Tutorial: adding a power switch to a Logitech Driving Force Pro steering wheel

[jasonbar]

I do enjoy my Logitech Driving Force Pro USB steering wheel, but it doesn't have a power switch.  Why do I care?  When you power up your PC & the DFP is plugged in, it will go through a "ghost driving" startup sequence where the wheel turns itself back & forth to calibrates itself.  It's fun to watch the wheel driving itself, but I play non-driving games 99% of the time, so I don't want it doing its startup sequence every time I turn on my cab.  Not to mention the extra current draw or wear & tear on the wheel mechanism (I know that's probably negligible, but it's the principle...).

So, I installed a power switch so that the wheel can be powered up only when needed.



My tutorial follows.


Thanks,
-Jason

[jasonbar]

1: Remove 8 screws & pull off top of case.  Pull out USB cable from PCB if you want to.  The PC end of my USB cable was already semi-permanently installed in my cab, so I yoinked the cable from the wheel so that I could bring the wheel to the garage to work on my workbench there.

2/3: see that 24V DC power plug?  Pull that out of its pocket @ the back of the housing & unplug it from the PCB.  We're going to modify this subassembly.

4: I used Radio Shack P/N 275-0014 illuminated LED switch.  Sure, it's rated at 12V instead of 24V, but it's rated at 20A, & this wheel draws waaaay less current than 20A, so it'll work fine.  And it's cheap!  It was important to me to have the  switch illuminated (preferably, or at least have another power indicator LED elsewhere) because there's a few-second  delay when the wheel is powered up before it starts its calibration sequence, & if the casual user doesn't see something light up, they might flip the switch a few times quickly in confusion.

5: Drill a hole & install the switch.  I chose to place it centered along the axis of the wheel, about 2/3 of the way from the wheel towards the back edge.  This turned out to interfere a little with the large metal brace going down the center of the wheel mechanism (see Step 1).

6: Solution: bend the leads!  Note that I also dremeled/fatigued/filed away the inner stiffening ribs of the top housing so that the switch would sit flush against the ceiling of the wheel cover.

7: Cut & strip the red lead (24V) of the power cable.  Also strip (but don't cut!!!) a portion of the black ground wire (not shown).

8: Solder an extension of wire to each end of the split red wire.  Make sure they're long--it's easy to trim them later.  These 2 wires are going to go to the switch to interrupt the power line.  Then solder in an 1200ohm (1.2kohm) resistor to "T" off of the black ground wire.  This will essentially drop the voltage from 24V to 12V for the "12V" LED.  I put "12V" in quotes because it's surely a lower voltage LED that already has a resistor in the switch package to let it operate at 12V, dropped down to whatever its rating is.

[jasonbar]

9: Extend a black wire on the other end of the resistor from Step 8.  Crimp some female quick disconnects on each of the 3 wires, which will all go to the illuminated switch.  I also recommend flowing some solder into the crimped connections, just to make sure you've got great electrical connection & to reinforce the mechanical connection.  And yes, close observers will see that I cut one of my red wires too short (do as I say, not as I do!) & spliced another piece to it to lengthen it.  *blush*  Install the power jack into the wheel housing & attach the power plug to the PCB.

10: Attach the wires to the switch.  Now, normally, with a plain old switch, it doesn't matter which wire gets attached to which lead on the switch.  But this switch has a 3rd lead for the integral LED, so I it does matter here--if you swap "POWER" & "ACC", then the LED will always have power & be on all the time (which is fine if you want that, but I want it to illuminate only when the switch si closed).  Black goes to "GROUND".  The red wire from the power jack goes to "POWER".  The red wire from the connector that goes to the PCB goes to "ACC" (for "ACCESSORY").  Because I had to bend the terminals on the switch & because the wires & crimp connectors were close (or even touching) the metal brace in the wheel, I added some  when it was all assembled, I put some heat shrink tube over the quick disconnect crimp connectors to make sure nothing shorted.

11: Make sure everything's plugged in & you have enough wire length to comfortably open & handle the wheel case.

12: Insert the power jack back into its pocket & carefully reassemble the wheel.  Don't forget to install the USB cable if you removed it earlier!

[jasonbar]

13-16: Clamp to your Frankenpanel & enjoy the illuminated power switch!

17: For extra clarity & user-friendliness, if you want, slap on a power sticker.  I had 1 leftover power icon from my set of vinyl stickers purchased from Pongo (I recommend him for your vinyl needs).

[jasonbar]

18-20: If you're inspired by your coworker Ross' neatness & attention to detail when working with electronics, braid the 3 cables (USB signal, DC power, connection to pedals) & put on a few cable ties to keep them together tight.  This should also help keep the power & pedal cables from coming unplugged accidentally, as they both now have strain relief by being attached to the secure USB cable.

21-23: If you're tight on room & want to have all your arcade accessories neatly attached to your cabinet when not in use & not take up any floor or shelf space head to your hardware store & pick up some eye screws or eye bolts & some plastic-coated hooks.  A few hooks can capture & retain the pedal assembly.  I use the same system to store my X-Arcade 2nd trackball on the right side of my cabinet.  I've found that the rubber coating on these hooks is prone to breaking at the tip & the exposed steel hook can scratch your parts, so I cap them off with small rubber screw covers from the hardware store.  A pair of eyebolts of the right spacing & hole size make for a simple place to hang your wheel (via the table clamp hooks) when not in use.



So, did anybody notice that I removed the chromed plastic "GT" wheel hub?  That's for a bit of flair that I'll document later, when it's all done...  =D



Thanks,
-Jason

[jasonbar]

So, did anybody notice that I removed the chromed plastic "GT" wheel hub?  That's for a bit of flair that I'll document later, when it's all done...  =D

Due to overwhelming interest & activity in this thread   , I *finally* have the results of my tease of a comment above.


Thanks to some assistance from our company machine shop (under the guise of "training" for a new machinist, our local anodizer (bribed w/ an In 'n' Out gift card), & one of my BattleBots buddies (who's working with a powerful laser for a client), I now have an extra pimpy wheel hub!

Thanks,
-Jason


PS--I also pimped up my spinner knobs: http://s242.photobucket.com/albums/ff97/infernolab/Arcade%20Game/?start=all