Wickie´s 6DOF Sim

Hello together

After reading in this great forum for some time and reading a lot about your great projects, I would like to finally make my contribution and present my own project which I have been working on for about 9 months - namely the development of a 6 DOF platform for race and flight simulation. Since tinkering and developing is one of my hobbies, it was also clear to me that I would like to develop and build the linear actuators myself.
I also have a small workshop in the basement with an old lathe, so I can also make some more difficult parts.
The development of the linear actuators has now been completed and a first prototype works very well.
The linear actuator is based on a 1605 ball screw (600mm long). As motor I use a Hobbyking KEDA 63-64 190KV Brushless Outrunner (2000W max.). The motor control "Odrive" which I use is still not common, but seems to be perfect for building simulators. The whole structure of the powertrain becomes very simple (apart from the configuration of the software). The Odrive control is connected on one side directly to the USB port of the computer and on the other side with the motor. Power supply unit on and ready! .

Here ist the current CAD-model of my sim:


And here the current prototype with the Odrive motor-controller :



Introduction to be continued…..

Wickie

Seems good!

What's your power supply?
And positioning system?
Been looking at those motors also. Had the idea of making a prototype for a new actuator.
Want it to be more silent, closed, and compact. Just what you have.
Those motors are powerful and compact. Had the idea of using PVC pipes to make it cheaper.

Good job! Curious to see it moving.

Hi FlyPT

I'm very happy to see you here in my new thread, especially since I'm a big admirer of your work on the interface software!

Currently I'm using a power supply from Meanwell 36V, 10A for the prototype tests. But I would like to have a bit more power for the later 6DOF simulator and so I'm still thinking about choosing a somewhat stronger power supply. For the current load tests with 30kg per actuator the power supply would be sufficient.




The positioning is done with help of an AMT102 encoder, which sits directly on the motor shaft and is connected to the Odrive motor-controller:


To improve the acoustics I made a cover out of a rubber mat. I think the acoustics are not bad now, but I still want to improve it even more. A big step will be to use quality ballscrews from TBIMOTION instead of cheap ballscrews.

I hope I can already link a video of the running actuator with my next post......I'll try it right away

Wickie

Hi all!

Here is a short video of the prototype running with a load of aprox. 30 kg:



It seems that the actuator has an easy game with all the weight put on it! – And after aprox 15 minutes testing, the motor and the power source remained cold !!!

Wickie

So you can control two motors in each Odrive right?
Those sensors are a good choice.
People are missing this and should pay more attention.
Motors are around 50€ each and the sensor 20€ (2048ppr).
The Odrive is 120€, but for two motors. So around 130€ electronics for each actuator.
Now expense is on the power supply side. But those motors seem to be fast! and powerful. Many use them in e skates or small e scooters.
How many rpm can you reach? And binary?
There's someone else here with one of those rigs. Sorry, can't remember the name right now.

Hello pmvcda (or should I stay with FlyPT?)
the cost statement already fits quite well. I will post all components and sources with costs later. A clean documentation needs a lot of time - let's see what I can do in the next time.
The Meanwell power supply cost 44,- € on Ebay.
The maximum speed settings that worked with the power supply and the 30 kg load was 300000 to 400000 counts per second - above that the power supply switches off. My encoder is set to 8192 cpr (counts per revolution). So the ballscrew rotates about 36 to 49 times per second. This corresponds to a speed of 180mm/s to 245mm/s with a ballscrew pitch of 5mm.
I did not measure, but my feeling is that the speed hardly changes under load. So this should also be the real speed.

The names of the two guys (in the Odrive community) who have already built a simulator with Odrive is "Zennix" and "Stijn_Carelsbergh".
Zennix is for me the "father of the Odrive simulators". He was the first to get the software and the interface up and running. Without his preliminary work, my project would not exist at all.

Hello, everybody,

here are some more details about my Project - The cardan-jonts.
When it came to the selection of cardan joints I spent hours searching the web for suitable cardan joints. But unfortunately I was not successful. Either the joints were too small, or much too expensive.
So I decided to make them myself.
I have also found a very good and cheap manufacturer for the sheet metal parts (https://www.laserteile4you.de/home.html).
If you should order something, always look what a larger number of parts costs - often the double number costs only little more!

The center parts of the joints are made from POM - in a form like I could make it on my lathe and how I found it beautiful.
Surely the joints can also be made very well with a 3D printer - but I don't have one.
The cost per joint is about 25,-€ , so 300.-€ for all.
After the tests I can say that the joints work perfectly. They are almost backlash-free and can easily carry the weight of the platform and the resulting torque comming from the actuators.

I hope you like my ideas

Here are some CAD and real pictures:








The final cylinder rods will not have those scratches

here is a current section through the actuator. The image should be quite high resolution - so just enlarge it



Wickie

Awesome work dude I love it !

I'm gonna have to change my upgrade plans now !!

I was going 24v DC brushed but this has changed my mind entirely, is the any other controller board/driver that will work with these motors or is it limited to the ODrive ?

Some good deals on these type of motors and you get a lot of power for the money

can you estimate the cost to build one actuator pls

The Odrive card is similar in price to a Sabertooth 2 x 32, so certainly worth a look. Maybe some cooling/ventilation for the motor? All that heat has to go somewhere...

Hi SilentChill

As far as I know and after my research there are no real alternatives to the Odrive. Someone in the Odrive chat once said that there is a similar controller for BLDC, but it's supposed to be very expensive - so no alternative for me .
The configuration of the Odrive control is sometimes very tricky, but fortunately the Odrive community is quite good and mostly helps.

During my load test with 30 kg the motors and the power supply always stayed cold - not even lukewarm. If the motors should become much warmer later, I can attach a small fan wheel to the back of the motor. The cylinder tube can give off the heat well over the whole length.
"Zennix" told in the Odrive community that also his motors get only slightly warm. See:
https://discourse.odriverobotics.com/t/simulator-rig-with-odrive/848/64?u=wickie
He also uses the Odrive-motorcontroller and the same motors like mine

Here are the costs of my prototype-actuator (+/- some €). I made it with a medium price ballscrew, but will go to high quality ballscrew. It will cost further 100,- €.
It would be interesting to see the real costs of other 6DOF-Sims!

I am really wondering how e.g. InsectaTech can sell his professional 6DOF-sims so cheap! I think they are complete from 8000,- € to 12000,-€ or so. I do not think the parts are cheaper - it has many milled parts that look very expensive.. Hmm…. I am really wondering.

So here are my true costs:
1 motor 30 €
1 coupling 8 €
1 Ballscrew 1605 75 €
1 distant ring 2 €
1 Encoder + Cables 44 €
2 angular ball bearing 9 €
0,5 Odrive (costs for 1 motor) 90 €
1 Zylinder-pipe 17 €
1 Stainless steel – pipe 2“ 20 €
1 inner pipe 6 €
4 distant bolts 7 €
magnets 10 €
screws 10 €
2 Reed-switches 10 €
materials 30 €
miscellaneus and delivery 30 €
2 universal joints 50 €
4 vibration dampers for motor 6 €
1 cover for reed-switches 12 €
4 threaded rod 4 €
1 rubber mat 30 €

500 € (including motor-Control)

Wickie

That price doesn't look too bad, i was expecting more but then when you have to times that by 6, i guess that's where the cost comes from for a home DIY builder... Haha

Hi Wickie,

You can decrease that cost more if you use real servos, the AASD-15A servomotors instead (about 250USD each) and the AMC-AASD15A servo controller (280usd for controlling 6 servomotors)... Oh and you will save on power supplies too, these wire directly to 220v (or 110v too as well now).


Plus you will have less wiring to deal with, those odrives need encoder connections except power, plus limit switches wiring etc...

Just saying...

i would like to know dimensions of your CAD sim model...

im trying to figure out how should i size my frame, chair mount and stuff...

your build coming nicely.. i wish i went your route, i spent the last 5 months building the DIY version and im not even finished...

any info much appreciated! @PeterW

hello Hannibal,
sorry for my late reply - had a lot of work.
The exact dimensions of my platform are not yet fixed, because I concentrated on the construction of the actuators. I've done a lot of collision Research in the biginning (see Pictures), but I'm not sure until I've determined the seat, seat position, steering wheel, pedals...as well.
Therefore, I can only give you the dimensions as the simulator is currently constructed:

Wickie

Hello, Thanos,
I appreciate your work very much and have already thought about using your control in the past, but finally decided on the Odrive control.
I think Odrive is a new way and we should give the controller a chance. Using hobby brushless motors opens up so many new possibilities...
In addition, the motor I use can be completely integrated into my 90mm cylinder barrel. I love that...
I have also considered the costs of both systems (see below), but have not found any real savings.

Wickie

No problem. But it seems you forgot to include the hundreds of meters of wiring your solution still needs... all wiring is included in the AASD-15A servos already, and its plug and play.