The big board arrived and panel test

A project log for Beat707

A MIDI sequencer

Frank BussFrank Buss 08/26/2019 at 17:510 Comments

The big board arrived. Frank soldered all components on the back side and placed all components on the front side:

The buttons are original Omron B3F buttons. They cost more than the cheap no-name clones, but quality is better. They last longer and the contacts are not dirty, as they are sometimes with the clones. For this model you can buy different caps. With this cap, it looks like this:

There are spacers to mount it on a base board in the enclosure, and to mount a panel on top:

For the labeling Frank tried to engrave the red front panel and then sprayed acrylic color to it, wiping off the rest with isopropyl alcohol (you need this to avoid etching the acrylic red panel). Could be better, but good for a start:

After some struggling with FreeCAD to export a file for the Nomad 883 CNC machine (e.g. it outputs a command to use inches, but then outputs millimeter coordinates), milling a small part the panel for testing was successful. Frank tried different spacer heights, and the 8 mm version, in combination with sanding off the 4 edges of the 7-segment display, was perfect:

There are some minor details to improve, e.g. for the screws there needs to be milled some countersinks for a flat surface, and the engraving for the text needs to be smaller (all milled with the same 1.6 mm drill bit, should be changed to 0.8 mm for the engraving). But now the LEDs can be soldered, because the right lead offset is known, and then the board can be tested.

Meanwhile Gert started to write a user manual. Shouldn't take long now to finish the first fully working prototype.