DIY Soldering Reflow Oven

They say you are only as good as your tools. This is a statement I can vouch for, as better tools can make the difference between a sleek and well designed prototype and a rats nest covered breadboard. Unfortunately as an electronic hobbyist you don't always have the budget of a big tech company at your disposal. But hey, that's what DIY projects are for!

Starting off as a hobbyist or even small tech company designing and building electronics you will soon learn that most of the fun IC or MCU chips are either cheaper in, or only available in, surface mount form, and fancy reflow ovens are expensive.  But a soldering oven isn't much different from a toaster oven--  the only difference is the accuracy and temperature settings.

That is why I'm going to show you how to build your very own Soldering Reflow Oven for under $100 from an old/new standard toaster oven, thermocouple and a microcontroller.

Note: This project can be accomplished many different ways with many different MCU's and components.  I wanted to use Freescale Processors and StickOS BASIC, but I look forward to see how other people do this.

-Elipsit

Step 1: What You need: BOM and Tools

Requirements:
-Basic Knowledge of AC wiring (eg: Black = hot, White = Neutral, Green = GND)
-Soldering experience
-Some Microcontroller experience

Bill Of Materials:
-Toaster oven new or old
-Fiberglass insulation or fiberglass pipewrap
- K Type Thermocouple
- Max6675 K Type Thermocouple to-Digital Converter
- SSRD-240D40R Solid State Relay (Mechanical ones will be too noisy), 40A
- Note: This relay is now obsolete but I had it lying around so I used it.  You can use any SSR-- just make sure it is rated for double the current that you need, as it will be derated due to high temperature. If you're not sure how much current your toaster uses, calculate it from (Power = Voltage * Amperage).  For example my toaster was 1500W at 120V, therefore I = 1500/120 = 12.5A
-All Round steel strapping
-16X4 Character LCD - White on Blue
-Adapt9S12DP512
-5 button joystick
-Wire
-Screws and nuts and standoffs
-Acrylic face plate
-Protoboard or prototyping card
-Dip to SO breakout board

Tools:
-Soldering Iron
-Solder
-Fume extractor (Optional)
-Laser cutter (optional)
-Screw driver
-Drill Press
-File/sand paper
-heat-shrink / marrettes

Comments

[chasiscorto]

Hi! Thnks for sharing this. Well, I work with Picaxe and I would like to give this a try but I can't see the values of temperature you are using or when you turn on/off the convection fan. Could you post it? How do you estimate the temperature range you need to keep? How high do you pre-heat the oven? When do you turn on/off the fan? Thanks in advance.

[ToyMaker]

quote: They say you are only as good as your tools.
This should be reversed, tools are only as good as their user. There are many fine projects produced with crude tools and there are many pieces of junk produced with the finest tools.