Lew's CCD Camera and Telescope Rework Plans

Plans for the CCD Camera, Telescope Mount and Finder
CCD CameraBuild Cookbook CCDCamera completed, in final testing
Telescope MountConvert from tangent arm drive
to friction drive
1.48 inch pinion driving 35.5 inch wheel
Finder upgradeProvide alternate images to CCD from finderInternal finder with switchable optical path being designed around filter slide
Drive1 rpm synchronous motor to 60:1 speed reducerShaft directly coupled to drive pinion
Digital telescope positioningInstalled encoders on RA & Dec axesLink with TheSky using BBox ( Software Bisque)
Slewing and slow motions
Fast RA via differential from reversible drill motor
A power drill motor is used with a worm and worm gear driving the differential box
RA Slow Motion by variable speed drill control relocated from the stock drill via cable
Fast Dec - cable driven large wheel from friction driven small urethane wheel in turn driven by a variable speed power drill. Slew rate about
Slow dec - variable speed drill turning a worm gear. Controls moved to cable for use at the computer
Problems identifiedProposed solutionAnalysis
Drive slips due to imbalance of scopeScope has a 30 ft-lb imbalance due to the weight of the declination wheelRelocated counterweights in mirror end of telescope away from declination wheel side
Added counterweights to RA Wheel
Drive slips due to low coefficient of friction between stainless steel drive pinion and aluminum bandSeveral improvements tried, with small degree of successCurrent solution: Contact cement on fiberglass window screen on drive pinion and fiberglass window screen contact cemented to rubber innertube material cemented onto wheel rim seems to work OK (one night's testing)
Drive slips due to friction in idle rollerdrive idle roller or reduce frictionA brass collar was applied over the pinion to increase the torque on the idle roller - seems to be working
Scattered light causes gradient across fieldScattered light reaches CCD directlyExtend length of tube
Darken interior of tube with black paint
Collimation variableSecondary mirror supports flexingRemount secondary