1891 Bausch & Lomb Shutter repair

EastCityStudios · May 7, 2020

I have just started trying to repair an 1891 Bausch & Lomb shutter that I got. It is missing three screws and a few bolts, I think they are 1mm machine screws, but I wasn't sure what they would have been using then? and have had a hard time finding out. also, I have been unable to find information on how to do anything with the pneumatic pistons? any help would be appreciated.

also I have tried to find other threads relating to this topic but couldn't find any.

ic-racer · May 7, 2020

Even though B&L is Canadian and the founders German, didn't it start in New York? Therefore, maybe not metric. Let us know what you find.

Walthers's (model train) sells small SAE hardware. I have never used them, because I don't own anything that takes small SAE hardware.

shutterfinger · May 7, 2020

For the screw size measure the diameter of the threaded area and look it up in a screw table. http://www.fasnetdirect.com/refguide/Machinescrewthreads.pdf
For the thread pitch measure from the base of the head to the tip then count either the valleys or the peak of the threads, divide the length by the number of peaks or valleys, Use inch for SAE or millimeters for metric screws. B%L is in the states so its products are SAE or inch.

For the pneumatic cylinders polish the inside of the cylinders and the outside of the pistons with metal polish or buffing compound and a buffing wheel. For severe pitting use a red scotch brite pad made for metal polishing.

EastCityStudios · May 8, 2020

shutterfinger said:
For the screw size measure the diameter of the threaded area and look it up in a screw table. http://www.fasnetdirect.com/refguide/Machinescrewthreads.pdf
For the thread pitch measure from the base of the head to the tip then count either the valleys or the peak of the threads, divide the length by the number of peaks or valleys, Use inch for SAE or millimeters for metric screws. B%L is in the states so its products are SAE or inch.

For the pneumatic cylinders polish the inside of the cylinders and the outside of the pistons with metal polish or buffing compound and a buffing wheel. For severe pitting use a red scotch brite pad made for metal polishing.

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Thank you so much for this helpful information regarding the how to figure out the type of screws, as well as regarding the Pneumatics. The images you included of the automat are for a different shutter, mine is an Iris Diaphragm, which is much more complicated in its construction compared to the Automat looking at the pictures.

thuggins · May 8, 2020

B&L was in Rochester, NY. Those are number size screws. An 0-80 is .060 and is the likely "small" size. There are 00 and 000, but those would be uncommon,

shutterfinger · May 8, 2020

In 1890 screws were made by hand so the measurements will not be as precise as machine made screws.
Does your shutter have a name?

thuggins · May 8, 2020

The screw machine dates from the 1860's. Screw threads were standardized in the last quarter of the 19th century. A screw from 1890 was most certainly not made by hand.

shutterfinger · May 8, 2020

My info may be incorrect but wood screws were irregular for a given size in wood cameras of that vintage.

EastCityStudios · May 9, 2020

shutterfinger said:
In 1890 screws were made by hand so the measurements will not be as precise as machine made screws.
Does your shutter have a name?

It seems to be an 1891 Iris Diaphragm Shutter? but I couldn't fin a name on the shutter its self (or the lens that was on it?) I found the name by searching the patent date (jan. 6 1891) to see what patents where filed by Bausch & Lomb that day. It seems to match with photos I've seen online of other Iris diaphragm lenses.

EastCityStudios · May 9, 2020

shutterfinger said:
My info may be incorrect but wood screws were irregular for a given size in wood cameras of that vintage.

I don't know? but I only have the lens, not. a camera. the screws, are for the brass clockwork mechanism. (ill be making my own wooden camera to take this, and my dallmeyer lenses)

EastCityStudios · May 9, 2020

thuggins said:
B&L was in Rochester, NY. Those are number size screws. An 0-80 is .060 and is the likely "small" size. There are 00 and 000, but those would be uncommon,

Thank you so much, this is incredibly helpful

1891 Bausch & Lomb Shutter repair

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