The subject of this project is realization of CNC milling machine, designed for production of smaller machines light alloy and PCB components. This will be subject to selection of mechanical components and drive. The mechanical construction should not be too complex due to limited production means, however, a laser cutter is available and the possibility of producing smaller parts on conventional machine tools strojfch. Also included is the design and manufacture of stepper motor control interpolation units evaluates the machine status.
The interpolation unit will connect to the personal computer via USB port and will communicate using its own protocol, which will specify the coordinates and type of movement tools. the creation of driver software to control the machine is also included of this project. The software should be able to interpret G-k6d, which is the most widely used language CNC machine control, drilling plans in Excellon format, and also data for plotter in format Gerber RS-274-D. Support for additional input data formats may be added as needed. Also is Planned programming of simple graphical simulator serves only to verify used production data, programming of complete CAM software is not planned.
the first part of this document describes the selection of mechanical components and materials for implementation mechanical construction. The construction of the milling machine mechanics is also documented. Another part is dedicated design and implementation of interpolation unit, where the resulting parameters, electrical diagram, description communication protocol and meaning of individual connectors. in the last part all are described driver software functions, description input formats and shortened instructions for use.
COMMUNICATION PROTOCOL
The interpolation unit is controlled from the PC via USB bus. As a USB converter is use the integrated circuit FT245R.
POWER SUPPLY Stepper motor drivers need a power supply of about 35V for efficient operation. Spickove maze read through both phases of stepper motor winding current up to 3A, however due to inductive character load should not exceed about 100W for all 3 drivers. The power supply was to be sure it is designed for double power, ie 2OOW. It is also necessary to provide power to the microcontroller and other logic circuits. This is done by an independent backup power source, which is in operation as long as the interpolation unit is on. This concept is mostly broken computer resources type ATX.
TL494 The operating frequency of the power supply was chosen to be about 170kHz. Power supply has stabilized voltage. The TL494 is output via a GDT driver transformator. It is full type bridge and is powered from the same branch as TL494.
STEP ENGINE DRIVER WITH TB6560AHQ
Bipolar stepper motor driver can implement eight switching transistors and microcontroller or programmable logic array. Another option is to do this integrated circuit. After searching different product offerings, it was selected integrated circuit TB6560AHQ
The AVR ATMEGA64 microcontroller [18] is used in the interpolation unit. Ma sufficiently The port amount and AVR performance calculation is sufficient for this application with 32 and 64b arithmetic as well. from internal peripherals are utilized by 1 of the timer, external interrupt for RF245R streaming
and one UART for possible communication with other devices. As an algorithm for interpolation usingcky Bresenham’s algorithm for 3-dimensional space was used [19]. Arc interpolation algorithm a spiral based on trigonometry and compares the square of the distance of the point from the center to the other power of radius. As a result, it is determined whether the step should be straight or oblique. At this only 64b arithmetic should be calculated. This algorithm is more time-consuming than Bresenham the algorithm for the circle, but it is preferable because of the universality because the beginning and the end
circles or spirals can be found at any point.
FILE DOWNLOAD LINK LIST (in TXT format): LINKS-26246.zip
Published: 2019/08/08 Tags: avr project, microcontroller projects, tl494 circuit
Projets CNC TB6560AHQ ATMEGA64
Le sujet de ce projet est la réalisation d’une fraiseuse CNC, conçue pour la production de petites machines en alliage léger et composants PCB. Cela dépendra de la sélection des composants mécaniques et de l’entraînement. La construction mécanique ne doit pas être trop complexe en raison des moyens de production limités, cependant, une découpeuse laser est disponible et la possibilité de produire des pièces plus petites sur des machines-outils conventionnelles strojfch. La conception et la fabrication d’unités d’interpolation de commande de moteur pas à pas évaluent également l’état de la machine.
L’unité d’interpolation se connectera à l’ordinateur personnel via le port USB et communiquera en utilisant son propre protocole, qui précisera les coordonnées et le type d’outils de mouvement. la création d’un pilote logiciel pour contrôler la machine est également incluse dans ce projet. Le logiciel devrait être capable d’interpréter le G-k6d, qui est le langage de commande de machine CNC le plus utilisé, les plans de forage au format Excellon, ainsi que les données pour le traceur au format Gerber RS-274-D. La prise en charge de formats de données d’entrée supplémentaires peut être ajoutée au besoin. La programmation planifiée d’un simulateur graphique simple sert également à vérifier les données de production utilisées, la programmation d’un logiciel FAO complet n’est pas prévue.