Homebrew PCBs

Since you can measure your exposure with accuracy, reduce your distance and
increase your time.  For example, 6" distance should equate to 6 minutes.
(half the distance, 1/4 the time).  One thing that I haven't dialed in yet.
The bulbs have a lifetime, they wear out.  Longer they are on for each job,
the fewer the jobs before replacement.

On Sun, Feb 14, 2010 at 2:02 AM, DJ Delorie <dj@...> wrote:

>
>
>
> Barry Demers <sdad@chipchristy.com <sdad%40chipchristy.com>> writes:
> > Now, if you can dial in that closely then go for it.
>
> Sure, just pick up a transmission step gauge and a timer. I've got my
> UV box down to exactly where the film says the exposure should be, and
> I know how far over or under I can go and still get good results.
>
> In my case, I have 8 steps of working range, or a 16x time difference
> between "just enough" and "almost too much", which means a window from
> 1.4 minutes to 22 minutes (I use 5.5 minutes).
>
> What I'd like is a box that can do both sides in less time, which
> means *more* UV. If you need 24 minutes with a 15 watt bulb, then I'd
> need four 30 watt bulbs - per side - to improve on my exposure times.
>  
>



-- 
Thank you,

Barry


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