MATERIALS

I set out to build this telescope as cheaply as possible-you can buy one like this, new, for about £350-£400. Most of the main build is produced from scrap material, the base is melamine coated chipboard-basically an old self assembly bedroom unit destined for the dump. The tube is the difficult one-I tried everywhere to buy plastic "pipe" (to suit the mirror dia of 6.25")-large diameter pipe (in small quantities) appears to be difficult to source in the UK and is not cheap-(anything from £35-£40)- in the end I got an old, dirty piece of irrigation pipe (or drainage pipe) from a site that was being refurbished locally ie they were doing some bridge repairs and replacing drainage system-so I comandeered a piece of pipe that was obviously going to be scrapped! The tube diameter must be larger than the mirror diameter-THIS IS IMPORTANT. I built scope around a 6.25" primary mirror so the tube diameter is 7.375" internal diameter. The focuser is a friction type which works adequately, you may want to invest in a rack and pinion type, mine is made from a piece of pvc plumbing 2 way connector. The secondary mirror is held in position on a piece of angle bracket held in place by a long piece of threaded rod. The primary mirror is bolted in position on a home made fully allignable cell assembly. Full details for optical alignment, positioning of hole for focuser, secondary mirror location are provided later-THESE ALL DEPEND ON YOUR PRIMARY MIRRORS SIZE, FOCAL LENGTH, AND TUBE DIAMETER, the basic calculations are simple and easilly adaptable for your own requirements. Listed below are main piece parts and indicative prices.

Tube-FREE-plastic irrigation pipe-sturdy and solid-easy to drill/saw as required.

Base-FREE-Chipboard, old cupboard.

Mirrors-£65-second hand from auction at Scibid-6.25" primary 1.25" secondary flat.

Eyepeice-£25-25mm russian plossl.

Focuser-£2.50-plumbing connector piece.

Mirror cell assembly-FREE-chipboard

Dowels-£1.50

Screws/nuts bolts/springs etc-£10.00

Gloss paint-£5.00-for base-external type blue gloss

Acryllic paint-£5.00-white spray paint for tube

Cage-FREE-chipboard-assembly that fits round tube to be supported on base

Cage bearings-£2.00-electrical connection things-circular-bolted to cage as bearings

Azimuth bearings-£3.00 3 pieces of teflon rod to allow smooth rotation on azimuth

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