Yahoo Groups archive

Homebrew PCBs

Index last updated: 2026-04-09 22:20 UTC

Message

Re: [Homebrew_PCBs] Setting exposure with a step gauge

2009-06-02 by DJ Delorie

Philip Pemberton <ygroups@...> writes:
>    (using Thinktink's numbers as an example) Dry film requires 42.5 mJ/cm^2

ThinkTink's film requires 150-300 mJ/cm2

>    Double that = 1307.58 seconds exposure

That's 21 minutes.  Sounds about right for an initial step gauge test.
I'd use 16 just to make the math easier ;-)

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.