Simplicity in idea, maybe not so in reality, but here's the idea.
The replicator wouldn't necessarily take a great deal of power, as its function is not to create matter from passing asteroids. Add an item, be it a simple component or a complex machine, and the pattern is stored. When you select a pattern from the menu, it will take the materials needed from an adjacent chest and build the item true to the original pattern if the materials are there. Without sufficient materials the item simply will not be built.
Understandably you would have to select components the build the pieces of a complex machine, such as circuits would have to be assembled for a solar panel before the panel could be built, but with a few clicks the finished product would be deposited back into the same chest to be retrieved or used in a more complex recipe as needed.
Perhaps not a true replicator, but it sounds nicer than lazy-ass assembler bot.