Stijn Coenen

Most commented posts

  1. Resistor Decade Box — 10 comments
  2. 3D Printer UV Curing Device — 6 comments
  3. Dust extraction – Part 4: Solid State Relay — 4 comments
  4. 12V 25A PowerSupply — 3 comments
  5. Dust extraction – Part 1: Valves — 3 comments

Author's posts

UV-Exposure box V1

This project was my first UV-Exposure box. But it didn’t work as it should. Therefore I made a new version that works better.

Schematic:

UV Belichtingsbak V1 schema

Pictures:

The glass plate with the lamps beneath it.
UV Belichtingsbak V1
The timer (Black box with the grey knob on the outside).
UV Belichtingsbak V1
Working
UV Belichtingsbak V1

Parallel port interface

This is a project I made in 2003. It is a box with 8 leds in it that can be controlled by the parallel port of a pc.

schema
Source.

Pictures:
ppi

ppi
ppi

ppi

CNC drill/mill machine V1

This is the first version of my cnc.

The parts are recycled from old printers.

printerprinter
A few of the steppers from the printers:
stappenmotor stappenmotor

stappenmotor stappenmotor

Temperature sensor:

I wanted to know how hot it gets inside the stepper driver case. Therefore I build a 4digit 7-segment temperature meter. (From Conrad, order nr 192147 – 8B)
tempsensor
tempsensor tempsensor
tempsensor tempsensor

The stepper driver:
schema sturing
sturingsturing
sturingsturing
sturingpcb sturing

Power supply:

I used an old 150W AT pc power supply. The light bulb is to provide a minimum load (the power supply doesn’t start otherwise)
voedingvoeding
voeding
Case
struringstruring
struringstruring
The plan:
tekening
Pictures:
opbouwopbouw
opbouwopbouw

As you can see I had it partially build, but I had to take it back apart because the base plate was crooked. Therefore I started a second version.

Safety transformer V1

I received 2 140VA transformers and decided I’m going to build a safety transformer with them.

Circuit:
schema

Safety transformer V1 – Update

I made an aluminium frame to mount the transformers:
scheidingstransfo
scheidingstransfo

Lathe speed controller

I have an old lathe that only turned at 1 speed. I wanted a adjustable speed so I connected it to a frequency controller.

A couple of pictures:
The frequency controller:
frequentieregelaar
The lathe:
draaibank

The control box with “emergency stop”, right/off/left switch and a potmeter to control the speed.
bedienening

Etching Tank Heating

When the weather is too cold I can’t etch because the etching fluid freezes. So I made a heated etching tank, the heating element is recycled from an old washing machine. It consisted of 2 heating elements, a large 2Kw and a smaller 1Kw, I cut the 2Kw off so it would fit in my tank (and 3Kw would be too much). 1Kw is still a lot off power so I put a dimmer on it. To regulate the temperature I made a temperature controller with a pic16f676. The temperature sensor is a LM35 with heat shrink around it. The display is a 2x7segment display (Datasheet).

The hex file for the pic can be found here: Link.

The circuit:
Schema

The pcb (PDF):
print

etsbakverwarming
etsbakverwarming
etsbakverwarming
etsbakverwarming

CNC drill/mill machine V2 – Mechanical Part

Because the first attempt failed I started a second version. Here is a drawing of how I want to make it:tekening

CNC drill/mill machine V2 – Mechanical Part – Update

My new Z-axis construction:

z-asz-asz-as
z-asz-as

CNC drill/mill machine V2 – Mechanical Part – Update

I’ve gotten 2 pieces of guide rail from my internship company. Unfortunately I didn’t got the bearings, but I can make them myself.

rail
rail
rail
Thanks to Jan, Roger and internship company.