Homebrew PCBs

Marko Pavlin wrote: 
> I retrofited famous "Peach" to Peach Vario with variable distance
> between rollers. I made new side walls and improved gears with
> additional holders.

Very ingenious and simple your spring load system! Thanks for sharing.

You said it's only for toner transfer use, but since you are doing it,
almost from scratch, with a few extra tricks you can make it as good for
dry film as the real expensive ones. The hot rubber rolls seem to
already have a diameter large enough. But for dry film the rolls should
run free. Without motor attached. The motor is attached to a second pair
of normal rubber rolls. 

The dry film is viscous not solid, if traction is applied with the
pressure and temperature, the dry film can wrinkle. Mega and other
vendors sell GBC laminators modified only to hold the big dry film
rolls. And those laminators are known for wrinkle the dry film in a
stressful way. Bungard sells a super expensive laminator from a glass
etching vendor which has the hot rubber rolls running free.

The hot rolls shouldn't drive the movement, they should be driven by the
dry film movement. The hot rubber rolls should only apply pressure and
temperature.  The second pair of normal rubber rolls drives them all,
moving pcb with dry film already applied. The 3rd thing is the dry film
roll stands, which as a 'brake' thing, needing some force necessary to
pull dry film, making dry film always stretched in the hot rubber rolls.
The brake system is made by a multiplying transmission between dry film
roll and the roll that remove the undercover sheet. Since can't exist
different speeds for each roll, it can't run, but the transmission has a
clutch which let it run after a minimum force used (Except the simple
implementation works so bad, but they seem to changed the design in
newer models).

Since no homebrew need big dry film rolls. It can be made by Adam
Seychell good way. Having two plastic plates (upper and lower) at 45�
with pcb movement, in which a piece of dry film is hold by water surface
tension, nicely stretched. If a loose end of dry film is left in the hot
roll front, when the user push a pcb through it should grab the dry film
too, hopefully aligned.

Hope to have helped anyone interested.