Thrustmaster Ferrari F1 wheel add-on with SIMR-F1 display, switches and encoders

Pascal H

I completed my Thrustmaster Ferrari F1 wheel add-on mod using a SIMR-F1 display a few weeks ago. This display is really close to the MacLaren PCU-6D display used in real F1 cars, except for the orange colored lateral displays. The SIMR-F1 is HUGE and barely fits the Thrustmaster F1 wheel, but in the end I'm really satisfied with the result:

The wheel now has:

1. 1 SIMR-F1 display

    ¤ 15 LED rpm display (5 green, 5 red, 5 blue)
    ¤ 6 additional LEDs (pitlane, optimal shift point, overheat ...)
    ¤ left display panel (rpm, water temp, oil temp, current lap, remaining laps, laps before pit ...)
    ¤ center display dedicated to current gear
    ¤ right display panel (best laptime, optimal laptime, delta to best, delta to opti ...) 

2. 8 buttons

    ¤ stock buttons connected to the display (k, n, pit, pump, pl, drs, +10, -1)

3. 5 up-down encoders

    ¤ 2 stock encoder connected to the display (dif in, chrg)
    ¤ 3 additional encoder (mix, grp, trq)

4. 3 12-way switches

    ¤ left display panel variable selection (boost)
    ¤ right display panel variable selection (rev)
    ¤ Ferrari knob (MF)

5. 3 3-way switches

    ¤ 3 stock 2 way switches are replaced (bo, start, wet)

6. 2 d-pads

    ¤ both d-pads are connected together

7. 2 paddle shifters

    ¤ stock paddle switches connected to the display

On the SIMR-F1 the following inputs and outputs are used:

    ¤ 30 digital inputs (buttons, encoders) out of 32
    ¤ 3 12 position switches out of 9
    ¤ 0 analog inputs out of 2
    ¤ 0 external LEDs out of 7

Here are some short videos with the wheel in action on iRacing:

In the following posts I will explain all the steps required to mod a Thrusmaster Ferrai F1 add-on wheel with a SIMR-F1 display, 12 way switches and encoders. My mod has been split over time into 3 stages:

    ¤ Stage 1: The main PCB of the wheel is kept. Additional controls are wired on the SIMR-F1 display
       (2 12-way switches, 3 encoders, 2 stock thumb encoders)
    ¤ Stage 2: The main PCB is removed. All the controls are wired on the SIMR-F1 display
    ¤ Stage 3: Same as stage 2 with an additional 12-way switch for a fully functional Ferrari knob

This writeup is split into 7 chapters, each chapter being one post:

    ¤ Chapter 1: Hardware and tools required
    ¤ Chapter 2: Disassembly of the Thrustmaster F1 wheel
    ¤ Chapter 3: Integration of the SIMR-F1 display
    ¤ Chapter 4: Integration of additional switches and encoders
    ¤ Chapter 5: Wiring
    ¤ Chapter 6: Configuration and tests
    ¤ Chapter 7: Conclusion

Pascal H

Hardware and tools required

1. Hardware

    ¤ 1 Thrustmaster F1 wheel addon (obviously!)

    ¤ 1 SIMR-F1 display

    ¤ 1 SIMR-F1 enclosure

    ¤ 1 set of SIMR-F1 cables

    ¤ 3 SIMR-F1 12 position switches

    ¤ 2 knobs with indicator

       or SRW-S1 knobs (this is what I used)

    ¤ 3 quadrature encoders and knobs

    ¤ 1 coiled USB cable

    ¤ 1 piece of plastic (40mm x 30mm x 1.5mm plexiglas)

    ¤ 1 sheet of adhesive paper for laser printers

    ¤ 59 pin male/female 2.54mm header connector

    ¤ black, red, green, blue wires
    ¤ 177 3mm heat shrinks, 1 8mm heat shrink

2. Tools

    ¤ Set of Philips screwdrivers
    ¤ Set of flat head screwdrivers
    ¤ Set of files
    ¤ Small needle nose pliers
    ¤ Small cutting pliers
    ¤ Cutter knife
    ¤ Dremel with cut-off wheels, 3mm milling tool and 3mm drilling bit
    ¤ Drill with 6mm and 10mm drilling bit (drilling bits for wood work best for plastic)
    ¤ 8mm, 12mm, 13mm, 14mm open wrenches
    ¤ Soldering station
    ¤ Hot air gun or lighter

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Pascal H

Disassembly of the Thrustmaster F1 wheel
1. Opening the wheel

    ¤ Remove 2 small long screws on the front side (red circles)
    ¤ Remove 8 small short screws on the rear side (red circles)
    ¤ Remove 4 large screws on the rear side (blue circles)


    ¤ Open the wheel with caution because the front and rear sides are still connected together with wires from the paddle shifters
       and from the connector to the wheel base

2. Disconnecting the wires connecting the rear side to the PCB

    ¤ First disconnect the lower connector linking the PS2 connector inside the quick release to the main PCB.
       The easiest way is to gently pry the connector with a small flat head screwdriver while gently pulling the wires (red circle)
    ¤ Disconnect both upper connectors linking both paddle switches to the main PCB (red circle)


3. Removing the PCB

    ¤ Disconnect the remaining connectors (2 x 1 top buttons, 2 x 1 top encoders, 2 x 3 lateral buttons, 2 x 1 d-pads)
    ¤ Remove 4 screws (blue circles)


    ¤ Take out the PCB

4. Removing the buttons and the d-pads

    ¤ Remove the glue from all 8 buttons and 2 d-pads. Don't remove the silicone from the wires: the glue to remove is
       usually located inside the clearance between the button/d-pad and the wheel (red circles). The easiest way to remove
       the glue is to use a small flat head screw driver and to gently pry the glue out of the clearance


    ¤ Remove 8 buttons and 2 d-pads from the wheel by pushing in 2 tabs for each button/d-pad. These tabs are located on the side
       of each button/d-pads inside of the clearance between button/d-pad and wheel. The easiest way is again to use a small flat head
       screwdriver to push the tabs in


    ¤ There is no need to remove the encoders as they are not in the way.
       The encoders are also quite difficult to remove as a special wrench is needed

5. Removing the Ferrari knob

    ¤ Remove 2 screws (blue circles)
    ¤ Take out the Ferrari knob


6. Removing the 3-way switches

    ¤ Remove 3 nuts and locking washers (red circles) with a 8mm wrench
      ¤ Take out the PCB with the 3 3-way switches soldered on it


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Pascal H

Integration of the SIMR-F1 display
1. Integration decisions

    ¤ There are several ways to integrate a display into a wheel:

       * The bare display is fastened inside the wheel with openings to see the display through

       * The display with its enclosure is simply  fastened on top of the wheel

       * The wheel is cut and walls are reconstructed to fasten the display and its enclosure on top of it like on a real F138 wheel

       * The display and its enclosure is integrated into the wheel without fully cutting it

    ¤ The first option was rejected because I wanted to keep the look as close as possible to the real thing
    ¤ The second option was rejected because despite the easy integration it was looking erally weird.
       The SIMR-F1 enclosure being 21mm tall, it was really standing out much too much
    ¤ The third option imposes to cut the rear wall of the wheel. This rear wall being part of the structure of the wheel,
       I was worried by the potential loss of structural rigidity of the wheel. So I rejected this option too
    ¤ This is why I decided to take the 4th option: partial integration of the display and its enclosure into the
       wheel without cutting the rear wall

2. Drawing the location of the SIMR-F1 display

    ¤ First, download the template files of the SIMR-F1 display from the SimDisplay
    ¤ Print the PDF template file at a 1:1 scale
    ¤ Cut out the template, but remove the red tabs, as those areas should not be cut out of the wheel.
       These tabs will be used to fasten the display to the wheel

    ¤ Put the template on the wheel aligning the top of the template to the top of the aluminium insert, as we want to
       keep the upper wall of the wheel. Both screw holes should be just touching the template
    ¤ Draw the outline on the wheel


3. Machining of the wheel front

    ¤ Cut open the wheel front with a cut-off wheel. Don't cut into the rear wall as we want to keep it.
       Don't cut too deep: to keep the wheel as strong as possible, the rib below should be kept.
       4mm of residual height for this rib is enough to clear the display


    ¤ Then use a milling tool to enlarge the opening up to the outline previously drawn. To ensure a precise milling process,
       I found that the best is to hold the Dremel firmly in one hand and to use the other hand to guide the Dremel.
       This is best done by putting the fingers of the second hand on the wheel as a reference position and to use the thumb
       against the Dremel to guide it.


    ¤ Use a flat file to finish the top of the opening: it should be flush to the rear wall. Use a round file to finish the corners.
       In the picture below, the upper part of the opening is completed: the shape of the opening is perfectly matching the
       shape of the display enclosure. It can be seen how the tabs of the enclosure will fit below the wheel, near the holes


    ¤ The lower part of the opening should be milled flush with the flat surface of the wheel. The aluminium face has to be
       removed using a flat head screwdriver. It is only held with double-sided tape. The template is used to adjust the shape
       of the lower part of the opening. The thumb encoder enclosures have to be milled quite a lot


4. Drilling holes for the bolts and fastening the display enclosure to the wheel

    ¤ Put the SIMR-F1 enclosure upside down into the milled opening and use it as a template to drill both 3mm holes in the wheel
    ¤ Slide the display into the opening with fastening tabs of the display enclosure below the wheel face
    ¤ The 3mm hex bolts can then be fitted: they should pass through the wheel face, then a 3mm washer and a 3mm nut used as
       spacers, then fastening tabs of the display enclosure, then a 3mm washer and a 3mm nut


    ¤ The 3mm nuts can be seen on the picture below. They should be moderately tightened. A small screw has been added
       (just below the PCB) to pull the display enclosure against the wheel for a better fit


    ¤ The fit is almost perfect. The small voids as well as the small screw holes could be filled with black putty or sugru


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Pascal H

Integration of additional switches and encoders 

1. Integration decisions

    ¤ The real Ferrari F138 wheel has 5 knobs in addition to the multifunction Ferrari knob

    ¤ On the Thrustmaster F1 wheel these 5 knobs are not functional, they are just represented by embossings on the aluminium face.
       The Ferrari knob is not functional either: it is simply fastened to the wheel with 2 screws

    ¤ To get the most out of the SIMR-F1 display, 2 SimDisplay 12-way switches should be used to cycle through
       the variables displayed on the left and right 14 segment displays. The best is to use both upper locations
    ¤ For stage 1 and 2 of my mod I didn't implement a functional Ferrari knob because I thought it wasn't very useful
       in-race as it is quite far from your fingers so you must take one hand off the wheel to manipulate it. I finally
       implemented a fully functional Ferrari knob in stage 3 of my mod, but I don't use it much while driving
    ¤ In the 3 lower knob locations, 3 CTS-288 16 steps/revolution encoders from SymProject have been mounted

2. Drilling the wheel face

    ¤ The base idea was to keep the same location as the F138 wheel for every additional encoder/switch.
       But the location for each additional encoder/switch has to be planned carefully as there are several constraints:

       * If the main PCB has to be kept, the 3 lower controls and the Ferrari control can only be encoders.
          12-way switches are too tall and would not fit
       * If both upper controls are 12-way switches and the main PCB has to be kept, the main PCB has to be cut.
          The minimum remaining width of the PCB is 24mm
       * If both upper controls are 12-way switches, the positions of the F138 wheel can't be used because the large
          diameter of the switches (27mm) won't clear major structural pillars of the wheel

    ¤ The following locations for the controls have been chosen: F138 position for the 3 lower encoders and a slightly
       lower placement of both upper 12-way switches. The following picture summarizes the control placement:


    ¤ The base radius for the addtional controls is 41mm. The distance between both upper 12-way switches is
       29mm (56mm - 27mm) which clears a machined main PCB. The Geogebra geometry file as well as the picture
       file can be found in the attached file 
    ¤ I would recommend printing the geometry file or the corresponding picture at a 1:1 scale to use it as a template
       on your wheel. Cut out the center 21mm hole from the template to easily align the template on the wheel.
    ¤ Start by drilling 3mm holes at points B, D, E, H, J to get a precise positioning. Then enlarge the holes to 10mm

3. Milling of front and rear cover ribs

    ¤ Use the Dremel with a 3mm milling tool to mill off the ribs of the front cover for all 5 additional controls as
       displayed in the picture below. The 12-way switches being quite large (diameter 27mm) a large part of the
       reinforcement rib has to be removed. To keep the best possible structural strength of the wheel, the amount of
       reinforcement rib removed has to be kept to the minimum


    ¤ Test-fit with all controls in place to check if enough rib has been removed. The soldering pads of the encoders should
       be oriented towards the top of the wheel. The soldering pads of the 12-way switches should be oriented towards the
       top or towards the bottom of the wheel, but not towards the side of the wheel as it is a very tight fit. The 12-way switches
       have a stop to ensure a precise angular positionning. These stops can safely be removed as the switch won't move
       with a well tightened nut


    ¤ If the main PCB has to be kept, test the fitting of the cut PCB now. On the following picture, you can see that the
       12-way switches just clear the upper stuctural pillars as well as the cut main PCB


    ¤ With these tall 12-way switches, the rear cover of the wheel won't clear because reinforcement ribs are located just in
       front of the switches. Two ribs have to be removed to clear both upper 12-way switches (2 lower red ellipses). One rib
       has to be removed to clear the Ferrari knob 12-way switch (upper red ellipse). On the picture, the last rib hasn't been
       milled out yet as the picture was taken during stage 2 mod


4. Cutting encoder shafts

    ¤ The CTS-288 encoder shaft is much too long for our purpose. To keep the knobs almost flush mounted on the wheel,
       they have to be cut to a length of 7mm. This is best performed with a Dremel cut-off wheel. It should be done in several
       short steps to let the shaft cool down. Overheating of the shaft could lead to failure of the encoder 


5. Cutting and milling of 12 way switches shafts

    ¤ As for the encoders, the shafts of the 12-way switches are much too long. The shafts of the switches should be
       cut to a length of 8mm
    ¤ A flat is then milled or filed on each shaft to fit the selected knob. The milling or filing depth is approximately 2mm.
       Be aware that the orientation of the flat is important as it determines the orientation of the knob. The orientation of
       the switch can't be changed much as it is a very tight fit: the wiring pads should be oriented towards the top or towards
       the bottom of the wheel, but not towards the side 


6. Machining of encoder and switch knobs

    ¤ The CTS-288 encoder is sold with a knob that has an opening that almost fits the encoder nut. To be able to lower
       the knob as much as possible to get a flush mount on the wheel, the knob has to be milled to give some room to the
       nut. This is best achieved by using a Dremel 3mm milling tool. The knobs should be milled up to the middle of the 3
       small cercles


    ¤ The SRW-S1 knob has also to be milled for a better fit: 2mm of plastic should be removed on the inside (see picture below)


7. Fabricating a fully functional Ferrari knob

    ¤ For my stage 3 mod, I decided make the multifunction Ferrari knob fully functional. This is not as easy as it seems
       as there is a 21mm hole in the wheel where the 12-way switch should be put. Therefore an adapter piece has to be
       built: the switch will be mounted on this adapter piece which will in turn  be mounted onto the front wheel cover. To
       fasten the adapter piece on the wheel cover the holes designed to fasten the Ferrari knob will be used
    ¤ The hole in the wheel front cover having a diameter of 21mm, the distance between both screw holes being 28mm
       and the width around the screw mounting holes being 7mm, the shape of the adapter piece has to be the following:


    ¤ I used a small piece of 1,5mm thick plexiglas, as it is strong and easy to machine. I traced the shape on the plexiglas
       with a scriber, drilled the 3 holes and then cut the outer shape with a Dremel cut-off wheel. On the following picture
       it looks worse than it is because you can see all the small defects through the plexiglas


    ¤ The adapter piece is then test-fitted on the 12-way switch. The stop of the switch is cut to avoid weakening the adapter
       piece with another hole. Even without the stop the switch will not budge if the nut is well tightened


    ¤ The adaptation part is then test-fitted on the front cover of the wheel. It must be noticed on the picture that the fastening
       screws have been cut to length to avoid damaging the switch because it is a really tight fit. Countersunk 3mm screws
       must be used for a flush mount on the outside


    ¤ The Ferrari knob must now be opened. Push the 4 tabs of the yellow cover to the inside while pulling it from
       the black knob. The center of the knob is easily found and traced with a compass. The black knob is then drilled
       with a 6mm drilling bit. Be aware that the flat inside of the knob is slightly slanted. The knob can then be test fitted.
       Check the centering of the hole by rotating the knob around the switch shaft


    ¤ The shaft of the 12-way switch is then cut to length to be flush with the knob surface. For a good fit, 1mm shims
       can be used to space the knob at the right distance from the wheel. The knob should rotate without touching
       the wheel cover. 1.2mm holes are then drilled vertically between the knob and the shaft. 2mm screws are screwed
       into these holes to fasten the knob to the switch shaft. It should be tight. The angular position of the knob has to be
       set carefully taking into account the position of the Ferrari logo on the yellow cover


    ¤ The final fit can be seen in the following picture. Please notice the gap between the knob and the wheel cover.
       The yellow Ferrari cover can then be put back on the knob. I would suggest to cut the four fitting tabs in half to
       ease a subsequent removal. If you keep the small hooks at the end of the fitting tabs removing the yellow cover
       can turn into a nightmare 


    ¤ To improve readability, an indicator can be added to the Ferrari knob. I did it by filing a notch with a triangular file.
       The notch is then filled with white paint for a very good readability:


8. Decals

    ¤ I started working on a set of decals when I came across an excellent post by Krzysiek on Marcus Hwang's Blog
       He shared a file containing all the decals needed for a F138 steering wheel. 

    ¤ When I first tested these decals, they seemed a little bit too small, with my knobs covering the text.
       I then printed the decals at size 120%, which gave me a perfect fit with the text size matching the text size
       of the wheel cover and the knobs not hiding any text
    ¤ For printing, I used adhesive PVC sheets from At first, with standard settings of
       the laser printer the ink wouldn't hold well on the PVC surface leading to a very poor result. On my laser printer,
       I had to select printing on photographic paper to get a slower paper speed inside of the printer for a higher
       temperature on the PVC and a perfect printing. As can be seen below, the result is really nice


9. Choosing knobs

    ¤ The click locking of the CTS-288 encoders not being too strong, the encoders can be operated with one finger which
       is what is needed
    ¤ The click locking of the 12-way switches is really firm, but with the large diameter of the Ferrari knob it works very well
    ¤ Both top 12-way switches having a firm click locking, using them with small knobs requires you to apply a high torque
       to overcome a click: this can be distracting or even annoying. This is why I chose the largest knobs I could find that made
       the feel acceptable, as those controls won't be operated very often during a race

 Back to Table of Content

Pascal H


1. SIMR-F1 display wiring diagram

    ¤ Despite its small size, the SIMR-F1 display can be connected to many input and output devices:

       * 32 buttons or 16 quadrature encoders (1 quadrature encoder takes 2 inputs)
       * 9 12-way switches
       * 2 analog inputs
       * 7 LEDs
       * All these inputs and outputs have to be connected to the SIMR-F1 display using connector 1 and
          connector 2. I would recommend buying the SIMR-F1 cable set from SimDisplay
          ( as wiring directly to the connectors on the
          SIMR-F1 connectors won't be practical. All the wiring information displayed below can be found in the
          SIMR-F1 manual that can be downloaded at          ¤ Input/output connectors wiring diagram

       * Connector 1


       * Connector 2


    ¤ Wiring buttons to the SIMR-F1 display

       Buttons are very easy to connect to SIMR-F1 display as a button input is considered 1 when not
       connected and 0 when connected to ground. Therefore one terminal of the button is connected to
       the input, the other one to ground: 
       Connector pins
       *  Ground: connector 1 pin 1
       *  Button input: connector 1 pins 2-25 and connector 2 pins 1-8

    ¤ Wiring quadrature encoders to the SIMR-F1 display

       Quadrature encoders are connected as 2 buttons: 2 digital inputs tied or not to ground depending
       on angular position of the encoder. Be aware both digital input used for an encoder have to be
       consecutive as displayed on the connector 1 wiring diagram above. Decoding the quadrature digital
       signals is performed by the SIMR-F1 internal software as explained in chapter 6. The USB HID signals
       generated are pulses on the first button for forward rotation of the encoder and pulses on the second
       button for reverse rotation of the encoderWhen using connectors to connect the encoders to the wiring
       loom, the best option is to connect ground to the center pin. It make it easy to exchange forward and
       reverse buttons just by reversing the connectors.  

       Connector pins
       * Ground: connector 1 pin 1
       * Encoder inputs: connector 1 pins 2-3, 4-5, 6-7, 8-9, 10-11, 12-13, 14-15, 16-17, 18-19, 20-21, 22-23, 24-25
          and connector 2 pins 1-2, 3-4, 5-6, 7-8

    ¤ Wiring 12-way switches to the SIMR-F1

       The SIMR-F1 12-way switch is an active component that generates a digital signal depending on the angular
       position of the switch. Being a active component, it needs a  ground and a +5V connection. This switch is
       not compatible with Leo Bodnar's 12-way switch which uses a fully analog technology. Be careful to reverse
       +5V and ground connection as it could detroy the switch  

       Connector pins
       * Ground: connector 1 pin 1
       * +5V: connector 1 pin 26
       * switch input: connector 2 pins 11-19 

2. Cutting the main PCB of the Thrustmaster F1 wheel

    ¤ When using the upper additional input device spots to fit 12-way switches, the main PCB of the wheel
       won't fit as the switches are too tall. The easiest way to keep the stock operation of the wheel (to keep
       compatibility with the T500RS/PS3 or TX/OneBox combo) is to cut out unused parts of the main PCB
    ¤ Using the following template, only 8 straight cut with a Dremel cut-off wheel are needed. The existing
       holes are used as guides and so the cuts are really straightforward. Be careful not to cut any PCB track
       between both vertical cuts


    ¤ The cut Thrustmaster F1 wheel main PCB should look like this:


3. Input devices connectors

    ¤ To be able to remove the back cover of the wheel from the front cover, to be able to remove a single button/encoder/switch
       without desoldering, to be able to perform tests easily, every button/encoder/switch has to be connected to the display
       through a connector
    ¤ Standard connectors can't be used as they are much too large given the limited space inside the wheel. I tried 2 types of
       miniature connectors that take little space: 1.27mm pitch headers and 2.54mm pitch headers. The 1.27 pitch header
       connectors I found, although they were really tiny, could not be cut to length and were not tight enough. I finally used
       2.54mm pitch headers: they are larger but easier to solder, very tight and easy to cut to length


4. Stage 1 wiring

    ¤ For stage 1, the idea was to keep the main PCB and keep as much as possible stock inputs connected to the main
       PCB. Among the stock inputs, only the following have been connected to the SIMR-F1 display:
       * Both stock thumb encoders. When the wheel was used on a Thrustmaster TX wheel base, under high FFB conditions
          the stock encoder inputs on the main PCB triggered randomly which was very annoying. By moving the encoders to
          the display, the problem disappeared
       * All 3 lower switches. Although these are 3-way switches, the upper and lower positions being connected together on
          the daughter PCB, only 2-way operation is available: open or closed. The daughter PCB has been removed and 6
          digital inputs of the display have been used for 3-way operation of the switches: open, closed 1 or closed 2

    ¤ Additional inputs connected to the display:
       * 2 12-way switches
       * 3 quadrature encoders

    ¤ Stage 1 wiring diagram
    ¤ Stage 1 wiring loom: the stage 1 wiring loom as pictured below has been wired according to the stage 1 wiring
       diagram. On the diagram, it is easily noticed that all inputs need a ground wire. This is the most difficult part of
       the wiring, because on a single pin there are often several ground wires that need to be connected together.
       I chose to not connect ground wires together in the wiring loom, but routed the ground wire to a connector pin and
       from there to the next one and so on. Every wire to a connector if fitted with its heat shrink (10mm length) to avoid
       any risk of electrical short circuit


    ¤ Inputs to be connected to the SIMR-F1 display are wired to male connectors. I chose to do so to avoid having dangling
       +5V wires in case a connector gets loose. There is no risk with a wrong connection except with the 12-way switches,
       because they are powered by the display. I chose use a blue colored wire for all +5V connections to make the check
       easy. Every wire to a connector if fitted with its heat shrink (10mm length) to avoid any risk of electrical short circuit


    ¤ Inputs are connected to the wiring loom. Wiring loom is connected to the SIMR-F1 display


    ¤ There is just enough space for the cut main PCB. Be careful not to pinch wires between the encoders and the PCB


5. Stage 2 wiring

    ¤ The stage 1 wiring was working but there were 2 major problems:
       * To remove the 3-way switches from daughter PCB the switches had to be heated up too much, which led to random
          operation of the switches. Therefore I replaced all 3 of them
       * The SliMax software used to control the display doesn't recognize the Thrustmaster TX wheel base as HID device.
          So the stock wheel inputs can't be used to operate SIM-F1 functions: for example the Quick Info button can't be a
          stock Thrustmaster TX button

    ¤ As the wheel isn't used on a console, I decided to remove the main PCB and to wire all the inputs to the SIMR-F1 display,
       for a total of:
       * 8 buttons
       * 2 d-pads (on the same inputs)
       * 5 quadrature encoders
       * 3 3-way switches
       * 2 12-way switches
       * 2 shifter paddles

    ¤ Stage 2 wiring diagram: it is based on the stage 1 wiring diagram. Buttons, d-pads and shifters connections are added to
       the wiring loom. Both d-pads (left and right) are connected together, as dual d-pad functionality is not useful: 4 digital inputs
       are saved by doing so

    ¤ Stage 2 wiring: it becomes tight. Connectors take up a lot of space


Stage 3 wiring

    ¤ For stage 3, I decided to add full functionality to the center multifunction Ferrari knob for several reasons:
​       * The main PCB having been removed, there was now space to mount an additional 12-way switch below the Ferrari knob
       * I really didn't like the idea to have a fully functional wheel, except one knob: the most visible one, the Ferrari knob. When
          touching the wheel, most people try to operate that knob first
       * There were still many 12-way switch inputs available

    ¤ ​Stage 3 wiring diagram: it is based on the stage 2 wiring diagram. Only 3 additional wires are linking the Ferrari knob 12-way
       switch to the SIMR-F1 display 


7. USB cable wiring

    ¤ What kind of USB cable?

       Using a standard USB cable to connect the wheel to the PC is not very practical as it is dangling down most of the
       time. It cannot be shortened as the cable must be long enough to wrap the wheel hub when reseting the wheel base.
       A coiled USB cable is a much better choice, being very extensible. I used the following 50cm cable, 3m streched 


    ¤ USB cable wiring

       The USB be cable must be cut and soldered to the SIMR-F1 ribbon cable connected to the alternative USB socket
       according to the following wiring diagram: 

       Finished cable:


    ¤ Wheel rear cover disassembly

       The 4 screws fastening the spring cover are removed (center of the picture)


       Springs and rocker shifter are removed

       Wheel hub and rear cover are then disassembled


    ¤ Cutting the hub and the rear cover

       The wheel hub is then cut open using a Dremel 3mm milling tool as pictured below


       A slot is cut on the lower side of rear cover of the wheel in front of the hub opening using the Dremel milling tool


       The USB cable is placed in the slot. The cable is routed through the hub opening. The hub can then be mounted back on
       the rear wheel cover



       For stage 2 and stage 3 mods, as the main PCB is removed, the PS2 connector linking the main PCB to the wheel
       base can be safely removed. To do so, simply remove the screws on each side of the PS2 connector (see picture above)
       and remove the connector

    ¤ Alternative routing

       Alternatively, the USB cable can be routed to the top of the wheel below the rocker paddle on the rear cover. This routing
       takes up less space inside of the wheel and eases the closing of the wheel

8. Closing the wheel

    ¤ The wheel should close without applying any force. If it is not the case, then a wire is pinched between a switch and the
       rear cover or a wire is pinched between front and rear cover or a rib is touching a 12-way switch
    ¤ If you experience a 12-way switch not switching or switching randomly when the wheel is closed, it is usually due to pressure
       applied to the PCB of the switch by a pinched wire or a rib 

 Back to Table of Content

Pascal H

Configuration and tests 

1. Hardware configuration

    ¤ Download the SIMR-F1-Manager.exe configuration software package from the following address:
    ¤ Run the SIMR-F1-Manager.exe configuration program. If the following error message is displayed, check the
       USB connection between the SIMR-F1 display and the PC. USB connection problems can be debugged by first
       connecting the SIMR-F1 display to the PC using a standard USB cable connected to the USB socket on SIMR-F1
       display. If it then works, your home made USB cable wiring is wrong. If not your SIMR-F1 display is broken ...


    ¤ SIMR-F1-manager main window:


    ¤ Select the Options/Setup/Encoders submenu
    ¤ Configure the quadrature encoders as displayed below


    ¤ 2 Stock Thrustmaster F1 wheel thumb quadrature encoders: those are connected to digital input 1-2 and 3-4.
       Therefore BTN 01 - 02 and BTN 03 - 04 are checked to treat these inputs as encoders. Frequency is set to 1:4
       for both as these encoders generate 4 pulses for each click
    ¤ 3 CTS-288 quadrature encoders: those are connected to digital input 5-6, 7-8 and 9-10. Therefore BTN 05 - 06,
       BTN 07 - 08 and BTN 09 - 10 are checked. Frequency is set to 1:1 as these encoders generate 1 pulse for each click
    ¤ The debouncing time is set to 60ms, which is adequate for a manually operated quadrature decoder
​    ¤ All the other checkboxes are left unchecked as digital input 11 to 32 are used as standard digital inputs

2. 12-way switches test

    ¤ Run the SIMR-F1-Manager.exe configuration program
    ¤ Select the Options/Test device/Switches submenu


    ¤ Check every position of each switch available in the drop-down list (2 for stage 1-2 and 3 for stage 3)

3. Digital inputs test

    ¤ Run the joystick control panel by typing "joy.cpl" in the search bar above the windows start button.
       You should see the following window:


    ¤ Select SIM Race F1 if rhere are several game controllers installed. Then click the Property button.
       The following window should be displayed:


    ¤ Quadrature encoders test
       * Right hand thumb encoder: button 1-2
       * Left hand thumb encoder: button 3-4
       * Lower center encoder: button 5-6
       * Lower left encoder: button 7-8
       * Lower right encoder: button 9-10

       Quadrature encoders should generate 1 pulse per encoder click. Odd numbered buttons should
       be pulsed for forward rotation of encoders and the corresponding even numbered buttons should be
       pulsed for reverse rotation of encoders

    ¤ Buttons, 3-way switches, d-pads and shifters test
       * Center 3-way switch: button 11-12
       * Left hand 3-way switch: button 13-14
       * Right hand 3-way switch: button 15-16
       * Right hand buttons: button 17-20
       * Both d-pads: button 21-24
       * Left hand buttons: button 25-28
       * Shifters: button 29-30

4. Configuration of SIMR-F1 internal use of controls

    ¤ 12-way switches can't directly be used in-game, but they can be used to select variables displayed
       on the right and left 14 segments displays using SliMax Manager software package. Quadrature
       encoders and buttons can also be used to dynamically alter the way data is displayed on the SIMR-F1
    ¤ To configure how the controls are used, run SliMax Manager


    ¤ From the Options menu, select Controls Mapping...
       * 12-way switches
          Configuration parameters that need 12-way switches inputs are prefixed with SW. I wanted the upper
          left switch to control the SIMR-F1 left display (SWLEFTDIGITSCTRL = S1 SIMRACE-F1) and the upper
          right switch to control the SIMR-F1 right display (SWRIGHTDIGITSCTRL = S3 SIMRACE-F1).
          The Ferrari knob is used as a multifonction switch: each position of the switch selects a configuration file,
          allowing each control to behave differently for each switch position (SWDRIVINGCTRL = S2 SIMRACE-F1).
          In this case, buttons and encoders can't be used directly in-game as a HID control but should generate
          keypresses according to the switch position
       * Quadrature encoders
          Configuration parameters that need quadrature encoder inputs are postfixed with CTRLUP and CTRLDOWN.
          I wanted the lower center quadrature encoder to adjust the SIMR-F1 brightness level. This encoder is
          generating button 9 pulses on forward rotation (BRIGHTNESSCTRLUP = B9 SIMRACE-F1) and button 10
          pulses on reverse rotation (BRIGHTNESSCTRLDOWN = B10 SIMRACE-F1) 
       * Buttons
          Configuration parameters that need button inputs are postfixed with BTNCTRL. I wanted the quick info (QI)
          button to be the lower left button (QIBTNCTRL = B18 SIMRACE-F1)


    ¤ To select the variable displayed on the SIMR-F1 displays as a function of the 12-way switch position selected
       above, from the Options menu, select Advanced Options..., then expand the SIMRACEF1 tag in the settings
       list. Double-click F1LEFTDIGITSPANELS or F1RIGHTDIGITSPANELS to set the variable displayed for each
       switch position


    ¤ To select the variables displayed on the left and right 14 segments displays while the QI button is depressed, 
       from the Options menu, select Advanced Options..., then expand the SIMRACEF1 tag in the settings list. Click
       F1QIFUNCTIONLEFT or F1QIFUNCTIONRIGHT to set the variable displayed


    ¤ To set the brightness of the SIMR-F1 display,  from the Options menu, select Advanced Options..., then expand
       the BRIGHTNESS tag. There you can set the maximum brightness (MAXBRIGHTNESS), the initial brightness at
       startup (GLOBALBRIGHTNESS) and the brightness steps (BRIGHTSTEP) for each forward and reverse click of
       the above selected encoder


    ¤ To display a state variable on a given LED, being it one the 6 built-in LEDs or one of the 7 external LEDs, from the
       Options menu, select Advanced Options..., then expand the LED tag. For each of the state variables in the list
       (there are many), one LED to display the state can be chosen. One LED can therefore display several functions.


5. Configuration of SIMR-F1 external (game) use of controls

    ¤ The SIMR-F1 display is seen by the PC as a HID device. Some kind of joystick incorporating 2 axis (both analog
       inputs) and 32 buttons (quadrature encoders and buttons). All these inputs can be directly mapped in-game


    ¤ Each action on each input connected to the SIMR-F1 display (or even other HID devices) can the be translated
       into key presses by the SliMax software package
       To generate keypresses each time a given switch changes position, from the Options menu, select Advanced
       Options..., then expand the SIMRACEF1 tag and click SW1CHARSMAPPING for switch 1. Then click true/yes
       to activate the function 


       To define the keypresses generated when a given switch changes position, click SW1CHARS. Then, in the following
       table fill out the keypress sequences including modifiers (shift/ctrl/alt) and delays for each switch position 


       To generate keypresses each time a given button is pressed or a given encoder is rotated, from the Options menu,
       select Advanced Options..., then expand the SIMRACEF1 tag and click BUTTONCHARSMAPPING. Then click
       true/yes to activate the function 


       To define the keypresses generated when a given button is pressed or a given encoder is rotated, click BTNCHARLIST.
       Then, in the following table fill out the keypress sequences including modifierw (shift/ctrl/alt) and delays for each button/encoder


Back to Table of Content

Pascal H


1. Mass, inertia and feeling

    ¤ Mass: When I started this mod, I was worried by the additional mass that would be added to the wheel.
       But in the end it wasn't that much: of course the display and its enclosure, encoders and switches as
       well as wires and connectors were added, but a lot of the hard plastic was cut-off, somewhat compensating
       the added mass.
       * Mass of stock F1 wheel: 950g
       * Mass of stage 3 modded F1 wheel: 1032g

    ¤ Inertia: Mass is not that important for rotating parts, what matters is the moment of inertia. The moment of
       inertia is expressed as I=integral(r².dm), which means that mass located near the rotation axis has a much
       lower impact on the moment of inertia than mass located far away from the rotation axis. This is exactly
       what happened with this wheel mod: the mass added far from the rotation axis has been compensated by
       removing plastic from the shell and mass added (encoders, switches) is close to the rotation axis. Thus, the
       resulting moment of inertia should not be impacted much

    ¤ Feeling: The modded wheel feels heavier in your hands, but as soon as it connected to the wheel base, no
       difference can be felt between the stock and modded wheel. Same response time an zippy reaction and no
       damping or filtered FFB at all

    ¤ In the future, some measurements using the iRacing wheeltest utility will be performed with the modded wheel
       and displayed in this write-up. If anyone has results with a stock F1 rim on a Thrustmaster TX, I would be glad
       to show the comparison

2. Time spent

    ¤ Planning, reading, documenting every component took quite a lot of time. Much more than modding the wheel
    ¤ All in all the cutting, machining of the wheel and parts, wiring and mounting took around 30 hours. It took that
       long mainly because the work was performed very carefully, taking time for each step

3. Total cost

    ¤ The following cost includes international shipping and handling:

       Thrustmaster F1 wheel: 132.00 €
       SIMR-F1 kit: 198.85 €
       Additional SIMR-F1 12-way switch: 9.00 €
       CTS-288 encoders: 23.67 €
       Decals PVC sheets: 15.06 €
       Header connectors: 4.00 €
       Heat shrink tube: 5.00 €
       Coiled USB cable: 3.76 €
       Total: 391.34 €

    ¤ Expensive? yes, but for the kind of result there is no cheaper option

4. Final thoughts

    ¤ Will this kind of mod make you faster? No!
    ¤ What is the major benefit of this mod? Immersion
    ¤ Do I use all the encoders, switches a lot? Less than I thought I would!
    ¤ Would I do it again? Yes  
Thanks for watching! 

Back to Table of Content


Great tutorial !

Race Like Santa

Pascal H

By: Krassi
Great tutorial !
Thanks smile


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