OnStep for EQ5 (SkyWatcher) Mount

Last crawled date: 5 years, 4 months ago

Adapting EQ5 (SkyWatcher) telescope mount or similar types to OnStep goto controller, by Howard Dutton project.
Accessories recommended
OnStep Controller and Box on base STM32 Blue Pill

OnStep SHC Smart Hand Controller

Alternative OnStep Mini 2.0 Cotroller and Box on base MiniPCB2 and Teensy3.2
BOM
2x JK42HM40-1684 NEMA17 0.9 Degree Stepper Motor 1.68A
2x GT2 Timing Belt 6mm wide 2mm pitch 136mm-2GT 68 teeth
2x GT2 Timing Pulley with 16 Teeth and Bore 5mm for 6mm belt
2x GT2 Timing Pulley with 40 Teeth and Bore 6mm for 6mm belt (Optional)
1x M8x10mm Inbus screw
1x M8x40mm Inbus screw
2x M8 nuts
9x M3x10mm Inbus screw
1x M3 Assortmen
2x M3 worm
2x M3 nuts
2x M4x20mm Hex Head Screws
2x M4 wing nuts
2x M4 Assortmen
18x 2x6mm self-tapping screws
2x RA and DEC PCB
2x RJ14 6P4C Right Angle PCB Jacks
2x JST B4B-XH-A socket
1x 3mm Red LED
1x 3.5mm Stereo jack and cable
OnStep Config for TMC2130 drivers

// Axis1 is for RA/Az

// calculated as : stepper_steps * micro_steps * gear_reduction1 * gear_reduction2/360
// EQ5 : 400 * 64 * 2.5 * 144/360 = 25600.0
#define StepsPerDegreeAxis1 25600.0

#define AXIS1_DRIVER_MODEL TMC2130_QUIET_LOWPWR
#define AXIS1_MICROSTEPS 64
#define AXIS1_MICROSTEPS_GOTO 64

// Axis2 is for Dec/Alt
// calculated as : stepper_steps * micro_steps * gear_reduction1 * gear_reduction2/360
// EQ5 : 400 * 64 * 2.5 * 144/360 = 25600.0
#define StepsPerDegreeAxis2 25600.0

#define AXIS2_DRIVER_MODEL TMC2130_QUIET_LOWPWR
#define AXIS2_MICROSTEPS 64
#define AXIS2_MICROSTEPS_GOTO 64

// PEC, number of steps for a complete worm rotation (in RA),
// (StepsPerDegreeAxis1*360)/gear_reduction2.
// EQ5 : 25600.0 * 360/144 = 640000
#define StepsPerWormRotationAxis1 64000L

#define MaxRate 24
#define STEP_WAVE_FORM PULSE

NOTE
FreeCAD sources on Github
Another recommended link:
3D printed - Small Travel EQ telescope mount
OnStep for SEBEN EQ3 mount
My all desing for Astronomy telescope