Arduino - DIY GS-4 Seat

Hi. Having seen Martin's (@Schluzu) thread - Ultraforce GS-4 DIY - Software, I am seriously interested in putting together a DIY version of the GS-4 seat, using a Kirkey seat. I've purchased a couple of Arduino Nano V3.0 boards together with two Multi-purpose Expansion Boards - see images.



These are of course very cheap (thankfully) but with no documentation I'm at a loss as to know where to start. Any Nano manual that I find online is more like a brochure. Can anyone recommend a good starting point - so that I know to connect it up even would be a good start.

The plan is to use 10 x Turnigy S8166M servos, three on each of the two base plates and two on each of the two back plates. So one Nano will drive the base plates, the other will drive the back plates. I have managed to pickup some info on these excellent forums but it's a bit daunting at the start. What code, how many Axis' to setup etc. etc.

I'm sure that I will be relying a lot on these forums once the project starts but at the moment I could really do with some basic help, so that I can start to get my head around it.

Thanks .......

A Kirkey. Crikey, you're not going for the comfortable cruising style of bucket seat then.

Interesting set of servos. I'm intrigued as to how these work out. Sorry I can't help, that's way over my head. But i'll keep my eyes on this thread to try and learn more.

Should have added - I've connected each of the Nano's to the PC and loaded the 'Blink' test, then loaded the RC Sim Model V2 sketch from @eaorobbie (thanks). This basic step looks to have gone Ok but can't do anything with it yet as I have yet to obtain the Servo's. At the moment it would help to know where to connect each set of left and right servo's to the expansion board. I assume that I will need to amend the sketch for the seat application - each Nano is going to drive 1 x Axis - yes ?

Thanks

Managing slowly to answer my own questions here so hopefully this will help other users. I've found a couple of good pinout diagrams for the Nano, see below. Nothing on the Expansion Board but this is pretty much self explanatory now that I have the info on the Nano. G V and S on the connector strips refer to Gnd, +Ve and Signal (helped when coming across a very similar board that used black, red and green base strips - good thinking whoever designed that I thought).

Making progress. Need to get hold of a couple of servo's now I think and start getting to grips with the next stage, the code

For anyone contemplating their own DIY GS-4 seat using a Kirkey seat as a base then you will find some really useful photo's here, a few include dimensions (so you could scale to ascertain dimensions of other parts in the same photo).

http://www.ultraforcesim.com/pub

http://www.ultraforcesim.com/pub/GS-4/Pictures/

Ok I connect the servos directly to my Uno , same with the nano, if the servos requires more power than the nano/uno can provide then you need to connect the power and gnd from each servo to an external power supply and feed the signal wire directly from a pin from the Ard.

From code you can set the pins for where the servos are located, as in its changeable.
No expansion card is needed, but if you wish to use it then I will look into it, can you do a simple wiring sketch in MsPaint. Will help.
And we can change the code to suit what you want and you can release it as your modified code to run a G-Seat, the code is provided free to mod change and reclaim.

Hi. Thanks for the help eaorobbie. I'm sure I'll need more but things are coming together slowly. I bought the expansion boards mainly because they were so cheap and and provide an easy way to mount the Nano and connect to it. Knowing where the servo's would connect to the Nano makes it easy to see where they would connect on the Expansion board so that's Ok.

I need to run some calculations on the number of servo's required. From the photo's linked to above I can see that the GS-4 seat uses 16 x Hitec HS-805BB servo's (Torque: 19.8 kg/cm) in paired links. With the additional metal gearing sets, also in the photo's, this would be much more expensive than the Turnigy S8166M servo's (Torque: 33kg/cm) which are much beefier and have metal gearing as standard. I think that two of these per back plate and three per base plate should be Ok - as Martin (@Schluzu) is using in his project. Power I will run direct to the servo's.

Hi
with these rc servo's I think I would be wary of the specs for torque and power quoted, for example a pololu 12v geared motor is rated at about the same torque, drawing at 5 amps.

might be worth getting a servo to test.

regards Terry

Hi Terry. Thanks for that. Sounds like a good idea.

Hello!
@telfel : What motor have you seen ?

@Roadster2 : Did you estimate the total cost of your configuration?

Cool now understand clearly what the expansion card is for, the pin you use for the signal can be changed with the code, easily when you are at that stage.
Right next step, setup a couple of servos , plus code and do a test , I think.

@telfel the motors Im using on the Jrk12v12 are 200w pulling 45-48amp on direction changes. And are 20Nm

Hi RacingMat. A new Kirkey Economy seat is around £140 but I'm hoping to pick up a second-hand seat. Arduino Nano's and expansion cards were cheap at £27 including postage and I've managed to source a brand new Meanwell 55A power supply for £28. Servo's are going to be the main expense, currently looking at around £180 for ten, £216 if I need twelve (4 for each base panel and 2 for each rear panel). On top of that incidentals such as servo levers, push rods etc.

I have a good friend with who runs a fabrication shop so hopefully I can get the mechanical side of things done quite reasonably, especially if I can work out sizing and placement of the panels etc. from the photo's of the GS-4 seat.

All in all a huge amount less than buying a GS-4 .....

If I can sell a few more items from my current Marketspace sales then I can purchase the servo's

Hi
@RacingMat link to motor http://www.pololu.com/product/1447

the Turnigy Servo is rated at 40kg/cm, I very much doubt if the case or the gearbox could stand that sort of torque, the Chinese are known for over rating products. The HiTec servos are rated as one of the better makes.

@eaorobbie I was just comparing the rating of the Turnigy servo to a Pololu motor gearbox, 5a stall current at 12v, means the servo stall current at 6v would have to be 10a. smoking?

regards Terry

Hi
@Roadster2 If your buying a seat a cutting bits out?, don't know if this is of interest to you,home made seat

http://www.xsimulator.net/community/threads/2dof-wiper-motor-car-simulator-by-deriy-sato.2405/page-6

regards Terry

Hi Terry. Thanks for the link but I'm very limited in the size of seat I can use as it has to fit with the Racestar cockpit - see the Avatar
It's going to take some doing to fit the Kirkey but well worth the trouble I think.
Thanks, Iain

Hi
Have you seen this blog for flight sim? the belt tensionner looks good

http://meintourenbuch.net/simpit/g-seat

regards Terry

According to the concept, belt tensionner is not needed because the plates push you forward -> hence tense the belt ;-)

Hi
Negative G, bottom plate moves down, belt tensions?

regards Terry

Hello Telfel,
you mean "negative heave" ? in this case, I would suppose no belt tension.
if "positive heave", the belt tension is obtained naturally by up movment.
Do you think it should be different?
yours,
Mat