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[on:]

I considered to create a diy reflow oven with an Arduino. But then I wondered how much it would cost. At Ebay I found offers for

T-962 IC Heater Infrared Reflow Wave Oven 962 180m T962

for less than USD 350. If they work well I would not bother to build one on my own. Has anyone ever tried such a cheap oven? Is this a good deal or should I better create my own? That is: are the temperature curves reliable? Durability would not be a really big issue. If it would outlast 100-200 boards I will most probably never need a replacement.

Any experience with such ovens here?

Udo

[Reply #1 on:]

I read an article in "Elector" magazine a little while ago.
I dont think I still have the magazine.
The writer used a £20.00 tabletop oven.
He got a good result without any modification except having a temp probe on his mutli meter.
He made up a metal tray to hold the pcb and clamped the probe to the board.
He put the board inside and turned the oven on with both the grill and oven elements on.
He turned the oven off just before it got to the upper temperature and let it cool.
The temperature curve was pretty much spot on.

With that particular oven you would just need a temp probe and controller to turn it off.

So its still worth looking into.
I havnt got to the stage of smd components yet but I would give this a try when I do.

Gordon

[Reply #2 on:]

There's a lot of example making reflow oven out there using ATmega.
But you can also buy something like this: Reflow Oven Controller together with any oven of your choice. You can save a lot money from there.

[Reply #3 on:]

I did a little write-up of doing reflow in a toaster oven:

http://www.freetronics.com/pages/surface-mount-soldering-with-a-toaster-oven
--
Jon
Practical Arduino: www.practicalarduino.com

[Reply #4 on:]

Jon,
You make it look easy.
Good writeup.

Gordon

[Reply #5 on:]

@Jon: nice writeup
@48x24x48: I think this hint was what I needed. Once I got the point I started to think and figured that maybe this kind of controller is available in a slightly more professional setup. Then I looked at Ebay and figured that I can get a professional PID process controller for a similar price (or much less if I either drop autotune or automatic ramping). However this would need some additional parts (PT100 + SSR). Still much better than doing it on my own.

Now I am left with some much better choices than the cheap oven

Thanks a lot.
Udo

[Reply #6 on:]

Another article about the toaster oven:

http://www.seattlerobotics.org/encoder/200006/oven_art.htm

[Reply #7 on:]

I have the same oven, its not too bad.  Does the job with the preset waveforms and has 2 adjustable profiles so you can create your own.  The oven is a little uneven sometimes, but some heat pads below your pcb to raise it a little helps alot.

It could do with another heating element, but thats just a small mod

[Reply #8 on:]

some heat pads below your pcb to raise it a little helps alot

What kind of pads?  

I was researching Toaster Ovens on target.com and noticed they have a Pizza Stone cut to fit into a toaster oven (about $22 shipped).  I was thinking about using one of those as a way to help evenly heat the PCB.

[Reply #9 on:]

Pizza Stone cut to fit into a toaster oven

I expect that will be a problem because it will introduce a lot of thermal mass, and hence inertia. The problem that cheapie toaster ovens have is heating up and cooling down fast enough to track the recommended reflow profile: the profiles I've seen are (from memory) around 2C / second, and my oven can't do that. Then in the cooldown stage you need the oven to dump heat quickly, and the pizza stone will tend to keep it hot.

Rather than a pizza stone I think you'd have more success with a simple sheet of metal, which would have smaller mass and conduct the heat quickly across its surface.
--
Jon

[Reply #10 on:]

I used heat proof fibre board(usually used around heating boilers) its only around 13mm thick but works well.

[Reply #11 on:]

spam (srry need to post a link in a topic i want to make)

[Reply #12 on:]

@thegeekway: which oven are you talking about? A toaster oven or the t962?

Udo

[Reply #13 on:]

The T962

[Reply #14 on:]

Where is the heater element? Is it heating from above or from below? If from above: why does raising the pcb help?

Udo