GraLab 300 question:

[Charles Webb]

Has anyone wired or modified a GraLab 300 timer to work with a foot switch?
I have little experience with such things, I question weather it is even worth
the trouble, but I have two brand new ones still factory sealed in their original boxes some twenty years ago. I can of course buy new ones that accept the foot switch but would like to use what I have. Any ideas?
Thanks,
Charles

 

[glbeas]

It would be easy with a few of the right parts. If you just want it to run while the foot switch was depressed it would wire in quite easily. To use the pedal to start and run the unit would require using a holding relay. Theres plenty of room in the box to add all you might think of using so have at it.

 

[gnashings]

I may be wrong.. not entirely sure - but I could swear I saw foot switches for the GraLab 300's for sale, made by the company itself. Can anyone confirm or otherwise?

 

[Bob Carnie]

Hi Charles

I have tried over the years to use a foot switch. I hate them!
trying to find the little bugger when you are doing multiple exposures and burns is difficult. I move my body a lot over the easal when burning I find a foot switch a major pain in the a.... to find if my feet move.
If you are so inclined I would say an electrican could wire it up for you.

 

[Donald Miller]

The Gralab 300 is electro mechanical, in my understanding, so it would appear to have a latching relay in the circuitry as it comes from the factory. If that is the case all that would be required would be to punch a hole in the side and, using a monentary normally open foot switch, wire into the circuit of the mechanical actuator.

 

[glbeas]

As far as foot switches are concerned I don't put mine on the floor, I put it on the opposite side of the easel from the timer so I have a button I can push from either side.

 

[Bob Carnie]

Gary
You know I have been doing this printing thing for a while , and I never thought of that, I feel well downright silly, what a good idea.

 

[Charles Webb]

Thanks for all the input, There is no recepticle on my brand new old GraLab 300's, I was certain it could be done, but not sure I could do it myself. The hole and installing the receptical is no problem, but what to connect to was/is.

Thanks everybody, I appreciate your help!
Charlie

 

[glbeas]

From what I've seen of the Gra Lab analog timer, unlike a resettable timer, is they have no relays in them. Rather the contacts are actuated by way of a cam on the timer motor. So to use a foot switch it would need to be a click on/ click off type wired in parallel to the on/off switch or be a momentary contact wired to a holding relay. The holding relay has dual contacts, which are wired in such a way that it remains energized until power is dropped to it. I don't have any schematics handy to post but a search should bring something useful to light.

 

[vet173]

I installed a foot switch on mie. I installed a dedicated wall socket for the foot switch so I could remove it when not wanted and wired the switch in parallel with the focus position on the timer.Peice of cake.