I'm involved with building a bus-based computer for primarily climate control and irrigation in greenhouses.
Each expansion card has 32 (maybe 34) signals and the cpu-card has 40 signals.
I'm searching for suiting connectors between the expansion/cpu-cards and the backplane. The expansion/cpu-cards will be connected to the backplane in 90° and the backplane is 50 mm wide. The cards are expected to be replaced perhaps 2-6 times during the computers lifetime so there will not be much wear on the pins.
For the expansion cards we have been thinking about using standard 2,54 mm sockets because of price and availability. 2,54 * (34 / 2) = 45 mm, so it fits. But for the cpu-slot it would exceed our limits. We are also a little worried that it will be hard to insert cards with this kind of sockets, and 2 mm would be even worse.
Do you have any suggestions?
Price is not the most important factor, but we will standardize on 8 expansion slots, while perhaps only 2-3 are used in many cases, so prices less than 4-5 euro are preferred. The computer will not be produced in very large quantities, perhaps 15-30 per year.