My third project - 4 dof

Good morning to all simbuilders,
I started my new project and I am pleased to be able to share it with those like me who live this passion. As I have already written other times my school education has nothing to do with mechanics, electronics, mechatronics. But I have always had a great predisposition for manual skills and some motor engineering knowledge ... motorcycles and cars. Making a simulator was not at all easy for me, especially with regards to the electronic part where I often "grope in the oxen". But with the help found in the various forums and in particular of some of you I have been able to realize my first projects.
I decided to publish this project on the 3 main forums of enthusiasts that I attend
We come to the point.
The inspiration comes from here

The projects that I have tried to read and analyze to get the best inspiration are these
https://pcshm-simulateurs-homemade.clicforum.com/t580-4-DOF-Wanegain.htm
https://www.xsimulator.net/community/threads/mwb-4-dof-simulator.8968/page-7#post-154724
everything stems from the desire to create a sim without the central cardan joint to try to replicate the heave effect that I believe is the one that generates "feeling" more than others. This project requires rather powerful engines, aware that this implies, as someone has amply demonstrated, less detail. I read (I do not hide with great difficulty for the language problems) the long thread of Wanegain, and at the bottom of it also his reflections, not encouraging on this type of solution. But I want to try, applying the same solution, taking advantage of the wise advice dispensed by Momoclic and using more "performing" materials that I hope will give me a good result.
Here is my shopping list:
- Aluminum 90x45 - 45x45. I found an Italian supplier with reasonable prices and close enough to be able to supply without shipping. I don't like the color of aluminum very much so I decided to cover each used piece with carbon-like black and shiny red adhesive paper
- 4 Transtecno ECM 24V 350w motors each with 50: 1 reducer and a speed of 75rpm
- 2 Sabertooth 2x32 boards
- 2 24V 100Ah power supplies
- Mirco S3000 seat
- Steering wheel OSW Mige 20Nm
- Fanatec V1 hospital
Place some photos and I await your considerations.
The positioning of the motors and the angle of the arms respects what is suggested by momoclic with its very clear and explanatory drawings. The equilateral triangle consisting of the 3 connection points has sides of 69cm. The angle of the arms of the rear engines will be 30 ° compared to the center of the lever and the arms of the front engines will be mounted according to what he suggests
The bar is very rigid and the front anchorage will be very advanced, almost under the pedals possible

ciao gigi Sono felice che il progetto sta continuando, mi congratulo con voi, molto bello e ordinato. Ora sto aspettando di vedere in movimento

Hi Spyderwash thank you very much, your compliments are a great encouragement to me. mechanically everything should be ok. the bar seems solid, the structure also, I respected the indications suggested by momoclic making the three fixing points of the 4 motors represent an equilateral triancolo and respecting the angles suggested for the levers. Next weekend I should complete the assembly of the electronics .... then the configuration will come. get ready .... i feel that i will come to bother you to ask you for suggestions .... as you know electronics is still a mysterious world for me

Ciao Spyderwash ti ringrazio molto, i tuoi complimenti sono un grande incoraggiamento per me. dal punto di vista meccanico tutto dovrebbe essere ok. la barra sembra solida, la stuttura anche, ho rispettato le indicazioni suggerite da momoclic facendo si che i tre punti di fissaggio dei 4 motori rappresentino un triancolo equilatero e rispettando le angolazioni suggerite per le leve. Nel prossimo week end dovrei completare l'assembllaggio dell'elettronica....poi arriverà la configurazione. tieniti pronto....sento che verrò a disturbarti per chiederti suggerimenti....come sai l'elettronica è ancora un mondo misterioso per me

great Gigi I look forward to the videos and I renew the compliments I really like it

Gigi look great videos and renew the compliments I really like

Thank you: D
Beautiful project that I am looking forward to seeing working

Thank you very much Momoclic, this project is born from an idea that I saw developed for the first time by Wanegain and that had your important support. I am convinced that this solution, if optimized, first of all respecting your indications (angles, measurements, dimensions, etc.) can be excellent. We'll see. For the moment I have almost completed the harvare part. Finished structure, osw steering wheel installed, I just have to shorten the two pillars that support it, gearbox and handbrake installed, electronics practically completed. Now all I have to do is set up the sabertooth cards and load the codes for the arduino cards. I was thinking of using the one made by wanegain that I thought was perfect for the 24v 350W engines. Unfortunately, in this field I have large and large limits and I will not be able to understand if it will be appropriate to change some values such as the PID. I'll ask here ... I know you're there. For the moment I add some new photos showing the little progress made.

other photos

It seems to me that it would be good to discuss this with Wanegain, since he wrote the code

My friend is completely crazy !

... the real crazy are those who do not know they are

Hi Gigi,
nice project.
I read that you have also created the software for 2 Arduino, congratulations !!!

Ciao Gigi,
bel progetto.
Leggo che hai realizzato anche il software per 2 Arduino, complimenti!!!


Ciao

hello Alexdrako I thank you for your post. Maybe I spelled it wrong or you read it wrong ... I didn't create the scketch for arduino but I used the one created by Wanegain. So 24v 350w motors

Hello,
I confirm I read poorly, my English is poor. I use google translate.
Your project is interesting, I said to read everything well and then ask yourself some questions especially about the hardware (boards for electric motors, software, etc.).
I made my sim 2 DOF:
https://www.xsimulator.net/community/threads/2-dof-f1-simulator.12308/#post-162102 (hardware and software) from the tutorial of RACINGMAT:
https://www.xsimulator.net/author/racingmat/
and so if I wanted to increase the DOF I'd be in trouble.

ps: I read above some messages in Italian, you are Italian. I do.

Ciao

Hello everyone ... first test and first problems.
First the cables. I'm trying to use 2.5 mm cables and therefore the right size for the 24v 350w motors. Only audio cables and I noticed that after just one minute of testing they get very hot. The cards are also quite hot. I remember that when I used 12v 250w engines with my previous simulator, the cards always remained cold, at best warm even after an hour of intense use.
Second problem. .... during testing with the heave without load the engines are fast but if I get on the simulator (I weigh 80kg) the engines go into crisis. At the suggestion of spyderwash I measured with the tester the voltage coming out of the board. Well they come out at most 6.5-6.8V. I believe they are few.
Second, what's the problem? Sabertooth tab settings?
In the arduino boards I have loaded the sketch that created the magic Wanegain and I have only changed the P of the PID from 100 to 150
Furthermore, for each motor n.2 resistors 100w 6.8 ohms in parallel. But I don't think they are the cause of such a low output voltage
I thank you for helping me

what kind of power supply do you use?

For each sabertooth I use psu 24v 1000w bought from simukit https://simukit.com/alimentations/11-alimentation-24v-1000w.html
I read in sabertooth manual that output voltage should be 95% of input voltage. to my card arrived 24,2 V how can be possible that max output is only 6,5/6,8 V?

ok that's not the problem then.

I use Aliexpress power supply. there is an adjusting screw. with which you can adjust the current. I can set it up to 30V. so my 24V motor didn't work had to reset it to 24v first. thought that might be your problem.

[Quote = "Joeri post: 177.021, membro: 32695"] ok che non è il problema allora.

Io uso l'alimentazione Aliexpress. v'è una vite di regolazione. con cui è possibile regolare la corrente. Posso impostare fino a 30V. quindi il mio motore a 24V non ha funzionato ha dovuto resettarlo a 24V prima. pensato che potrebbe essere il problema. [/ QUOTE]

Also mine psw can be set the voltage. but if I have 24,2 from psu I should have 23V (95% )in output from card to motor but I have only 6,5v

Hi Gigi,
what I would try to do first is to replace the cable at least for a motor line and test again If this line will be ok that's the problem. Remember that the wrong cable resistance can make the cable hot. If the temperature of the cable increase increase its own resistence and the the temperature increase more and you fall in a loop.
wrong resistence = temperature incresae = cable resistence increase=temperature increase again ...... = volts to the motor decrease.
I don't know if is this the problem but I would try

Ciao Gigi,

one more thing about your problem. Also if the cables are not the problem, 2.5 mm is a little small.
350W with 24 V means 14,5 amps. Normally we consider for DC
3 Amps each mm so 2.5 mm in my opinion are anyway to small