heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Also, found the datasheet for this sensor (attached to this post). Looks like it's almost entirely self contained and requires very little supporting bits. It's very likely that all that's inside the BMW box is the orange sensor itself and a resistor. At least this is what the example circuit that the manufacturer included in the datasheet looks like.

They're everywhere on eBay for cheap, but most of them ship from China, so no idea about quality/genuineness. I did find a seller in the US with a bunch of NOS parts, so ordered a couple to add to the stash in case the sensor on the car ever fails.

[Obioban]

Ha, that's the most modern DIYer cover. CAD, lasered parts, 3d printed brackets/feet. You just need to work a Pi into there somewhere, and you'll have it all.

[heinzboehmer]

Ha, that's the most modern DIYer cover. CAD, lasered parts, 3d printed brackets/feet. You just need to work a Pi into there somewhere, and you'll have it all.

Craziest part is that it was both cheaper and quicker to do it this way than by hand.

[heinzboehmer]

Now that we're on the topic of overengineered things, here's a look at the project that I started working on this past weekend.

Have always wanted the driver's side euro cubby, but I assumed it would require a dash swap, so never actually considered doing it. However, something prompted me to look at the area again and I noticed something interesting about the construction of the dash. I suspect the dashes were made like this:

• Inner hard candy shell is formed (same part for all markets).
• Outer vinyl layer is formed with different geometry depending on target market.
• Inner and outer layers fixed in some sort of jig and foam injected between them to take up any space.

Hit up the junkyard with Bry5on and 3D scanned/destructively disassembled some dash cutoffs:




Suspicions all but confirmed! Inner layer has the locating features, the necessary recess and what appear to be cut reference lines for the euro cubby. Here are some pics stolen from e46fanatics that show how the cubby fits with the dash, for reference:







Seems like I can just cut a hole in the dash and throw the cubby in.

But of course I won't. I want it to look as close to stock as possible. The last pic above shows just how different the geometry of the dash is, which makes my life a little harder. Fortunately, the foam comes off of the vinyl very easily, which can then be formed into shape somehow.

Some pics of the destructive testing I did on the junkyard parts, mostly to see how well the vinyl holds its shape after heating up and cooling back down (answer is extremely well):




Here's my plan for how I'm going to approach this:

1. From the inside of the dash, cut the necessary opening in just the inner hard plastic layer.
2. Rip out all the foam in that area, but do not touch the vinyl.
3. Make any necessary relief cuts in the vinyl (will need to experiment with the junkyard dashes a lot, as the vinyl rips quite easily)
4. Thermoform the vinyl into its new shape.
5. Fill void between inner layer and vinyl with foaming adhesive.

And to thermoform the vinyl I've designed this:


Just a set of dies that heat up and are bolted together. I still need to figure out the shape that the vinyl has to be in, but that should be fairly straightforward once I receive the euro cubby in the mail.

I will likely need to design two different inner dies, one for thermoforming and another for holding everything in place while the glue cures.

Very much an unnecessary amount of work for a thing that can store a couple pairs of sunglasses, but it'll be a fun project!


Also, not as interesting as the stuff above, but I picked up a near perfect set of rear seat trim pieces at the junkyard. Mine had a bunch of broken posts/clips and weren't looking great. Top is new, bottom is old: