You need to post the maximum and minimum diameters that would be useful to you.

A surplus scanner?

I have some first surface mirrors that should suit. send me a PM.

Robert G8RPI. (Cambridge UK)

Pete, if you are going to mount a surface mirror it needs adjustment in x and y planes. The ones I used had three adjusters. The mirror mount was mounted on 1 ball bearing and the adjustment screws held the mount onto the ball. The best were made from Titanium, solid, about 15mm thick. Not glass but polished up very well and of course flat.

I surveyed a damaged ships engine bed after a con rod bent which from the survey ended up bent like a banana. I measured at 300mm intervals and drew it out and it had 230 Thou. droop at both ends and 180 thou in the middle.

Have a look at Orion optics in Crewe.

The disk in a scrap hard drive may be useable. If you have one to take apart the disk is aluminium so easily cut. Don't know how well it will work for your application but it may be a suitable stop gap until you get exactly what you want.

Martin C

I've used this lot in the past for telescope optics.

**LINK**

regards Martin

Coventry gauge and tool at their Gt Yarmouth plant made optical measuring instruments that used mirrors that were polished at the plant back in the late 60s. They used the name Kandux and the machines were optical comparetors. The mirrors were quite a few inches in diameter – it might be worth looking for an old unit, as I expect most have gone now but the mirrors might have survived. I worked there. Noel.

Found a front silvered mirror off of a H&W shadowgraph? Also thought I had one of the mirrors you pictured but so far can't find it.

Hello Pete, had a look through all my bits and peces and found two round mirrors, one is 28mm dia. but has slight surface marks. the second is pristine and is a stepped body of about 65 mm dia and the mirror part at 55mm. This body is about 20mm thick.

PM me if you are interested.