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

Originally Posted by rdholtz

Modified Monitor Mount

Although I don't expect I'll want to change the angle of my screen, it's a possibility. I got to considering what I'd do with the monitor mount if that possibility turned to reality. That meant it was time for some work in Sketchup: I modified the top and bottom angle of the bracket tabs and added an inch of depth to them.

Here's how that bracket looks on the system if the monitor were angled back 10 degrees:

Click image to enlarge.

As designed, it could handle at least 15 degrees of tilt either forward or backward, and it will allow at least 1.5 inches of height change. Minor modification of the brackets would allow more tilt, if necessary.

I won't drill the bracket mount holes until I have the chassis on the Toyota dash mounts and I decide on its permanent location.

Those simple changes add a lot of flexibility. Now, rather than being specific to my car, they make this more of a universal double-DIN chassis.

Everytime you post a new sketchup it starts to look more and more like the screen holder you designed on page 4 of your worklog. That was really cool. Will being able to angel it look good in the bezel? Like when tilted, wont parts stick out, like the corners of the screen? Unless the screen is going to be recessed in the dash. If its gonna be flush though, it may look odd.

Originally Posted by HiJackZX1

Everytime you post a new sketchup it starts to look more and more like the screen holder you designed on page 4 of your worklog. That was really cool.

Yeah, that was my first attempt at relatively complex sheet metal work, and it turned out fine. I designed that first one on the fly, with no real plan. After completing that early mount, I realized there were two parts I could have combined. I think I remember commenting that I learned I should do the design in Sketchup first so I could catch errors and conflicts.

I took my own advice this time, and using Sketchup has really helped. In this chassis design, Sketchup has helped me visualize things without ever setting foot in the shop. A good example is the decision to build it so I could angle the screen if I want to.

Originally Posted by HiJackZX1

Will being able to angle it look good in the bezel? Like when tilted, wont parts stick out, like the corners of the screen? Unless the screen is going to be recessed in the dash. If its gonna be flush though, it may look odd.

I didn't make clear what I meant, I guess. I don't want to be able to change screen angle after installation. I just want to be able to choose the best angle for it. I'll drive with the system in various positions for a while until I find the one I like best. Then I'll drill the mounting holes, screw it down, and build the bezel based on that installed position. It won't move after that.

The entire monitor will be recessed inside the bezel, as I see it today, and the bezel will be made to come in and barely touch the monitor's case. I expect there will be about 3/8 inch of monitor case showing on the top and sides, and an inch or so -- including the control buttons and the infrared eye -- at the bottom.

I'm not trying to make my installation look OEM so much as to be a nice, clean install. I suspect an OEM installation would move the buttons to some other location. I want to install the monitor as a single, fully functional, replaceable part, just like it comes out of the box (without the stand).

But, in someone else's installation, the same chassis could be positioned differently, have the uncased LCD screen mounted any of several ways, use a different bezel, and look completely OEM.

Originally Posted by rdholtz

Yeah, that was my first attempt at relatively complex sheet metal work, and it turned out fine. I designed that first one on the fly, with no real plan. After completing that early mount, I realized there were two parts I could have combined. I think I remember commenting that I learned I should do the design in Sketchup first so I could catch errors and conflicts.

I took my own advice this time, and using Sketchup has really helped. In this chassis design, Sketchup has helped me visualize things without ever setting foot in the shop. A good example is the decision to build it so I could angle the screen if I want to.



I didn't make clear what I meant, I guess. I don't want to be able to change screen angle after installation. I just want to be able to choose the best angle for it. I'll drive with the system in various positions for a while until I find the one I like best. Then I'll drill the mounting holes, screw it down, and build the bezel based on that installed position. It won't move after that.

The entire monitor will be recessed inside the bezel, as I see it today, and the bezel will be made to come in and barely touch the monitor's case. I expect there will be about 3/8 inch of monitor case showing on the top and sides, and an inch or so -- including the control buttons and the infrared eye -- at the bottom.

I'm not trying to make my installation look OEM so much as to be a nice, clean install. I suspect an OEM installation would move the buttons to some other location. I want to install the monitor as a single, fully functional, replaceable part, just like it comes out of the box (without the stand).

But, in someone else's installation, the same chassis could be positioned differently, have the uncased LCD screen mounted any of several ways, use a different bezel, and look completely OEM.

Thats not true, having the complete screen can look very OEM, take mine for example, it looks like it should be there. Only thing that gives it away is the non OEM looking paint job (gloss black). I am actually ordering a original color one so it looks 100% OEM. Also doing it because the paint shows scratches easily. Now I understand though, your just doing it to see what feels right, then it will be permanently bolted.



Only other mod to the screens i'm doing is removing that dumb auto adjust button that will screw up the screen when pressed.

Originally Posted by HiJackZX1

That's not true, having the complete screen can look very OEM, take mine for example, it looks like it should be there.



Only thing that gives it away is the non OEM looking paint job (gloss black).

Oh, I didn't mean to tell you a complete screen wouldn't ever look OEM, and yours looks great. But I don't think a complete screen will look OEM in my car. I'll still do my best to have it look OEM quality. And I may be surprised how OEM it looks.

Originally Posted by HiJackZX1

I am actually ordering a original color one so it looks 100% OEM. Also doing it because the paint shows scratches easily.

Instead of ordering a new screen bezel, you might consider going to a different paint. It might be interesting to give it a coat of PlastiDip, which is used for tool handles (you might have to thin it a little). It's available in matte finish, and it has a rubberized feel. I don't think rubbery stuff is going to scratch too easily.

Holes and Slots Added to the Chassis

I've made one last change; the flanges are now all 7/16 inch (11mm) wide, instead of 3/8 inch (9.5mm). This places the centers of all the fastener holes at .25 inch (6mm) from the edges.

With that change, I've frozen the sizes and shapes of the panels. Now we're really close to production of a sample.

Here's the chassis with holes drilled and slots added for adjusting height and angle of the monitor.

Click images to enlarge.

The partially-exploded view shows how the slots are placed to allow 1.5 inch (38mm) of vertical movement and at least 15 degrees of angle forward or backward. But the vertical slot will still be covered by the mount bracket, so there shouldn't be much air coming in the open area of the slot. Realistically, any open area could easily be covered by a small piece of silver a/c tape or even duct tape.

I won't decide on the positions of the holes used to mount the mainboard and PSU rails until I do some testing. That will happen once I have the side panels formed. I may even do the initial PC build in the case with the rails temporarily in position, held on with heavy double-stick tape. Adding all the cables into the case tends to jam things up a bit, and I may have to change the bracket positions based on the way I route the cables.

I expect to add one more pair of holes in the monitor mount -- one on each bracket -- but those would be drilled after the mount position is determined, and would be used to make sure the monitor doesn't slide out of position later on. I'd drill them through the mount brackets in line with the vertical slots, or through the chassis in line with the horizontal slots, probably at the point where I could get them the furthest from the "pivot" screw on each side.

Originally Posted by rdholtz

Instead of ordering a new screen bezel, you might consider going to a different paint. It might be interesting to give it a coat of PlastiDip, which is used for tool handles (you might have to thin it a little). It's available in matte finish, and it has a rubberized feel. I don't think rubbery stuff is going to scratch too easily.

Technically Dodge doesnt make their head units with a rubber feel. The issue is the buttons. Overtime they wear the area around them out. Thats what happened to mine. So now I have chipped paint all over it or should I say missing. If I use the bezel that came with the screen originally as is, then it actually looks almost OEM. It just need to be a slight shade of darker black. Also once I get the new bezel, I am removing all the buttons, except the Source and Power. I dont want to fry my screen again.

Anyways, your sketchup is looking better and better.

How Much Adjustment Do We Get With Slots?

Slots are a really effective way to get a lot of adjustment with good stability. I thought it would be an interesting exercise to roll the monitor mount around and see how much height and angular adjustment we can get from it.

The result is the four images below, showing the mount at the extremes of movement with an imaginary fastener through the slots. You may notice that the last one -- with the mount all the way down and rolled back -- looks like it could go further back; but the back of the monitor would be resting against the top edge of the case as it's shown, so it can't go back any more.

Fasteners for the Chassis

The end panel in this chassis provides a solid core for it -- all the other panels attach to it, and to each other. That means the chassis should be rock solid -- if I use good fasteners.

The panels could be pop riveted together; that assembly system is quick and easy. But pop rivets are also ugly, and they're a hassle to remove if I decide to change anything. Since this chassis is a testbed, I already know it'll be disassembled and reassembled several times.

And so, instead of pop rivets, I'll assemble the chassis with machine screws and rivet nuts (if I can find the rivet nuts in my packed-up shop supplies). That will be slower building, but more professional-looking and easy to disassemble, modify, and reassemble. The rivet nuts will go in the flanges. They install a lot like pop rivets, but we wind up with threaded fittings on the back side of the openings. A machine screw through the matching panel locks the parts together. Because they're just screwed together, the panels are easily disassembled and reassembled.

Rivet nut images are attached. The first is a couple of uninstalled rivet nuts, and then a cros-section of one that's being installed, and finally an installed one sawed through so you can see how the shank compresses and locks it into the material. This is the most basic type, and the one used in light material. Heavier ones may have serrated shanks, as well.

You may notice that the images show two sheets of material locked in by the rivet nut, but that isn't required.

For the board brackets, which are just angle, I'll only use double-side tape for position testing. Once I'm sure I know where I want the panels, I'll drill holes in the side panels to match the Rivnuts in the brackets, and screw them in.

A Fly in the Ointment

I went and bought the rivet nuts I want to use for the new 2-DIN chassis. While I was looking at them on the way home, I remembered that they have one clear downside: the rivet leaves a raised ridge in the flange where it is supposed to ride flush against the matching surface. You can see that in the pictures in the previous post. That means there's not a good surface match unless I countersink the holes for the rivet nuts before installation. Countersinking isn't a big deal in metal this light, but it's an imprecise process unless I use a die.

I could make a countersink die, or I could just take a whole different route and use Nylon-insert locking nuts. There isn't much cost difference. The nylock nuts are technically only good for one use in a high-stress environment, but I think this is pretty clearly a low-stress, non-critical application, so that's not a worry.

I'll use standard fasteners -- screws and nuts -- until the final installation, when I install the rivet nuts and add locking washers, or go with the nylock nuts.

The rivet nuts with locking washers is still the route I prefer, because it means disassembly and reassembly takes only a screwdriver. There are 28 fasteners in the chassis; except for the 4 that hold the monitor mount, all would be countersunk.

I may be able to do the countersinking without any special equipment; after I punch the holes I need, maybe I can simply use the punch to produce the countersinks, too. If I switch to a flat or concave punch and a larger die, I think I could simply press a ball bearing down into hole, bending the countersink area down into the die. That should give me a consistent countersink easily, and I should be able to do all countersinks in a few minutes.

I'll be testing that this weekend . . .