Glossary of Terms
This is a developing page of terms use in the documentation for RepRapFirmware and the Duet Electronics, along with 3D printing in general. See the RepRap wiki's glossary for more general terms (but some of that is a bit outdated)
It only has a few examples on at this time. Please feel free to suggest more additions on the forum (or add directly to this page)
A sensor at one or both ends of an axis which determines if the carriage has reached that point. The sensor may be a switch, magnetic hall effect based, optical or other type. Endstops are sometime called limit switches. The Connecting endstop switches page describes how they are connected to the Duet electronics.
As the number of microsteps increases so the number of steps required to move a specific distance increases, at some point the maximum frequency that the firmware can generate steps for a specific speed is reached. The TMC2660 stepper drivers used in the DuetWifi have an interpolation mode which will sub divide each step sent to them by 16. That means if the Firmware is setup to use 1/16 microstepping, interpolation will result in the stepper drivers generating a 256 microstepping motor control signal. After 1/16 microstepping the resolution achieved does not improve, however the noise level is significantly reduced using interpolation. This allows the printer to run at high step rates but low noise.
The Duet Electronics is designed to control stepper motors, there are a type of electrical motor that can be driven, by a stepper motor driver (such as the TMC2660s on the DuetWifi) in accurate "steps". Typical stepper motors used in 3D printers can be driven in steps of 1.8 degrees or 0.9 degrees. 1.8 degree steps require 200 steps per full revolution of 360 degrees, 0.9 degree steps require 300 steps per 360 degrees. In order to get smaller steps to increase the resolution of the printer and/or to reduce the noise some stepper drivers allow "microstepping" which divides the full steps up into a number of smaller steps. for example 1/16 microstepping, divides each full step up into 16 smaller steps, giving 3200 microsteps per revolution for a 1.8 degree motor. See Interpolation for information about microstepping with interpolation.
PT100 temperature sensor
A type of resistance thermometer based on platinum wire which can accuratelysense changes in temperature through a change in resistance. PT100 sensors are increasingly commonly used to sense the temperature of hotends or heated beds, and have very good noise rejection when used in the 4 wire mode. See Connecting PT100 temperature sensors for how they are connected to the Duet electronics. Compare with thermistors and thermocouples
A special type of resistor designed to be used to sense changes in temperature through a change in resistance. Thermistors are commonly used to sense the temperature of hotends or heated beds. Thermistors are normall limited to about 300C, although higher temperature versions are becoming available. See Connecting thermistors for how they are connected to the Duet electronics. Compare with PT100 sensors and thermocouples
A thermocouple senses changes in temperature through a voltage difference generated through dissimilar metals. Thermcouples can be used to sense the temperature of hotends or heated beds, they also tend to have much higher maximum temperatures than thermistors. See Connecting thermocouples for how they are connected to the Duet electronics. Compare with PT100 sensors and thermistors
The main positive input voltage to the machine via the Duet electronics. This is normally between +12V and +24V. See the Duet WiFi wiring diagrams for how it is connected.
A Z Probe is a sensor, normally mounted next to the hotend, or using the hotend itself, to calibrate the Z axis of the printer. Z Probes can be constructed using a simple switch or many other types of sensors. See Connecting a Z probe for more information on how to connect one to the Duet electronics and Setting up automatic probing of the print bed for an example of how a Z-probe can be used.