Scion xB '06, in-dash Atom 330, Lilliput 889GL; details, pictures, links. Index: pg 1 - Page 4

rdholtz · 03-13-2008, 04:21 PM

Screen Mount Final Assembly

I need a place to mount the screen's printed circuit board, and the PCB has to stay almost as close as it would be if it were still in its case, because the cables are pretty short. A simple panel attached to the brackets behind the screen works well because it provides a strong support for the brackets. This mount will sit a bit below the top of the bracket, because there are cables that connect at the top of the board, and they have to clear the bezel.

I cut a piece of the 22-gauge steel, 5"x9-5/8", filed the edges smooth and rounded the corners. Then I bent down the ends to give a final length of 8-7/8", exactly the same as the width of the screen. The resulting legs are approximately 3/8". I laid the PCB on it, used a spring-loaded centerpunch (less than $3 from Harbor Freight, and a really good addition to any shop) to mark the hole locations, and drilled 9/64" holes for the standoffs. I used serrated lock washers to make sure the standoffs stay in place.

I'd have sworn I took pictures, but I can't find them on the camera or the computer. I'm sorry to have to leave them out. I'll add some shots later when I disassemble for paint.

Next, I drilled matching 1/8" holes in the PCB mount, the screen support rail and the brackets, and tested their alignment with small nuts and bolts. Alignment was crucial, because I don't want to flex the screen. The screen slipped into place with the holes perfectly aligned. I did a vehicle fit check to make sure everything is what it should be. The alignment checked out, so I did the final assembly with pop rivets.

I was short two standoffs; they'll go in the open holes when I get them. Here's the assembly:

Click images to enlarge.

When I installed the screen and PCB, I noticed that the 1/4" standoffs for the PCB are so short that it's difficult to move cables around under the board. There's a cable from the screen that attaches to the back of the PCB, and it needs to run between the screen and the mount. I'll have to install the cable before I put the board on the mount.

Here's the assembly:

The small printed circuit board hanging down in back is the touchscreen board (I think). It was held inside the case with double-sided foam tape. I expect to use the same material, and I'll attach it to the back of the screen support rail. I'll drill a 9/16" hole in the driver's side bracket to pass the cable through.

Another fit check with the complete assembly in the vehicle shows everything lines up nice and square. Now I can exactly match the position of the screen mockup to this, and lock it down tight. I'll use that to build the bezel while the real screen stays safe.

There are a couple of last jobs on this:
(1) Strip everything off it and drill the hole to run the small touchscreen cable through.
(2) Give it a good cleaning, and hit it with a coat of rust-preventive paint. This would have been eliminated if I'd been able to find galvanized or stainless steel.
(2) Reassemble and make sure no cables will wear from rubbing as the vehicle moves.

I still need to figure out a place for the button strip to go. I could hide it, I guess, or maybe I can build it right in the dash bezel that slips over this.

rdholtz · 03-14-2008, 06:34 AM

Post-Mortem -- Screen Mount

This seems like a good time to do an assessment of what I learned building the screen mount. What would I do differently, if I had it to do all over again?

(1) I'd design the whole thing in Google Sketchup or one of the free CAD programs, then just build to plan, instead of building a piece and then building stuff to make it work.
(2) I'd build the whole thing in the lightweight galvanized steel to test the theory. That stuff is so easy to work with that I'd have saved time in the long run, because I'd have seen the conflicts in the mockup.
(3) I'd use galvanized or stainless steel, instead of plain old cold-rolled steel. With galvanized or SS, there's no paint necessary.
(4) I'd build a little adjustability into those back tabs, and maybe all the tabs, because the dash components aren't perfectly straight. Just 1/8" or so would work; I'll need to add two 22-gauge shims under the rear driver's side tab to get this in perfect alignment, even though my mount is dead straight. I needed to make some allowance for the factory variances. In the automotive industry, variance is pretty common -- ask anyone with a body shop.
(5) I'd consider designing the screen support rail and the PCB to be a single bent piece, instead of two pieces. In this build, the rail was an afterthought (see Post #45).
Overall, I'm pretty happy with the result. It's strong enough and accurate enough that it should work for a long, long time.

rdholtz · 03-14-2008, 06:39 PM

Screen Wires

I took some pictures of the wires coming off the top left face and the lower right side of the screen to help anyone else planning to use the Lilliput 10.4" without its case:

Click images to enlarge.

I had to modify the bracket design to allow for these wires.

rdholtz · 03-16-2008, 09:04 AM

How do these wires connect?

If you've uncased your Lilliput 10.4", Model 1042, I could use some help. In disassembling mine, I accidentally (violently) detached the four small wires that appear to be for the touchscreen. They look undamaged. There are two yellow wires and two black wires. I need to reassemble the plug they go into, and wonder if anyone can tell me how they connect. Here's a picture of the wires -- in order as they come off the board -- plus the two plug components, plus the board they plug into.

Click image to enlarge.

-----

EDIT: I got this answer in the LCD/Display forum:

Quote: Originally Posted by GiODi

Ha... i did the same thing with my first lilliput. I'm pretty sure they go in the order that you have it there. I don't think it matter too much anyway because it would correct itself in calibration.

So, thanks, GiODi. I'll just hook it up as pictured and test it out.

I added this information to the Everything You Wanted to Know About Your Lilliput FAQ.

rdholtz · 03-16-2008, 07:43 PM

Polyethylene Adhesives

It's time to get back to work on the bezel. I'll continue to practice plastic welding until I get to the point where I can avoid warping and get an acceptable finish. But I'd like to use adhesive for such things as attaching mounts, and maybe other ways. I've been researching polyethylene adhesives, and so far I've found three that I've considered.

The first, Plastic Weld, sounded really good. It's manufactured by Solder-It Corp. in Cleveland, OH (which also has some other very interesting looking products). I didn't see enough information on their website, http://www.solder-it.com/solderpaste.asp, so I tried to contact them. Unfortunately, my attempts have all failed. Their email bounced as undeliverable, and the phone has a message that refers me to a NY number that's disconnected. If anyone has any information on the product or where to find it, or if you happen to know that they've gone under, or gone on vacation, or something, I'd sure appreciate the information.

Second, there's Poly-Bonder, from Mr.Sticky's, available at some Ace Hardware stores and TAP Plastics, among other places. This 2-part product requires that we heat-prep the surfaces to be bonded with a torch. It's $9.95 for 30 grams (just over 1 ounce) of hand-mixable material. The same product in a dispensing system is much more convenient, but also more expensive -- at TAP Plastics, it's $21.75 for the 57-gram container and one mixing/dispensing tube, plus $44.95 for the gun, and $9.95 for 3 more mixing/dispensing tubes. Using the mixing/dispensing tubes probably also means a good deal of wasted product. Here's a video that shows the process.

The third product is 3M's Scotch-Weld DP8005 Acrylic Adhesive. Here's the product page. This product is a 2-part structural grade adhesive, and simply requires a cleaned surface for bonding. It's priced about the same as the Poly-Bonder, and requires a similarly-priced gun and mixing/dispensing tubes, with a similar waste factor. Hand-mixing is not recommended by 3M, and shelf life is six months from date of shipment, if refrigerated.

Initially, I expect to try the Poly-Bonder, simply because I can hand mix it and see if it does what I want. Now I just need to find it locally . . .

bambam · 03-17-2008, 07:12 AM

Are you mounting the buttons anywhere? If not, how are you powering it on (I'm asking because I've searched forever for the auto on code...)

rdholtz · 03-17-2008, 11:05 AM

Quote: Originally Posted by bambam

Are you mounting the buttons anywhere? If not, how are you powering it on (I'm asking because I've searched forever for the auto on code...)

Auto-On Codes

There are two threads under LCD/Display that discuss auto-on codes:
Lilliput Programing Guide - Auto Power On
Lilliput Programming Guide, More Reset Codes

These are not specifically for the Model 1042, and I don't know if they apply. I haven't tried them.

Screen Button Location

I like the idea of keeping the buttons. I see three options that seem workable:

(1) Lengthen the ribbon cable and build the button strip vertically into the side of the dash bezel that will slip over the screen. This is the original bezel, but you'll get the idea; buttons would go in the silver part:

Click image to enlarge.

If I can locate a second button strip, I may look at using it on the opposite side to control the PC and PSU functions. If I were to do this, button strip installations would be secondary after I have everything up and running; I'd just hide them at first and use the remote.

(2) Lengthen the ribbon cable and build the button strip into the face of the bezel below the climate control panel, between the DVD player and the head unit. This would be a simpler option than the first idea.

(3) Raise the top of the bezel about 3/8" and put the button strip right above the screen. This is the simplest of all -- it wouldn't even require lengthening the cable.

rdholtz · 03-17-2008, 07:50 PM

Lilliput 10.4" Screen Dimensions

For those planning to use the Lilliput 10.4" uncased, it might be good to have all the dimensions in a single post:

The screen itself is 7" x 8-7/8", and about 7/16" thick, but you'll need additional depth behind it for the main printed circuit board unless you plan to extend the cables and put it elsewhere. The PCB itself is 5-3/8" x 8-3/4". Allow well over an inch of thickness for the board plus standoffs, and remember that there are cables coming off the top and bottom, and a very flat one that mounts to the back of it. I used 1/4" standoffs for the board, and they're the bare minimum.

Cables come off the top left face and lower right side of the screen (see post #48 above), and one comes out of the back toward the left side.

There's a second very small PCB for the touchscreen; it's only 2-3/4" x 1", and is mounted with double-sided foam tape. Overall thickness with the foam is probably about 3/8".

I tried designing a mount for this before I got it, but I was way, way off because I had no idea about the layout required by cable connections, how to attach it, or even how big the components were. Once I got it out of its case, the path to a decent mount was much clearer.

rdholtz · 03-21-2008, 04:32 PM

Screen Mount in Final Position

I must have had brain fade. When I completed the screen mount, I wrote in post #46 of this thread: "Now I can exactly match the position of the screen mockup to this (mount), and lock it down tight. I'll use that to build the bezel while the real screen stays safe." But, later on, it dawned on me that I don't need to use the whole mockup and all its cobbled-together bracketry; I could just fasten the mock screen panel into the completed mount and build to that, still keeping the screen safe, but making sure I have it exactly in its final position. So here's the completed mount with the mock (plywood) screen in it, plus a picture of the stock dash area where the mounts attach and a shot of the mount and mock screen in the dash, ready to build the bezel around:

Click images to enlarge.

When I installed it, I found I can only get fasteners in the top tabs of the new mount. The bottom tabs locate on pins, but, while there are holes for screws, they're effectively unreachable. That could have been a flaw in my mount design, and would require that I make slots in the sides of the mount so I could get fasteners and a driver through. But the configuration of the mount saved me; the combination of the lower locating pins and the upper screws, plus the angle between them, keeps everything solidly in place. The picture in the center shows the pin below and the upper and lower fastener holes; you can see the angle between the tabs.

Checking for Glare Issues

Driving with this installed in the dash shows that the dark window tint should keep side sun from being much of a problem. In the in-dash picture on the right, you can see that there's some sun coming through the tinted right side window and hitting the screen and mount. The same picture shows full sun coming in through the untinted windshield and hitting the upper dash area, but the vertical angle of mounting should keep windshield sun from affecting the screen.

The mockup isn't glass, but it's on glossy paper, and the resulting reflection issues seem to be what I've seen in any mobile screen. Until the built-in screen is installed, I'll keep using my laptop sitting on a homebuilt laptop holder that plugs into the cubbyhole (see this thread). With the laptop, screen reflection has never been much of an issue. The mockup has about the same amount of reflection, although this screen rides higher than the laptop.

The screen looks and feels positioned just about right. That's a good thing, because I'm far enough down this path that I don't want to start redesigning.

rdholtz · 03-23-2008, 06:07 AM

Bezel Building

I've started, at last, to finish building the polyethylene bezel. Earlier in the thread (pages 1 and 2), I showed how I've split the bezel sides to allow additional depth, and cut off the HVAC outlets because they have to move up about 3/4". The first step was to weld that filler in to get the faces one single piece again. Here's the first side with the initial face welding done, plus a closeup of the welded area:

Click images to enlarge.

It isn't very pretty at this stage, but the shape is accurate, and it's solid. Typically, welded areas aren't quite as strong as the original molded parts, so I'm adding some thickness on the back. These will be very strong once the split is filled in. I'll have a lot of sanding to do after it's all together, and I may have to do a little more finish welding to make the surface even smoother, but I'm most concerned with the raw shape right now.

I learned the hard way about making sure to get full weld penetration, and about making sure my extra thickness additions are completely bonded. After all my practice welds with good results, my first weld on the bezel itself simply weakened and broke as I was jostling it around doing a fit check. It turned out the actual weld was less than half of the thickness, and the faces, where the greatest strength is, weren't bonded; the added depth wasn't bonded either. I had paid far too much attention to the appearance of the weld, and not enough to its quality. It looked really pretty, but it didn't have any strength. I had to go back in and re-weld it. Subsequent welds have held up just fine, and I haven't been gentle in testing them once they're cold.

Next I'll build the part of the center section face that will go over the top of the screen. Then I can configure the sides to meet it precisely. After that, it's just (1) cut plastic to shape, (2) weld in place, (3) let it cool, (4) do a strength check, (5) do a fit check, and then repeat these steps until I have a completed bezel.

I'll have pictures . . .

rdholtz · 03-24-2008, 11:34 PM

Making Plastic Parts with the KC Pro

The KC Welder Pro from Urethane Supply (see post #19 of this thread) is a really good little tool. It heats up fast, and operation is reliable and predictable. It was shipped the same day as I ordered it, and follow-up customer service has been great. There's good information on the Urethane Supply website, too. Thanks, guys.

It took some practice to get used to the tool, but I'm really happy with it. I'm glad I spent the extra $10 and got the Pro version, which has almost twice the wattage (80W, versus 45W in the base model), because I never have to wait for it to get back up to temperature -- it's always ready to work.

One thing I've learned when welding 1/8" thick material like this is that, although beveling the matching parts is recommended, it's unnecessary. I just put the parts in position, turn the weld head on its side (about 45 degrees), and melt a groove at the joint. Then I turn the head back flat, put the filler material into the groove, heat it until it melts, and keep heating until the substrate melts some, too. Remove the heat, and it all bonds. After a little smoothing, I let the part cool, turn it over, and groove and weld the other side so it's bonded all the way through. I'm taking it slowly and working only about an inch at a time. With two pieces in process, I can switch back and forth.

A trick I learned by accident is that thin-walled PE containers -- the ones I'm using contained antifreeze -- make great stuff for building thickness. I just cut a piece off the (cleaned) container, trim it to the shape I need, and melt it into the part. I also learned to make sure it completely bonds, and doesn't just act as a separate "skin", as mentioned in the post above.

I learned to watch shrinkage, too. When I did the first fill, I wanted the face to be 3/4" longer, so I cut an add-on piece 3/4" long and welded it into the gap. But I apparently pushed the parts together as I held them for welding, and the part ended up only about 5/8" longer. I had to lengthen the part again by adding more material. That's something I hadn't checked in my practice welds. Now I lock the parts in position before welding. These funky-shaped parts are difficult to fixture, but it's necessary to hold them tightly so I get consistent dimensions and straight lines. Working on a small area at a time helps, because I can position the parts just right and pin them down with weights. I'd been using hammers and such to hold the parts, but they were too big, too clunky and too unwieldy. There has to be a better way.

rdholtz · 03-24-2008, 11:48 PM

Let's Make Some Sandbags

I figured small shot bags or sandbags would be a much better way. I wish I'd had some old shotgun shells laying around . . . or at least the shot from them. But my neighbor gave me half a bag of Play Sand from Lowe's (you can find it at Home Depot or the hardware store, too); it's clean sand for playgrounds and sandboxes, and a 50-pound bag is a under $5.

I put some of the sand in a plastic baggie, sealed it up, and put that in an old sock, so it would have a layer of protection. I tied a knot in the sock. As soon as I squeezed it, it popped the baggie. Okay, how about a heavy duty baggie? I started over, and that worked, although the resulting sandbag isn't as flexible. It should be fine as long as I don't lay the welding iron on it and melt the baggie. I wound up with a bigger sandbag than I'd wanted, but, it worked okay, and I made three more. They're good and heavy.

But I needed some smaller ones, and I wasn't sure I liked the baggies. I wanted something more stretchy, like women's nylon stockings. But there are no nylons in my house, so I looked around the garage, and there on a hook was an old bicycle tube. That was it; I cut an 8" length off it, closed one end with a tie-wrap, filled it with sand, and closed the other end with a second tie-wrap. It looked like black bratwurst, but it worked fine, so I made eight more out of the rest of the tube. The first one was pretty stiff, so I didn't make the others quite as full, and they're a little more flexible. For those into tech specs, it was a 26 x 1.9 x 2.125 tube.

In use, they do just what I want, positioning the pieces, holding them steady, and staying out of the way. If I ruin them, they're cheap, and I can make all I need. Here's a picture of a couple of the inner tube sandbags, and then a picture of them at work with one of the bigger sock sandbags. Everything is black, so it's a little tough to see; I reconstructed the whole setup on a white background to make it a little easier. The area I've welded is just to the right of the big sandbag; the third picture is zoomed in on it.

Click images to enlarge.

I'd still rather use steel shot, lead shot or even BBs instead of sand, but this was a free, easy and fast solution, and I'm back to welding.

-----

Uncle Dick notes that if we put one of these little black bratwursts on a bun, it would be a sand-wich.

rdholtz · 03-26-2008, 11:05 AM

Plastic Welding -- Gotta Have Ventilation for Smoke

Good ventilation is an absolute requirement for this plastic welding. It's a smoky process, but it's more than smell that's an issue. I've been reading that breathing the fumes from it can result in chemical asthma -- permanent chemical asthma, not just something that goes away overnight. For people who already have asthma, plastic welding might be a process to avoid.

One thing is for sure: you really don't want to do this inside your house. I had to figure out a way to get the smoke and fumes away from my workspace. I started out using a 24-inch fan blowing out of the garage, but it wasn't enough. This stuff was like smoke from a campfire -- it seemed to follow me around. Now I've rigged a smaller fan right on the workbench to pull air away and direct it to the bigger fan. I'm breathing easier, now.

rdholtz · 03-26-2008, 11:37 AM

More Plastic Material Sources

While I was developing my plastic welding skills, I was using HDPE material from a crunched recycle bin I rescued and chopped up. The walls are about 1/8", like the bezel, and they work just fine. For welding rod, I've been using scraps of the same material, or 1/8" square strips cut from it.

Another source is pieces of an old pickup truck bedliner that a friend gave me. It's heavy-wall polyethylene -- about 1/8" -- with one side textured and the other side smooth. By the time I finish this bezel, I should be pretty good at this plastic welding, and it may be a resource for material to make such things as custom divider boxes for my tool cabinet. It would also make a good battery box, because PE is impervious to battery acid. If nothing else, it could be cut into about a half mile of 1/8" square PE welding rod.

If you'd like to find a scrapped bedliner for your own uses, an auto boneyard may be a good place to look.

To get brand new HDPE material for the bezel parts, I went to a local plastics supplier. Sheet stock is surprisingly inexpensive when you just want part of a sheet. At my local shop, I bought two pieces, bigger than I wanted, but I took the whole thing so they wouldn't have to do any cutting. I got a 2' x 4' piece of 1/8" black PE and a 1' x 4' piece if 1/16" black PE, all for $1 a square foot. That's $12 out the door, and it's enough material to build these bezel parts several times. That's a good buy.

Now I'm back to designing the bezel's center section and getting it formed.

turbocad6 · 03-26-2008, 01:41 PM

I sometimes make a jig to hold everything in place, it can be as simple as a piece of cardboard & duct tape, or elaborate as a wire hanger form or wood, sometimes even screwing the pieces down depending..

looking good so far... & yeah, the plastic fumes are killer

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