On Apr 9, 2:49 pm, "John" wrote:
On 8 Apr, 22:34, "Matty F" wrote:

Very interesting thanks. But nobody will be able to guess what I'm
making. It will be very useful if it works.

A laser projector?http://heim.ifi.uio.no/haakoh/avr/

Well yes, in a way. I want to project to a screen about 1000 metres
away.
I think I'll just shape the disk so that the edge gradually slopes
away from the vertical, and stcik the mirrors directly on the edge. No
adjustment needed. Since I'm not drawing pictures it doesn't have to
be that accurate.