New project

I built a 2DOF seat about 20 years ago,
using a car universal joint and 2 electric window motors.
The problem then was that software tools didn't exist, so I could integrate into games output.
My knowledge of electronics is basic, so it didn't work well and in the end I broke it up.

The "feel" of 2 axis around a central pivot in a 2DOF system is not very realistic, more like arcade. The problem being its a too rigid, no give, in a real saloon car you "feel" tyres & suspension working.

So I'm planning a new 3DOF or 4DOF project, I want to "feel" acceleration & cornering.
My best game on PC is: codemasters GRID Autosport
(although Race Driver 3 is most realistic, the graphics are now too old).

I have plenty of time and can do frame and software, the problem I will have is the electronics and controllers, so want to pick the easiest option with these to get running.
Budget is limited to approx. £500 all in, so I'll use second-hand electric motors.

I have spent many days scanning this website...
I think I'd like to use 2 x Arduino + 2 x Moto controllers (for 4 electric motors) but some one said jrk controllers where easier to setup ?
Do either controllers come with wiring / setup instructions ?
Also I assume 4DOF will "feel" more like a real car ? and be easier to understand setting up ?

Hi, Thank you for the links
I was hoping for more people to respond to the vote, so that I could gauge with controller was most used / liked, Ardunio/MMs or JRK.
I'm getting some advice and will draw a daft design out at some point, once I've built a small test rig with a controller / motor working.
Electronics was the problem previously, so I'm solving this issue first.

Hi @Kass55 IMO you need to decide on a design, especially if you do not want to use a centre pivot and then chose suitable motors/controllers/drivers.

Thanks, following advice, I have ordered to JRKs for ease of setup.
I have also decided to build another 2DOF seat first, before going to 3 or 4. Start off at walking pace at lower budget.
So single pivot to start with, while getting going.

I attach my design drawing below, Seat movement only.
I placed motors at the front because I have limited space behind me (small bedroom).
Tennis balls are to create less direct rubber like feel, similar to tyre feel.
Bass speaker is to create engine vibrations in the seat, may replace with kicker depending on how well it works.

Tip: I use 2 fans attached via USB to blow air over hands & lower face. I think this works well, giving more feel of speed/moving.

Please take a video when you carry out tests with a test pilot on it . IMO I think tennis balls would allow the chair to oscillate under a riders load and likely fail over time . Maybe better to try suitably rated shock mounts.

@Kass55 , I ve done what you are looking to do
http://www.xsimulator.net/community/threads/desk-racer-2dof.5326/

May I suggest forget the tennis balls, once you get a good profile, you feel like you are in a car racing.
The tennis balls could absorb some of the finer vibrations, you said this "Tennis balls are to create less direct rubber like feel, similar to tire feel."
My question to you would be, have you actually been in a proper competition vehicle? Because Ive spent time behind the wheel and as a passenger and they usually are as hard as hell in suspension, You cannot feel any tire suspension.

Thanks Noorbeast, I'll mount motors & rods as suggested.

I have driven real race cars, the suspension needs to be firm & controlled but still needs to move / give a bit.
I think bump stops or old BL mini damping cones are too heavy duty for my weight.
Shocks and springs to expensive and too little room.
I was thinking tennis balls or similar because they are cheap and I double / triple up as needed.
I'm simulating a car rather then a train on rails. I will feedback / video once I get it going.
I want a little give, without flopping about, to dampen bumps a bit but not completely.
I planning engine vibrations will come from the bass speaker directly mounted to the seat, but haven't tested this either yet.

I just thought of something @Kass55 , generally in game, the motion and action of the car is reflected in the motion of the seat. I was playing AC last night and driving an old Audi , and it was a boat to drive, very sloshy and very little heave motion, then I played a more modern car, and the difference was night and day. Much more response and nastiness in motion.

I also Do not suggest the "tennis ball" idea. All you'll be doing is working the motor's harder than they need to be.

Update, I have bought:
1 race seat, 1 universal joint, 2 wiper motors, 2 Jrk controllers and 2 hall sensors
Connected motor, Jrk and hall sensor to spare 500w PC power unit (I measured output volts 15v and 6v)
and installed software to separate PC

With Feedback set to NONE, motor works well with no errors.
I measure Vout and hall sensor is working.
However, with feedback as Analog, I can calibrate feedback with "Learn" fine,
but motor does NOT run but Jrk reports no errors.

Anyone had problems / suggestions to get Hall sensor and Jrk working together, as I am stuck ?

Did you find the centre point of the hall effect pot?
Go to feedback tab, reset to full range, apply settings and watch the graph the right hand corner, turn the pot shaft t find its centre. Then match it with the lever, Then go set feedback

Thanks both. The problem is related to PID tab.
Nothing happens while the top three values are zero.

So I set same values as noorbeast used and .... the motor shakes arm , very small movement back & forth.
Plots graph shows feedback swing approx. 100% to 100%
Errors tab shows max current exceeded (I have limited max current to 10A - which drove motor fine, before feedback was enabled).
Increasing max current to 12A flips out PSU.

I'm now going to connect up a separate 5v power for the hall sensor, to test if motor draw is effecting hall sensor,
and try a spare higher 650w PSU.

Good news, new separate power supply fixed issue, motor now moving up and down,
I just need to fine tune feedback.

I don't understand PID settings, has anyone used different setting from: 0.39, 0, 0.5
What does PID settings do anyway ? (effect motor power ?)

>>For now just leave the Max Current at 0 and let the JRK work it out.
My PSU should shout off at 30A,
So this setting safe ? Also I have not yet fitted heatsink cooling to Jrk.

PID can be a curly one, essentially using P is how fast the motor moves and D is how fast the motor stops, but both play a role in stopping them motor from twitching like a bastard.
I can end up with different PID and motor settings on each motor.
But working with motor power settings can help.
Heres a bit of a guide.
Guide to setting PID and motor settings on JRKS

max accell and max duty at 500, max duty while feedback out of range 500

current calibration 130

max current 0 (unlimited)

PID period 20ms

Integral limit 10000

With PID, Leave I alone and at 0

Using the slider bar in INPUT tab of utility only, no simtools, this is how its done.

Set P, I , D to 0 in the decimals, apply settings, now start with P only and work up in increments of 0.1 , aplly settings, go to INPUT tab, tick the box "automatically set target", click run motor and either slide the bar fast from side to side or use the home/end buttons to do max, min motor throwing.

Work up in 0.1, so next would be 0.2, then 0.3, etc. Until you find when you move the slider bar, the motor twitches like a bugger. Once you get that, halve that figure you have in P. So if its say 0.7 , you would put in 0.35.

Now dont worry if when you click apply settings, that the number is not exactly what you typed in.

Once the P number is halved like I said, go to D and work up in increments of 0.1 like you did with P. Apply settings, go to INPUT tab, and run motor and move the slider back and forth fast until the motor lever stops overshooting its stop point and starts to be very solid in stopping.

So for example, you may have a final figures of P 0.3672 , and D of 0.8231 for example. Do not use those figures, I am using an example of what may be the final numbers.

I have found when I do put in say 0.8, apply settings, it gives me 0.79999 or something like that.
Leave max current at 0 (unlimited) , JRK is protected internally and will not nuke, just shut down.

Thanks bfst
This makes things more clear to me.