Homebrew PCBs

Hi all,

This my first message in this forum. I must admit that I have spent hours reading a lot of interesting stuff here before posting AND daring to buy and modify a GBC laminator :-)

The results are IMPRESSIVE (at least compared to the traditional "iron" method..

The mods I have done are :
- hack the CTN by adding a potentiometer to increase its resistance. With that I can reach 190°C
- but the laminator started to melt...
- so I have also milled new supports for the moteor and the rollers

The result is here : http://www.youtube.com/watch?v=UCMnc30hRe8

Many Many thanks to all of you and your great ideas

Cheers
JP


Oups I have forgatten to introduce myself :

I am from France, 49, and I enjoy sharing informations, I love CNC, electronics, computers... and kites and RC planes ... and much more !



--- In Homebrew_PCBs@yahoogroups.com, "sailingto" <sailingtoo@...> wrote:
>
> The way I get the temperature of the laminator is with a sensor clamped to the same spot on the aluminum frame as the original thermal switch - I do NOT think this reflects the "true" temp of rollers, but is a close as I can come. 
> 
> My first attempt as temperature control was using a type "J" thermocouple clamped in place of the thermal switch, and I would watch the temperature as it heated up to around 400F (I had a Brother printer that required high temp), then run my PCB thru a few times to do the TT.  One day I forgot, and when I came back the temp was up over 500F - maybe close to 600F? (as measured by thermocouple) - and the plastic frame holding the rollers inside had melted.... THAT is when I decided I had to get a "real" temperature controller rigged up.
> 
> I have heated to 425F several times in past with no problems.
> 
> I took the "spare" I had ordered, and wired in a homebrew temperature controller, using a AD22100 150C Sensor clamped to the aluminum frame in place of original thermal switch.  I wired a solid state relay where the old thermal switch was and control via a PWM signal so as temp approaches setpoint, the heating is slowly dropped so as not to overshoot so much.  With this setup it holds around ±3ºF.  The temp will overshoot a 310F setpoint to about 311 or 312F, then start cooling, heat is applied slowly at 310F, temp will fall to maybe 306/307ºF before starting to rise again.
> 
> I've looked at using a PID algorithm to "tighten" up, but it works good anyway.
> 
> After melting the first laminator I had, I ordered the 3rd one for a spare, the 3rd is the one that came back as the single heat version. I had hoped it was the same except for being single heat, but looks like it's not?
> 
> Still having fun:)
> 
> Ken H>
>