G-Seat Project

Hi,

I'm starting DYI project for the G-Seat. I found this site while waiting for SimXperience GS-5 G-Seat to come out and I found some super inspiring posts and decided to put it together as DYI project. I figured it will be fun project and if everything goes as planned, the result might be actually better than commercial product which must fit all sizes of drivers etc.

I will base the project on the knowledge from thread G-seat Addon to 3DOF Rig, from sberns, many thanks, great resource!

Sorry for not including links or images yet, as I must post 3 posts to get the privilige... I'll update this post with images and links once I can.

Right now I'm in the planning stage, I would like to finalize design / components here, hopefully with some of your feedback

I will be using aluminium Kirkey Seat - 65 series as a base construction.



My plan is to use 5 different paddles:

1) Legs from below - 2 servos

2) Butt from behind - 1 servo

It's separated because butt will likely not move and it would harm back paddle as it would be limited in movement.

3) Back - 2 servos

4) Body side - 1 servo

Paralel movement without hinge

5) Legs side - 1 servo

Paralel movement without hinge

It is 10 zones / 14 servo setup, this would allow for different feeling just for acceleration on straight vs cornering.

I'm planning on using JX PDI-HV2060MG servos. I have found them much cheaper on AliExpress than local shops, do you think it is safe to buy them from China or these cheap ones could be fakes and it's better to buy them from more reputable distributor?



Speed (7,4V): 0.13sec/60°

Torque: (7,4V): 62kg.cm

I'm really begginer in electronics etc. I could use some suggestions for driving these servos, if anyone would be so nice to help me out.

I have 2 options I identified so far:

a) Arduino + Shield

Do you have any suggestions for specific models?

It should be able to drive 16 servos JX PDI-HV2060MG.

b) Yost Servo Center 4.1

It should support 4.8V/6.0V servo supply voltages.

Anyone can suggest adequate power supply for these 16 servos? Closest I have found to 7,4 V is for example this HRP-300-7.5 Mean Well, which is 7,5 V instead of 7,4 V, would it be problem or it should be inside some tolerances? Is it enough to power all these servos?



How would I connect these to power supply and the to Yost Servo Center? Anybody could help me with some wiring suggestions?

Programming

I have couple of options for programming. I could have some custom software - already have working telemetry for some games in dot NET project.

Or possibly to hook it up to xsimulator software, but I haven't seen much documentation, I don't know if it would work with that Yost Servo Center.

That Yost Servo Center instructions / documentation looks very nice and it supports some advanced commands, so it might offer more functions / responsivity for programming than Arduino. Arduino seems easier for the coding. I'm still doing research.

If anybody could offer me some suggestions I would be super happy!

As I said, I'm really begginer in electronics so I'm quite struggling. Hopefully mechanical part will be easier for me to get right

Thanks!

Thanks for link. I'm definitely considering Arduinos. I will just have to use some shield to be able to connect 16 servos and I suppose the code / connection will be quite different.

I'm looking for some specific recommendetion whether to use for example:

a) Arduino + shield

Arduino UNO R3

+ some shield like this?



Anyone can recommend some specific shield?

b) Designated board compatible with Arduino

24 Channel Servo Motor Driver Controller Module For Arduino Robot




Thanks for idea with making some smaller mock model first.

Thanks, I will look into this Adafruit board and code.

For Adafruit I have found some simple connections so I have idea how to connect it directly.

I still will have to figure out how to power the servos externally as the board is not able to provide sufficient power.

Waiting for the GS-5 as well.. BUT will be following here closely as I'm tired of waiting. Contemplating DIY as well. Thanks for documenting your effort Michal!

We will see how it goes. Today I'm trying to find a way how to get aluminium Kirkey seat to Europe, and it won't be easy, fast and neither cheap. Shipping by ship will take 4 - 7 weeks if I choose to go this way and will be 300 USD. Including import tax and customs I'm looking at 1000 USD just for the seat itself. I'll take a look into some other options, but I don't have any right now. There is one distributor in UK, but doesn't have 65 series, which I like the most in eshop - https://www.sportseats4u.co.uk/kirkey-racing-seats/cat_551.html I'll try to ask, if they can order it on demand.

Meanwhile I will probably start with building harness tensioner to have at least some smaller intro to Arduino, servos, software etc.

I was going to wait for GS-5, but got tired and start searching. I think GS-5 will be great, but probably on back order - so long waiting time, it will also be expensive. I think custom solution might be better in the end, so I decided to take my chances This will be long project, but hopefully it will be fun along the road I will be posting parts lists, connection schemes and photos along the way.

So I have ordered the Kirkey seat from US https://www.kirkeyracing.com/catego...k-Road-Race-Containment-Seat-with-Black-Cover I went with 17'' size, it will be very tight fit with all the paddles I'm planning, but I hope I will manage to fit my butt inside I have opted for ship delivery, so I have to wait for like 6 - 8 weeks.

In the meantime I will get busy with the electronics.

1) Servos - I have been looking into these servos http://www.jx-servo.com/English/Product/3047215143.html I have read, that brushless servos are more expensive, but have better durability and also they have variable voltage according to required power as opposed to normal servos which draw full power even if they are not moving at all if I understand it correctly. Brushless might be little more quiet as well I hope as I read, that GS-4 is quite loud.

These are up to 14V and has Stall Torque (14V): 47kg.cm and Operating Speed (14V): 0.10sec/60°.

What power supply should I use? Should I go for full 14V or for durability it might be better to go little lower, for example 12V?

Anybody got better idea what servos to use?

2) I was looking at this power source Meanwell SP-320-12 - https://www.alibaba.com/product-detail/MEAN-WELL-SP-320-12-300w_60252120982.html

It has voltage adjustment range 10 - 13,2V. Or should I go for something powerful like Meanwell SP-320-13.5 to have range 12 - 15V to be able to deliver full 14V which servos can handle?

3) I have been looking into Adafruit servo driver https://learn.adafruit.com/16-channel-pwm-servo-driver?view=all + Arduino R3.

I have put together some preliminary connection scheme. Would anybody be so kind and could look at that if I understand it correctly? See image below or full PDF here.

The servo has separate V+ and ground / signal and ground connectors which is great and makes things lot easier http://www.jx-servo.com/English/Product/3047215143.html.


As it has these 2 connectors I need to just put together board for powering these servos.



I will split the load on three +V branches the Mean Well SP-320-12 has. I'm not sure if I used good practices as I'm new to electronics, but it kind of makes sense to me, but it might be completely wrong as well

As I will need to connect all the pins in one row (or at least several to power 5 servos on one branch).



Do I connect it like this as shown in this video?



It would be great to be able to connect it on one board using pins. Or are there any other alternatives how to connect it?

I would like to first figure out part's list, I would need to get one servo running and then I will order everything and will start experimenting with actually putting it together and then also with coding etc.

Many thanks!

I'm choosing power source, and I'm not sure how powerful it should be.

I will be using these servos: http://www.jx-servo.com/English/Product/3047215143.html and I will need to power around 16 of these.

According to manufacturer, maximum power draw for 1 servo is around 2,5A, if I would go for worst case scenario, I would need 40A power source which is starting to get really expensive.

Do you think that 22A power source like this https://www.tme.eu/gb/details/sp-320-13.5/built-in-power-supplies/mean-well/ should be enough as all servos won't be going 100% of power all the time?

If I find out in the future, that 22A is not enough, would it be possible to add some capacitor / battery to handle peak loads? Getting stronger power supply seems like overkill right now.

I found for example this capacitor used in car audio www.amazon.de/Mac-Audio-Caps-1200-Hochleistungskondensator/dp/B00KDGQNA2 can this be used?

Any ideas?



Thanks.

Thanks, looks good, very cheap, what would you say about quality / reliability? I know someone recommended me Mean Well to be good, quality power supplies.

I know for PC, good PSU is really important.

Also I'm located in Europe and therefore shipping + tax will probably make it not worth it. I will look into it, if I can't find anything similiar in Europe.

So I got little bit of progress.



I have the testing setup done and running .



I have Arduino UNO R3 + JX BLS-12V7146 servo. As it is 12V, I'm powering it from the old PC power supply for now. I'm waiting for ADAFRUIT 16-CHANNEL 12-BIT PWM/SERVO DRIVER - I2C INTERFACE to control more servos.

Servos

I have opted for brushless servo - I read that they have better lifetime as brushes won't wear. I also read, that standard servos are on their maximum torque / power all the time, even when in stable position. As opposed to this, the brushless servos are using their torque / power only when required to move or overcome some pressure applied to them which tries to force them out of designated position.

Does brushless servos have some disadvantages over regular servos? I found these JX PDI-HV2060 maxi servos interesting as they are stronger and cheaper, but also little bit slower. In the end I went with those brushless 12V which I understand is their top of the line product labeled as "industrial grade".

I will be using these brushless servos for initial tests and probably for harness tensioner, so I can still switch to other servos for g-seat.

Anyone got idea what servos should I get? I also have low noise levels as priority.

As you built g-seats, are these servos suitable for bottom paddles (yellow) which has to lift lot of persons weight? Can they handle the stress over time or should I expect to change them regularly?



Small hobby servo motors vs bigger ones

I was thinking, that maybe some bigger motors could be suitable at least for these more stressed paddles.

These smaller servos are getting quite noisey, especially when many of them used simultaneously, maybe one bigger motor would be able to handle the load much easily and it won't probably be as loud as these smaller hobby servos which are small form factor and are excessively geared.

I'm still trying to wrap my head around what motors to use if not using small hobby servo motors. My priority would be also low noise, small to medium size (to fit 2 of them under the seat), alongside with sufficient power for this usage, I could do with little bit higher price.

Should I choose some smaller DC motor, for example like this or here are some compact ones with gearing included? Or some servomotor or something entirely different?

I would just need to point me in the right direction also with regards to connection of these motors to Arduino + some control board like motomonster etc. if required, and then to SimTools.

Right now, there's some many types of motors etc., so I don't know where to start as I haven't seen thread here using smaller motors (people usualy use something bigger for motion).

SimTools

I will be buying SimTools, but I have couple of questions regarding SimTools and I'm struggling to find info in documentation.

1) What are the plugins for SimTools?

If I understand it correctly SimTools take telemetry from game and convert it to it's own simplified telemtry as shown in image below?



These values can be regarded not as movement of the car in space, but rather g-forces? So when breaking, the surge parameter is increasing/decreasing with acceleration? And I would for example connect arduino code for servo position to this surge parameter to control the paddles when accelerating? It would be probably hard to do it right for all movements, for example connect it to turning (yaw + sway?), bumps (heave) etc.?

Is there something in plugins I could use or at least use as a reference to get me started?

2) Can I modify or write own plugins? Is there some API documentation etc.? What programming language is used?

3) Is it possible to alter speed of those hobby servos or bigger motors so that the rotational speed adjusts over its travel, so that linear motion it produces using come connecting rod is correctly tied to values of the telemetry?

4) Is it possible to alter the torque servo is generating? For example if the paddle is close to it's bottom position and is for example just 1 degree from it's position, where it's supposed to be according to Arduino commands, is it possible to say it it shouldn't fight the counter force of the persons weight so hard and just lower the torque? On the other hand if it's at the bottom and it's destination is further away, it would use it's full power.

---

I hope when I buy the SimTools, I will understand it little bit better how it works, as I'm struggling to find some coherent documentaion or explanation how it works as it is scattered over long threads

Sorry for long posts with lot of questions, I'm still trying to get into it, but it's so wide area of knowledge I have to gain, I could use little bit of nudge in the right direction

Thanks for any input!

So little bit of progress

I installed SimTools 2.2.5 demo. I have followed @eaorobbie advice here https://www.xsimulator.net/community/threads/my-project-guide-me.5682/ ,thanks for this!

I have found out, that in new version of SimTools, the axis have additional letters a and b. So I changed the code to R<Axis1a>~L<Axis1b>~, so I had to change this as the guide in the thread was for older version of SimTools.

Otherwise I set Output Rate to 1 ms, as it feels more smooth and works great, if there will be some problems, I will change it to something higher.

I noticed, that I don't get 180 degrees travel. I found out initial setting for actuator scaling is const int kActuatorScale[kActuatorCount][2] = { { 0, 179 }.

I have couple of issues, I couldn't figure out, perhaps you could help me little bit @eaorobbie if you would be so kind.

1) When I call R179~ in Serial Monitor, the 179 gets scaled to 125 (it seems I'm getting around 125 degrees of trave).



However max value can be 0 - 255. When I call R255~, it gets scaled to 179 and I get like 165 degrees of travel, so still little bit is missing. EDIT: This is weird, now when I go above R255 it stops moving around +45 % of axis value in SimTools and it makes electrical noise as it tries to go over it's max value so that's probably not healthy So I went back to max R179~, however now even at R179, the servo has bigger travel than before at R179 value (before I was getting around 125 degrees of travel and now I get that 165 degrees), so I hope I haven't damaged it. However it seems to operate normally in this now increased range of motion... I will get second servo, so I will see then.

Should I try to modify Pulse Width as described here with servo.attach(pin, min, max): https://makezine.com/2014/04/23/ard...microseconds-and-optional-command-parameters/ in order to try to get the full travel? I'll try to get the min - max pulse widths from the servo manufacturer, as it's not in their documentation on web.

Or is less than 180 degrees normal for some servos?

2) I was wondering, if there is any way to turn of the PWM signal when the servos are not in use? With this code, the servos get fired up once I switch on power supply. Is there any way how to pause it when not in use?

Does SimTools have any states which would allow to let the Arduino know to switch off sending of PWM to servos? The servos are really quiet when not in use, but it still clicks little bit in them when I put my ear close and I feel the force in them when I try to move them.

It would be great if they wouldn't have to run all the time unnecessarily, which I think could lower their lifetime, especially when one forgets to turn of the power and they would be running for hours.

Thanks.

So I got myself oriented and got the full travel of the servo using command for altering servo signal width: actuatorSet.attach(kPins, 500, 2500), this is specific to each servo.

@Zed @SeatTime Hey, I got inspired by your designes here and started building harness tensioner.

I'm using these 2x servos with Arduino and @eaorobbie code.

I got the servo running and now I'm trying to figure out how to set up SimTools. I need to move servos only in one direction, the way SimTools work by default is that they have zero value for axis and then it has negative and positive value.

When I translate it to servo 180 degree travel with surge for example, when the car is standing still, it is at 90 degrees. However, I would need it to be 0 degrees when still and when braking, I would like it to move to full 180 degrees. When it's at 90 degrees by default, I'm losing 90 degrees of travel and also strength of the servo. I think this would be possible to do with modifying @eaorobbie code quite simply. However I would like to add some sway to it and that's where it gets complicated.

For example when turning left, I would like left harness strap to tighten and also right harness strap to tighten but to lesser degree, let's say just 50 %. I would probably use sway for it.

1) From what I see from SimTools config, it's not possible to do it in SimTools directly like this:



This will give me combined axis and I don't see a way how to make it work with my requirements as above with sway I need.

2) I would probably need to make sway as separate axis like this:



And then mix it in Arduino code myself? Or is there some other way how to do this?

3) Is there some possibility to set interface output to RDOF1<Axis1aDOF1>~RDOF2<Axis1aDOF2>~ so I don't use up axis unnecesarily? I haven't found if this is possible.



If this was possible, I could probably get along with just one axis like this:



And use negative or positive value of sway to determine if the car is turning left / right in Arduino and calculate proper servo position correctly.

4) @eaorobbie code is using 0-255 values. The data from interface are just those 255 steps or float value?

If it's not float and I alter the code and map movement of 128 - 255 range of those steps to 180 degree servo travel, it would give me 1,4 degree of servo movement per step, what could be too coarse and make the movement jittery.

Any solution for this? If its float, then it's not problem. I haven't seen in documentation in what format the interface is sending the values.

---

If you point me in right direction how to approach this it would be great, or if anyone would be willing to share some code / setting for harness tensioner it would be awesome

Thanks!

Hey @Michal Burisin - I am not certain but think those are ints. But I haven't set that kind of circuit up to know for sure or used @eaorobbie's code on an Arduino. Someone else with experience might be better to comment but you could also check the Arduino code to see what it expects.

Also, for belt tensioning, you didn't explicitly ask, but @SeatTime's bowden cable method is the better way to go IMO. I plan to switch over to that but just havent done it yet. Unfortunately, once I got my system running, I fly or drive in my spare time at home.

I just went with straight deceleration to yank on my belts and didnt mix in sway so again, not much help. The controllers I used let me specify the travel limits so i wasnt stuck at mid position.

So I finally got to the point, where I can start working on the G-Seat.

What's important for G-Seat part of the project is tactile installation on the seat, which consists of 3 BK Concert + 1 TST 239, so it's pretty powerful tactile, so I must make sure nothing rattles, this will be challenge as there will be many moving parts.





I'm using Kirkey Aluminium Seat, link is here.

I have 17'' version and it fits me like a glove I'm 168 cm, around 66 kg, quite thin with broader shoulders and it's so so, especially with the G-Seat paddles. I'm striving to take around 2,5 cm of space from the internal volume with paddles.

Here is the parts overview:

A) Bottom paddles - with big space between them - I don't want to simulate heave, maybe just a little, but it's intended mainly as pressure from the sides.



B) Main back paddles - narrower gap between to allow for some pressure during acceleration.

C) Additional back paddles for sides - just for thin guys, I made them removable to allow someone with bigger butt to fit in there



I spent day and half measuring etc., here are some images of progress:





Now when I printed it on A3:



And with additional paddle from the side:



I'm really happy it worked so well! I just have to correct 2 lines where the plate would be bent and that's it! I don't need to tweak the shape any more, it fits perfectly!

I will be probably using 4x ASME-04A servos for 4 paddles and 2 for seat belt tensioner.



The servos for bottom paddles will be located on red profiles like pictured below, on these profiles will be also servos for seatbelt fastener.

Servos for back paddles will be mounted to the seat.



The servos axles are goint to be extended by this connection - 8 mm to 12 mm, for 12 mm shafts I use aluminium hollow shaft with 2 mm thick wall.



The shaft will be like 0,5 m long, so at the end, it will be fixed in ball bearing with housing connected to the seat to prevent shaft bending.



Along the way there are going to be 2 points on each shaft with fixed clamp.

At each clamp, there will be 2 connecting rods, these are just M4 so I want to be on the safe side.



Yes, I went with gold, will be nice addition to BK Concert gold stickers and Fanatec DD clamp

I still need to figure out servo arms, if I won't find anything, I will either 3D print or will make it from aluminium.

I will need to cut holes to the seat to allow for movement of the rods, but I hope it shouldnt be necessary for the holes to be big. I don't want to connect main attachment profiles between each other to keep L / R tactile separation as clear as possible. I hope I won't break the seat in two pieces with additional holes cut out

I'm planning to use same approach for back paddles.

I have ordered couple of things. Now I'm waiting for a precise protractor to measure the angles for bending and then I will put it to manufacturing. In the meantime I will order rest of the stuff. I already have 2 servos, so I'll test their strength / speed on seat belt tensioner.

For that, I will be using bowden approach.

For guiding seatbelts, I will be using linear prismatic rails and carts.



It wasn't cheap and it sure isn't light but it's totally tactile proof .

These rails will be between vibration mounts already mounted as you can see here:



I didn't like metal sound with carts moving that was transferring to the seat, I got some vibration mounts leftovers so I used them here

Sorry for links for parts to my local distributors, shouldn't be hard to find internationally though

I made the paddles close to size of the orignal ones, so it should be possible to fit the cover over the top of the seat, but the side compartments of the seat cover should fit over the paddles nicely, so it will look nice and there won't be no need for some ugly cover I think it will work perfectly



I need now to find some tailor to make the holes bigger for the seatbelt fastener, but I hope it shouldn't be problem

I will use SimTools for running the servos, I will need to do some custom coding for this G-Seat project, as I haven't found anything suitable, this will be also big challange, but I hope it won't be such problem in the end

For mounting paddles to the seat I recommend these. Super sturdy and no wobble at all, it's tactile proof

I have been busy yesterday with seat attachment profiles.

I made new inward side profiles to bear servos for G-Seat - these are on the right side of the photo with 4 holes. I tried to make servo brackets, but it would be awful work. I will 3D print them.



Anyone have suggestion for 3D printer? I have been looking at Prusa i3 MK3 which looks quite good. I have no experience with 3D printing, but I hope it won't be rocket science

These are side support profiles.



Here's the result.







The side supporting profiles are going to bear side paddles. It will have another bridging profile like this.



On this bridging profile, there will be hinge like this (red) with paddle (green).



With design like this, this G-Seat will be basically completely in contact with body and not just some limited regions.

These side paddles will be responding just to lateral forces, whereas back and bottom paddles will respond to mix of acceleration and lateral forces.

I will firstly do just bottom and back paddles and then I will see if it's worth the trouble adding additional paddles for sides, but I think it could work very well, let's see

The side supports also stiffen the seat. When I was lifting myself from the seat with full force, it was bending, so this is another reason why I did it.