Telescope Mount Details

Telescope Mount details
(Best viewed using

etscape @ 600x800)

	The base of the mount is perhaps the most bulky part of the whole telescope because it cannot be collapsed further than this. It carries two roller-skate wheels ; one is free to turn while the other is driven, turning the split-ring at sidereal rate. Adjustable feet are used to level the mount while removable caster wheels enables the whole telescope to be moved as a unit when fully assembled.
	The split-ring can be collapsed to easily fit into the boot of a motor car. The two alluminium brackets that secure it in it's erected position can also be seen.
	The split-ring can be set up by one person in a matter of minutes. It simply unfolds where after the brackets are bolted into position using four wing-nuts, making it into one rigid unit. At the top, two counterweights for balancing the ring are visible. (See this mail from my Telescope FAQs Page how their weights were determined, how the ring was cut round together with some measurements.)
	The split-ring is then put into position on the base by inserting the polar axis pin into the nylon bearing on the base. The angle (which equals my latitude of 33°) causes it to always slide towards the bearing and therefore staying in position.
	The assembled telescope then gets picked up by the two handles and slid into position on the mount. The two declination disks fit snugly between teflon pads to prevent the weight of the telescope from distorting the ring out of round while at the same time providing side support to when the telescope leans far over in RA. The "bearings" are formed by teflon pads onto Formica surfaces which gives very smooth movement without sticking. The bracket also carries some of the load causing it to counteract the weight of the telescope trying to force the hinge open. (This mail from my Telescope FAQs Page explains the DEC axis operation.)
	The drive uses a stepper motor driven by a homemade circuit which can either run off mains or 12V from a motor car battery. Speeds for slew, set, guide and track are all controlled from a little handset. The unit carrying the motor and gear-wheel, was taken from an old photocopier focus mechanism. It was then mounted on a machined piece of angle iron with adjustments to square the drive-wheel onto the ring. To enable the telescope to be slewed by hand, a wing-nut inside the driven roller-skate wheel provides friction control. (This mail from my Telescope FAQs Page explains how the gear ratios were determined.)