SRT80 actuators

The SRT80 are actuators based on 80ST servo motors, 80×80 aluminum profiles, and a special ballscrew that allows a travel of 220mm (compared to about 130mm for the OpenSFX).

For each step, there is a dedicated channel on the Discord to help you (go to SRT80 ENGLISH after choosing the language in verify-first.

Summary :

1. How to start
2. How it works
3. Shopping list
4. Control Box
5. Wiring
6. Driver settings
7. Arduino Code
8. FlyPT configuration
9. Simtools configuration
10. 3D files
11. Assembly
12. FAQ

1) How to start

All the necessary documentation is available on this page. If you have any questions, the FAQ is there to answer them, and if you don’t find what you’re looking for, take a look at the Discord to find the whole community!

The SRT80s are very similar to the OpenSFX100 in their operation. The opensfx.com site is a source of additional information.

To succeed in this project, it is necessary to test your work at each step: the motors alone, the mechanism alone, then the two sets, then the whole on your simulator.

I reiterate the warning: Voltages, torques and speeds are important. Take all necessary precautions. I am not responsible for any problem.

2) How it works

The SRT80 actuators are based on a ball screw with a ball nut on it. The ball nut moves up or down as the screw turns. The screw is attached to the shaft of a motor called a “servo motor”. The servo motor is controlled by a driver. The driver receives instructions from the arduino which tells it how many degrees to turn (pulse), and in which direction (dir).

It is the FlyPT software that retrieves the data from the game, and sends it to the Arduino.

The servo drivers are activated by the Arduino board. Once activated, the drivers emit a very slight aïgu noise, noise covered by the general operation of the simulator.

3) Shopping list

The shopping list is available here. The kit proposed by Industry&CNC is proposed in economic delivery for Europe (delivery by train, indicated by “seller’s shipping method”). This shipping method takes about one month (do not take into account the Aliexpress estimate). Please note that the tracking number provided by Industry&CNC will only be functional at the end of the transport.

Moreover, do not hesitate to contact me if the rates or the shipping costs are aberrant. We tried to offer the best rates on all means of delivery, but there may remain some errors related to the system.

The shopping list is separated in two parts: the first one indicating what is included in the kit, and the second one what is not, and must be ordered separately.

It gives the details of the parts needed to manufacture a cylinder. Industry&Cnc offers a discount on most of the items when you buy 4 of them.

“What is the difference between the A and C drivers?” Unlike C drivers, A drivers emit a high-pitched noise when they are active. This high-pitched noise is covered by the operation of the simulator.

4) Control Box

The control box which houses the arduino is available in several versions:

Standard Control Box	Smart Control Box (Patreon exclusivity)	Competition Control Box
4 actuators	4 actuators + TractionLoss 3 buttons Feeback LED : connection, error.	4 actuators + TractionLoss 3 buttons Feeback LED : connection, error. Plug & Play Emi Shielding
Complete documentation	Complete documentation	Complete documentation

5) Wiring

Caution : Voltages, torques and speeds are important. Take all necessary precautions. I am not responsible for any problem.

a) Driver and motor power supply

It is difficult to make a mistake in the wiring of the motor. This part is detailed on page 8 and 13 of the drivers manual.

b) Wiring between Arduino and driver

We reuse the pulse/dir connectors on the DB25 socket of each driver. On the arduino side we use a 5 pins GX12 connector.

Schematic :

For info: pin 13 of the Arduino is also a mass thanks to the code.

6) Drivers settings

The drivers, similar to AASD, have 200 parameters, fortunately you don’t need to change them all.

They are detailed on page 38 of the manual. This video shows how to modify the parameters.

I highly recommend testing the motor operation via flypt with the engine disassembled!

7) Arduino Code

At this stage, you have your motors wired to the Arduino, without the reste of the mechanical parts. You can flash the Arduino code that is specific to your Control Box (how to flash a code).

We will be able to test the connection between the arduino and the software you are using (Flypt or Simtools). Once the connection has been verified and the motors tested, you can move on to assembling the mechanics.

8) FlyPT Configuration

All the electronics are ready: Arduino flashed and connected to the drivers, configured drivers, and connected motors, without the mechanical part.

You can now load the dedicated FlyPT profile.

To load the FlyPT profile, launch FlyPt (v3.4.2), right click>file>open and select the profile.

To finalize the installation, click on the “Output::serial” tile, then on “update ports” and in the “port” list select the arduino port. Then click on ” connect “. The motors are all supposed to turn in the same direction smoothly and then stop: this is the simulator that starts from the bottom position to the middle position. Now click on disconnect, and the motors perform the same movement in the other direction: the simulator moves from the middle position to the bottom position. If everything went well, you can continue. Otherwise, see you on the Discord.
Now in the main menu, click on the tile of the simulation of your choice, then click on connect, and check if the motors are reacting to the games inputs.

The FlyPT website contains documentation that you should read if you want to take advantage of it : each game need a specific configuration

Once you have your actuators working and your installation is running smoothly, I also recommend watching this video to understand how to use the filters.

9) Simtools Configuration

Here is the configuration for Simtools V3

And here is the assignment of the axes:

You can launch the game and check if the behavior is as follows:

1) All motors rotate in the same direction at start-up (the simulator moves from the bottom position to the middle position)

2) In game, the engines seem to follow the movements of the car

3) When you leave the game, the actuators perform the opposite movement of 1), the simulator goes from the middle position to the bottom position.

If the behavior is ok, continue with the assembly

10) 3D files

The 3D files are available on the download page.

If you don’t own a 3D printer, you can order them here.

You will also find a step file which will allow you to integrate the actuators in your CAD.

Each file contains a printing instruction in the form xx-xx. The first number is the precision, the second the filling. For example 02-30 means accuracy of 0.2 and filling at 30%. It is also useful to double the thickness of the walls.

The mention “support” indicates that supports are needed…

I also recommend to activate the adhesion to avoid warping (part that comes off the support).

I recommend using the Cura slicer.

All the parts are in the ideal orientation for printing.

The box containing the Arduino is available separately here.

9) Assembly

10) FAQ

My electrical installation is in 110V, what to do (ex : Canada)

A priori the servos are designed to work with 220v. You can buy a 110v>220v converter (Amazon), or set the drivers to accept 110V, at your own risk of course.

Can I use this actuator in Push-Pull mode?

Yes, just screw in a 22mm ball joint like a POS22.

Why don’t I see any information about the emergency stop button?

Basically there are two failures that can occur: either the motor starts to turn endlessly in one direction, or in the other. In one case, the slider comes to a stop on the linear bearing support, and blocks the motor: no dramatic consequences. In the other case, the slider can break the linear bearing support, then come out of the rod. This is less funny. The problem is that the motor is so fast that you probably won’t have time to cut… That’s why I don’t usually include it in my setups.

Why an Arduino Uno instead of the Leonardo used on the OpenSFX? 

Because the Uno is cheaper, easier to find, and also because it has a USB type A connector that is more resistant than the micro USB of the Leonardo. Moreover, the computing power is the same.

Is the SRT80 compatible with Thanos controller ? 

Yes.

How can I prevent my chassis from jumping when making big movements?

The actuators are powerful enough to make the chassis jump. You need to limit the speed of the actuators or secure them to the floor.

FlyPT or Simtools?

I personally use FlyPT and prefer it because its presentation is more logical (although confusing at first), and it’s much easier to see what’s going on. Furthermore, it is much more practical to share a FlyPT setting than Simtools. That said, Simtools is more popular, its Simtools community established, support is responsive, and software development is very supported. In both cases your experience will be excellent.

2-actuators configuration?

The 2-actuators configuration allows you to obtain a high-quality 2DOF simulator, and to limit the expense before adding the 2 other actuators. To do this, you’ll need a pivot positioned at the center of gravity. A shock-absorbing foot will do the trick nicely. The two actuators are positioned at the front. M1 is the right front, M2 the left. You can then use this specific FlyPT profile.

3-actuators configuration?

The 3-actuators configuration is not recommended: it does indeed produce a 3DOF, as with 4 actuators. But the triangular positioning of the actuators makes the chassis unstable and prevents you from taking full advantage of the actuators’ power. It also means that the “middle actuator” has to be positioned quite a long way in front or behind, which reduces angular travel.