Homebrew PCBs

Simao Cardoso pravi:
>  
>
> Slavko Kocjancic wrote:
>
> >
> > If that's true then there are different laminators.
> > I use Peach model's and Rex have same principle the heater heat
> > parabolic curved alu extrusions and this is on one side
> > of roller. That heat roller and in other side the laminated object is.
> > The heather transfer area cover just little more than 1/2 of roller
> > circumfanse. The only hoot item near laminated object is roller
> > itself.
> >
> > If you are correct. ie board are preheated and after that just pressed
> > by (cold) roller then slowdown should help. But I'm in doubt if the
> > roller itself can handle raised temperature as cooper has good heat
> > transfer compared with paper and plastic. I assume that in your
> > laminator the rollers are just little heated by medium. In my
> > laminator the roller itself heat medium.
> >
> > That can be mystery solved why some laminator roller's are destroyed
> > if heater is forced to aprox 200centigrade.
>
> Slavko, you are absolutely correct. In expensive laminators the rubber
> roller has the heater itself and they heat the board to the desired temp
> in a single pass. Cheap laminators have rollers heated like 'oven
> cooking' (rolls inside a chamber with heaters) and very low termal
> transfer to a pcb, that's why people use multiple pass. I would say that
> temp and speed control modifications of this laminators is kind of
> useless or a way to damage the rubber roll but i don't want to insult
> anyone.
>
> After use a 5 digits priced laminator every laminator i look for was
> cheap crap or inaccessible expensive. I ended buying a GBC H400 A3
> laminator with temp control by 80eur. They said it had 4 rollers which
> convinced me to buy it. I expected the 'holy grail' but was a bad
> choice, besides the ugly bad circuit inside, the 2 front rollers are
> also 'toasted' to heat up. It still makes the best toner transfers i
> ever done (after multiple pass) and it can handle thickness of 2mm
> easily, but i want one with better rolls. I should search for print
> shops scrap instead.
>
> I find the temp control useless, the sensor is below the aluminum frame
> not on the roller surface. And i guess at least 1000W per roller is
> necessary to heat the board while running, mine has 700W in total. The
> motor in my laminator seems a AC Permanent-split capacitor motor, not
> the easiest to speed control (btw, changing the capacitor value
> works??). Running it slower can burn the exposed rubber on the roller, i
> guess the manufactor defined the speed by the rubber termal specs,
> changing it seems always bad. Worst in my case, i wish only the back
> rollers attached to the motor and the front ones free, only a little
> stuck to stretch a dryfilm sheet. But for good termal transfer and good
> stretching there is Adam Seychell method.
>
> Slavko, Peach laminator models does not have the rolls built in heater
> or 4 rolls? Few time ago a fellow from Slovenia posted an hacked peach
> laminator, i described another hack to improve dry film use but i
> thought the aluminum profiles were his add not a 'toasting' heater. Only
> the rolls with built in heater can heat without rolling, the 'toasted'
> type must be rolling while heating or may burn.
> (btw ebay item 140359297404 has a nice internal picture with visible
> rolls, not inside 'toasting' chamber, but without visible electric
> connections to the rolls).
>
> Sim�o
>
> __._,_.
There is a long forum thread at *http://tinyurl.com/3aypb4a
*It's in Slovenian language but here is a lot of pictures that talk 
universal language...
In our little country I think all home PCB makers read this and have 
success..

Slavko.
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