This extruder feeder upgrade replaces the stock mechanism on the following 3 Makerbot Printers (It also fits Wanhao/FlashForge/MagicFirm printers which are similar to the Rep1):
More information can be found at www.devilsinthedetails.ca
You can download and print the housings and install hardware yourself or order a kit manufactured from billet aluminum and PEEK engineering polymer for long life and durability under extreme temperature (PEEK performs well up to 480*F so it will continue to work if you choose to print ABS/Nylon which requires higher temperatures). Here are some of the features:
1) It employs a bearing to provide even force to the filament as it varies in thickness. This force applied is easily adjustable without the need to replace parts or disassemble anything.
2) It re-positions the stepper motor rearward so that the gripper wheel can engage the flat on the motor shaft. No more need to file the shaft yourself possibly damaging the stepper motor with metal filings in the bearing.
3) It allows easy access for visual inspection as well as tool access in case of a jam which might require scissors to remove the filament.
4) It's also possible to release the bearing pressure easily and quickly to allow filament changes mid-print.
5) It has clearance allowing for adjustment in the vertical height of the thermal barrier tube.
See where these extruders are now:
This upgrade began development in April 2013. Since the closure of Makerbot Operators Group, status/feedback can be found here:
You can see the full development history of this design in this discussion:
Since then, the design has logged over 2200 hours of printing combined between 2 printers.
This upgrade/hardware can be ordered here:
Here are some videos showing the upgrade in action (while still in the prototype stage).
Prototype Extruder Install:
Filament Load & Unload Process:
How easy it is to swap filament mid-print:
The printable parts can be sliced with the latest Makerware using the following settings:
0.1mm layer height
Place them on the build surface oriented as shown in the Makerware screenshot.
Check out the full instructions on how to install it here: