… continued from Part 1

The donor oven arrived and I began the modifications to make it turn on when it’s plugged into power bypassing all the safety and panel controls.  This unit will be plugged into an outlet switched by the PID controller which will control the temperature and feature a safety override switch (to be covered in Part 3).   The modifications to the oven were pretty easy.  Here are the steps needed to turn the Black & Decker Infrawave oven into a Reflow Oven:

1) To get access to the board and relays that control the heating elements you first need to remove the following screws from the bottom of the oven.

2) Once the six screws are removed the bottom panel comes off easily.  The board is mounted to the plastic bottom with screws.   You can chose to remove the board or work with it mounted.  I removed it and soldered 12 gauge stranded wire, you could use anything from 12 to 16 gauge (as the power cable on this unit is 16gauge, I wouldn’t run anything smaller).  There are three bridge points you need to make.  You can also ground the relay to keep it permanently on, I like the idea of bypassing any electronics completely as the solid state relay/PID will be doing all the controlling.  Here is a photo of which points you want to bridge:

3) Once you solder everything, mount the board and bottom panel back to the oven.  There is one last thing you need to do.  There is a safety door switch which turns off the oven if the door is open.  You will want to disable this.  I drilled an 1/8″ hole and used a screw to hold it down.

4) Plug in the oven, the heating elements should turn on automatically.  You have completed the oven mod.

In Part 3 we will be drilling the back of the oven and installing the thermocouple and wiring up all the electronics in our project box.  Stay tuned…

Please Note:
Your safety is your own responsibility. These projects are not intended for use by
children. Use of the instructions and suggestions on Mavromatic is at your own risk.
Mavromatic, disclaims all responsibility for any resulting damage, injury, or expense.
It is your responsibility to make sure that your activities comply with applicable laws
and building codes.

I’ve needed to step up production of Myro:Bridge and that means I need a better way to solder all the small SMD components on the boards quickly and with higher quality.   After hours of researching reflow ovens, I decided instead of purchasing one (which can cost thousands) I’ll do it in the tradition of Mavromatic and build one myself. I compiled a list of components needed and placed the orders.

Here is a list of what I’m getting:

> Black & Decker Infrawave Oven – This will be the donor oven.  What led me to this oven was the folks over at Silicon Horizon.  They have a reflow controller and recommend using the IR based oven because it seems to work with many reflow profiles nicely.  It seems like they are on hiatus right now so ordering their controller was not possible.  And that led me to the following critical component…

> Shinko JCL-33A PID Controller with Ramp/Soak function –   I searched high and low for a controller that offers MM:SS timing as the typical seems to only be HH:MM.   This controller only offers one program and up to 9 steps which works perfect for my application. I also wanted a RS485 (programming and charting via PC) interface and SSR driver output.  The end result was the JCL-33A from Shinko.  (I went with a true PID controller versus an Arduino or PIC based controller because I wanted something more reliable and the programming and charting software comes free with the JCL-33A).

> 25A Rated SSR DC/AC – Solid State Relay – This pretty little device is what the PID controller controls and the SSR (solid state relay) controls the IR element in the oven.

> Omega K-Type Thermocouple Probe with Fitting – This is what connects to the PID controller and reads the temperature very accurately.

A few other parts (which I already have) include: outlet with box, wiring, RS485 to USB converter, project box to mount PID and SSR in.

Now, I just need to wait for all the parts to arrive and begin the modifications to the oven.

… Continue to Part 2, The Oven >>

Please Note:
Your safety is your own responsibility. These projects are not intended for use by
children. Use of the instructions and suggestions on Mavromatic is at your own risk.
Mavromatic, disclaims all responsibility for any resulting damage, injury, or expense.
It is your responsibility to make sure that your activities comply with applicable laws
and building codes.