ETX TECHNICAL TIPS
Subject: mounting finderscopes Sent: Wednesday, June 13, 2001 21:43:53 From: firstname.lastname@example.org (richard seymour) What i did to add a RA finder to my ETX90 (leaving the straight-thru in its original position) was to take two short (15cm) pieces of plastic water pipe. One about 4 inch (10cm) diameter, one about 1.5 inch (35mm) diameter. Cut them lengthwise to create C-crossectioned chunks of cylinders, cut the 1.5 inch a bit shorter than the barrel of the finder. Place the two pieces open-side-down on a table (forming two tunnels?) With a file or a sanding block, flatten the top of each of those. Now glue the two flat areas together. This puts the short, small-diameter one onto the back of the big one. Strap the big one to the ETX barrel with rubber bands. Strap the viewfinder to the saddle the little one now provides. (i wish i had a photo)(i'll try to find one and send it later) This places (on my scope) the RA finder ahead of the normal eyepiece. It allows it to point straight up, keeping the mental gynastics of which way to slew to a minimum. It -does- place my chin into my main eyepiece given certain orientations of me, the barrel and the sky... attached is a GIF of the two pieces cut from plastic pipe glued together to create a "saddle" for a Right Angle viewfinder.
The screws are used both as attachment points for the rubber bands (plasts? in the UK?) which hold the finder to the saddle and the saddle to the telescope. They are drilled and tapped through the plastic to -also- serve as adjustment screws (like the regular finder), by pushing the saddle away from the ETX barrel, and/or the finder away from the saddle. I used pan-head nylon screws (US: 4/40, metric: 3x.8) to avoid scratching anything. slap-dash engineering at its finest... --dick
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