Two-phase stepper motor, 42 steps. Size: 42 * 42 * 48mm
RepRap 42 two-phase four-wire stepper motor --3D printer parts the most important driving force
Simply put, the stepper motor is controlled by current pulses to precisely the amount of rotation of the motor, the current pulse is supplied by a stepper motor drive unit. The so-called "step" is a current pulse, each "step" are fixed length, so the stepper motor applications that require precise positioning applications. Stepper motors are mainly two types of bipolar and unipolar, the RepRap Both are available in principle, we just need to pay attention to the following main technical parameters, they will not choose the wrong motor.
step angle: 1.8o degrees / step
Voltage: 12V ( Stepper Motor It is not directly connected to DC 12V ! )
Rated Voltage: 2.7VDC
Rated Current: 1.5A
Phase resistance: 1.8 ± 10% Ω / phase ( 20o )
Phase inductance value: 3.8mH ± 20% mH / phase ( 1khz 1v rms )
Lead Style: AWG26 UL1007
lead with four
holding torque: 4.8Kg.cm Min / 550mN. m
insulation class: B (130o c)
Pin design: red, blue, green black
RepRap bipolar stepper motor used is NEMA 17 type, this code is in line with the United States on behalf of an electronics manufacturing standard sizes. It defines the surface dimensions of the motor (if a plan is the "footprint") but is not defined length. NEMA 17 is the representation 1.7x1.7 inches, NEMA 23 is 2.3X2.3 inches. But not the larger the size, says the greater torque, NEMA 14 may also be more powerful than NEMA 23. Size is not the most important, but the choice of a medium-sized motor can meet the performance requirements and lightweight design is necessary.
A stepping motor for Prusa step angle of 1.8 ° is required, in other words can rotate at a step 200, because 1.8 ° x 200 = 360 °. You can choose the angle of smaller and more sophisticated, but if the angle is greater deceleration is required with the use of gears.
Current and power
Select stepper motor need to pay attention to see the rated voltage and current parameters, typical is 2.8V and 1.7A. Just stepping motor drive unit is able to control the current output, in theory, you can use any higher than the rated motor voltage supply voltage. If the drive unit can not control the current, you will need to use the same rated voltage approaches the supply voltage, otherwise there is the risk of overheating the motor.
For the three axes of the motor, we recommend a minimum holding torque is 13.7N-cm (0.137Nm or 19.4oz-in). For Wade extrusion nozzle, because of the need to print extruded plastic raw materials, so the need for greater torque, we recommend at least a 40N-cm (0.4Nm). In principle, five stepper motors do not have exactly the same, but for the two Z-axis, preferably the same specifications.
All Mendel printers default motor shaft diameter should be 5mm. According to the standard NEMA 17 motor size, pitch between two mounting holes should be 31mm. This information is collected for his old classmate motor should help.
There are several stepper motor wiring specifications, 4-pin, 6-pin and 8-pin are common, it can be used for RepRap applications. 5 needles have, but not for 3D printers.
1 2 3 4 5 6
A C B D
Most of the technical parameters described stepper motor coil is energized after temperature rise 80 ℃, that is to say the operating temperature of up to 100 ℃! So the installation of the motor has been melted plastic stents may, we can only use part of the load.PLA is relatively ABS heat resistance worse, 60 到 65 ℃ start of, while ABS is about 105 到 120 ℃ between the start of the so heat-resistant plastic parts 3D printer is best to use ABS to print .
The motor current as long as 1.2A, output torque up 5Nm, great performance, at least compared to most of 1.7A for the operating temperature of the motor will be much lower.You need a total of 5, X and Y axes of each one, Z axis 2, an extrusion nozzle.