• How To Build Rudder Pedals With Toe Brakes

    How To -- Make Your Own Rudder Pedals With Toebrakes

    By Rob Barendregt

    If you are you interested in making your own very accurate rudders pedals with toebrakes for less than US $25 worth of material, please read on. All you need is a free (analog) game controller port on your PC and some easy-to-get parts, 8 hours of spare time, and be a little handy with tools.

    Features:

    • Self-centering, sliding rudder pedals with simulated force feedback.
    • Differential (left/right), proportional toebrakes.
    • A switch for e.g. setting the parking brakes.

    Note: Proportional braking is a feature for FS2002 only, contrary to FS98/FS2000 which only support on/off brakes. So the toebrakes in my design only operate for FS2002, but at the end of this article I will describe how to make them for FS98/FS2000. You can use these pedals in combination with a yoke/joystick on a com port or USB port; if your game controller port is already used by your yoke/joystick, you can still use the rudder feature and can make the (optional) toebrakes as described for FS98/2000.

    Introduction

    Flying with rudder pedals instead using the auto-coordination feature really enhances your flightsim experience, especially during taxiing, flying in real weather or when flying helicopters. My first home-made rudder pedals (see How-To article) worked fine, but were not very realistic: the rudder pedals had no left-right coupling and operated via a up/down instead of a sliding (forward/backward) movement. Moreover, they lacked toebrakes.

    With the new proportional braking system of FS2002, the experience of my previous pedals and inspired by other home rudder pedal makers (thanks!), I decided to make new ones. As I explained in my previous article, the operation of these rudder pedals and toebrakes is based on the principle of an analog joystick: a joystick axis is just a variable resistor (called potentiometer or pot).

    In my flightsim setup I use a CH Flightsim Yoke LE on USB and these rudder pedals on the analog game port (driving axis 1,2 and 4). For helicopters or military aircraft I use a Logitech FF joystick on a COM port, because they give a better feel than the yoke.

    Braking System Of FS2000 vs. FS2002

    Both FS2000 and FS2002 internally support proportional braking; however, only FS2002 supports using this feature via an external axis controller (FS2000 only supports buttons/keys). However, with the use of Peter Dowson's FSUIPC freeware add-on module you can use these proportional toebrakes with FS2000 as well. See chapter "Installation" below. FSUIPC can be downloaded from Peter's website at: http://www.schiratti.com/dowson.htm

    TIP: Did you know you can use FSUIPC to precisely calibrate your yoke/joystick? This is especially useful if you have a problem with applying reverse thrust in FS2002 or if you have problems with calibrating these rudder pedals/toebrakes.

    What Is Needed?

    Of course you can make the pedals with your own dimensions, but here is how I built mine. Note: sorry for you non-metric guys, but I'm Dutch so I'll use metric sizes :-). Most parts can be scrap material (like I used), but you can buy them in any hardware and electronics shop.

    The main components you need, and how they are used:

    • Plate material. You can use either planed deal or plywood. 18mm thick will do fine.
      • The Base plate. 40*36 cm.
      • Two Rudder plates. 12*36 cm each.
      • Two Toebrake pedals. 18*12 cm each. For proper feeling, the pedal plates should be rounded on one side (fig. 2B)
    • Two deal poles, which hold the pots for the toebrakes. 3,5*6,5*20 cm each
    • A control arm, which connects the rudder plates. The control arm construction causes the left rudder plate being pushed forward if you slide the right rudder plate backwards v.v. Use solid wood, like Meranti. Size: 40*4*1,2 cm
    • 4 Sliders (fig. 7B). This type (with ball-bearings) are preferred to the ones using wheels, since the inner slider can move both ways and they are very low. Size: 35*3*1 cm
    • 2 Hinges (fig. 7A), 8 - 10 cm wide.
    • 8mm steel bolts (fig. 7K), for fixing the control arm on bottom plate and rudder plates. 2 of length 4 cm, 1 of length 7 cm.
    • 6 8mm self-clamping nuts (fig. 7E).
    • 3 Potentiometers (fig. 7H), value 47 KiloOhm LINEAR (not logarithmic), preferably with an iron shaft. Since you have to calibrate the controller axis, any value between 25 and 100 Kohm will do.
    • Two knobs for the toebrake pots, preferably with a fixed dial plate (prevents the elastic band and string from slipping off). If you can't find them, use normal knobs and glue them onto iron rings. Diameter of the knobs should be 3 - 4 cm; this determines the swing of the toebrake pedals. Replace the fixing scews with longer bolts, because these will hold the band and string. (fig. 6)
    • 2 elastic bands (fig. 7C), which forces the toebrakes pedals upwards. Try differents sizes and strengths to get the best feeling for pedal force.
    • 2 pieces of strong string (fig. 7F). These connect the toebrake pedals to the pot knobs
    • 2 pieces of thick elastic (0,5 cm). See fig. 7G. These provide for self-centering, and the force feedback on the Rudder movement. I bought this in a shop that sells sailing boat stuff. Again, experiment with thickness and length for the best feeling.
    • Two toothed wheels (fig. 7J). These wheels transmit the rotating movement of the control arm to the rudder pot. Transmission rate: 1:2,5. I used plastic wheels from 'toy' construction material of my son, called K'NEX (available here in Europe).
    • Two small plates of aluminium (7*3*0,3 cm), which fixes the toebrake pots onto the poles.
    • A footswitch ('make' contact, 'open' in rest position). Use any kind, and figure out how to mount them. I used an old footswitch from my synthesiser :-).
    • Shielded (audio or computer) cable; see text below.

    Assembly Instructions

    It's not a full instruction, but I'll give some tips about the important parts. The pictures should speak for themselves.
    • Drill a hole in the toebrake poles, to fit the pot. See fig. 4A.
    • Solder 30 cm of shielded twin-cable to the toebrake pots (fig. 4A/B and 8).
    • Mount the pots onto the aluminium plates, and screw these onto the poles.
    • Fix the knobs onto the pots:
      • Center the pot shaft in middle position.
      • Important. Without rotating the shaft, fix the knob onto the pot shaft, with the fixing bolt pointing straight upwards.
      • Insert screw (fig. 6b) into the pole. This prevent the pot shaft from being rotated fully anti-clockwise.
      • Fix the elastic band between the knob bolt (fig. 6A/D) and a small nail at the bottom of the pole (fig. 3D).
    • Screw the poles onto the rudder plates.
    • Drill a 9,5 mm hole into the rudder plate, and mount the self-clamping nuts (one from the top, one from the bottom). Position of the hole: about 12 cm from the top of the rudder plate.
    • Screw a small beam (2*2*12 cm) on the end of each rudder plate (fig. 2C), for better grip.
    • Fix the rudder plates onto the bottom plate with the sliders. (fig. 5A) Make sure the sliders are mounted exactly in parallel, or they will cause friction when slided.
    • Make the control arm. Note the slots at the end (see fig. 3C). The slots should be approximately 4 cm long, 8 mm wide, and 2,5 cm from the end of the control arm. Bolts 3A should slide in them easily. This will allow the rudder pedals to travel approxmiately 10 cm forward and backwards from the center position. The control arm rotates around bolt 3B, which is fixed in the bottom plate (see fig. 5F) with 2 self-clamping nuts and a normal 8 mm nut. This is a very solid construction, needed to handle the forces on the control arm. And there's no pressure on the pot shaft.
    • Screw the large toothed wheel onto the bottom of the control arm.
      Some arithmatic: given the dimensions of the control arm slots, the control arm will rotate +/- 40 degrees around the center bolt, causing the Rudder Pot to rotate 2,5 * 2 * 40 = 200 degrees. The total rotation of a pot is 270 degrees, but since the beginning/end of its resistance material is usually non-linear, I advise not to use the full 270 degrees swing.
    • Mount the control arm on the base plate and rudder plates. (fig 3A/B)
    • Fix the rudder pot (fig. 5D) onto a small aluminium plate (fig. 5B); fix the small toothed wheel onto the rudder pot shaft with a small screw (fig. 5C), and screw the aluminium plate onto the bottom plate. The large wheel should drive the small toothed wheel without friction. Important: With the rudder plates and control arm centered (fig. 3), the rudder pot shaft should also be in center position.
    • Screw the toebrake pedals onto the the rudder plates with the hinges (fig. 2A and fig. 3).
    • Fix the rope string between the toebrake pedals and pot bolts, anti-clockwise. Note about the length of the string: when the toebrake is fully pressed (the pedal rests on the bolt that holds the control arm to the rudder plate), the knob on the toebrake pot should rotate approximately 180 degrees (so knob bolt horizontal again) from the rest position. See fig. 3E, 6C.
    • With the eye-screws (fig. 7M), fix the elastic cord to bottom plate and rudder plates (fig. 1B)
      To get a proper centering and avoid wear of the elastic, the length of the elastic cords should be such that both are only a tiny bit stretched (2 cm) when the rudders are centered.

    Now, try the mechanics of the pedals: see if they slide smoothly, and if the toebrakes can be pressed fully even with full rudder. If not, adjust.

    Electrical Wiring

    See fig. 8 for a schematic diagram.

    Lead wires from the toebrake pots, rudder pot and foot switch to the top of the base plate (fig 4C), and solder them to a shielded cable according to the diagram. Solder a 15 pin gameport connector to the other end of the cable. Connect the shield of all cables (thick light-grey line), and solder it also to the 15 pin connector and pot housing. This will reduce 'jitter' on the controller axis resulting from electrical interference. Note for pot connections: always use the center contact and one of the outer contacts. Which outer contact is not relevant, since you can always use the 'reverse axis' feature when assigning the controller axis to FS2002 control functions.

    Installation Of The Pedals As A Windows Game Controller

    I can only make the description for Windows98, but it should be possible to get it working under Windows95/2000/ME as well.
    • Connect the cable to the PC game controller port.
    • Click Start - Settings - Control Panel - Game Controllers.
    • Add a new Controller: Click Add, and select '2-axis 2-button joystick', with the option 'rudder/pedals' checked.
    • Back in the Controller list the '2-axis 2-button joystick' should have status OK now.
    • Click tab 'Advanced' and organise the Controllers such, that new joystick has ID 1, and your other flight controller (in my case the Logitech joystick or Yoke) has controller ID 2. This is important, since for some (to me) unknown reason, FS200x gives an erratic rudder behavior if this analog rudder has another ID than 1.
    • Click the General tab, and click Settings - Calibrate to calibrate the rudder.
      • Simulate the 'circle' motion of the X/Y axis by pressing the toebrakes alternately. Click the footswitch (button-1) to confirm.
      • Calibrate the rudder by sliding them all the way forward and backward several times.
    • Click Properties, and observe the axis indicators in the Test tab for full swing.

    Installation Of The Rudder Pedals And Toebrakes In FS2000/FS2002

    For FS2002: go into the Options - Controls - Assignments window.
    • Select the '2 axis ...' under 'joystick type', and remove any default assignment (if applicable).
    • Assign the X (1), Y(2) and Rz(4) axis to resp. LeftBrake, RightBrake and Rudder axis.
    • Click tab Events/Buttons for '2 axis ...' joystick, and assign Button-1 to the SetParkingBrake function.
    • Select Options - Controls - Sensitivities, and select the '2 axis ...' controller.
    • Set the Sensitivity slider for Left/Right brake axis to MAX, and Null zone to MIN.
    • Set the Sensitivity slider for Rudder halfway, and Null zone a bit larger than MIN.

    Select your favorite flight, using an aircraft with a visible rudder movement. Go into the Flights - Realism Settings window and deselect the auto rudder checkbox. Check in spotplane view that the rudder is centered when the pedals are centered. If not, adjust the null zone in Sensitivities, or re-adjust the fixation of the rudder pot.

    When toebrake pedals are not pressed, no BRAKES message should appear. If it does, or if the rudder movement goes in wrong direction, select "reverse axis" for the appropriate axis, under Options - Controls - Assignments. Note: with the toebrakes assigned to controller axis, the standard (on/off) brakes keys will not work anymore (same as F1/F4 if you use a throttle axis). Check if the braking and rudder action is to your liking; if not, try experimenting with the Sensitivities and Null zone of the axis.

    For FS2000, install the rudder axis as described above. To install the toebrakes, please follow the instructions in Peter's manual of FSUIPC.

    Using The Rudder Pedals With A Yoke/Joystick On The Gameport

    If you want to use these pedals when your gameport controller is already used by a joystick/yoke, you cannot use the toebrake axis. However, the rudder can be used, and you can replace the toebrake pots by push-switches ('make' contacts). In this case, make the following modification:
    • Skip the pot construction at the top of the poles, but keep the toebrake pedals.
    • Instead, mount the elastic band (fig. 7C) between the pedal (fig. 3E) and a nail on the top of the pole; so the pedal is 'hanging' on the elastic band.
    • Mount a non-click miniature switch ('make' contact, 'open' when not pressed) onto the rudder plate underneath the toebrake pedal. So if you fully press the pedal, the switch contact is activated.
    • Like Switch-1 in fig. 8, connect one contact of the switches to pin-4 of the connector, and the other contacts to pin-7 resp. pin-10.
    • Connect the cable to the gameport via a 'Y' connector; add the pedals in the Windows game controller setup by checking the option 'rudder/pedals' of your joystick/yoke.
    • In FS200x, select the Options - Controls - Assignments window.
      In Events/Buttons, assign button-1 to SetParkingBrake, button-2 to ApplyLeftBrakes (key F11) and button-3 (key F12) to ApplyRightBrakes.

    Note: Obviously, in this setup, you lose the current function of buttons 1,2 and 3 on your joystick/yoke, since these new switches on are now in parallel with the buttons on your joystick/yoke.

    A Bonus Idea?

    As I stated earlier, I use a CH Flightsim Yoke LE USB, to which I made several enhancements.
    • Trim pots for ailerons and elevator.
      Instead of using the actual trim instruments, you can also trim the control surfaces of an aircraft by fine-tuning the main controls. And that's what I did.
      Although my yoke is USB, internally the yoke still uses pots. So, for both ailerons and elevator axis, I connected a pot (27 K linear) in series with the existing yoke pots giving enough trim capability.
    • Since my USB yoke only has a throttle axis, and the gameport connector described above still has an free axis and 3 free buttons (see pin configuration in fig. 8), I've build these pot and three switches into the yoke, with a seperate cable connected to the gameport (via a Y connector). I use this additional axis for mixture control, and the three additional buttons for resp. AutoPilot/Autothrottle and Reverse Trust activation.

    WARNING: Obviously, when modifying the yoke you will lose warranty. So be carefull if you do!

    A Final Word

    I know these rudder pedals / toebrakes may not look very professional. But make no mistake: when properly constructed, they work as accurately and are as solid as commercially available pedals. Moreover, the 'feel' of the pedals can be easily adapted to your own preferences. It took me some 8 hours to construct and install them (and making it was half the fun). They require little maintenance (maybe some new elastic every year), and last but not least: they cost a fraction a the price of commercial pedals: US $25, or less if you use existing parts like the wooden plates, and sliders from a cupboard drawer. In comparison: the CH Pro Pedals cost about US $160 here in Holland.

    Needless to say, I do not accept any responsibility if it shouldn't work or if my description messes up something in your PC or FS200x configuration. But, if you have any comments, questions, suggestions or need support, feel free to send me an email (please: no large attachments!).

    Happy flying .....

    Rob Barendregt
    rc.barendregt@planet.nl