Marko Grošelj, MSc

My basic undergraduate engineering degree is in Mechanical Design and Machine Building. A continued curiosity in my field led me in the Mechatronics. I now hold a Master of Science Degree in Mechatronics and LASER Technician Engineering. Both my studies were completed at the University of Ljubljana, Slovenia - EU. I have knowledge of CAD machine design, reverse engineering of machine parts and making 4-axis G-code for CNC milling machines using SolidCAM.

I have expertise in electronics, microcontroller programming and controlling algorithm implementation. I’ve supervised large industrial process production lines and in a more personal project, I built my own residential home. I am innovative,

I like to learn, and I love new technology and I'm very excited at the prospect of working as with a compatible international team.

Mechanical Design Skills

Mechanical CAD/CAM Production

I develop concept, design machine parts and assemblies, draft technical documentation and write code for the CAM production of designed parts on a 4-axle CNC milling machine.

Mechatronic Skills

Control System Design & Implementation

I can transform a specific physical process into a mathematical model and develop a digital controller for the described model. I can program microprocessors and implement developed digital controllers within the processor.

Foreigen Languages

Languages

My native language is Slovenian. I speak and write English very well. I am currently continuing my German studies. I also speak fluent Croatian and Serbian language.

Slitting Machine

Developed for the purpose of manufacturing electric transformer cores. The machine is driven by a synchronous motor with an inverter drive that allows adjusting the slitting speed.

Support Roller

Developed for a manufacturing process that utilizes round transformer cores. The main function of the supporting roller is to maintain a constant force in the process of winding the core. Constant force is produced using a pneumatic actuator.

Peristaltic Pump

Developed for the accurate application of a drug solution in the manufacture of plaster with analgesic effect. For precise dosing, the drug solution applocation is controlled using a microcontroller unit that drives a stepper motor in a feedback loop with an encoder.

Clamping Mechanisem

This clamping mechanism is one in a series of devices developed for manufacturing special transformer cores produced for measuring magnetic flux. The device is driven by a pneumatic cylinder that produces a clamping force for carving a small groove in the core of a hall sensor measuring device.

Linear Encoder Device

This image shows a modified linear encoder sensor assembly. The sensor wsa modified to improve the device’s resistance against dust, chips and fluid splash when mounted on a machine. The mounting tolerances and performance of the moveable sensor guideway assembly were also improved.

Operation of the Linear Encoder Device

This image demonstrates animated operation of a prototype for a linear encoder measuring device with realized improvements.

Honey Distribution Module

Developed to improve the manufacturing process of honey-coated healing strips. This module was an upgrade of an existing device. The function of the module is to evenly distribute honey over the active area of a healing strip.

• Huny distributor in operation

Mixing Device

Developed as a pilot project for the production of active substance for strips coated with analgesic treatment. The analgesic substance mixed prior to the production process. The mixing process is semi-automatic and  controlled by a PLC controller unit.

Winding Machine

Developed as a module component for a textile fibre plasma processing production line. The winding module is driven by two servomotors. One applies constant force and speed to the winding material, the second provides correct winding of material on the roll.

Plasma Cell

This plasma module was part of a production line for the modification of textile fibres with plasma blast. The cell was  designed and produced in-company, the plasma unit was designed in cooperation with EU partners

Vacuum Transport Module

This transport module was a modification of an existing device that failed to fulfil transport demand. The applied force is the result of  pressure difference - the module attaches transport material to a transport belt. At the end of the transport path are high-pressure nozzles that release the transported material. The nozzles are triggered by a controller as per desired speed.

• Part under operation

Tension Strength Tester

This tension tester was developed as a pilot project for the purpose of testing the tensile strength of a cotton line. It was mounted on an existing production line.

Cutting Cylinder with Peripheral Distributed Blades

This image shows the cutting cylinder used in the process of cutting cotton pads. The cylinder was first designed using CAD and then manufactured on a CNC milling machine. The base shape was milled primarily using special raw cutting steel, the cylinder was then heat treated with surface hardening to 45 HRC. The blades were then milled for final shaping.

• Milling process

Compressor Gears

These compressor gears were developed for the purpose of strengthening cotton swab material in a lateral direction. The gears’ teeth compress the material and clamp the fibres in a short lines pattern. The gears were designed using CAD and manufactured on 4-axle milling machine. G-code was written using SolidCAM software.

Engraving Cylinders

This image shows pressing cylinders for making patterns on cotton material. The cylinders were 3D modelled basis on an old cylinder with a different pattern. G-code for CAM 4-axle milling machine was written fpr the new cylinder. The machine part was manufactured and surface heat treated for hardening  surface material.

Press Jaw Segments

This image shows produced press jaws segment for compressing the cotton material. The jaws were modeled in 3D on the basis of an old component and some modifications were made. Then the G-code for CAM 4-axle milling machine was written and 8 jaw segments produced. Finally, the jaws were tested on the machine and the results were evaluated.

Sewing Machine Part

This image demonstrates a reversed engineered machine part for sewing machines. A 3D model was created based on an old component, CAM code was written and the machine part produced on a 4-axle milling machine. Finally, the part was tested on the sewing machine.

Knotter

This is a another reverse engineered machine part. A 3D was modelled based an old component, CAM code was written and the machine part manufactured on a 4-axle milling machine. Finally, the part was tested on the machine.

• Knotter in operation

Structural Analysis

This image shows structural analyze of the thin wall pipe under pressure. The pipe is modeled with shell elements and for the purpose of the efficiency, the symmetry is used. We can observe the concentration of the hoop stresses is in place with maximal curvature of the pipe.

Electro Magnetic Analysis

The picture shows magnetic flux density distribution B [T] between the air coil and a permanent magnet N35. The analysis was made with EM Works software, which on basis of the 3D model calculates the electromagnetic properties. The calculations are based on the FEM theory. The main goal of the analyze was to calculate the magnetic force between the air coil and a permanent magnet in the region of operation. The obtained results were then compared with experimental measurements and It was found out that there were only minor deviations.

Polyamide Fibre Production Line Hall

This image shows the base floor of eight polyamide fibre production lines. This is the fundation prepared for winding machines before concrete casting. Due to the 4-storey production lines, the fundation must be placed very precisely.

Equipment Assembly for the Polyamide Fibre Production Line

The photo shows the 3rd floor of the polyamide fibre production line. The floor houses extruder machines - equipment for melting and pressurizing polyamide material. This same floor also houses drive gears for polymide fibre casting stationed on the floor below.

Magnetic Levitation

Magnetic levitation is by default an unstable process that is not possible without a tuned controller. This system is based on a 32-bit STM microcontroller that controls the magnetic field of the air coil using voltage PWM a way that maintains the magnetic force balance of the gravitational pull so that the sphere levitates in mid-air. A discrete PID algorithm is implemented for stabilizing the system.

• Levitation in operation
• Controller traacking sinus reference signal
• Controller traacking step reference signal

Master's thesis:

Tracing Robot

This tracing robot is based on a Microchip PIC microcontroller. It operates on the principle of contrasting between the leading line and the colour of the floor. The robot has three sensors to distinguish direction in relation to the leading line. The tracing robot is also able to follow the line with a sharp radius.

• Tracking robot following line

Weather Station Wi-Fi Transmitter

The transmitter is based on a wireless ESP 8266 module that senses external weather using a BME 280 sensor. The weather station records temperature, pressure and relative humidity and wirelessly sends data through the home router to the ThingSpeak web server. Weather statistics are recorded every 10 minutes and represented on a time graph.

• Weather station home page (ThingSpeak)

Microcontroller Based Fan Driver

This fan driver was developed to control a computer chamber’s cooling process. whenthe original switching type driver was found to be inadequate. To resolve the problem, a PID controller was implemented. The prototype device was tested on an AC fan that needed a triac element. The controlling system is based on a PIC12f675 microcontroller and MOC3021 triac driver. The MCU senses the crossing of zero voltage and triggers the triac at a specific time in order to reduce the fan’s power.

Homemade Staircase Illumination

This staircase illumination was an atempt to make staircase more atractive for special events. The illumination is based on a special purpose RGB driver WS2812B which allows to individually control the color and illumination of individual light with minimal wiring. There are only three wires needed, two power lines an one data line. The RGB modules are connected in serious. For controlling the illumination is chosen an ESP8266 wifi module which allows changing lighting parameters over home wireless network.

• Staircase illumination video