6DOF motion platform using ODrive

Cool, thanks for clarifying. Nice project, looking forward to seeing the end result!

Hello to all and the Odrive team

I am so sorry, but I need to inform you that I stop working with the Odrive control.
Although I spend so much time understanding the system and studying the commands, I am not able to get a stable running system.
I’m so tired of running from one problem to another! :angry:
(I think I am not allone)

But dont worry, I will continue the development of my actuator and motion-platform-development with a great joy and like planned, but will look for another controller solution or wait until Odrive will release a stable and user-friendly software version. In my opinion this includes a modern user interface based on windows and a more simple and working flash tool.

If anybody will read this thread in the future and wants to take over the development of the motor control for my 6 DOF motion platform , he will always be welcome to join a great project.

But for now the Thread is closed from my side.
regards
Peter

Damn. I totally understand how you feel. I am in the same boat, wanting to use odrive for a simtools project. I have been watching the 3 simtools threads in this forum with the hope that you guys would get it resolved so I can follow. Thank you for documenting all you have so far! I was pretty excited to see Zennix get his project working but watching you and Carelsbergh struggle has been a bummer.

Back in Feb I too set off to imitate Zennix’s progress and ran into several problems that I couldn’t figure out. I am getting to the point where my hardware is ready to get installed in the rig, so I will give it another go soon enough.

Really sucks to see you go, but I get it. I’m posting here now in the hopes that the developers will take notice.

Hi guys

My simulator is ready, when I get the software working, I will share everything I did to get it working, I’m writing a guide.

Cheers

Carelsbergh Stijn

Hi Peter,
I’m realy sad about your frustration. But I can understand you. I don’t know how to support you more than I did in the past.
The issue with the ASCII interface is known since last year and there is no progress. I could not understand the developers. ODrive is a great product in my eyes but the developers are more interested in adding new features as fixing the basic functionality.

I’m lucky, that my sim is working. The software version I’m using is quite old, but for a sim there is only a minor functionality neccessary. Never stop a running system.

Hopefully the devs will read this and decide to fix that issues, so we can see your proffessional looking sim come to fly.

Best wishes / Zennix

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There is a suggestion in this thread by Robin that the problems are caused by a bad USB driver in Windows. Not confirmed though, but it might give a clue to why the devs haven’t been able to fix the issue.

Agreed, I would love to help write a Windows program in C++ to interface with the ODrive through the serial commands, but without a stable connection, I don’t see the worth yet.

wayneStock

Hi,
here is the issue:

Here is the programm to simulate ASCII commands from Windows:

grafik
Testprogram: https://drive.google.com/open?id=1kKuIi_Zo5Npc25uD6jVV-5sX5PyVmX6X

greetings / Zennix

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Hi cfisher, Zennix, Stijn , Barsk and wayneStock !
Thank you so much for your participation and understanding!
At the moment I am extremely confused and dont know what to do.

Imagine, that all our simulators would work good with the Odrive! - I think it would change the whole sim building scene! And lot of people would follow our work!!
I hope so much, that the ODrive developers can see this potential and will fix the problems soon !

kind regards
Peter

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I fully agree Wickie, when odrive finally is easy to setup in simtools people will be using it a ton. They just need some good inspiration. Cant wait to see this take over the ever present sabertooth and dc motor solution!

In the meantime, I’m sure we could use an arduino to pass the serial to uart perhaps?

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Hey Wickie,

Is it too much to ask for your CAD models? I would need to change a lot due to my county’s archaic measurement standards but it would be a great starting point. I completely understand if you don’t want to share them.

I’m searching for rotary shaft seals and I can’t seem to find reasonable ones rated for higher than 10 psi. What pressure rating did you go for?

Thanks,

Steve

Hi Boardy

I am still in the prototype phase of my project and some features are still under design. So its too soon to share some plans - sorry. But I can help you with answering some questions.
Regarding your question: I use a rotary shaft seal from a Ebay seller.

Link to Ebay seller

(Edit: or you can search for “BABSL NBR” )

The shaft seal is suitable for pressures up to 145 Psi. But we need much less.

Regards Wickie

Hi cfischer

I am not familiar with electronic interfaces, so I cant rate whether your proposal would work (“we could use an arduino to pass the serial to uart”). Are you experienced with these things and would you help us if Odrive will not be able to solve the USB communication problem?

Meanwhile I (maybe) found a backup solution for the Odrive in the Xsimulator-community.
Here is a link:
[FlyPT 6DOF](FlyPT 6DOF)

FlyPT uses Brushless Motors with internal hall sensors and a Arduino. The solution is not as elegant as the Odrive and also under development… but the motors would fit somehow in my actuators. We will see….

Regards Wickie

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Bit late to the party, but I just wanted to chime in and say I like your linear actuator design. Thanks for taking the time to post detailed pictures.

Hi all!
After some days of confusion and frustration I calmed down a little and continued my project. Thats also because I made a small redesign around to motor area in order to be able to have have the possibility to use other motors that I might have to use for a relapse solution. That removes a little the fear from a complete failure. Now I could use motors up to 100mm length :slight_smile:

So I started to think about some noise improvements.
I tried to wrap my yoga mat around the actuator to see the impact in noise reduction . And because it is a verry heavy mat (thats important!) made from natural rubber (also important :wink:) , it seems to be perfect for damping noise. So I deceded to sew a jacket and ordered the same Joga mat in a prefered colour that fits in my living room :grimacing:…only for a while :rofl:.
And what can I say - It was such a fun to sew the jacket together with my son, although we had no experience with sewing…
Although the actuator never was loud, now it purres like a cat :cat: …and looks so cool with its new jacket.
Here you can see the result and our short sound check with highspeed ( the loundspeaker of the TV was fairly low at this test!)


(note: this is not the final cable cover, but showes how it will look like later)

@Jake_Ketchum
nice to have you here at the party! You are allways wellcome!

kind regards
Wickie

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Hi

Have you already been able to use FlyPT or do you still use SimTools?

If so, what are the commands you are sending with FlyPT, do they look like this:
[p 0 ]
Or like this:
p 0 <13>

Cheers

Carelsbergh Stijn

Hi Stijn
sorry, I still “work” with Simtools. As I wrote some posts bevore, my work with Odrive is a little on hold and I concentrate more on optimizing the mechanical design. After this I will continue with some measurements about the power consumption. Today I ordered a 36V, 350W power supply from Meanwell for first Tests with my actuator.

I hope so much, that you can manage to solve the problems you still have. I follow all your comments, but cant really help - sorry!
Good luck!!!

kind regards
Wickie

Hi all,
the last two weeks have been very productive with help of my son. I got the lasercut- and bent parts for the universal joints. They look really great and are very precise. So I could finish two komplete joints and add them to my actuator prototype.
The joints are extreme robust and dont have any recognizable backlash.

So for the low material cost of aproximately 25,- each , the design of the jonts could be a also a great solution for other DIY sim builders.


(ups, forgot one washer…)

Yesterday I build up a simple test stand. It ist made from cheap wood and although its creaking like a old castle door it works good.

Finally I put the new 36V, 350W power source from meanwell to the system.

To simulate the load of the platform and driver I put aprox 30 kg weight onto the build.

What we have seen at the first runs was mindblowing :scream::scream:!!! :

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 !!!
Because all test were done without the internal air spring and the tests went good, maybe the airspring seem not really be necessary for the 6DOF simulator. I will do more tests and see…

The next steps will be again to optimise the actuator design taking into account all what I have learned so far.

What still need to be solved is the motor calibration sequence that needs to be done without or only with little load. My tests showed me, that with a load of aprox 10 kg it still works, but with 15 kg it fails.
Maybe a short spring or a rubber damper in the lower internal endstop can help…

kind regards
Wickie7

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Hi

You are back on track, well done, I’ve also posted an update on my racesimulator, take a look :wink:

What is your speed limit set on?

Keep up the good work!

Cheers

Hi Wickie,
nice to see your progress.
Greetings / Zennix