Concrete Cellar

Build Projects - Home Made Telescope Mount

I am attempting to build a computerized go-to telescope mount for my observatory that will carry about 100 lbs of imaging equipment with enough stability for astrophotography.  The plan is to use my lathe and shop equipment to make the gears and drive and my version of the On-Step telescope controller using stepper motors and a Teensy microcontroller.  The working parts of the mount is built and the controller and motor driver is up and working. 

I have been testing it in the observatory (Sept 2023) and am working through issues.  At first the tracking error was very high (PEMpro reported 300 arc-seconds!).  I have since then carefully reworked the RA axis worm and worm gear to much finer tolerances and polish.  The reported tracking error is now less than 10 arc-seconds and about 1.5 arc-seconds with PHD2 guiding and periodic error correction. 

Recently (Nov2023) a new base was constructed that places the centre of gravity properly over the mounting point and has fine adjustments for azimuth and altitude polar alignment.  I also added homing switches on both axis so if alignment needs to be reset I can reset to the home position so the alignment is saved.  Also, added handles as this is now over 50lbs assembled.   Now testing continues to see if periodic error can be decreased with recent changes to the RA drive design.

 I will update this page as I make progress…….. or erase the page if it is a fail 🙂

Upgraded base Nov 2023
Homing Switch Cam
Ready for Testing in Observatory
First Axis Built
Hobbing the worm gear
New RA gear with more precision and polish
Final assembly of testing base in workshop
Upgraded Base
Alt-Az Adjustment
RA Axis with upgraded stepper motor - more torque
New RA Drive design 3:1 gears and bearing pivot for spring loaded worm
Home made On-Step Controller
RA assembly on workbench
Complete worm made with single setup for precision
PEC Index (Hall Effect Sensor) and Worm Gear RA