Advanced CG5 (EQ5) Conversion - Complete! #EQ5 #mks #wemos #tmc2209


I bought this Adv CG5 from a user on CloudyNights.  Although the electronics were perfect, I wanted a pulley system and control through my phone/iPad, so I sold the entire Celestron electronics package and went down the path of an OnStep conversion.  First and foremost, thank you to everyone on this forum...especially Howard Sutton, the guru who wrote this unbelievable platform and shared it with the world.  I have to also thank Khalid Baheyeldin, Dave Schwartz, Drew and Pete Ingram who replied to many of my posts and with whose help I could not have completed the project.  Before I started, I had no idea what a Step Stick driver was, let alone, SPI, UART, bipolar stepper motars and much more.  I do hope to stay active and help where I can, along with continuing to ask questions as I do plan some future upgrades (hand controller, maybe faster slew speeds, auto guiding, PEC).

Last night was the final test, and the mount slewed and aligned to the correct position, just with a rough polar alignment.

My build:
CG5/EQ5 mount
OnStep 3.16
MKS Gen L v2.0 controller
TMC 2209 v3.0 drivers (32 Microstep config)
Nema 17 400 Step Motors 1.5 A, 0.42 Nm, 59 ozin
60T GT2 pulleys (6mm bore) on both axis (200mm belt on DEC, 180mm belt on RA)
16T GT2 pulleys (5mm bore) on both motors
WeMos D1 Mini (firmware 2.4.2) (This was the only module I had to solder)
24V 150W power supply (all-weather brick used for outdoor LED lighting)
24V cooling fan
Plastic junction box from Amazon
Various hardware, screws, bolts, hack saw, epoxy, files, drill bit, and so on (but nothing complex)

It took two months from start to finish, though it could have gone much faster.
The link below has more detailed pictures on how I mounted the motors, which was the most complex job (especially the RA motor).

The one thing I would suggest to help very newbie users (like myself), is on the choice of step stick drivers and configuration.  It was only at the very end that I discovered that the microstepping feature had to be set by jumpers and not by software.  It was not obvious to me until I did the first GoTo tests which were over-shooting significantly.  I will add this detail to my construction log and have Khalid update the file he uploaded.

Thank you all again!

Khalid Baheyeldin

Thanks for sharing.
Your conversion is in the showcase now.

Yes, we need a table somewhere on what specific x driver goes with y board, as it is not obvious.
In the meantime, users can either look at other conversions, or ask on the mailing list.