Making the Prototype Parts
The basic side panels were pretty simple: cut out with tin snips and drill the top holes. Then it was time for test-fitting. The fit check produced a clear need to trim the bottoms off the side panels, and trim the tops off the base side panels. Once I had them trimmed so they worked together well, I laid out what I thought would be the best positions for the slots, drilled the end holes in all four slot sets, and cut away the webs with the Ryobi rotary tool.
The Ryobi -- it's an 18-Volt-battery-powered version of the Dremel -- is easier to handle when the battery is a little tired. The RPMs come down, and that makes it more docile. That realization prompted me to wish for some sort of speed control on it, rather than the simple on/off switch. I'd really prefer something between dead stop and full throttle. On the Dremel-type tools that are powered by house current, it's easy enough to plug in a rheostat to control speed, but the battery powered version doesn't have that capability if it isn't built into the unit's switch. Maybe that'll be in Ryobi's next model.
A few days ago, when I first decided on slots, I dug through my stash of fasteners and set aside the bolts I needed for the slots. They weren't ideal -- they weren't carriage bolts, and they had slotted round heads rather than Phillips heads -- but they'd do the job. Today, when I finished the parts, I got the serrated washers that fit the bolts, and dug through the tray of nuts. Uh-oh. These are 10-24 thread, and I don't have the 10-24 nuts. That means it's time for a trip to Home Depot to get them.
Maybe it's even a good reason to go on a field trip to Park Center Hardware in Riviera Beach, a sort of mini-Heaven for those of us who spend way too much time in our shops (and I guess I qualify -- I was once told the perfect home for me would be a four-car garage with attached house.)
If you're in the West Palm Beach area, Park Center Hardware is in the Sav-A-Lot complex, a block north of Blue Heron on Broadway (Dixie Highway). The address (a new location for them) is 80 East 30th Street, Riviera Beach, FL 33404. The place feels like the other end of the world from Home Depot. It's an old-style hardware store, and it's been run by the same person for 35 years. Every single person who's waited on me is a character in one way or another. I enjoy going there, and I recommend it if you're in the area.
If you're in the Mid-Michigan area, another fantastic hardware store is Casler Hardware. This is truly an old-time hardware store, with the wooden floors and the classic old-hardware-store aromas. It's at 125 N Jackson St, Jackson, MI 49201. They dispense hardware and advice and a good, friendly, small-town feel.
I'll pick up the fasteners tonight.
Assembling the Prototype
Okay, no field trip to Park Center Hardware. I was in a hurry, and the sky was looking like a major rain was rolling in from the southwest. I just stopped at our close-by Home Depot and grabbed the 10-24 nuts I need, and I got some 10-24 wing nuts for temporary use. The wing nuts will likely make it easier to get the head unit locked into its the semi-permanent position. I'd say "permanent position", but I know a carPC installation isn't really ever finished.
I haven't found mini-carriage bolts like I'd prefer to use. I have one I picked up somewhere, probably when I was disassembling a piece of equipment, but that's the only one I've found. I'm a fastener packrat; I don't pitch them into the metal recycling unless I have plenty on hand.
Here are the assembled parts from the front and rear, and then a shot with the head unit mounted on them:
Click images to enlarge.
You can see that the center flange is missing from the base. It cracked when I made the original tight bend on it, and it finally broke right off while I was test fitting. It's no problem; the final part will have a rounded bend there, and that won't crack.
If you enlarge the middle picture, you can see how the slots work. Unfortunately, you can also see that I really screwed up one of the base-unit slots by drilling holes that were too large (it was late and I was pretty tired; when I saw what I'd done, I quit for the night and started again in the morning). The good part of this error is that it shows how forgiving slots are; even with a wobbly slot or an oversize slot, the parts lock together well. They'll be more accurate in the final product, I promise.
Now for a test fit.