Mystery tool

[Slick111]

Official name ? Yes I have google it 10 times.We just call it the hookah bomb sight

[JRouche]

Crasy. I have one, not with a holder attached though. Its a nice piece. I would try to remove the holder. JR

[JRouche]

Official name ?
]

Center sight. JR

[alanganes]

We used these on some of the custom machines we have at the place I work. They always called them "centering scope" or "Centering microscope".
Googling centering microscope brings up lots of them. Not sure if that makes it the official name, but it's what the people who make them seem to call them.

[old mart]

We have one at the museum, made by a Swiss firm with the Name of IOSMA or similar. It came with an ISO30 spindle fitting and I made an R8 arbor for it to fit on. Unfortunately it now has an error in the crosshairs of about 0.002" and I don't know how to re zero it.
I'm not sure what it should be called, it is an optical centring scope.

[Fasturn]

We have one at the museum, made by a Swiss firm with the Name of IOSMA or similar. It came with an ISO30 spindle fitting and I made an R8 arbor for it to fit on. Unfortunately it now has an error in the crosshairs of about 0.002" and I don't know how to re zero it.
I'm not sure what it should be called, it is an optical centring scope.

We called them centering scopes. Looks like off a Sip jibore. We had both Hauser and Sip. They had the same error mounted on the machine. I would always set zero ( DRO ) and bore a tiny hole in something. Then I stall the scope and check error. With known error it's very useable + - the error on the cross line location. Not even the Hauser ( one of the best ) was spot on.

[boslab]

I’m old I recognised it instantly, I remember opening a brand new sip one, cost a bloody fortune at the time, when I left the steelworks it came with me because I pulled it out of a dumpster!, I ask you £40k in a bin! 5s my arse
mark

[Tillie's in a bottle]

I have a korean immitation of it with a 3/8 straight shank. I haven't had much luck with using it for centering the workpiece to the spindle, but on a indicator holder it makes a good-enough shop microscope.

[djc]

Unfortunately it now has an error in the crosshairs of about 0.002" and I don't know how to re zero it.

Manual for one downloadable from here:

https://groups.io/g/oldswissmachines/topic/schaublin_centering/73051522?p=

Direct link:

https://groups.io/g/oldswissmachines/attachment/470/0/13-1.370%20Leja%20Zentrier%20Mikroskop.pdf

Effectively is it like a four jaw chuck.

Isoma themselves provide instructions on this page:

https://isoma.ch/en/miniscope-en/

[old mart]

The adjustment instructions are interesting, I will have a close look at the one at the museum tomorrow. I don't remember seeing the four screws, though so I'm keeping my fingers crossed.

[genea]

Optical boresight is another name for it.

[redgrouse]

Used one may times mainly when working on Newall Jig borer's ; we called them Optical entering scopes, however if you put "centering scope for milling machine" in a search engine it brings up lots of results.
They were good for picking up marking out lines etc, accuracy was or appeared to be pretty good but defiantly not reliable to jig boring standards where tolerances were in the order of tenths. Would be good for work in the home shop !!!