The circuit board with 5 SiPo’s (74HC595) to control 40 outputs.
View of the back of the circuit board.
Putting the laser-cut parts together to form an early structure. The material used is white and black 2mm thick perspex.
The front plate with all the letters on it. Due to the high density of characters, the temperature probably got to high and parts started to melt. The plate is curved and I’ll have to think of a different approach to create the plate.
zoomed in on the front plate
Inserting the logic in the structure
adding the LEDs and resistors + connecting them with the circuit board.
Switching on the power to light up the LED’s in ‘groups’.
problems during the assembly:
- I forgot to cut out some holes to put the LEDs through. This was solved by using a construction hole as a LED hole. The downside of this will be a small light leak to neighboring words… Reason of this mistake was that those holes were on a non-printable layer in Adobe Illustrator.
- The ‘ground line’ of the transistors was broken on 3 places. This was first discovered after assembling two rows so it was still doable to detach the whole circuit board and solve the problem. The strength of the bonding was tested while doing this and found to be more than good. After assembling some more rows, I noticed a similar problem. It appeared that the ground line was now broken on two extra places. I tried to repair it but had to remove a transistor in order to reach the parts. Luckily, there were some spare outputs left. The ground line wasn’t interrupted before assembly (was tested and can be seen on photo) so it must have happened during assembly. Probably by pressing to hard on the board while making a glue connection.
- The perspex plates were cut out with the ‘plastic 3mm’ setting. The white plates cut out nicely but the black ones were not completely cut through. I could not find any specifications about the material I used, nor if black perspex is denser than white perspex. For the front plate, I decided to change the settings to ‘plastic 4mm’ to be sure the characters are completely cut out. It appeared that the laser now passes two times along the same path, increasing the temperature. The edges of the characters are melted and the faces was bent afterwards… Next time I will try the 3mm setting again but remove the protection foils in advance.