Homebrew PCBs

I've read many of the responses to this initial post, but decided to 
reply to this first post to address what I see as something that 
needs to be looked into - before hacking your GBC-91 laminator.

I use a GBC "Heatseal", model-200 to do toner transfer when 
fabricating my printed circuit boards.  This GBC model has plenty of 
heat to produce excellent toner transfer.

The concern that I have is that the GBC-9 may not be able to produce 
the required heat to properly transfer the toner from the paper to 
the copper-clad.

If this is the case, hacking a temperature controller into the GBC-9 
won't provide any benefit toward good quality toner transfer.  If the 
heat content isn't there, no amount of control or precision will 
increase the heat content of the heating elements.  Too small, is 
simply too small.

I'd hate to see you spend unnecessary time and money on a project 
that might otherwise be an effort of futility.

Before I would spend any time on a hack for an external temperature 
controller, I'd look inside the GBC-9 and see if there is an 
adjustment on the thermostat controlling the heating element.  If 
there is an adjustment on the internal theromastat, you might be able 
to raise the operating temperature a bit to acquire better toner 
transfer.  Then you can move forward with the controller hack - after 
you are sure that the heating elements can, in fact generate the 
neccessary heat content.

At a minimum, you could examine the heating elements and determine 
the wattage that is being used in the thing.  There might even be a 
ballast resistor in series with the heating elements that could be 
reduced in value to push the operating temperature up a bit.

But if the heating elements won't deliver the heat content, hacking a 
controller won't provide any benefit.

I hope this helps you a little, before you spend time & money that 
could be used to achieve your goal by other more practical methods.

Have a great holiday season.

--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
>
> 
> Anyone hack digital temperature control into a laminator?  My GBC 9"
> laminator seems too cool for toner transfer and too hot for 
photofilm.
> 
> I'm pondering adding something to mine to let me control and monitor
> the temperature more accurately, using a K thermocouple where the 
old
> temperature switch is and a triac to power the heater.  Add an MCU,
> LCD, potentiometer, and external enclosure...
> 
> Anyway, anyone done this before?  Any gotchas I should be aware of?
>