flexMendel

thingiverse

This printer features an easy assembly process with minimal parts for convenience. It is user-friendly and hackable, but may require sourcing machined parts if you don't have access to a vertical mill. The printer has a smaller footprint and larger print area than its predecessor, the Aluminum Mendel. It boasts precision and efficiency while ensuring low friction through machined UHMW inserts on the y and z axes. Balanced forces throughout the printer provide smooth printing. The assembly process requires following the provided drawings and BOM, adding a bed heater and power supply of your choice. DXF files are available for laser cutting aluminum parts, while Z-brackets require additional countersinking. Ordering multiple sets can reduce costs. Manual prints are also provided for aluminum parts, with the extruder plate being the most challenging. Printed slides can be used but require silicone spray for reduced friction. The flexMendel follows key design principles, such as minimal restraint on axes and balanced forces. Components need to float or flex in various places, and reciprocating masses are kept low. The frame serves as the sliding mechanism, eliminating alignment issues. This results in an efficient, precise machine. The Y carriage is loosely constrained, with gravity holding it down. Proper y-belt tension prevents yaw. Care should be taken when assembling the x axis ends with smooth rods to ensure they can slide freely. The top bushings on the x carriage constrain the extruder in y and z, while bottom bushings allow flexing in z. Threaded z rods are tightly constrained in z but float slightly in x and y. The nut cap must not be over-tightened to prevent binding. Flex couplings with radial and axial compliance should be used. The common spiral aluminum couplings lack radial compliance. Finally, the extruder shaft must float slightly for proper alignment, and a short length of filament can help in this process.