AxleCam and Video Display (See AxleCam Movie)

PartsExpress Electronics

LCD 5.6" Video Module #205-016 - $138.50

 

MarkerTek Broadcast Supplies

Submersible B/W camera SG-4960 - $148.00

AxleCam is useful for overcoming that 10 foot blind spot over the Suburban's front hood, as well as having a close look at what the rear end is about to slam into. With a video display inside the cab and waterproof cameras on the front and rear ends, you are able to see up close the rock/log/whatever you are about to run your differential into. AxleCam also makes for fun video recordings of the nasty trail you made your way through.

AxleCam for the 2001 Suburban posed several difficult issues. The big ticket items for the cameras were 1) Which cameras to use, 2) How and where to mount them on an IFS front end, and 3) Where to run the cables into the cab. For the display, there are the problems of which display to use, where to locate it, and in what type of housing. On the '89 suburban, this was all easy, just place a camera on the front and real axles near the differential, run the cables through holes in the firewall and into a switchbox, then attach this all to a small display stuck onto the dash. For the new 2001 Suburban, a little more care was taken to make things fit in.

For simplicity, lets start with the video display. A standard NTSC (composite) display is the choice due to affordability, simplicity, and size. In a grander scheme, it would be nice to use a 6 to 8 inch VGA capable touch display attached to a PC of some kind. The PC could then be used as an interface to MP3 music, GPS mapping, APRS positioning, ODBII automotive computer interface, as well as the AxleCam. However, due to the complexity of such a task, the AxleCam project at hand is designed to use a standard composite video display, carrying a video signal directly from the cameras.

The display chosen was part number 205-016 ($138.50 special price) from PartsExpress., is 5.6 inches diagonal (display/electronics module size 5.5 x 4.25 x 1.25 inches), and can be made to fit in the front section of the center console cup holder. This display also has the ability to flip the image such that it goes into rear view mirror mode, and is wired such that switching to the rear camera also flips the display image in this way. A Plexiglas case was built to hold the display, and appropriate mounting was built into the cup holder console to allow the display slide nicely up and down in its holder.

That last part above was the hard part, taking the better part of 6 months to finally get around to building. From the start it was clear the display would live in the slot section of the center console cup holder, but after the Plexi case was built, work on AxleCam stalled. The problem to solve was mounting the display housing such that it would be out of the way yet easily accessible, while at the same time keeping the cab uncluttered. Ideas ranged from motorized extensions that would lift the display up and out of its slot, to a spring loaded hinged rail system that would allow for one click popup and locking of the panel.

In the end, the option was simple mechanics of friction. Semicircle Plexi rods were glued to the sides of the display housing, which would act like guide rails. Two-part plastic (polyurethane Quick Cast) was used to fill the gap between the display housing and the sides of the cup holder section the display would live in. These two filler parts were then ground, filed, and sanded until the display would slide up and down nicely along the grove. To add some friction (and cut down on rattling) on the display, felt padding was placed on either side of the filler part's guide grove. The filler parts were fastened to the cup holder with extra sticky carpet tape since glue does not stick very well to the material the cup holder is made of. Carpet tape is thin, allows the filler parts to fit snugly against the cup holder, and does not preclude a better design later.

The bottom of the cup holder was cut out to allow the display to slide down and out of the way. A plastic sleeve was built which simply extended the portion of the cup holder the display would slide into. The extension was made from sheet plastic, heated to form the bend required to fit the display, and then attached to the cup holder by industrial strength Velcro (again, so as not to preclude a better design later). The inside walls of the extension were covered with felt to help prevent scratching, and the base covered with foam rubber padding for the display to rest on in the lowered position. A slot was cut out from the back of the sleeve to allow the display cable to side up and down as the display is raised/lowered to/from its viewing location.

When the display is in its lowered position, it sits level with the top of the cup holder. In the viewing position, the bottom of the display rests on the cup holder, and the back of the display sits back and rests against the front center console against the MP3 player. Our friend gravity keeps the display nicely positioned in its viewing location, but the suitable use of stabilizing Velcro may be called for when push comes to shove on the trail when gravity is no longer our friend.

The actual camera used is the Submersible B/W Camera SG-4960 from MarkerTek Broadcast Supplies, costing around $148.00. This camera is 12V powered, waterproof to 100 feet, has 100 feet of cable, is small, has a wide field of view, and is very good in low light situations (such as under the truck, in the woods, in the shadows, where you are most likely to slam your diff into something you'd rather you didn't).

Mounting the camera is relatively straightforward. First, find a 1 inch pipe repair clamp (looks like a door hinge that has been bent around a pipe) and weld a short section of channel bar to it as in this photograph. This section of channel bar will be the mounting surface to the frame/axle/whatever of the truck via a suitably sized hose clamp. Thread the hose clamp through the channel bar on the camera mounting assembly (pipe repair clamp), and loop it over the rear axle and tighten. The rubber pad that came with the pipe repair clamp may be used between the channel bar and the axle to give a more secure mount point. Lastly, find a cushy mountain bike handlebar grip, cut the ends off, and slide it over the camera housing. Clamp the camera into the mounting assembly using the handlebar grip as a cushion and the installation is complete.

Except for a few little details. First, the front camera is not yet mounted. Finding a suitable location is problematic in that there is no front axle, and mounting it to the bottom of the front skid plate just seems like a bad idea. Next, the camera cables have not yet made their way into the cab. The first problem to tackle is the front camera mount point, and two options present themselves:

Option 1 - Mount the camera to the top center of the torsion bar brace. This camera angle would give a good view of the oncoming dangers, but also gives a rather dull view out the front end due to the camera's wide field of view. From this vantage point, the view would be undercarriage in the upper 70% and road in the lower 30% of the image.

Option 2 - Mount the camera to the upper lip of the skid plate, well out of harms way. This vantage point gives a nice view of the road ahead, makes for interesting video recordings of the roads traveled, but does not give an exact view of the oncoming dangers as Option 1 above provides. This option also requires a slightly different mount technique, as the hose clamp around the torsion bar brace plan of attack will not work on the skid plate.

email:SubRider

12/01/01