Thread: Scion xB '06, in-dash Atom 330, Lilliput 889GL; details, pictures, links. Index: pg 1

Big Progress, Part 1

I worked on the chassis a lot this weekend, particularly on Saturday. We were in the garage working 'til after one o'clock in the morning, so Sunday was a lot less productive; I was bagged.

I'll go over the progress and include pictures as I get them written up.

New Screws
I replaced all the standard 6-32 case screws (salvaged from old computers) with 6-32 hard drive screws (also salvaged from computers) because the hard drive screws have lower heads, so there's more clearance when I slide the chassis into the dash. It also cleans up the appearance of the chassis. With all those case screws sticking out, it looked sort of like a porcupine; now it has a somewhat sleeker look.

I'll be the first to admit that I used way more fasteners than necessary for an .042-inch chassis. Apparently, I like overkill even more than I thought. My friend, Ed Heischman -- a machinist of near-mythical skill -- has a saying for this: "If a little will do a little good, then a lot will do a lot of good."

A picture with the new screws is in the works. You can see a couple of them in the picture below, holding the bottom panel in place.

Chassis Mount Brackets

I had originally planned to use the original Toyota head unit mounts to hold the chassis into the dash. But, after the move to Atlanta, I couldn't find them (moving an entire shop sucks). I took that as an opportunity to rethink what I wanted, and decided to go with simple angle brackets made from 1-inch (25mm) aluminum angle. The upper ones are shortened 1/4 inch (6mm) for an easier fit into the dash. Each mount is riveted to the chassis with a single rivet; that lets me do very slight alignment changes to be sure the chassis sits in the car the way I want it to. Here are the chassis mount brackets installed:

Click image to enlarge.

The bottom brackets have two holes each; the outer ones go over OEM positioning pins molded into the dash.

I may drill out the pop rivets and use 6-32 hard drive screws and nuts, once I know the exact angle I want the mounts to be.

Big Progress, Part 2

More progress notes from the weekend:

Mainboard Mount Brackets
These are made from 1/2-inch (12.5mm) aluminum angle cut to the length of the mainboard and mounted to the sides of the chassis. I drilled holes in them for the standoffs, which are tall enough to clear the nuts on the attaching fasteners. Here are the mount brackets with the standoffs installed:

Click images to enlarge.

There's another approach that I could take to these brackets: I could have used short lengths of the angle stock -- maybe 1/2-inch (12.5mm) lengths -- at each mount point. That would have taken far less material, and there wouldn't be any loss of strength from the change. It would make the chassis less generic, but I don't plan to change mainboards any time soon.

I got the mainboard mount brackets installed in the chassis. Here's that image:

I screwed the mainboard down on its standoffs. Now it's really starting to look like a PC:

PSU Mounting Brackets
I had previously built brackets for the M2-ATX. I pulled out the manufacturer's diagram of hole positions and drilled holes in the brackets for the single standoff each will support. These would mount to the side panels with two screws -- or two pop rivets -- each.

But I may not need these brackets, after all. Now that I have the system nearly complete, I'm wondering if I can eliminate the brackets and simply mount the PSU upside down on standoffs fastened through the top panel. There should be plenty of airflow across the PSU to keep it cool.

Originally Posted by captcol

How well will this work with the wiring? as in when you remove the top of the case will you have enough wiring length to be able to safely unplug things to completely remove the top panel? do you want to have to remove the power connections to take the top of the case off?

That's an interesting point, and one I've been pondering. I think there's enough wire length to do it comfortably. I agree that the brackets would make it easier to get in there. But putting it on the lid would allow easy access to everything if I open the case. It's an interesting decision, and one probably easiest to make with all the parts in my hands. But an even bigger problem has reared its ugly head:

Missing Power Supply

I discovered that I've misplaced my M2-ATX power supply; I've looked everywhere I can think of, and it's a mystery where it went. If I can't find it soon, I need to order another PSU. The M2-ATX is about $75, but I thought I'd look at the Opus 120, which is about $130. While the M2-ATX has a good reputation, the Opus has a simply great reputation and a legion of loyal fans. But I'm having a hard time figuring out how to place it in the case; the system was designed for the smaller M2-ATX, which would fit sideways across the case.

The Opus is too long to fit that way; it's 7.08 inches (180mm), and that's the external width of the chassis. I can't get it in that way, even with a pry bar, and the fuse sticks out beyond that. If I run it lengthwise above the mainboard, it blocks half of each fan. It seems that using the Opus unit requires a major redesign.

I just don't want to wait to order. As soon as I get the PSU in place, I can actually power up the system and get the software installation going (and play with the Lilliput touchscreen).

Missing Power Supply, Part 2

After deciding it was too much work to cram the Opus 120 into the chassis, I decided to move up from the M2-ATX to the M4-ATX, which handles 200W (about 3 times what I need ). The M4-ATX is a little more advanced unit; for instance, the settings are by DIP switch rather than by jumpers, and it has timing settings that are programmable via USB cable.

The unit was about $97 shipped from Logic Supply, and it was shipped today. It actually fits even better than the M2-ATX: the M4-ATX is 4.8 x 3.7 x 0.7 inch (122 x 94 x 18 mm), so it should fit beautifully over the mainboard. Now I need to determine a mounting system: on brackets, or on the inside of the lid. When it gets here -- that should be Friday -- I'll be ready to install software. Weekend project -- Woohoo!

Screen Mount Built

I went back to Josh's original suggestion for the design, and cut a slot in the end panel. I had originally intended to build a shelf system, but this seemed so much easier, and it turned out to be very stable. It takes advantage of the locating slot system in the back of the Lilliput panel.

Here's the completed system, mounted to the LCD panel:

Click images to enlarge.

I had a large stainless steel 1/4-20 bolt (1/4-inch diameter, 20 threads per inch) with a very wide, flat head, a leftover from living in Florida. This type of bolt is used to install wood hurricane shutters, so it's available at Home Depot and Lowe's, at least in hurricane country. I ground the sides of the head down flat so the width of the narrow part of head is 1/2 inch (12.5mm), which is the nominal size of the slot in the LCD panel. Then I cut the bolt to length -- so it would extend through the panel and leave enough for a nut and lock washer -- and ground it smooth.

I cut a 9/32-inch (7mm) vertical slot in the end panel so I could move the LCD panel up and down to wherever I need it when I build the bezel. That was a matter of drilling two 9/32-inch holes in the panel, using the saber saw to cut out the material between them, and filing the resulting edges.

Here are the parts:

. . . and a closer view so you can see the ground-down bolt:

Cooling Fans Installed

I cut the 40mm fan mounting holes and mounted the fans in the top panel (the 40mm measurement is the center-to-center distance between adjacent mounting holes). To cut the large holes, I drilled a 9/32-inch (7mm) hole near the edge of each of the holes, and used the saber saw to cut very close to the line I marked. Then I went back and filed the edges smooth and sanded them with emery cloth. The small holes for the mounting screws were just regular drilling, and I added a little countersink for the screw heads.

Here's how the top panel looks with the fans installed:

Click image to enlarge.

Originally Posted by captcol

You may have mentioned this elsewhere but are these extraction fans or intake, if intake can I suggest some kind of grill, on my desktop I have 4 intakes over my video card and cpu and the grills are always collecting a layer of dust and cat hair (not so much of a prob in carputers I admit - the cat hair that is)

Their extraction if i recall.... We had a lengthy amount of posts here on how it should be set up. My setup does use intake and extraction fans, and you are correct, even in a Car PC environment dust and stuff still collects on my grills.

Rdholtz, the case is looking top notch. Very professional. Frankly, I'm quite jealous, lol.