QuadSID, keyboard frame
Starting from the early stages of this project I’ve been thinking about using the C64 keyboard frame for mounting pots, switches and LEDs. This approach would make the whole control interface a single detachable unit and the switches, potentiometers etc. would be more accessible when maintenance is required sometime in the distant future (worn out switches etc). Also, mounting all the controls to the original keyboard frame would allow me to hide all the panel mount crap under the actual front panel. The upper surface of the keyboard frame is pretty close to the top side of the casing, but there’s still a bit of space in between for potentiometer nuts, circuit boards and cabling. So, time to put this design idea into practise!
First up, the outer and inner surfaces of the keyboard frame had to be trimmed down to as smooth as possible for the encoders to fit in nicely. As-is, the shafts of the keyboard buttons and springs were too deep and narrow to fit the encoder shafts or even mount them. So, I spent quite a while trimming away the plasting with a variety of side cutters and files. A totally tedious task; I sure couldn’t help thinking several times about tossing the whole thing and making a replacement frame from a sheet of plastic. Doing this type of mechanic reworking with a bad/improper selection of tools really sucks big time. I bet f.ex. Dremel with a cutting bit (or such) would’ve cleaned this sucker up in no time. Anyway, after about an hour of trimming I had most of the inner side sorted out..:
On the inner side of the frame, the small studs still need to be removed but I’m leaving these alone until I have the final layout for the front panel sorted out. At that time, I can just trim away the studs that are in the way instead of trimming all of them immediately. As it seems at the moment, it’s quite likely that I have to aim for a more dense layout than what Thorsten’s design is as the LCD element for this project is bigger.
As for mounting the encoders, the installation depth is as about a dead-on match as possible. No need for any further tweaking, yay \o/ .. With the knob installed there’s around 2,5 mm between the top side of the enclosure surface and the lower edge of the knob. As the front plate will be made from 2mm aluminium, this leaves 0,5mm room for the encoder push-switch travel. Here’s a few pictures from my encoder test mount.. :