Rab:
This issue has been discussed many dozens of times. Do a search on this forum for "CopyCad", Copy Cad", "zinc", "power supply", etc., and you'll have more information than you can read in a day.
Having said that, to get you going quickly:
- get some masking tape
- put it over the volt meter
- turn the volts knob half-way (more than enough for a 50v supply)
- set the current to whatever is needed for the size of your parts
- plate away
Voltage is IRRELEVANT. Do NOT try to set voltage, it will self-adjust to whatever value is necessary for the amps you specify.
ONLY set the amps, ignore voltage.
Now, if you want to know what the voltage has settled in at, remove the masking tape and see. In the small 1.5-gallon kit, you're never likely to get above 1 volt.
Sean