Once the printer “knows” where the print head is positioned, homing will just work, and you should seldom need to adjust it. the the will
Even if the nozzle should collide with print bed, the rubber hose connecting threaded rod will slip and the extruder be protected.
Endstops are a good safety backup but newbies may find their installation frustrating. You want to print as soon as possible and do less wiring work! QuadRap will let you do that with minimum risk.
The hot end is connected to the cold end with a 35mm x Ø8mm PEEK tube. I desperately wanted to avoid including any exotic materials, but it appears to be just a great, amazing material. The complete extruder implemented very simply, and is very compact and light. It weighs only 320 grams (11 ounces).
RAMPS Ventilated Cage
The Extruder Flint Wheel: The flint wheel of a used cigarette lighter appears to be the perfect candidate for pushing filament of any diameter. It has an internal diameter compatible with the 5mm stepper shaft, provides great friction, and has a small diameter reducing the required torque. You only need a small bearing to press the filament against the flint wheel, and here also a bike chain link is perfect for the task. Balanced Thermal Design: By experimenting with different hot end sizes I found that the temperature does not rise over a specific level, and this varies depending on the size of the hot end. Using the same resistor type for extruding PLA requires a longer hot end than ABS, and I have successfully printed non-stop for up to 7 hours without any temperature control. So, by excluding the need for temperature control, QuadRap gives the newbie a greater opportunity to start printing earlier, with no need to purchase thermistors, fans, and wiring, and no need to deal with calibration. The QuadRap doesn’t prevent you from installing other types of extruders and/or doing digital temperature control, but it allows you to save on this part and get started earlier.
Ramps ventilated cage
Installing the RAMPS between two ventilators is a very simple design that provides so much directed cooling that the heat sinks for the Pololu A4988 can be eliminated, even the homemade heatsinks I experimented with on the QuadRap blog. This also saves the cost of the thermal glue required to attach the heatsinks.
Firmware Settings I’ve been successfully using Repetier and Marlin firmware and love the Repetier host. Neither Marlin nor Repetier firmware includes settings directly applicable to the QuadRap (but this may soon change!). The QuadRap uses two stepper motors for the X direction and one stepper motor for the Z direction, whereas most RepRap printers use two Z motors and a single X motor, REPRAPMAGAZINE