Finished (sort of) autofocuser build

[that_guy]

After months of procrastinating and frustration trying to get the myfocuserpro2 MT working (minimal with temperature) I found instructions for a MUCH simpler and easier assembly. It took me a total of 15 minutes to assemble and test. Minimal soldering (which I am just... awful at anyways).

This is the link (http://www.scopefocus.info/arduino-focuser-2) to the build I followed.

The motor I used was the popular NEMA17PG27 which has very high torque and small enough steps to not require half steps or smaller. I quickly sketched up a 3D model of the bracket on tinkercad and printed it using the local library's printing service. Printing at ABS 65% fill (which is nigh indestructible) cost me around $25. If anyone wants a link to the bracket design for Esprit 100ED (it might work for other esprits I'm not sure), let me know and I'll post it. Zip ties seem to work ok for securing it for now. As long as it doesn't slip.

Here's a GIF (https://i.imgur.com/QqXDBVW.gifv) of it in action

[pmrid]

Hi Tony. That's a good idea. I don't imagine my local council offers such a service. Pity. But I'd like to follow up on this anyway. I'll PM you my email address if you would be kind enough to send me the design file for your project. I've had a look at TinkerCad and right now, haven't been able to see how you did it. But then I've never used CAD stuff before so I expect a bit of a learning curve.

Peter

[that_guy]

Hi Peter, it took me a few hours to get used to tinkercad but for simple shapes like the bracket, I used basic shapes and holes to sort of chisel the bracket. Using the integrated ruler to make sure they're all the correct measurement is also super useful. You know what they say, "measure twice print once" ;)

[Spartacus]

Hi Tony,

Chris and I built one of these based on Rob Jones MyMotorFocuser. We 3D printed a nice bracket and motor enclosure to fit to the Esprit 120 focus assembly. I designed the 3D stuff using FreeCAD which I found much easier to use than TinkerCAD. If you are interested I can PM the .stl files. I think that the focuser on the Esprit 100 is the same. I will post some photos although I think that you have seen it at Astrofest and Maleny attached to his Esprit and Astrophysics 1100 mount.
I have also recently finished an all in one enclosure that includes a 3 channel thermostatically controlled dew controller (again a Rob Brown arduino design), the motor focuser with temp calibration, 4 X 12V DC outputs, a powered USB hub with 3 inputs, and an Odroid running Ubuntu which uses KStars EKOS to automate everything. After some frustrations with the astrometry, it's now all working well using offline astrometric plate solving and a home made polar alignment camera that makes polar alignment a breeze (use the SharpCap polar tool. I use an ethernet connection to a wifi extender to my home network or to a laptop in the field.
Happy to share any DIY ideas.
Mike

[that_guy]

Hi Mike, been a while since astrofest aha, I wouldn't mind having a look at the stl file, the one I have is super basic that could definately use some improvements.

[Spartacus]

Hi Tony,

Yep we are hanging out for some nice dark skies. Transparency has been terrible recently in Brissy.
I think that I will have to pm you the files as the stl format does not appear to be accepted.
I will send some photos of how it fits. Use 40% density as this gives good structural strength without the weight. I use load spreading washers or a metal plate to attach to the focus body. 4 X machine allen head bolts are enough. We use a 9 pin serial connector in a home made cable in this particular one but in another I have used a 4 pin microphone connector as it is really secure and has a screw in collar.
All the best

Mike