This is a modification on the spring loaded replicator. It is optomized to use the least ammount of purchased parts neccesary (i actually used only parts that came with my printer). I removed the peg and widened the bearing space, so it would fit the larger bearing that came with my macine (which is a flashforge knock off of the replicator).
To assemble the thriftystruder, print this file along with parts from the spring loaded replicator file. Take the old extruder block off the stepper motor (unload the filament, and turn off your printer), and carefully pry it apart. There should be a bearing within the old block. Remove it, and set aside for later.
take the longest screw in the printer care kit along with a corresponding nut, and insert it into the far hole on the thriftystruder arm. Screw the nut on, until snug on the arm. Use glue to secure the nut in place(i used hot glue, and it seemed to work well).
the only pice used not included in the care package is unique among printer users. It is a screw that serves as the shaft for the bearing. Depending on the diameter of your bearing shaft, the size of screw may differ. Use a screwdriver to create a pilot hole for the screw later on. the rest of assembly is pretty self expiatory (use the spring loaded replicator video to help).
When installing, loosen the tension bolt before screwing on the arm. Put the printer back together, and load the filament. Slowly apply tension to the filament untill the extruder grips it and pulls it through.
This thing is a remix of the spring loaded replicator by makerbot.