On the site of microcockpit it says that each output can switch up to 500mA. So unless you got a really powerfull stepper, all the relais are not necessary.you would only need a diode because of the inductive load.Is there somebody (with more electronics experience than me) that can verify this.Ps, my stepper comes from an old 5" hard drive. It's got 5 wires, which is a dream! Bad thing is that it's 7.5

the 32point module contains the ULN2805A IC (4 of them)600mA peak, 500mA continuous. And outputs may be paralleled for higher currents !!!DESCRIPTIONThe ULN2801A-ULN2805Aeach contain eight darlingtontransistors with common emitters and integralsuppression diodes for inductive loads. Eachdarlington features a peak load current rating of600mA (500mA continuous) and can withstand atleast 50V in the off state. Outputsmaybe paralleledfor higher current capability.Five versions are available to simplify interfacing tostandard logic families : the ULN2801Ais designedfor general purpose applicationswith a current limitresistor ; the ULN2802Ahas a 10.5kW input resistorand zenerfor 14-25V PMOS; the ULN2803Ahas a2.7kW input resistor for 5V TTL and CMOS ; theULN2804A has a 10.5kW input resistor for 6-15VCMOS and the ULN2805A is designed to sink aminimum of 350mA for standard and Schottky TTLwhere higher output current is required.All types are supplied in a 18-lead plastic DIP witha copperleadfromandfeaturethe convenientinput-opposite-outputpinout to simplify board layout.

..I wonder if using a solid state relay would then solve those issues?Once again, the difference between high-school electronics and College-level electronics rears it's ugly head! ;-)

Some solid state relays are based on MOSFETs rather than SCRs or Triacs so they can work with DC loads. A bit pricey, though.