Research and development of laser engraving and material cutting machine from 3D printer

This article deals with the adjustment of a 3D printer for laser engraving and material cutting. The print head can be fitted with a solid laser diode module, which achieves a compact size while retaining its useful power. Two paths lead to the use of such a concept. It is possible to equip the existing print head with a module, which also brings a number of disadvantages such as, for example, the reduction of the printing space or the need for a suitable mounting design. A more elegant solution is to consider this in the design of a 3D printer and design a system to exchange the print heads for 3D printing and laser engraving. Such a solution allows full utilization of the workspace and simple installation of the effector for the required type of work. According to the installed power of the laser diode, it is possible not only to engrave but also cut material such as thin wood, veneer or acrylic glass. The use of such a machine is not only for graphic elements but for the creation of various stencils, boxes or simple models, which can be made up of plastic-burning pieces. The laser module is controlled by a driver, which is designed for the device. This is connected to a 3D printer control board. It is, therefore, necessary for the control board to have at least two pins, which can be controlled after adjusting the control firmware. Most laser modules are normally equipped with an adjustable lens, which is used to concentrate the focus of a laser for the given distance against the worktop. Thus, the modified 3D printer can perform its function as a multi-purpose CNC machine, while a basic platform similar for both devices is used.Web of Science281524

Měření točivého momentu na hřídeli kolesa velkostroje

Bucket wheel loading at the present time (torsional moment on wheel shaft, peripheral cutting force) is determined from electromotor incoming power or reaction force measured on gearbox hinge. Both methods together are weighted by steel construction absorption of driving units and by inertial forces of motor rotating parts. In the article is described direct method of the torsional moment measurement, which eliminates mentioned unfavourable impacts except absorption of steel construction of bucket wheel itself.V současnosti se zatížení dobývacího orgánu (točivý moment na hřídeli kolesa, obvodová síla kolesa) určuje z příkonu pohonu kolesa nebo z reakce pohonu měřené na reakčním závěsu převodovky. Oba dva způsoby jsou zatíženy vlivy tlumení ocelové konstrukce pohonu a setrvačnými silami rotačních částí pohonu. V článku dále uváděná přímá metoda měření tyto vlivy eliminuje s výjimkou útlumu v ocelové konstrukci samotného kolesa

Vliv délky přeplátování a životnosti na zatížení jednoduše přeplátovaného spoje

A production process is various in single industrial branches; it usually has one common ele-ment – bonding pieces of material. We can say on the base of the production sphere analysis that simple overlapped adhesive bonds are the most common adhesive bonding technology application. The research publicated in this paper deals with then too. The Influence of an overlap length and lifetime of the adhesive bond were evaluated during the time interval 1000 days. Results set an opti-mum criterion of the adhesive bond constructional shape i. e. the influence of the overlap length, and unit costs related to acquiring the adhesive.Výrobní proces je V jednotlivých průmyslových odvětvích různorodý, má však obvykle jeden společný prvek a tím je spojování materiálu. Na základě analýz výrobní sféry je moţno konstatovat, ţe nejrozšířenější aplikací technologie lepení jsou jednoduše přeplátované lepené spoje, kterým se věnuje I výzkum zveřejnění V tomto článku. Hodnocen byl vliv délky přeplátování a ţivotnosti lepe-ného spoje po dobu 1000 dní. Výsledky stanovují optimální kritérium konstrukčního tvaru spoje tj. vliv délky přeplátování a jednotkové náklady vztaţená na pořízení lepidla

Maitenance management and the production company management

A systematic and processional attitude to the maintenance management, as processional technical activities, has to be followed by firms and production companies for their organization processes including the maintenance. Then, an excellent level can be achieved according to the theory of vitality. In practice, it means that the maintenance is controlled in right way and the principles of the vitality theory have to be applied into the maintenance management. Application principles of the vitality theory in the management for maintenance management as a processional technical activity

Universal machine for prototype production

With development of new technologies the production is growing as well. Considering this the emphasis is placed on effectiveness and speed with which it is possible to test and make a new product. A 3D printer is an ideal utility in the area of prototyping. It is applicable for fast production of covers, ergonomic component and also small function elements. It is often necessary to design simple electronics in various areas of industry and at the same time to be able to test it. In this article we elaborated a possibility of replacement of a working head of a 3D printer with parallel kinematic in exchange for a head for subtle engraving of predominantly printed circuit boards. The main body of the 3D printer's effector is equipped with exchangeable system. It is enough to disconnect control cables, undo arrestment and replace working desk. Then it is necessary to connect controlling electronic. Moreover it is essential to improve working table. The working desk with clamping system is placed on the heated bed printer.Web of Science20203773376

Computer systems supporting the management of machines/equipment in hard coal mines. Case study

Computer systems supporting the management of machines operation and maintenance in companies have been successfully applied in many branches of industry. Over the last few years these systems have been considerably transformed. It also seems that using them for operating mining machines in hard coal mines is inevitable, as maintenance generates high production costs. If implemented, the systems will allow for optimization of stocks, spare parts and materials, supplies, outsourced services as well as maintenance-repair works. Application of a system supporting the management of mining machines/equipment will also enable a better, more effective use of employees. As a result of these actions, the time needed for preparations and repair will be shortened, which will translate directly into the economic effects of mines.Web of Science27314313

Vplyv druhu obrábaného materiálu na drsnosť povrchu pri elektroerozívnom rezaní

In the manufacturing process of complex components we use unconventional or progressive machining methods which can efficiently and with great precision achieve the desired result. We are talking about electro discharge/erosive machining. From an economic perspective, these technologies are used in manufacturing of high precision and complex parts, where it is necessary to achieve accu-racy to the thousandth of a millimetre with the machined surface roughness Ra = 0.1 m. These tech-nologies can be used to machine all conductive materials and materials that are difficult to machine by conventional methods, such as sintered carbide and hardened steel. Most commonly used progres-sive machining methods are sinker EDM and wire EDM. [2]Pri výrobe zložitých súčiastok využívame nekonvenčné, alebo progresívne metódy obrábania, ktoré dokážu efektívne a s veľkou presnosťou dosiahnuť požadovaný výsledok. Hovoríme o elektroerozívnom obrábaní. Z ekonomického hľadiska sa tieto technológie používajú pri výrobe veľmi presných a zložitých súčiastkach, kde je potrebné dosiahnuť presnosť až na tisíciny milimetra s drsnosťou obrobeného povrchu až Ra = 0,1m. Týmito technológiami sa dajú obrábať všetky vodivé materiály, a materiály ktoré sú bežnými metódami ťažko obrobiteľné, ako napr. spekané karbidy a kalené ocele. Najčastejšie používané progresívne metódy obrábania sú elektroerozívne hĺbenie a rezanie

Long spindle design for grinding

This article is focused on design issues concerning the long spindle used to grind the internal pipe diameters. In the article an example of spindle design for an internal pipe diameter grinder can be found to process 11 m long pipes with external diameters ranging from 270 to 610 mm. Furthermore, this article offers a theoretical proposal for the spindle stroke in connection with its engagement, taking into consideration the internal diameter of the ground pipe and the outside diameter of the grinding wheels. The pipes used in this example are designed for transport in the mining industry, requiring a high quality of inner pipes surface for their long service life.Web of Science20203768376

Determination of the coefficient of friction in a pulley groove by the indirect method

In lifting systems used for the vertical transport of bulk materials and individual items or persons, so-called frictional force transmission between a steel cable and pulley is used. Due to the sufficient contact pressure between the pulley groove and the surface of the steel cable, the steel cable moves as a result of fibre friction. In general, it is possible to define fibre (also called belt) friction as the resistance that is imposed on a flexible steel cable sliding over the rounded surface of a pulley. The frictional transmission of the tractive force is considered safe if there is no slippage of the cable in the pulley groove. In the event of insufficient cable pressure against the pulley groove or insufficient friction, the transport process fails, and the lifting device is unable to perform its function. The purpose of the article and of the created measuring devices is to obtain by experimental measurements the most accurate true value possible of the coefficient of friction acting on the contact surface of the cable with the pulley groove. The values of the friction coefficients obtained by indirect measurements on laboratory equipment when the tractive force is transferred by friction differ in many cases and do not coincide with the values calculated using theoretical relationships. The aim of the paper is to present a method of measurement and to identify the magnitude of the forces acting on both sides of a cable belted in the V-groove of a cable drum. From the results obtained from the experimental measurements, to express the value of the random variable is based on the knowledge of the known values obtained from the measurements for their use in a failure analysis. This paper presents results that can be applied in the field of online monitoring of this type of lifting equipment for failure analysis, prediction and evaluation of their operational indicators.Web of Science125art. no. 60

A laboratory device designed to detect and measure the resistance force of a diagonal conveyor belt plough

This paper presents a laboratory device simulating a section of a conveyor belt on which a diagonal plough is installed. Experimental measurements were carried out in a laboratory belonging to the Department of Machine and Industrial Design at the VSB-Technical University of Ostrava. During the measurements, a plastic storage box, representing a piece load, transported on the surface of a conveyor belt at a constant speed was brought into contact with the front surface of a diagonal conveyor belt plough. The aim of this paper is to determine the amount of resistance generated by the diagonal conveyor belt plough when it is placed at different angles of inclination β [deg] in relation to the longitudinal axis, based on the experimental measurements performed using a laboratory measuring device. Based on the measured values of tensile force required to keep the conveyor belt moving at a constant speed, the resistance to the conveyor belt movement is expressed, with a value of 20.8 ± 0.3 N being attained. Based on the ratio of the measured value of the arithmetic average of the resistance force and the weight of the used length of the conveyor belt, a mean value of the specific movement resistance of the size 0.33 [N·N − 1] is calculated. This paper presents the time records obtained by measuring the tensile forces, on the basis of which it is possible to determine the magnitude of the force. The resistance during the ploughing operation of the diagonal plough when acting on a piece load placed on the working surface of the conveyor belt is presented. From the measured values of tensile forces presented in the tables, this paper reports the calculated values of the friction coefficient obtained during the movement of the diagonal plough when moving a piece of load with the defined weight from the working surface of the relevant conveyor belt. The maximum value of the arithmetic mean for the friction coefficient in motion µ = 0.86 was measured at an inclination angle of the diagonal plough of β = 30 deg.Web of Science236art. no. 313