Showcase: Built With OnStep


Khalid Baheyeldin
 

Great work Kenric.

Added to the showcase page on the wiki.


bryan_ramsey_pterodyne
 

Here is my harmonic drive onsteo mount slewing  video with an AT10RC in tow and camera/filter wheel and no counterweights.

https://youtu.be/AEWINQ5Pta0

The real test is under the stars, but CLOUDS.

Build thread:
https://groups.io/g/onstep/topic/new_build_harmonic_drive/16745737


JoAnn
 

Here is my harmonic drive onsteo mount slewing  video with an AT10RC in tow and camera/filter wheel and no counterweights.

https://youtu.be/AEWINQ5Pta0

The real test is under the stars, but CLOUDS.

Build thread:
https://groups.io/g/onstep/topic/new_build_harmonic_drive/16745737

Nice work! Can't wait to see some astrophotography!! 


Matthewabey@...
 

Looks cool let us know how the harmonic drives work out. Im interested for a future build.


Chris Vaughan
 

That's one beautiful mount 


Gintautas Drazdauskas
 

Finally I had time to do some tests with my mount and Onstep. By the way at that time I have built SHC as well.
Excellent team's job again. Thanks Howard and everybody who have had hands on.
There are very first graphs of periodic errors. The gear ratio was not adjusted so that is why the raw graph goes up.
It is very first my GEM mount so may be I have to much expectations.I thought that PEC should do it's job better.
I have had used for this test Guide rate 0.5. Should I better use 1 for it?
And regarding PEC buffer. My worm period is 241 s. Is there any reason to set the PEC buffer more than 241 s?
If it is set let's say 482 s, would it calculate errors for a two periods? But "Record" works only for a one period.

PEC OFF



PEC_ON



PEC_ON_GUIDE_ON


tomofreno2000
 


Khalid Baheyeldin
 

Tom,

That is impressive! With that aperture, inspecting the craters on the dark side of the moon is a breeze ...

I added a link in the Showcase page on the Wiki.

The pictures show that you have steppers with gear heads for reduction. Which ones are these, and how is the backlash and precision overall?


Gilles Gagnon
 

Well, thanks to this group, I am in the process of converting my Astro-Physics AP400 mount with goto capabilities. I thought it was not possible at first but decided to take the plunge after I took the mount apart to re-grease it and found that I could probably be able to replace the original motors (48 steps, 150:1 reduction) with NEMA14 200 steps motors without too much problems.

My setup is using the MiniPCB board with the following configuration: 200 steps/rotation (OMC StepperOnline 14HS20-1504S), 32 microsteps (TMC2130), GR1 = 2.5, GR2 = 192 and MaxRate = 96. Things seem to be working fine but the real test will be under the stars. I will be controlling the mount using either SkySafari from my android tablet, or kstars and Ekos (indilib) environment with which I have a few minor problems that I hope to sort out soon (longitude and UTC error, I'm at 75W; I thought this issue was solved but maybe I should get the latest of everything).

Here are a few photos of the modifications. The prototype motor mounts were 3D printed with ABS. The final mounts will be machined using 6160 aluminium by a friend.

I could provide the motor mounts drawing to people interesting in converting their old AP400 to goto capable AP400.

Thanks to all for their effort in this great project.



AP400_OnStep.jpgAP400_OnStep_MotorMount2.jpgAP400_OnStep_MotorMount.jpg


Khalid Baheyeldin
 

Added to the showcase page on the Wiki.


Roman Hujer
 

Hi all I created an alternative box for OnStep SHC and added additional accessories for on tripod holder. Details are here: https://www.thingiverse.com/thing:3212339

Other modifications are: Two new PCBs: one for classical resistors and a second for RJ12 (RJ45) input port for easy replacement of the cable. PCBs are here: https://easyeda.com/hujer.roman/HC-20e242d665db4c85bb565a0cd0b52233

Teensy 3,2 is now in socket.

Roman


Howard Dutton
 

A nice improvement to the SHC design.


Khalid Baheyeldin
 

Roman,

Just added a link to this message on the Wiki Showcase page.


tomofreno2000
 

Sorry Khalid, I didn't see your question until just browsing around now.  Motors are from stepperonline, with "precision" planetary gearboxes.  Backlash is spec'ed as <=25 arcmin. I am using the 30:1 on the Alt drive and 50:1 on the Az. Overall reduction for both axes is about 850:1. The backlash is obvious at 100x. Still haven't done further work on the scope to test backlash compensation due to projects around home. Stuff keeps coming up - spent the last few days replacing the back of the chicken coop where a bear ripped it off, and repairing damage to the pen.

https://www.omc-stepperonline.com/precision-planetary-gearbox


Roman Hujer
 

I am create 3D printed - Small Travel EQ telescope mount on base OnStep https://www.thingiverse.com/thing:3327081

Happy New Year 2019

Roman


Dave Schwartz
 

Oh, my... and here I am with a new 3D printer... I might be forced to make this.

On 2019-01-01 3:02 p.m., Roman Hujer wrote:

I am create 3D printed - Small Travel EQ telescope mount on base OnStep https://www.thingiverse.com/thing:3327081

Happy New Year 2019

Roman


Butchf
 

Very cool:)


Khalid Baheyeldin
 

Very nice!

I added it to the Showcase.


Butchf
 

Very cool, I was thinking harmonic drives would be the way to go.  High ratios and zero backlash.... do you have a clutch on the ra to handle balancing the counter weights?  


Gilles Gagnon
 

Here is a photograph of my OnStep Smart Hand Controller. Built on a prototyping PCB similar to a breadboard strip and installed in a Hammond handheld enclosure. Fits nicely in my hand. The only 'problem' is the small 0.95'' display which is hard on my eyesight. Will try to get the 1.3'' one or better, a 2.4'' (SSD1309) OLED display that is unfortunately unsupported for now.