Thank you Dave! That was my next project before I had to move. I am hoping to make an adjustable slit. I have some old veneer heads laying around. Now I just have to rebuild my metal shop. I think it will be a year before I can do ATM projects inside again. I have 3 of the objectives. I also have some prisms to make rotating slit motion. I never found the ones from old movie projectors so I am going to have to glue up some normal prisms. 4 sides will give me a start. If I find some old projector parts I can redesign later. I keep looking on Astromart for a large flat for a heliostat bu so far I have net seen one and had the money at the saem time.