Homebrew PCBs

I have played with this more.

The original Pizzaz pizza oven comes with a 12" or so pizza pan that spins
around.

To know if there is a pizza pan on top, the unit has a small push down
interlock switch on the top.  The motor turns with a small rotating motor
close to the front by using a shaft protrusion.

I did some modifications and now it works even better!

What I did was I put a 8"x6"x1/4" thick piece of aluminum plate on top of
the interlock but not cover the motor shaft protrusion.  Now the unit turns
on but doesn't rotate.  Also the entire plate is between the top and bottom
elements now.

The unit works great in this mode.  I did more tests from a COLD start and
it reflows in 4:30 seconds - no hot air gun needed.  There is easily enough
working space underneath to push parts around that moved out of place.

The unit is compact and easy to use.  Great value at $45.  It produces 1250W
of heating power through two heating elements and also has circulating fan
that pushes hot down onto the heating zone.  Previously with the spinning
mechanism, it would not stay on one place very well.  The power is perfect
so that it reflows but doesn't melt the board.

Previously I had a GE hot plate but this thing is 100x better.  The GE unit
I used twice and never tried it again.  This unit I will use everytime for
my small prototypes.

Henry


On Sat, Mar 20, 2010 at 2:04 PM, Henry Liu <henryjliu@...> wrote:

> Got my oven from Walmart and tried it out.
>
> It works pretty well!
>
> A few points:
> -12 minutes was enough to back some test SOICs I put on with some solder
> paste from a cold start.
> -Because the oven rotates, it is not ideal for heating as the temperature
> drops pretty quickly as it leaves the heating zone.
> -I tried a second set when I used 5 minutes heating on the rotating oven
> and 30 seconds heating with the hot air gun and it was perfect.
> -The rotating design ensures even heating
> -The open design of the pizza oven makes it very easy to adjust parts while
> they are heating.
> -The temperature is not high enough to melt the PCB even with the dual
> heating modes enabled.  Next time I will watch it with my infrared
> thermometer.
> -I think the temperature is perfect for preheating but just slightly lower
> than needed for leader solder paste.  This lower temperature requires more
> than double the time to bake it alone as it does with some extra help from a
> hot air gun.
>
> In summary, the oven makes a perfect cheap preheating platform but I still
> recommend a hot air gun to touch up trouble zones.
>
>
>


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