Homebrew PCBs

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