Scratch Build – In Progress Tragbarer Rechner — Final photos! (08.03.17)

Hello again.

You may have seen my previous work, “Felix”. Today I'm going to start here a worklog of my another project, which, at this time, will be dedicated to German electronics of WWII era. I decided to name it simply “Tragbarer Rechner” (portable computer).

Main ideas:

– totally scratch build without factory case parts;
– mATX motherboard and full-scale components;
– combination of retro and military styles;
– lots of gauges, knobs and switches;
– usage of original vintage parts;
– CPU and RAM load measurement, temperature monitoring and fan speed control.

I've started this project four years ago, almost simultaneously with “Felix”, and worked on them (and many others) in parallel. During this long time, the design and the idea have been changed more than once, but now I want to show you everything from the very beginning.

As it often happens, I've got the idea when I found an interesting thing. It was the aluminum casing of some old soviet apparatus:



It was empty and unmarked, so at first I did not know what device it belonged to. But the slides inside have prompted me that it had a pull-out design, and I decided to use this ability. First of all I started drawing a 3D model of the shell (it was the second time I used CAD software). It is remarkable that the housing width is only 0.2 mm greater than the width of mATX motherboard.



In contrast to the previous mod, where I've firstly designed the front panel, in this case I began from the rear one. It was planned to be made of 2 mm aluminium.



I tried to pack a quite powerful hardware: a full-size ATX PSU and a full-length graphics card (maybe even two). I also hoped that numerous ventilation slots in the housing will help me to provide an adequate air cooling.

After the addition of the “rails” and struts at the top I got an approximate view of future inner frame:



And once the design has become more or less clear, I began to think of the appearance of the front panel. Photos like this were the source of inspiration:



And what I got as a result, I'll show you in the next post.

 

Loved the Felix build, subscribed for this one!

 

Some good news in this crazy world, BootSector is back
Welcome back fella

I really liked the look & feel of Felix, and the shape and size of this one is great.

It looks like a Silverstone SG07/08 either fell in a time machine to the 70s, or got crossed with some vintage luggage!!

Looking forward to this, I need some more inspiration.

 

My body is ready.

 

Welcome back I look forward to this

 

Oh, BOY!

 

I created the first sketch of the front panel using photos of available soviet devices and knobs. Color of the panel and shape of the labels have been borrowed from old German radio stations, although some elements of “Felix” still could be seen, too.



First of all, I want to calm down my German-speaking readers: grammatical errors, that you can see on the labels, were corrected in the final version. This is nothing more than a sketch.

After a while I managed to find original German gauges of 40's/50's, belonged to some captured equipment. I've taken photos of them with the right lighting and then updated the sketch:



A big universal connector appeared in the bottom, as well as the already-familiar name, just in a different spelling. Mistake in “Tragbarer Rechner” will be corrected later.

After that I modified the 3D-model. You can see the HDD enclosure, the PSU support frame and the cutouts for the front panel elements. Also, I hastily sketched basic components (with a large margin), placed them in the assembly and made several renderings.



I was not going to install there two air-cooled video cards, indeed.



After making minor changes, I have drawn a stylized blueprint (just for fun):



Also there has appeared another version of the front panel design, but I liked it less, so I went back to the previous one.



The front panel drawing was almost finished:



Just in case I made the paper model of the front panel. In Russia we have a saying «Гладко было на бумаге, да забыли про овраги» (“On paper there had seemed no hitches. Alas! Forgotten were the ditches”).



However, it turned out to be OK.

 

^Computer making a knowing grin at the ohm meter...

 

Subbed! Felix was awe-inspiring, amazing, and a bunch of other compliments!!

 

Thank you for your interest, let's continue. After estimating the sizes I have created a combined model, where I could move the frame back and forth and see whether intersections occur.



It revealed a couple of places where the housing has to be a little sawed. To prevent the frame from falling down, I added an automatically folding support.



After final revisions the model began to look like this:



I sent drawings to the production site, and proceeded to work on the German heritage. Small meters were easy to
disassemble: I had only to loose three screws and to open the case with a sharp knife.





Since the gauge was originally an amperemeter, it had a shunt inside, which was absolutely not necessary for my purposes.



There was no gap between the scale and the case, so I couldn't put the LEDs behind it, like I did in “Felix”. But instead there was enough space at the bottom of the scale.



Now, the readings can be clearly seen in the dark.



Disassembling the large meter was much harder. After loosening the mounting screws I saw that it is still solid. Then I hooked the front frame with a knife very carefully (thin bakelite can be easily broken), and found that the frame was sitting on some strange mastic.



But the gauge still did not want to disassemble, so I had to remove the scale.



Only after that it became clear that the wire, that leads voltage to the coil, was passed through the mounting plate, cementing it to the body.

I put four LEDs at the top of the scale and added a strip that has raised them for a better light distribution.



Two more powerful LEDs, that were put at the bottom, provided an acceptable result, but in the future it would be better to apply the lighting scheme used on “Felix”.



Then I began cleaning and polishing the other elements of the front panel. I have used the most common in ex-USSR polishing composition — the GOI paste.



I applied the substance to the little polishing wheel, installed in Dremel.



I did not have the goal to bring the parts to the absolute smoothness and gloss, I just wanted them to fit the color scheme of the project and, at the same time, to look old enough to be plausible.

 

Hello again, finally I'm here after very long holidays and ready to continue posting.

I got most of the CNC-milled parts and assembled them into inner frame.









In parallel I did a lot of work preparing front panel parts for mounting.











The case began to look like this:

 

Aaaaaaaand subbed.

 

Looking fantastic.

 

Oh my word...subbed so hard

 

SWEET
It's made only awesome-er by the fact that the gauges will work.

 

My god yes!

 

I love this vintage look. Great details, make some use of the Amperemeters

 

I'm very glad to see that you like it, so let's continue.

I got steel parts from laser cutting and bending.







Then I made handles for the inner frame with the use of a steel rod.



Aluminium support and its axis:





And special fastening made to mount an old cooler on modern CPU socket:



A little filing...



Here it is!





Computer parts are rather expensive in Russia, so I try not to waste the ones I already have. But I hope that it will be a temporary solution.

In the next post I'll show you how I made labels for the front panel.

 

As you can remember, I planned to equip the front panel with labels, like it was done on real German WWII era electronics.



My first idea was simply to print them on thick paper, but then I invented something better. I took a copper sheet, 0.8 mm thick, sanded it and cleaned it with an acidic detergent and lighter fluid.



Then I inverted and mirrored the labels.



I printed this image with laser printer on glossy magazine paper and transfered it on copper with an iron.



After separating the paper I've got a toner-protected surface which was almost ready for etching.



Some areas were a bit cleaned with a needle and a sharp knife.



I used acrylic varnish to protect the reverse side of the copper sheet, and FeCl3 for etching. The vial in the middle occured to be unnecessary.



During the etching I stirred the solution with a brush.



After one hour I got these scary labels:



But after cleaning them with a solvent I found them to be glossy and rather precise.





Then I cut them from the sheet with a dremel and sanded.



The next stage will be painting.