EQM35: Low-Cost Belt Mod

[JeromeW]

Thank you. I'm very pleased with how well my new axis works.

I am expecting my teflon washers in the next few days. I'm very interested about working your DEC mod. I'll let you know how it works out.

[Kilohertz]

Cool, looking forward to hearing about your results.

I can now comment on the mount performance as I modded it as I have had 3 great nights of imaging finally. Using GSS and guiding with PHD2, my average RMS errors are .35 - .6", which I a very happy with.

Cheers

[JeromeW]

I'm very impressed with your results, I'm lucky to get +/-2 with my rig. Now that I finally got my guiding to work properly I have to start fine-tuning with the settings.

I'm expecting my teflon washers to arrive tomorrow.

Although I'm very happy with the performance of my 3D printed DEC Axis, I would prefer to have it stock. I'm concerned that a few hours in a hot car may warp the PLA plastic parts. Temperatures in the high deserts of California in a car can easily hit 160°F. My wife and I often take my telescope to Twentynine Palms for viewing.

[Kilohertz]

Thanks Jerome,

It's been 4 months in the works getting this far and FINALLY getting some images captured and everything working 100%, certainly been a learning experience, I learned never to do it again. 🤪

In the last few nights the guiding has been very consistent with only a few minor self caused glitches. I had the laptop out at the rig one night while I was focusing and putting a new battery into my camera, just the tiniest bit of me touching the gear caused PHD2 to complain and temporarily lose the guide star, I found out it is VERY sensitive to outside disturbances, cables binding or anything else that impedes complete freedom of the mount. FYI.

Cheers

[JeromeW]

I'm uploading a revised DEC Motor Bracket. This modification allows me to have interior space for the mini-circuit board and the wiring. It allows a cleaner look.

DEC Motor Bracket V2.stl DEC Motor Bracket V2.AD_PRT

[geekman42]

Hello, I've enjoyed reading about your belt mod.

I believe my Eqm35 ra motor is acting up, and want to give the belt mod a try. Thinking of getting a Nema 14 off Amazon, so it should bolt up to the existing bracket. Only thing I can't quite figure out yet is how to match the wiring on the new motor to the existing harness. I haven't been able to locate a wiring diagram for the existing stepper. 

Thank you for your thoughts 

I'm in Kansas, US.

[jif001]

There are some photographs and diagrams on page 2 of this thread showing how JeromeW and I independently wired them up. They should help, but feel free to come back if not. You could start by simply replacing the existing motor (I’m pretty sure it’s just a NEMA 14) and checking that it works as it should, before going for the belt mod. 
 

if I remember correctly, the arrowed section on the attached diagram shows the original wiring to the RA motor (you may find your NEMA 14 comes with the colours shown in the top right-hand corner of the diagram, but not necessarily!) 

[geekman42]

Awesome! And thank you!