Shutter Speed Timer for Nikon F?

On the Nikon F2 there's a feature where the self-timer can also be used to hold the shutter open from 2-10 seconds. Is there a screw-on accessory timer for Nikon F that fits onto the shutter button, where the timer can be set for a certain time with the shutter speed dial on B, and the timer will hold he shutter release down for the preset time? I don't mean a self-timer so you can run and get in the picture. I mean one that will trip the shutter and keep it open for however time you set it to. Remember the Nikon F shutter release button does not take the same attachment method as other cameras. Thank you.

I have a Bolex wind-up unit that does that. On the Bolex it runs the camera for a certain time, and there is a delay first, so you can get in the movie.

However, Bolex cable thread is straight, not tapered. So an adapter to fit over the Nikon button would not be something that could be available.

I don't have this one but I'd like to. I think this is what you want. I think they are rare and expensive. I got my Bolex timer free with a camera .


f

Some electronic home-made thing from GitHub might be the contemporary answer to the problem.

For example I made this for my Bolex with some spare RC car parts:

Just buy a Nikon cable release and count, one elephant, two elephant, three elephant, four... etc. After two elephants you are into reciprocity anyway and any small misjudgement in timing won't become a glaring error on the negative. In fact for landscape every now and again the sun will dim during a long exposure so I just add another couple of elephants on the fly.