a simulator. It is much better to use a G seat for this function and leave these axis for 'orientation through rotation' as they are meant to be in the real world. If you have the time have a read of my thread were I talk about some of the issues https://www.xsimulator.net/community/threads/building-a-better-mouse-trap.11739/#post-152491

Thank you, I will deeply read your post, that seems very interesting...

hello all,
next step... and a little delay because following the first real test I decided to make also the pedals movable ...
bye bye

Hi Oms
Nice job.

Have you start the test? Are these motor powerful enough to lift the adult's weight?

Thank you Fourteenary
motors are not powerful enough alone, but with my garage door springs... YEAH NO PROBLEM AT ALL UNTIL 120KG PILOT WEIGHT !!!
In fact I have finished my 1st motion simulator 3dof seat mover in October, but no time to do a movie until now. Thanks a lot to all of you who helped me. Now I am strongly thinking to my futur project (a very special & specific 6dof VR with +/-50° of pitch, a little less for roll and yaw, and around +/-15cm for heave, surge, ... and very compact)
I know that °/-50% seems not easily feasible... you have doubts ... I will explain you that in a futur post, but firstly...:


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GREAT SCOTT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!