Hi Daniel,
The PCB mates quite accurately with the connector in the DX7.
There are two small notches that stop the board moving from side to side.
The frame of the connector slot on my DX7 is plastic so doesn't cause any electrical issues. I've not had any problems with movement. I'll try to get some photos tonight when I get home.
With a box it does plug in more nicely. Unfortunately I don't have a 3D printer myself so I got some example boxes printed by an online service (3D Hubs) using an Form 2 SLA printer. They were quite expensive and would probably add approximately ?18 to the cost of each complete cartridge in small numbers.
The box is in two halves that clip together around the PCB. Unfortunately using a low cost filament type 3D printer the accuracy wasn't good enough for a good fit. If I could get the numbers up to over 200 units then injection moulding would be an option!
Ant.
