Miniature Amstrad PC1640 NTP Deskclock

Update: added the base plate, a final version of the keyboard base and a floppy box model.

This is a miniature model of a classic Amstrad PC1640 I made to house an oled screen and a ESP32 micro controller. I started this project to see if I could model a complex object with its real life measurements then scale it down for printing with openSCAD.

To build it you will need a long (~30mm) M4 screw and Nut. I recommend some rubber feet or a piece of 1mm rubber sheet since that is what I tend to use on all my prints nowadays to keep them from sliding around. It should be fine without it tho.

For the electronics you will need 2 3mm leds (red and green) as well as some kind of microcontroller to drive your display - I used an esp32 and an esp8266.

I included mounting inserts into the monitor for the common .96" and 1.3" OLED modules you can find on amazon and aliexpress.

I will add some more details in the next few days and maybe a link or two to the matching displays and boards.

Print Settings

Printer:

CTC Prusa i3 Clone

Rafts:

Doesn't Matter

Supports:

Yes

Resolution:

.1-.2 see picture for recommendations

Infill:

40 to 100% depending on part

Notes:

Printing of these parts can be tricky and active cooling is a must for the finer details to come out right. All of the Models are oriented in the way they are supposed to be printed. For ease of printing I added an alternative version of the monitor front but I personally prefer the version with supports since its mechanically more sturdy.

To make everything look good i recommend sanding it with 240 grid WET sandpaper.

Post-Printing

Sanding and Preperations

As mentioned earlier you should sand the parts with 240 grid wet sandpaper. If you start with say a bit of 180 grid then it goes faster. The sandpaper will give the base a nice matte finish (at least with the white PLA i used). The monitor back is a bit of a pain to sand tho and needs a lot of work. The Monitor front needs careful work to bring out the subtle curve it should have. the smaller parts need some light sanding to make them look good and fit better together when getting glued later.

Painting

Adding some opaque paint to the inside of the base is important since the PLA I used (and the other PLA i tried to a degree) is either slightly translucent or would show the strong light of a LED directly behind it especially if the Room is dark. Also inlays (like the one for the inner part of the case front) will shine through where it has tabs to hold it in place. To prevent this from happening a bit of white paint in the notches and on the tabs is needed(see picture).

Add a bit of paint to the notches of the front

For maximum effect you should add a layer of black paint after 2 layers of white paint to the inside. It is also completely fine to fill the LED pinholes with paint - they can be easily cleared after the paint has dried with a needle or a nozzle drill and it will massively improve the look in dark environments since the pinholes become very well defined by this.

If you use an Arduino micro with bright LEDs on it you might want add a layer of paint to the inside of the monitor as well or simply put a dot of it on the LEDs.

Gluing the parts

There are several parts that need gluing depending on what models you printed. The front of the case consists of 2 parts that fit into each other snugly and need to be glued on the tabs and the upper flat part to hold together when putting the drives in.

remember to add some glue to the top where there are no tabs

Once this is dry you glue them to the back of the case. You can then give the combined parts a light sanding to remove any slight misalignment between the parts.

I glued the monitor spacer to the base but that part is entirely optional since the screw will hold the spacer in place regardless once the model is assembled.

The captive screw holder needs also to be glued into the monitor. It can be used either with a regular or self-securing m4 screw.

If you want to have the closed drive light up you will have to glue the LED holder to the closed floppy drive. Please make sure you have painted the back of the floppy sufficiently and put in a piece of a floppy that you colored so its visible (I like to use red here because its easy to see and the Amstrad system disk was this color out of the box) into it. The floppy in the closed floppy drive model is not removable.

Electronics

//TODO: make pretty pictures of connected esp boards

Category: Office