Racing Simulator by Mr.Burns

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General information

The simulator consists of a ground base, a seat frame with a car seat, two SCN5 150mm actuators and several parts to connect them all together. All the dimensions and thread sizes given here don't have to be used, they should be adapted to the design. Threaded rods, bolts, balljoints and such can have any type of thread as long as they can be all connected (threads should match).
These parts are connected to each other and simulate the road conditions and G-forces in racing simulators such as rFactor, GTR2, Live For Speed, Race07, GTR Evolution etc.
At the end there will be a simple way to connect a wheel + gear shifter. The monitor and pedals don't attach to the frame.
If you live in an building with neighbors around you (2nd floor, 3rd floor etc) the vibrations will drive your neighbors crazy. I had to put a soft mattress with a big piece of wood on top of it under the simulator, but this will depend on what the walls of the building are made of.

For further questions or suggestions use following to my project thread:
http://www.x-simulator.de/forum/mr-burn-s-simulator-t1115.html

Parts

Frame

Aluminum Profiles (~ 7.5m or 295.27" in different sizes) - http://www.8020.net, they also have an ebay store. The profiles will need to be cut with a power tool, they are very hard to cut with hand tools. If the dimensions of the simulator are known it is best to try and get pieces that can fit without changes. For this project I cut them piece by piece while I assembled everything. The problem with this is that you end up with many small parts that can't be used for anything and aluminum is not cheap.
3/8" 24 fine threaded female balljoint (6 used): http://www.napaonline.com/ - usually they have to order them and are hard to find on the website, but they have them.
3/8" 24 fine threaded balljoint stud (2 used): http://www.napaonline.com/
M8 1.25 T-Nut (~110 used): http://www.8020.net
M8 1.25 16mm Button Screw (~220 used): http://www.fastenal.com, http://www.acehardware.com, http://www.lowes.com
Steel Spacer 2.54cm (1") long and 3/8" inner hole diameter (10 used): http://www.acehardware.com
3/8" nut corse thread (6 used - 4 for actuator connections, 2 for stabilizer rods): http://www.acehardware.com
3/8" corse thread 7.62cm long (4") bolt (4 used) - Used to connect actuators balljoints to frame) http://www.acehardware.com
3/8" 24 fine threaded rod 91.44 cm long, (3') (2 used, cut to length): http://www.fastenal.com
3/8" nut 24 fine thread (4 used for stabilizer rod to balljoints connections): http://www.acehardware.com
T-Bracket (1 used for back seat support connection, 4 for wheel + gearshift holder): http://www.acehardware.com
L-Shaped Aluminum Plate (2 used, one for seat frame to pivot connection, the other for seat frame stabilizer rods connection): junk yard
Seat From a Pontiac Grand Prix: junk yard - try to get a seat that is well balanced, this means it should weigh the same on both sides. This is hard to do on a junk yard, so I don't know how to go about it. Most seats from cars will be heavier on one side (they can have seatbelt, seatbelt connectors on one side and nothing on the other, or they are a little longer on one side. If the seat is not balanced it will tend to fall towards the heavier side, and you will notice that all the simulator effects tend to go more towards the heavier side. To compensate for this I moved the seat-frame to pivot connection a litte towards the heavy side. Small changes should be done, even 1 cm will change the balance of the seat. The best would be to get something like a Sparco seat (google), but it is very expensive ($350-$400)
3/8" corse thread special bolt 5.08cm long (2") (2 used. They have half of the head oval shaped so that the balljoint can bend over the head, I don't remember what they are called, look at the picture): http://www.acehardware.com
90 degree connection plates (~70 used) - these are used to connect the aluminum profiles: http://www.8020.net
Pivot (1 used) - seat frame with seat moves on it: http://www.vibrationmounts.com/Store.asp?Page=Products2.htm (Durulene), make sure it can support the weight.
Lock Washer for Pivot (1 used) - http://www.acehardware.com
Bolt/Screw for Pivot (size depending on pivot) (1 used) - http://www.acehardware.com
Washers (as many as required, for T-Bracket screws, balljoint Studs, seat frame bolts for stabilizer rods) (~35-40) - http://www.acehardware.com

Actuators, adapters and cables

SCN5 actuator (2 of the 150mm type - or 2 100mm) - http://www.miraiintertech.com, .
RS485 to RS232 adapter (2 required) - http://www.ebay.com (Hexin - should be plenty available and cheap $7)
Serial cable (2 required) - http://www.ebay.com (DB9 serial cable, length whatever is needed, but too long might hava a bad effect on the signal, $3-$4 for 6' cable)
RS232 to USB adapter cables (2 required) - http://www.ebay.com (serial to usb, $2-$3 for 2' cable. Comes with a driver to create a virtual com port through usb)
Grounded AC/DC adapter (2 required. 24V, 2A) - http://www.ebay.com (seller lcdpayless makes any kind you want). I use the laptop kind and cut the wires to connect them to the actuator.
Kill switch button (1 required) - http://www.radioshack.com - This is a button where you connect one wire on one side and the same wire on the other side. When the button is in one position no current is flowing through the wire, when in the other the current is on. In case of emergency you press this button and the movement of the chair stops.
2k2 Ohm Resistor (2 required) - http://www.radioshack.com
220 Ohm Resistor (2 required) - http://www.radioshack.com
Wires - http://www.acehardware.com or http://www.radioshack.com
- 2 wires for each actuator are required to connect the power wire to the ac/dc adapter (red = +24V, black = ground). The length depends on where you will want your ac/dc adpaters to be. Wire thickness should be at least the thickness of the ac/dc adpater wires.
- 4 wires for each actuator are required to connect the actuators to the RS485-RS232 adapter. They can be any color but if they are to match the SCN5 wires they should be white,green,black and red. Again, length should be enough to reach the RS485-RS232 adapters.
- 2 extra wires (+24V and ground, so red and black colored to match the existing wires) to make some extra connections at the end.
- If you want to be able to disconnect the wires you will need wire connectors. I used connectors that let me disconnect all the wires to be able to take the whole thing apart. Or you can can solder everything together and wrap the connections with electrical tape. Make sure you don't have any exposed wires.
- I suggest getting long wires and if they are too long it's not really a problem. If they are too short nothing can be done.
Connectors if making own wires -
It is recommended to make your own cables to extend the SCN5 cables so you won't have to cut them and lose the SCN5 warranty.
Then the connections would be like this:
For the RS485-RS232 adapter: SCN5 wire - SCN5 female RS485 connector - self made RS485 male connector - home wire - connection to RS485-RS232 adapter.
For the power wires: SCN5 wire - SCN5 female power connector - self made male power connector - home wire - ac/dc adatper.
RS485 connector: http://www.mouser.com/search/ProductDetail.aspx?R=172167-1virtualkey57100000virtualkey571-172167-1 (you need 2). Power connector: http://parts.digikey.de/1/1/327633-conn-recept-housing-14pos-2-5mm-df1b-14des-2-5rc.html (need 2). I didn't use them since I already had power cables. You will need the pins as well. The easiest would be to take the actuator to a radioshack or a store that has those parts and ask them what you need to make your own cables.
Note: If you cut the ends of the SCN5 power and rs485 wires you don't need to make the cables. But you probably won't have a warranty left for the SCN5 if you do that.

Building the frame

Required tools

1.) Mechanical saw to cut the aluminum unless you want to do it by hand. In that case a hacksaw can be used. I took the aluminum to a weld shop where they cut it for me after I measured it.

2.) Hacksaw to cut small parts like the stabilizer rods.

3.) Allen key that fits the button screws used. I don't recommend using a wrench because you will put a lot of torque on the screws and you won't be able to get them out.

4.) Flat or Phillips Screwdriver (depeding on what kind of head your screws have). A tiny phillips screwdriver to connect the wires to the rs485-rs232 adapter.

5.) Wrench (size depends on the size of the bolts/screws you use)

6.) Wire cutting, connectors and soldering stuff if you make your own wires. You will have to do some of this even with commercial wires.

This isn't a complete list. You might need different sized wrenches, more than one of the same kind of tool, pliers, adjustable wrench and so on.

General frame installation rules

1.) Don't tighten the fasteners (bolts,screws) too much so that it will be easy to move the aluminum profiles around. Tighten enough that parts won't be moving, but it should be easy to quickly turn some screws and move the profiles. You will have to do this a lot.

2.) Only when everything is in the final perfect position tighten everything good. Don't overtighten or you won't be able to remove the screws.

3.) Measure 10 times before cutting the aluminum. Make sure 100% it is right. Once cut, it's done. If it's too long you can cut more. If it's too short you can throw it in the junk.

4.) Make sure nothing touches when done. Pay special attention to the seat-frame to pivot connection so it won't hit the aluminum profile under it and to the seat-frame touching the stabilizer rods at extreme seat lean angles. If using 150mm acutators and not 100mm, the seat might need to be higher if you plan on using 100% of the actuator lenght or it will hit something.

5.) If something doesn't feel right when using it (such as too much lean some way and not enough the other way), you need to re-measure everything, make sure it is all the way it is supposed to be. Don't just continue using it.

Installation

I followed the next steps in the described order to assemble the frame, any other way will work as long as it can be put together.

Base

This is very easy. Connect 4 aluminum profiles in the size that you want. The sizes I used are:
Length: 59.6 inches (151cm or 1510mm) - there is some space in the front to attach something like a wheel holder.
Width: 36 inches (96cm or 960mm) - there is space to the sides to attach gear shifter, keyboard etc.
Length of aluminum profile inside the base width (the 2 shorter profiles in the base) - 33 inches (84cm or 840mm).

Seat Frame

The seat frame will hold the seat and is the part that moves around. It is connected to the base with the pivot and an aluminum plate. The aluminum plate will be connected to the seat frame with normal t-nuts and the pivot will be connected to the aluminum plate with a normal bolt and lock washer. The pivot is connected to the ground base (the previous part) with 2 scews and t-nuts. The seat frame consists of 2 parts. a.)the base b.)the backrest. The backrest will connect to the actuators to move the seat around.

a.) The base: This depends on the seat, but the base should be the width of the used seat. I connected the base to the rails of the car seat. To do this I drilled 4 holes in the rails of the seat and used the t-nuts in the aluminum. Then put 4 screws (one through each hole that I drilled).

To make sure the seat will fit the width of the base connect the 2 profiles to the seat and turn everything upside down (so that the seat is upside down). Then connect one more profile (the middle one) under the profiles that are connected to the seat rails. It should be somewhere in the middle (this one will connect to the pivot and will have to be where the center of gravity is - where most of your weight is when sitting in the seat - ). Before doing this one L-shaped aluminum plate should be connected to the profile because it can't be connected after the profile is connected (unless the t-nuts are already in the profile slots). The aluminum needs to be drilled to be able to put the screws through it and into the t-nuts. Make sure the aluminum is tough enought to support all the weight. This is the place that will hold most of the weight.

It is important to leave enough space in the back for the backrest. So the seat must be adjusted to the correct position and can't be changed after that unless everything is moved around. Make sure it is the way it should be. The backrest must go straight up from the back and be very tight against the seat.

b.) The backrest:

The backrest consists of one vertical bar and 2 horizontal bars. The bottom horizontal bar connects to the main base and the top will push against the seat to transfer the forces from the actuators. This is very straightforward. Cut the aluminum to the required lengths and connect them. On the bottom there is a small L-shaped aluminum plate that contains 2 screws that will hold the stabilizer rods. There are many ways to do this. I drilled through the aluminum plate to connect it to the backrest and to put the 2 long screws through it.
Make sure to use the t-bracket at the connection between the horizontal and vertical profile or the whole backrest will bend out of shape. The top horizontal bar that will push agains the seat should be in front of the vertical bar. It should also be at the height that you will want it to be pushing against the seat. I set it at a level where it is pressing straight against the seat and not just half or one forth or anything else.

Here is a picture of how it should look with the seat on. The seat will move a little no matter how tight the top bar pushing agains it is. There must be a way to connect it to the backrest so it won't move. This can be done by drilling through the seat and using some sort of plate on the other side of the seat. I used straps that I wrapped around the headrest and the top horizontal aluminum profile, but that is not in the picture. Either way, if it moves too much it needs some additional work to stop the seat from moving independently of the backrest.

The seat is conneted to the seat base with the normal t-nuts and button screws like this:

Connecting the base to the seat frame

The seat frame connects to the base through the pivot. The very important part here is the balancing of the seat frame (with the seat and you in the seat) on the pivot. You will probably need another person to help with this part.

First connect the pivot to the base then connect the seat frame to the pivot that is connected to the base. The pivot-seat frame connection must be adjusted so that your weight - when sitting in the seat - is on the pivot.

The idea is to have the actuators just push something around and not hold any weight. Think of it like this: When you sit in the seat of a motorcycle with your feet on the ground, standing still - if it's straight, you can balance it without a problem. Even leaned a little one way or another you can keep it up. But if it leans too much one way it will fall down and you won't be able to hold it up. Same for the actuators. If the weight is too much on them or the other way it will either crush them or pull the rods out of them. But balanced just right there will be no problems.

The pivot is connected to the base with t-nuts and button screws and to the seat frame with a normal screw and a locknut. You must of course drill the aluminum for the pivot-seat frame connection. Here are some pictures of this connection without the seat on so that the connections can be seen better:

To adjust the balance: Sit in the seat and adjust the pivot-seat frame connection so that the seat with you in it won't fall towards the back or the front. Try to get it as stable as possible. To move the seat frame forward or backward, the aluminum profile of the seat frame that connects to the pivot should be be moved.

Important: Once this is done only move the seat frame with the seat forward or backward by moving the aluminum profile of the base. This way the balance will be kept. Don't move the seat or anything that affects the balanced base-pivot-seat frame relationship. If you do the whole process must be redone. So try to get the seat in the proper position first.

Another problem is that the seat will now spin left and right. To prevent this from happening two stabilizer rods must be used. These rods will prevent the seat from rotating. There are many ways to connect the stabilizer rods. I used the balljoint studs on one end and the normal balljoints on the end connecting to the backrest. Basically you must get the seat balanced and then straight and have the exact lenght of the stabilizer rods. This is a little hard to do with one person, you will need somebody to help. When you have the good lenghts connect everything together and the seat will not spin anymore. It looks like this:

Connecting the actuators to the base and seat frame

The last stop in the assembly is connecting the actuators. First, they need to be at an angle as shown in this picture or you will not get the maximum forces applied to the seat:

This step will probably require 2 people: 1.) The seat frame must be straight and level with the floor and the actuator rods should be pulled to their half length. For example if the actuators are 150mm the rods should be extended 75mm. For 100mm they should be extended 50mm. 2.) Connect the actuator arms (the aluminum profiles that will hold the actuators) to the back of the base and setup the connections on the backrest of the seat frame. All the actuator connections are done with 2 aluminum connection plates, 1 long bolt, 2 spacers and washer+nut on the other side of the long bolt to tighten it. 3.) While the seat frame is straight and level with the ground mark on the actuator arms the height where they must be connected. The actuators with the rods extended to the half point must fit to the connections on the backrest of the seat frame such that the seat frame is level with the floor. This is very important.

Make sure the seat frame doesn't touch the ground with the actuators rods fully in or fully out. Also check for one actuator 100% extended and one 100% retracted and the other way around. They should not touch anything. It might not be possible to have them not touch the stabilizer rods, but it is recommended that you use some software limits so the maximum stroke will be less than the maximum stroke of the actuator. In that case they don't need to go full lenght without touching something if that happens after the limit set by software.

The actuators can be connected to the actuator arms in many ways. One way is to use some matching brackets,drill through the aluminum and put some screws through it. Another is to use aluminum connection plates to connecte them some other way. I drilled the aluminum.

Final steps

To attach a steering wheel, pedals, a monitor and so on something can be made that fits the size of the cockpit. The mattress in the following pictures is there to absorb the vibrations that would drive the neighbors crazy.

Actuator connections

The actuators connect to a rs458-rs232 adapters which then connect to the usb computer ports with rs232-usb adapters. There are also straight rs485-usb adapters but I didn't use them.

To connect the actuators to the rs232 adapter the scn5 wires can be cut or an extensions can be used, which is the way it should be done because it won't void the scn5 warranty.

Please read the scn5 instructions manual that explains the wires.

For the adapters used here the following applies:
Black to GND of RS485 adapter
Red to 5V of RS485 adapter
White to RS485 - A connector
Green to RS485 - B connector
You might also need to connect resistors if the signal isn't stable (as in the software detects the scn5 actuators and they are lost after a while with no changes made to the settings). More on this in the hardware thread linked at the end. From the thread -> "The TRx+ wire and TRx- wire (or called A and B) of RS485 are equiped with a end resitor of about 120 to 220 ohm. On short cables (1m) there is only one needed at the converter side. Some converter have such a resistor included, some not. You can measure them out or the manual tells you how to enable them. For beginners a short cable and a 220ohm resistor at the outputs of the converter will do the job always correct."
Please read the threads, they contain important information.

Then the rs232 side connects to the usb port on the computer.

For the power the following connections are required:

Please see the following thread for more on how to connect the actuators to the computer:
http://www.x-simulator.de/forum/scn5-hardware-thread-t1083.html for the hardware and
http://www.x-simulator.de/forum/scn5-software-thread-t1084.html for the software.

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