Refurbishing the 50mm finder

I went up to the roof deck clothes drying area, where my 10" telescope languishes in exile, and brought down some stuff.

Was chatting with Joel Munoz of ALP yesterday and he described a pretty nifty way to retrofit crosshairs to an ordinary eyepiece, turning it into.. a reticle eyepiece! Pretty darn useful for a finder. So I decided to retrieve my optical stuff and try it out.

Anyway, first item on the agenda: refurbishing the finder. The finder is made from a 52mm Surplus Shed 52mm cemented achromatic doublet (with some haze in the cement.. but what do you expect for less than $5 each?) and an orange schedule 40 PVC pipe of 2 inches (50.8mm) diameter of the right length. I had to sand a bit of the inside of the PVC pipe so that the 52mm diameter achromat would fit.

I taped a sheet of sandpaper inside the PVC tube to act as a nonreflective surface (PVC can be pretty shiny). I used a 1.25" eyepiece holder from an old plastic focuser (also from Surplus Shed) and a plastic drain pipe assembly as the helical focuser. Since the PVC pipe was orange and had a lousy acrylic paint job (I bought the paint from the craft supply section of National Bookstore), I decided to wrap it in butyl self-fusing tape for that faux shockproof finish.

Right now I'm using a 25mm Meade Kellner eyepiece (from our ETX-60 "robotic telescope") but I have an extra set of lenses from the Surplus Shed 26mm Super Plossl eyepiece set (two doublets and one double-convex) which I will use as the finder eyepiece. Or something.. on the other hand, having a 35mm eyepiece around is useful for the 10" (not to mention it's less lossy than my super-duper home-made wide-angle 24mm eyepiece with 7 elements, also courtesy of the Shed).