"Smart" Gauge Project Status

To repeat what tommykat1 has said, I also look for your progress and updates. Truly interesting from the start of this project to what you have created.

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PCBs and solder stencils have been ordered! Should be here in ~10 days.


PCBs and solder paste stencils showed up today! All looks great! Still be several days until I can do anything - still waiting on 500 LEDs coming from China, and the equipment needed to do the soldering.


Love to see a video of the soldering process.

What kind of equipment is needed for soldering?

Well, there’s the right way to do it (which is VERY expensive), and there’s the way I’ll be doing it.

The equipment I need is fairly minimal - a solder paste stencil, a temperature controlled hot plate, some solder paste, and a squeegee.

The stencil is exactly like a silk-screen stencil, except it is very precisely laser-cut into a sheet of Kapton (a high-temperature plastic) or stainless steel. My templates are stainless. It has cutouts everywhere solder needs to be applied. The solder used is a paste, a mixture of powdered solder and flux. The stencil is laid over the board, and precisely aligned so the cutouts all line up with the pads that need to get coated. Then a squeegee is used to spread the solder paste over the stencil, and push it into all the little cutouts. Then the stencil is carefully peeled off, leaving the solder on the pads on the board.

Then, the components are carefully put in their correct places on the board, and the board is placed on the hotplate.

The hotplate is heated and cooled through a specific cycle of several temperatures to heat it up to 120C, avoiding thermal shock (which can damage the board and components, and create residual stresses, particularly on the solder joints), then heat it further to 150C, melting the flux, then heat it further to 180C, melting the solder, letting it soak long enough at 180C for the solder to flow completely, then cooling it down to 100C slowly, again avoiding thermal shock.

My PCB “panels” are small (100mm x 100mm), each containing from 6-8 individual PCBs, and I should be able to fit four of them on the hotplate at one time. So, I can, in theory, solder up to 32 PCBs in one run. It is slow, tedious work, but this process is well suited to the low volumes I would be producing.

In a production facility, the ENTIRE process would be fully automated.


So Fascinating , love this whole process.

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Ray- Many of the hot plates I’ve used through the years have had significant thermal gradients across their surfaces. If not already done, I’d use several thermocouples to evaluate the thermal continuity and stability of your plate before subjecting your PCBs to it. IMO…

Just. Flat. Amazing. And so fascinating to this old soul who would love to be peeking over your shoulder.

If you can’t hit it with a hammer, I am out of my league.



Once you get these gauges sorted out to your satisfaction, here’s a little project that will challenge even you. Might need a bigger printer . . .

I’ve been watching 3D printed housing for several years, and can’t wait to see on in person. It’ll be interesting to see where they really fall out in terms of total cost. They should certainly be very durable. There have now been small developments of houses, and even a few office buildings, built by 3D printing, so it’s growing fast!


One has to get the slump test juuuuuustright, though!

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And if you don’t like the finish, it could always be faced with stone, plaster, stucco, etc. obviously arising the cost somewhat but still and really cool method.

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Might be a wee difficult to hang pidgers of our toy cars, and the grandkids!


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Actually, what is done in a plastered house, is to attach wood picture rail near the ceiling all along the wall. It has a recess on the back at the top so pictures can be hung with thin wires using hooks than clip over the top of the rail. It’s pretty foreign compared to what we normally do in a house with drywall, but it works. Was once the standard.

I expect some/many walls in 3D printed houses will also be covered with furring strips and drywalled. I think it will also be common to print only the load-bearing walls, and make the others stick-built partitions.

That seems to make most sense to me. Imagine the poor contractors working for HGTV-style remodelers in 20 years when they come in, waving their arms about saying “take this wall out, move that one back 6 feet, put a window in there, it will open up the space amazingly”… :smiley:

Wouldn’t work for me :anguished: this is just one wall in the dining area!


Grrrrrr! Makin’ my OCD flare up, with all those crooked pidgers!