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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

INDI focuser driver for Waveshare Stepper Motor HAT for Raspberry Pi / Rock Pi

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That is supercool! 
I had tried a similar design initially, but there was too much torque,  I could not make it work.  I used a different design instead, but it's more bulky. 

 

Yours is much more elegant.
Can you post the instructions and the STL files for building it?

Jo
 
Last edit: 2 years 11 months ago by Jose Corazon.
2 years 11 months ago #69450
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This is the motor I used. It is a minor miracle it actually has enough torque. But it manages with the very high gear reduction. It can get hot if it is run too much. And there was a one time issue when I left power to the HAT on while the Pi was shutdown. Thus my eNABL pin pull-up resistor bodge to prevent another meltdown.
www.aliexpress.com/item/32848283821.html...1.0.0.301c4c4dVCiy0M
The following user(s) said Thank You: Jose Corazon
2 years 11 months ago #69452

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Thanks for the link.  It looks like I was on the right track with this eBay listing I found ;)

ebay.us/mzsqFl
Last edit: 2 years 11 months ago by Eric Brown.
2 years 11 months ago #69453

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Thanks, Andrew!  

I was actually wondering whether you would be willing to share your 3D files for the worm gear.  Designing a worm gear in Blender is complex and time consuming, having the final STL file would go a long way.
I don't think I will replace the focuser I already have on my WhiteCat, it is working perfectly, just as well as yours is, but I would like to adopt this to some manual Nikkor lenses that I also use for wide-field imaging.  Torque does not have to be so high for those, they move more easily.  The ring around the lens will have a different diameter, though, but I can scale the worm gear accordingly in Slic3r.

Thanks for considering,

Jo
2 years 11 months ago #69466

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I haven't looked yet, but I bet there are decent gear/worm gear generators available for OpenSCAD that could be imported into your Blender project.  I've done that for regular gears in other projects.
2 years 11 months ago #69467

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Simple worm gears, yes. Globoid worm gears with variable gear ratios are a different story. But perhaps I am too much of a perfectionist here.
Thanks anyway.
Jo
2 years 11 months ago #69468

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Now you've got me curious.  I have no idea what those are and assumed a simple worm gear would work in this case.  It sounds like I've got some reading to do.
2 years 11 months ago #69469

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This is a globoid worm gear with a 1:120 ratio.

www.stlfinder.com/model/another-worm-gea...-1-pWx6wsw1/1842347/

I suspect that may even be the one Andrew used. I have used it before as well with a similar design as the one Andrew posted, but as I wrote, I had difficulties taming the torque.
I have not found a gear generator yet that allows me to adjust the dimensions for different diameters and different gear ratios so I gave up on that approach and moved to my simpler, but less elegant solution. Which works perfectly, really, but is not nearly as compact as Andrew's.
2 years 11 months ago #69470

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Wow... those are really cool.  I'm with you.  Nothing less will do now that I know/understand what they are.  I did find this on thingiverse, though I have no idea how good / applicable it is here:

www.thingiverse.com/thing:2776688
2 years 11 months ago #69471

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My worm and ring gear are in fact Globoids generated with OpenSCAD. I am hesitant to share the original STL files at this time as everybody I have shown this to has encouraged me to market it. But I do encourage others to take inspiration from it. I'm honestly surprised I have not seen anyone else use this mechanism yet.
I used the following script to generate a custom set that I added features to in other 3D modeling software. www.thingiverse.com/thing:2776688
*But this is an updated version if the script that may be better.
www.thingiverse.com/thing:4197625
You will want to unhide the Customizer under the View Menu. And I had to scale down the gears it created to the right diameter.
2 years 11 months ago #69474

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My latest creation, a NEMA17 short body stepper motor-driven autofocuser for my Explore Scientific 102. 
I prefer gears over belts, 
This design is easy to print and can be attached without any modifications to the telescope. 
The large gear fits directly on the fine focus knob and is held in place by three screws that lightly clamp it to the knob.  Rocksolid. 
 
   
Last edit: 2 years 11 months ago by Jose Corazon.
2 years 11 months ago #69611
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I have the wave share PI hat running on astroberry.  I followed all the instructions for installing it.  I see the xml file indi wmh in the usr/share/indi directory.  I can not get it to show up when I edit the ekos profile for indi devices.  Any ideas??
Second, why isn't this distributed as paart of the indi library?

Thanks Bruce
2 years 10 months ago #71169

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