Modification of Gamepad for Left Handed Operation
The purpose of this exercise is to produce an analog controller that can be operated with the left hand, in combination with a mouse in the right, for use in FPS computer games.
The modification utilizes a Belkin Nostromo n45 Dual Analog USB GamePad. This controller supports the mapping of keystroke to axes to allow its use in game lacking any joystick support. It also has large number of buttons that can be accessed without removing the hand from the device. With the modification, I can access ~15 buttons/keys without removing my hand.
Note: This procedure will immediately terminate your warranty on the controller. Do not attempt unless you are prepared to live without support from Belkin for this device.
The stock Belkin Nostromo n45 Dual Analog USB GamePad
First remove the silver “stabilizer” bar located at the ends of the handles. It is attached using two small screws. This part can be discarded, but you should hold on to the screws in case you need extra ones later. (Note: When working with self-tapping screws this small, use a fairly new screw driver and work carefully to avoid stripping the heads.)
Next, remove the copper-colored covers located on the bottom of each handle. It is necessary to remove these in order to access the screws underneath. Unfortunately, these are glued to the bottom of the handles. They can be removed using a small pry bar or a large flat-head screwdriver. Cover the end with tape to minimize scratches to the bottom of the handles. The handle covers have two “blades” that protrude into slots in the lower handle. By inserting the tool between the handle and the cover, you can pry off the cover by breaking the blades. Don’t try to do it all at once. Instead, start at the back of the handle and slowly work the blade progressively further under the cover. This will create stresses in the blades, and they will crack. If you have a Dremel tool, you can grind through the handle cover from the outside over the blades to speed up this process, just avoid going too deep. The blades are located approximately 1” and 2-7/16” from the ends of the handles, (measured from a plane parallel with the axes of the joysticks.
Once the covers are removed, you can access the screws that hold the controller together. The bottom half of the handles is molded as one piece and is held on with 7 screws, one of which is located under the label on the crossbar.
You can now access the top portion of the handles as well as the trigger assemblies.
The wires for the triggers are soldered to two riser cards, (small printed circuit boards), that project from holes in the bottom of the control module. These wires prevent the top portion of the handles from being removed.
Using a de-soldering tool, remove the solder holding the wires in place so the top portion of the handle can be separated from the module. Note the locations and colors of the wires so you can put them back in the correct locations.
Once the wires and the trigger assemblies are removed, you can access the screws that attach the top-half of the handles.
The major components of the gamepad disassembled.
To remove the top of the control module, turn it upside down and remove the two screws.
Keep the module upside down while you remove the top half; this will keep the switches from falling out.
The switches are membrane type, consisting of clear rubber domes with a black conductive disk. This disk shorts the contact surfaces on the PCB to close the switch. Avoid touching the shiny metallic surfaces or the black conductive disks to prevent contaminating the contacts.
There are two PCBs in the control module connected by a ribbon cable. The large one with the switches for the buttons is attached with 4 screws. The smaller one contains the two joysticks and is held in place with 3 screws. After removing the screws you can remove both PCBs. The USB cable is attached to the large PCB and can be removed as well
At this point the bottom of the control module is ready for modification.
First, the boss around the USB cable on the bottom of the control module is trimmed flush to provide a flat surface for the mounting bracket.
This was done with a razor saw. You can purchase one at most hobby shops.
The mounting bracket is made of two pieces. The first piece is a 3” Tee plate that you can find at a hardware store. I used one from Stanley, PN. 30-1604. It is stiff enough to hold the controller in place, but has a little flex to it so it can protect the controller from minor bumps. The two shorter arms of the Tee were trimmed to fit between the triggers. Using a hacksaw, I cut mine to 2-1/4 inches, or roughly through the center of the holes at the ends for the arms. Two 3/16” holes were drilled about 1-1/4” apart on the centerline of the shorter arms to accept the machine screws that will be used to hold the controller to the Tee plate.
I recommend that you bend the arm and drilled the holes in the Tee plate first, because it’s harder to get a precise hole in metal than in plastic, (unless you have a drill press). You can then mark the holes to drill in the plastic base using the Tee as the guide. Because of the location of the PCB in the control module, I didn’t use washers inside the controller housing. Instead. I used #10 x ½” socket head cap screws, and drilled the holes just large enough for the screws.
The Tee bracket was attached with washers and nylon lock nuts.
The heads of the screws, (inside the housing), were covered with small circles of electrical tape to reduce the chances of shorting the circuit board.
To move the triggers on the right side to underneath the left handle, first assembly the top and bottom handle by themselves.
Using the razor saw cut the right trigger arm just forward of where it joins the handle.
Since the right handle doesn’t serve any purpose and is located where it could be bumped, it was removed just behind the crossbar.
The openings were then covered with pieces of sheet styrene plastic.
Only glue the plastic covers to the bottom half of the handles and so the handles can be taken apart in the future.
Remove the PCB for right-side trigger assembly.
Carefully remove the bubble switch next to the wires to protect it from heat.
De-solder the short wires after noting their colors and locations.
Solder new 24-gage wires to the PCB.
Reinstall the PCBs in the control-module.
Re-attach the top of the control-module. Test the joysticks and the buttons using the software before continuing. You may need to program normal keystrokes to the three buttons in the middle to get feedback on their functioning.
The lower half of the right-trigger arm is attached to the left handle using #2 cap screws, washers and nuts. One is located at the back of the handle.
The other is located under the triggers at the front of the handle.
Washers and double nuts are used on the inside of the handle to secure it.
A notch was cut into the top half of the handle to provide more contact area to mount the right trigger arm.
Reattach the top half of the handle to the control module.
The left trigger assembly is reconnected to the riser card on the control-module.
The new longer wires for the relocated right triggers are fed through a hole drilled in the left handle, and are attached to the right switch riser card, (from the rear). The wires pass through the crossbar to reach the left side. Test the all switches before closing up the gamepad for good.
When the bottom half of the handles is installed, the whole assembly gets screwed together. Attach the other half of the right trigger housing and the controller should be finished
I mounted the controller to the underside of my desk using a piece of 12” x 1-1/8” mending brace. The mending brace was bent in a vise to match the 45 Deg. angle on the Tee bracket. There are large countersunk holes along its length that make convenient places to bend it. It also allows attachment with countersunk screws, to eliminate projections under the desk. Two holes were drilled on the angled section to position the controller at the correct height and it was fastened with the #10 Philips screws, washers and nuts.
If your computer desk has drawers, or you don’t want to drill holes in it, you can try a method I used for a relative. Using a 2’ x 2’ piece of clear Plexiglas, I drilled two countersunk holes on the underside. I inserted countersunk nylon screws through these holes and attached the mending bar on top of the Plexiglas. The weight of the computer monitor holds the controller in place, and the whole thing can be removed when not needed.
Belkin Nostromo Dual Analog Controller
12 x 1-1/8” mending brace
3” Tee plate, Stanley part# 30-1604
(2) #10 x ½” socket head cap screws
(2) #10 x ½” Philips head machine screws
(4) #10 nylon locking nuts
(4) 3/16 flat washers
(2) 3/16 x 1”dia. fender washers
(2) #2 x 1/2” socket head cap screws
(4) #2 flat washers
(2) #2 nuts
~2’ 24gauge copper wire
0.06 sheet styrene plastic
Last edited by deees; 11-01-2006 at 06:14 PM.