Showroom 2DOF for Racing

Hi everyone,

after years of being a reader of this site, I'm decided to start my project.
still deciding between a platform or seat shaker... (but I like the idea of feeling pressure on my wrist when braking) I have been acquiring the important parts and this week I will be fitting them together.

I bought and arduino two years ago, and built a prototype using RC servos, I was able to make ir work, but I like the JRKs so I have got a couple of them, they are expensive but now that I am finally decided I want the sim as wild as possible...

Here some photos, the only thing that I have done until now is modify a couple of IBM server PSU ($25 including shipping) and try the motors and the JRKs with simtools and LFS

the motors are form eBay (200W 50:1 12V), the joint from junk cars place, was cheap and looks very good to me, tomorrow I am taking it to a workshop so the can solder a base.

Hope you guys like this building process and could help with the questions that will be raising.

Still not sure... I really like a design like yours because they are very compact but from I have read, seems that for racing is better the shoulder mount... base on your experience what would you recommend?

I got a couple of fans and heat sinks from old computers, maybe they are too big... but that should not be a problem, in case a have problems to fit the heat sinks i could try to cut them in half.

Hi again,

after a 4 days, I picked up the levers from the workshop yesterday, but I have a question on how to attach them to the motors.
I asked for a 2mm whole in the lever bolt in order to fix the rotational movement, but it has some degree of play... when I thigh the nut of the lever the is movement at all, but i don't know if this is going to work when the sim will be working full loaded... do I have to take back the levers to the workshop and ask for a better on the perpendicular bolt or thigh the lever bolt would be sufficient? what are your experiences? I have try to find some info on the FAQ about how to attach the levers to the motor but seems there are not a detailed explanation

I am attaching some photos, seems to me that from my words is difficult to understand the point, so hope the pictures can help.

thank you very much in advance for your feedback

Sad day... I got today the levers mounted on the motors and I was very happy with the result, I was able to get one motor controlled but the on the other one I got fire on the Pololu main chip...

In my opinion I did not make anything wrong, in fact i was able to control the other motor with no issues.
The polulu was not working, the chip started getting hot, i disconnected the 12v PSU in order to prevent damage on the board I double checked there were nothing wrong, everything was ok so I tried to connect again and then fire on the main chip… the motor had free movement at all moment and the max current was set at 12amps
Real sad situation, stuck again... since I am form Mexico getting a new one its going to take time...

Hi again, it has been a long while without posting updates but I have been working on the sim and it is looking better

As i told before one of the JRK got burned while I was configuring it, Pololu send me a replacement for free after email them back and forward, I try the new one yesterday and it not working also... now I have a shortcut between Vin and A terminal. I am very frustrated, I have been looking this forum for years and now I am so close and so far at the same time... I don't now what is happening with the controller may be is really bad luck or maybe is something wrong with my installation... but the motor works good when i connect it directly to the PSU and the PSU seems that works good also and the installation is identical to the one that works with no problems... (I am using two modeified PSUs, one for each motor) coolers and fans, anyways the controllers got broken before I put them under load...

I think I am going to buy a new controller, since I do not think that the shortcut between Vin and A terminal is somthing i could possibly fix.

I will be posting construction details during the week, and if someone has recommendations about the controlers, please let me know. I am doing what the FAQ and forum says, based on others experiences but at this point Idont now if it was really bad luck or I am missing something or the PSU is doing strange things

does anyone know how to detect if the PSU is over powering the controller?

pololu is preatty expensive for a mexican devaluated peso currency (as you can see, i am in mexico too... i have the devaluation stuff...) why don't you try usign arduino and moto mosnter controllers from alliexpress they are ultracheap

best regards from mexico (guadalajara)

fer

(where are you from?)

(de donde eres compadre, yo soy de guadalajara, suena emosionante ver a alguien mas de mexico, no recuerdo bien cuando fue la ultima vez que alguien posteo de mexico perocreo que eres el primero)

nice seat, how much did you invested on it and where did you got it?... is it conformtable?

fer

I got it from summit racing and it is confortable enough for the price... https://www.summitracing.com/int/parts/sum-g1100-1/overview/

I did the multimeter test and it shows 12V, tomorrow I am going to do deeper analysis, I am thinking in connect the motor directly to the PSU and record the maximum and minimum peaks of current and voltage while moving the motor back and forward.

The PSUs: IBM 24R2730 Hot Swap Power Supply Artesyn 7001138-Y000 835w
I got them from eBay 25USD both, shipping included... may be the problem is that they were so cheap.

Here is the response that i Have got from Pololu,

Hello, Juan.

Thank you for the update; I am sorry to hear your replacement driver has also been damaged. At the point where multiple drivers are failing in your system, it is almost certain that either they are not appropriate for what you are trying to do, or something else in the system is causing them to fail (like your power supply). We test every unit and have had no other reports of problems, so we can be confident this is not a case of defects with the jrks.

By the way, having another jrk working in a similar (or even identical) setup is not evidence that these controllers are appropriate for your application. If you are exceeding the rating of the driver in some way, that is not guaranteed to break it, so you might have just gotten lucky with your other jrk so far, or you might be near some threshold where minor differences between the two setups (or even from unit to unit) mean the difference between breaking and not breaking.

If you would like to continue troubleshooting, can you clarify what error you were seeing (e.g. error #3 is not an error code specified for the jrk)? If you connect the jrk to your computer with nothing else connected to it, does it show any errors being triggered in the "Errors" tab?

As far as testing your PSU, you could look at the output with a meter or oscilloscope to see what the highest and lowest fluctuation is over a period of time. However, the only way to be really sure that the supply was not involved you would have to have been looking at it when the jrk was damaged.

Did this board get hot like the other one did before it was damaged? As mentioned in my previous email, we were a bit concerned that the jrk is underpowered for your motors. The "Max. current" setting in the Jrk Configuration Utility can help prevent some problems, but it is certainly possible that spikes of current can happen fast enough that the jrk cannot react before damage is done, and this setting is definitely not intended as protection against large, brief current spikes.

- Brandon

@noorbeast here is the photo with the soldering, I have checked the output and it is 12V on both PSUs, I configured the multimeter to record the max voltage value and made a record when I plugged in the PSUs and also while running the motors and the max value was 12.17 volts.
Now I am thinking that the problem may be the power of the PSUs, seems that everybody here uses PSUs ranging form 300 to 500W and the ones that I am using are 850W (one for each motor) so the could supply a nominal current of 70 Amps... The JRKs are configured with a limit of 12Amp, but maybe because of the power of the PSUs are some incontrolable spikes. Could it make sense???
Does anyone have succeed using 850W PSUs powering JRKs? I have been doing some research on the forum, but I have found anybody using PSUs above 570W

Thanks for your help!