Keys (2)

On 03-05-2010, in Enigma, Projects, by erwin

Last year, I wrote that I was going to scout for suitable material. As it turns out, a friend works at a shop where they have some nifty milling machines, capable of handling carbon fiber and plexiglass. He was more than willing to create the individual key parts, if I didn’t mind to wait…

Well, it was worth the time. The new keys are beautiful!

From left to right, the first key from last year, the second key from last year (both constructed from simple disks of plexiglass), the lower part from the new key with hole, the upper part from the new key with pin that fits the hole, the end result after applying some glue.

The end result looks like this:
keys installed

With a close-up:
keys installed (closeup)

The final bit is mounting the RS-232 connector, which will require cutting the last hole in the orange plexiglass. This company can ship pre-cut aluminium and plexiglass front panels, with all holes, cuts and engravings to your design. I will create a design and calculate the cost for an Enigma-E.



On 17-05-2009, in Enigma, Projects, by erwin

It is raining cats and dogs, so I can spend some more time on the keys of the Enigma-E. The plan was to cut two tubes, one with a diameter of 10 mm and a length of 10 mm and one with a diameter of 8 mm and a length of 10 mm. 

The hole for the key is 8 mm, so the tube of 10 mm will prevent the key from falling out, while the tube of 8 mm will fit through the hole and stick out above the surface of the frame. If the tube of 8 mm has a length of 3 mm, it will be as thick as the frame and not stick out.


This proves quite a lot of work, as cutting the tubes is not as easy as it sounds. But is worth the effort.

On a side note, the rocker switches have been attached to the steckerbrett using a bit of flatcable.


The keys look like this.

some keys

3 mm key close-up

10 mm key close-up

I really like the 3 mm tubes for the configuration keys. They will not stick out above the frame. The alphabet keys should stick out, but 10 mm is perhaps a bit much. I will try to fix a 10 mm disk with the required character on top of it, so it resembles a typewriter key.

For the tubes, I am going to scout various shops for suitable material, as I definitely do not look forward to cutting 35 x 2 tubes like this…


A bright orange day

On 16-05-2009, in Enigma, Projects, by erwin

I spent the better part of today drilling holes in the new plexiglass.

As it turns out, they are beautifully aligned!

orange holes

Now for bending the plaxiglass… Various sources on Internet suggest a temperature of approximately 150 degrees C. Hmmm, our toaster feels like 200 degrees, so that should work! Holding one side of the the plexiglass above the slit for about 30 seconds and then the other side, the plexiglass becomes soft and bendable.




Now let’s cool it a bit and put the circuit board in. As it turns out, the holes for the rocker switches are a bit deformed by the heating. It is best to drill these holes after bending.


And turn it on…


Next, I will have to attach the rocker switches to the steckerbrett and the powerplug to the main board. I will also experiment with shorter spacers for the steckerbrett (10 mm in stead of 15 mm), so the connectors will be more accessible.

The last details are the plexiglass keys, a job I am not looking forward to. Fortunately, these keys will be recyclable when I change the plexiglass frame.

And then of course the wooden exterior case…


Quick test

On 12-05-2009, in Enigma, Projects, by erwin

I found some time to drill the holes for the spacers, so I could test the new way of measuring. And it worked flawlessly!

Note to self: the holes for the lights should be drilled from the other side of the plexiglass. Do not mark them at the frontside…


New plexiglass, new chances

On 06-05-2009, in Enigma, Projects, by erwin

Together with the smoked plexiglass, I ordered some clear and bright orange plexiglass as well. Now I screwed up the smoked (I will be ordering some more), I decided to continue with the bright orange one.

I was not looking forward to three more nights of measuring, marking and remeasuring again. Then an idea hit me. In the kit is a template for the component placement on the PCB. What if I copied it, scaled it and transferred it to the plexiglass? It turns out that the A3-size template has to be scaled down by 73.117% to get an exact, real-life match. 73% is close enough and readily available on most copiers. 🙂

Scaled template

Transferring proved to be a challenge, so I punched small holes in the paper and after fixing the paper to the plexiglass, used a black marker to place marks at the exact spots. This works like a charm and can be done in about 1 hour.

Transferred marks

I was too tired to start drilling and had a number of blogposts to write. Drilling will be done this weekend.