Update: My 2DOF + homemade shifter

Hi guys,

I've been around for a while, I think I have read almost the entire forum now I finally decided to buy all the needed parts recently:
-2 motors 23A 12V from "motion_control_products" on eBay UK (60:1)
-2 potentiometers
-2 700W servers power supplies (ATSN-7000956-Y000)
-that's it! everything else comes from the garbage (and from my previous setup, a copy of the Playseat I made myself)

I initially bought 2 moto monsters (+arduino), but I've read so many posts about people having issue with the MM, I decided to order the JRKs.

This is how everything begins:


Painting:


First test of the electronic:


And this is how it looks like tonight:


I spent a lot of time on the JRK utility, first setting the feedback, then the PIDs (just put "0.5" to proportional PID and that's it) and finally motor parameters. These motors are really fast and I had to calm them down in order to get a proper response time with the feedback pot.
Anyway, I have a problem... when I move the slider quickly from left to right (or the other way around), like if I simulated what Simtool could send as orders when in game, my motors get stuck and produce some sort of vibration noise. It seems like they don't really like the quick changes of direction.
Is it because Pololu utility is not made for that and I should just go on with Simtool or is there a specific parameter I should look at?

Thanks for your help

Hi @noorbeast ,

I've downloaded the guide already, but I'm not there yet Still setting up the JRK via Pololu utility.

I may not have explained my problem correctly: when I move the cursor, the motor move and follow the instruction. The issue is when I change direction very quickly (like swiping the cursor from left to right, to left and so one), then the motor stop following me and seems confused. It makes this strange noise, it's hard to describe, I'll try to make a video tomorrow.

Here are my settings:

Ok you need to show ALL tabs, with a motor connected, but i can see you have no D number, so put 0.5 as a start.
Raise PID period to 20ms
and intergral to 10,000
Put brake duration at 0
wind current calibration down to 110
max duty cycle while feedback is out of range, change to 600
apply settings.

Nicely built sim , sounds like your JRKs are shutting down. Most only run 200W motors on a JRK, your 276w may be overloading them on fast changes were you can get up to the stall current of the motor (way more than the rated 23 amps). I'm guessing your running a heatsink on the JRK's? As advised already, try to tone the settings down, or worse case just use the MMs and ARD, which as a half bridge can handle more current.

Also what is the rated speed of the motors?

um pardon me, but you overloaded your gearboxes hence them chewing out.
Avenga76 had PID and motor issues because the motors on them were 5500rpm. We have found that any motor spinning more than 4000 rpm tends to error out JRKS. But some time spend sorting PID and motor power, then some time sorting profiles, overcomes any problems

Sorry to correct you, but I have had the 200 watt motors running 38 amp continuous. Yes I had a heatsink on the big chip. So thats 450 watts continuous. That didnt included I was pushing them at 45 amp spikes as well.
He has got to change his JRK settings as I have advised him.

Thanks a lot for your answers! I'll follow @bsft advises and let you know today.

The motors are "around" 3600rpm (60:1 gearbox and 60rpm on the gearbox shaft).
Regarding my JRKs, yes they both have a heat sink and they are both placed in a box with a 12cm 24V fan on top (running on 12V, still very good airflow and low noise). I did my first tests without fan (before installing everything) and the heat sinks were warm but I still could touch them. I will measure their temperature, but with the fan on top the heat sinks definitely remain cold (I'd say around 40C max, maybe less, though I know it will be more demanding in games).

Oh, and thanks for the compliments, I'll post better photos later on

yes and your design, which your feet sit low means you are trying to counterbalance a lot more weight and trying to pick it up. Thats why sims should have feet higher. Dont try to blame the gears, I have had a lengthy conversation with Shane of Motion Dynamics and he and his engineer have seen your sim and its design. And also, be careful who you are trying to fool here.

Change the settings like I said as well

Sure, that's what I meant by "advises"

I've open one of the gearboxes to reverse it: the first gear (kind of screw, I don't know the right English word, the one linked to the motor shaft) is made of brass, the second gear is made of plastic I believe and both "look" to be robust.

So far it's not yet a gearbox problem, when it fails, it's definitely an electric sound coming from the motor, not the gears eating each other

Gday @Vef445, love seeing good being recycled into a lovely new object , well done.

Firstly not sure if the PSU will have the balls to hold Jrks up at full rate but worth a go.

pic 1
Ok looking at your setting you are using nearly 180 deg of your lever travel, not recommended on a seatmover as from about 40 deg above centre (horizontal lever) and 40 deg below will actually result in very little movement on the chair, resulting in a loss of motion cues. Hence I tune my feedback to use 80 deg of the 180 deg.
Bring the analog samples up to 512 , the more the more accurate the position is , as in it checks the pot position 512 times per pid period.

pic2
Ok for those motor I would set the P to 0.39 and I to 0 and D to 0.39 as a starting point after testing you will know which one to adjust
PiD Period to 20ms, this too needs to be 20ms in the Interface Settings of the Game Engine, THEY MUST MATCH
Intergral to 5000 to 10000 again testing will tell
Feedback deadzone - use 0 and only about 2-3 if larger then throw out the pots they are crap.

pic3
Crank the puppies up.
I run flat out here
as in
600 duty
600 accel
No brake - just cause motor heat and missed motion cues.
0 - unlimited current

600 on feedback is out of range, get back to right spot as quick as possible.(rarely happens)

Hope that helps you along mate.

you should become a politician

@Vef445 , be cautious of your design, there are people here with FAR more experience than some members with too many coins and too much time putting everything into FAQ,
The gearboxes have a load max, yes, but the problem is the design of the frame, not the gearbox. Anything will break if treated the wrong way.
If you have a design in mind, there are SOME of us whom can advise correctly.