Prodigy's SimV2 - 2DOF - JRK's - ZYT90 DC Motors

[prodigy]

So, here is my second simulator project. The first one I haven't presented here because I've build it fast and destroyed it even faster Just kidding, I haven't destroyed it, my friend got really excited about it so I've decide to sell him the parts and build myself a new simulator with big motors and JRK controllers.

I will just put few pictures of the old simulator that you can see what it looked like. I used Velleman K8055 + Sabertooth dual driver + Wiper motors. It worked pretty good and total cost was a bit less than 300 $ (excluding the PlaySeat and G25 Wheel).



Now, moving on to new simulator I've decided to use ZYT90-155-12 motors from Motion Control Products and they are selling them specially over E-Bay (LINK) and their MCP4 Gearbox (LINK).

For the motors controllers I've decided to use Pololu JRK's 12x12 since they are very praised here and they work very well. They can be bought HERE and use discount code (XSIMJRK5).

I'll do some summary of the cost of this project and I will calculate 25% our VAT + shipping.

2 x ZYT90-155-12 DC Motors --- 98 $ + 25% = 122 $
2 x Gearbox for ZYT90 ---------- 65 $ + 25% = 81 $
Shipping ---------------------------- 86 $
TOTAL for 2 big motors: 289 $

2 x Pololu JRK 12x12 controller --- 190 $ + 25% = 237 $
Shipping ------------------------------- 45 $
TOTAL for 2 Pololu controllers: 282 $

2 x Linear 5K Potentiometers --------- 11 $
4 x M10 Rod Ends ----------------------- 36 $
14 x Caps for hiding frame holes ------ 3 $
4 x Levers / Arms for motors ---------- 8 $
10 x Screws with caps ------------------ 30 $
2 x Power Supply 12v 45A ------------ 126 $ + 25% = 158 $
2 x USB to Mini USB Cable for JRKS --- 8 $
Various screws and similar stuff ------- 20 $
Used uni-joint (cardan) from BMW ----- 35 $
TOTAL for peripheral stuff: 309 $

So, total cost for this project was about 880 $ - if I've missed to write something, I guess it wasn't something important. All the frame metal I've had at my backyard so that didn't cost me anything, in fact, my folks were very happy that someone will finally use that crap

After seeing flaws in my first sim, I've decided to do different type of frame for this project. I haven't done any sketches, I've done some basic measures and did other stuff "on-the-go". I wanted to do a more adjustable frame and tighter one which in the end it turned out exactly how I wanted.


Building up the upper base and using screws with caps for easier tightening.


Putting some corrosion protective colors and adding black later. Painting it was a bit of mine mistake, I've done it to early and later I had some stuff to weld that I've forgot, so basically, I gonna need to repaint it again


The first wheel plate I've did was a bit narrow, wheel wasn't tight, so I've decided to create a new plate and weld it on to smaller one.


Some 5K and 10K pots, plastic caps to fill the cut holes on the frame, rod ends, levers and some decorative frame additions that I will repaint in black.


Power of JRK's. They are so small, I was afraid not to break something while soldering jumpers


Used uni-joint from BMW, needed some cleaning but other than that it is very tight and smooth moving.


Created motor placeholders and mounted them on to the bottom frame.


Both frames completed


Simulator moved to livingroom for testing


And this is where my project it stopped for * I thought I would enter into new year with my new simulator but that didn't happened. Unfortunately, one of the ZYT90 motors doesn't work at all, it's like dead, and now I am communicating with people from Motion Products about next move.

Now we wait

UPDATE - 08. Jan. 2013
The motor was not faulty, it was just one of the brushes got a bit loose and I've needed to push it back. Thanks to support from Motion Control Products.

UPDATE - 18. Mar. 2013
Today I've finally got the 2 strong PSU's I've ordered. I was waiting for them more than 40 days because idiots at our customs didn't send me any notice that the package arrived. It was on customs for about 2 weeks until I've found out that it is there. After yesterday's not so pleasant phone call with customs they have send me the PSU's right away and today they arrived. Now I got the whole package to finish my sim. Waiting for parts was such a pain in the ass.

UPDATE - 21. Mar. 2013
Yesterday I had some time to play with JRK's and cooling system.



I couldn't find some normal heatsink, everything I've got from old CPU's were too big, so I've needed to cut something I've found from old graphic cards. Finally keeping all that old computer garbage turned out to be helpful
I've put some thermal paste on JRK chip, put a heatsink with small fan on it and glued the sink with plastic glue on the blue terminal. The problem is, if the heatsink gets too hot, the plastic glue will melt and heatsink will fall off. I'm gonna see if this would happen again, if it does, I'm gonna take MotionDave's advice and glue it with proper strong glue.

Later on I've decided to make some place to keep electronic on it, bought a piece of cheap black painted wood, cost about 4$. I think the small fans on the JRK's and 2 big fans on top would do the trick with keeping JRK cool, or to better express myself, prevent them from overheating.



I need to figure out how to mount the JRK's on the wooden plate, the holes on the JRK's are very small.
I wanted to do it with motherboard screws like this ones, but even they are too big for those holes.



I will try to do it like Floriske did, with some peace of foam between JRK and wood, and screw it with some thinner screws.

I hope the cooling on the JRK's will be fine.

UPDATE - 26. Mar. 2013
Unbelievable what just happened to me



I've accidentally scratched the small resistor or whatever it is with screwdriver when I was trying to screw that small bolt. On top of all, that tiny resistor felt in my carpet and there is no person in the world who could find it. What a luck..

I've tried to plug the JRK in the USB to see if it's working and it is. But even so, I don't know how important that resistor is, I think I'm gonna need to buy new JRK. There is absolutely no chance that warranty can cover this, I can only hope that people from Pololu would have some sympathy and give me some discount for the new JRK..

Unbelievable, the electronics were ready, everything prepared, today was the day to finally turn on the simulator and drive..

UPDATE - 28. Mar. 2013
While waiting for Pololu's answer, I wanted to test at least other JRK to see how will it go, and boy, those fans are keeping the JRK almost ice cold What a nice feeling to see that everything is moving well. A big relief for me. I've tested the motor with Assetto Corsa and rFactor 2, didn't mess a lot with making profiles, I want to do a quick test and tested only with brake / acceleration.

First 15 minutes went well, I've checked JRK tool for driver errors and saw there was 5 motor driver error which I didn't even noticed. Comparing to last test where I had hundred of them after two minutes of working.

I did some slight changes to PID, making the motor moving less jerky, then I've let the computer driving in RF2 and after 10 minutes, not a single motor error, YEE-HAAA

Here is just a short video of motor moving


UPDATE - 29. Mar. 2013
I did some testing with both JRKs today, damaged one worked fine. Left the autodrive in RF2 for 15 minutes, JRKs got a bit hotter but nothing noticeable hot, just a slight feeling on the finger.

Here is a video todays testing

[ferslash]

looks grate, some videos?

fer

[motiondave]

That's a nice set , and about the price range of a home built sim. Cheaper than a commercial and you will get better motion with some profile fiddling.
Bugger about the motor,but I am sure you will be moving in no time.
If you need help setting the jrks, heres some starts.
Pid 3/3 0/3 3/3
Max accel and max duty cycle 400
Current 0 - unlimited.
Give that a run. These are BASE settings to get you sorted.
Put a heat sink on the big chip of the jrk and fan cool it.

[prodigy]

Great news - motor is working!

Thanks to the technician from Motion Control who guide me through possible failure scenarios. The problem was rather simple, one of the brushes got loose so I've needed to push it back, but I didn't want to do anything on my own before their instructions, because of losing warranty.

OK, moving on to JRK's, how do you people apply heatsink on it? I mean, I have an heatsink from old CPU which I will need to cut it, but how to make it tight on the JRK, fixated so it doesn't move?

[motiondave]

Some people use thermal tape I have seen.
I used heatsink grease, sat the heat sink on and glued the edge to the blue wire terminals. It stays put. Not a firm sit on , but it does still transfer the heat.

[prodigy]

Thanks for the glue advice Dave. I've used some thermal paste and glued the heatsink with hot plastic glue on blue terminal. It's pretty tight right now, it did the trick

I have tested the JRK's yesterday and I have occasional motor driver errors. When that happens the motor starts to jerk and in the JRK utility STOP and START button switches fast, I've needed to click several times on STOP button very fast to hit it because it switches on and off fast.

That mostly happened to me when I moved "set target" slider in JRK utility a bit faster, when I move the slider very slowly than it is ok, the red and blue lines in the graph are moving together and so moves the motor to it's position. But if I move the slider faster, motor has a bit slower response and eventually I get motor driver error and it starts to twitch.

This also happened in the game, I have tested it with DIRT3, X-Sim setup was not the problem, I've got the motion, everything was fine but in the middle of the driving I get this error.

I have used 3/3, 0/3, 3/3 PID with 400 Cycle Duty.

Any suggestions about that problem?

[motiondave]

if it is a motor driver error, try setting feedback deadzone from 0 to 2 in PID, try setting motor accel , duty cycle and max duty while feedback is out of range from 400 down to 350.
If you find the motors a bit sluggish, move it up a bit at a time.
Remember to use collision effect on the forces as well.
http://www.youtube.com/watch?v=r4nSg0VVgP8
Also remember that JRKS are not really designed for simulator use, but they work, just a bit of fiddling

[prodigy]

I will try to do that, thanks.

One thing, does it matter if I have JRK utility open while playing? Will it conflict with X-Sim?

[floriske]

I had the same problem with my ZYT 90's but after tweaking the PID settings this was gone.

My settings currently:

PID: 6/5 - 13/8 - 3/2
PID period: 10ms
Integral limit: 1000
Feedback deadzone: 2

Max duty cycle: 450
Max acc.: 450
Brake duration: 0
Max current: 30A
Max duty cycle while feedback is out of range: 450

Here's the PID strategy I used after some online research (JRK manual) and tips from BobBuilt:

• Start playing with the test plugin to find the value for "P" at which it becomes unstable/overshoots
(Using 1 slider per motor, fastly moving the sliders manually and also setting it to auto at max speed so the sim starts rocking)

• Reduce the max "P" value with 40-50%

• Increase the value for "I" until the "error" is +/-1 and enable reset integral when proportional term exceeds max duty cycle

• Increase the value for "D" to prevent overshooting

• Start testing in game and reduce Max duty cycle etc. to a comfortable feel

[motiondave]

I will try to do that, thanks.

One thing, does it matter if I have JRK utility open while playing? Will it conflict with X-Sim?

No it doesn't, I have the utility program running as well in the back ground.

try not to set PID in the utility slider, set basic like I have suggested and then work with motion.
After 2 years of PID tuning, I have always found the motors to be very twitchy and getting errors in utility and even the old test tablet slider . The utility slider is mainly to test thatThe motor works and adjust feedback if need be.
The base PID suggestions exactly that , base. Then work with motion and change PID if needed as well as motor speed .
Try also raising integral limit to 10000 , this gives the JRK time to think and can reduce errors . Also match the timing in utility with x-sim. So if you have 10ms in utility, make sure it's 10 ms in xism.
Also try increasing timing to up to 25 ms. I found these big motors need higher timing depending on game and motion preferred .
Race07 I can run at 5 ms, dirt 3 I run at 15-20 ms . 25ms is a good setting to help sort and understand things.
Remember , there is no magic fix ,, and it may take some time to get it sorted.