GraLab question...

[Dean Taylor]

Please take a moment to clarify the features of the GraLab 300 timer--recent eBay purchase...

Specifically, the upper left hand corner switch reads (clockwise from nine o'clock) "time, timer/at zero, focus, timer/running." Also, and in the interest of avoiding improper setting and use of the timer's two hands, please provide a use scenario there as well.

thank you APUG pros!

Dean

 

[MattKing]

Dean:

There are a bunch of different versions of the Gralab 300, with very slightly different labelling for the switches, so at best I'll just run through how I use mine.

There are two power outlets on the timer. One is labelled "Enlarger" and the other is labelled "Safelight".

The idea is that when the enlarger is on, the safelight will be off. When the enlarger is off, the safelight will be on.

The idea is that when the switch is to the right, the timing function will work. When the switch is to the left, the focus function will work - i.e. the enlarger will stay on until you switch it off.

You start and stop the timer using the switch at the top left. You have to set the hands first, of course, to the time you want.

I use my timer for process control only, so the focus function doesn't get used much.

 

[henry finley]

A Graylab can be 20 seconds off in an hour, and any enlarger it controls, flickers. Best use it for chemistry timing only.

 

[Newt_on_Swings]

Matt has got it all down. I have one too but I just let it run continuously when printing so I know when to move prints. I have used it for enlarging in the past, but for precise work you would want a digital enlarger timer that allows for fractions of a second. You also want to set it to focus or off when setting the time, as you can potentially damage the gears inside if you turn back the hands when it is running forward. When you get it, make sure it zeros out correctly, with both minute and second hands coming to a rest at 12. If they are not you have to adjust it, very easy to do, an Allen key/hex wrench under the second hand, and a Philips head under the minute. (atleast those are the types on mine)

 

[David Brown]

http://www.gralab.com/pdfs/300.pdf