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Custom telescope mount using harmonic drives and ESP32

svendewaerhert.com

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Re: Custom telescope mount using harmonic drives and ESP32

#61

Post by jcims »

waerhert wrote: post #56
davidhyde wrote: post #17

Loved the write up, well done to the author. I get the same feeling building stuff with freecad and then printing it. Feels like there is no limit to what can be done. After going through the growing pains of designing stuff that was just poor and difficult to print I’m now confident enough to send it to be printed by jlcpcb or pcbway. And when they tell me to accept the risk of a failed print then I think, “I feel y…

Thanks, glad you enjoyed this. It's good to be in a place where you're confident things will turn out alright when you send your designs halfway across the world to be manufactured. I've so far only had positive experiences with JLCPCB, especially with issues that turn up during their review process. I forgot to add a fillet around the edge where the DEC axis sticks out of the tube and they sent me a quick message to…

I built a small two axis direct-drive mount (https://mjbots.com/ controllers are great) to track satellites and aircraft with an RF antenna. One of the things that stood out in the article for me was the yolo send to JLCPCB. It spoke volumes about your confidence in the CAD design, maybe one of these days I'll get there hahaha.

Great design and writeup btw, it looks as good if not better than most of the commercial designs out there. You might enjoy Bruce Van Deventer's vids on youtube: https://www.youtube.com/@djcheckonetwo/videos (direct drive mount with 26 bit renishaw ring encoder might whet your appetite a bit)

Re: Custom telescope mount using harmonic drives and ESP32

#62

Post by sfeng »

One tiny nit on this amazing project / write up. He mentions that the traces have to be extra wide to support 24V. In truth though, the higher voltage means lower current, which means if anything the traces can be less wide. The size of the traces is determined by the current they carry, the voltage determines how much space must be between the traces (but it’s unlikely to be an issue at these voltages).

Re: Custom telescope mount using harmonic drives and ESP32

#63

Post by jcims »

HorizonXP wrote: post #22

Amazing project and write up, very good timing too! I’ve been into amateur astronomy since I was 13, owning a few telescopes and spending many hours with family at star parties. This week I pulled out our big Meade 10” SCT and our small Meade 4” Newtonian to show my 7yo son the moon and Saturn from my parents Bortle 8 backyard. It was wonderful seeing his awe and surprise, and the fact that my parents were there to s…

>However, as much as I like the idea of GOTO, a big part of the fun is finding the objects.

I love reading this because it shows how different people are and how much room there is in the hobby for different interests. I am grateful for goto mounts specifically because finding the object is one of my least favorite parts of it. :D

Re: Custom telescope mount using harmonic drives and ESP32

#64

Post by waerhert »

jcims wrote: post #61
waerhert wrote: post #56

Earlier quoted context omitted.

Thanks, glad you enjoyed this. It's good to be in a place where you're confident things will turn out alright when you send your designs halfway across the world to be manufactured. I've so far only had positive experiences with JLCPCB, especially with issues that turn up during their review process. I forgot to add a fillet around the edge where the DEC axis sticks out of the tube and they sent me a quick message to…

I built a small two axis direct-drive mount ( https://mjbots.com/ controllers are great) to track satellites and aircraft with an RF antenna. One of the things that stood out in the article for me was the yolo send to JLCPCB. It spoke volumes about your confidence in the CAD design, maybe one of these days I'll get there hahaha. Great design and writeup btw, it looks as good if not better than most of the commercial…

Thanks for the compliment and links! Can you tell me more about the aircraft tracking? I've been toying with the idea of being able to select a nearby airplane on flightradar24 and instructing the mount to follow it as it comes into view. Not sure how I would even begin building that.

Re: Custom telescope mount using harmonic drives and ESP32

#65

Post by waerhert »

sfeng wrote: post #62

One tiny nit on this amazing project / write up. He mentions that the traces have to be extra wide to support 24V. In truth though, the higher voltage means lower current, which means if anything the traces can be less wide. The size of the traces is determined by the current they carry, the voltage determines how much space must be between the traces (but it’s unlikely to be an issue at these voltages).

Good catch and explanation!

Re: Custom telescope mount using harmonic drives and ESP32

#66

Post by davidhyde »

waerhert wrote: post #56
davidhyde wrote: post #17

Loved the write up, well done to the author. I get the same feeling building stuff with freecad and then printing it. Feels like there is no limit to what can be done. After going through the growing pains of designing stuff that was just poor and difficult to print I’m now confident enough to send it to be printed by jlcpcb or pcbway. And when they tell me to accept the risk of a failed print then I think, “I feel y…

Thanks, glad you enjoyed this. It's good to be in a place where you're confident things will turn out alright when you send your designs halfway across the world to be manufactured. I've so far only had positive experiences with JLCPCB, especially with issues that turn up during their review process. I forgot to add a fillet around the edge where the DEC axis sticks out of the tube and they sent me a quick message to…

I’ll look up that plugin, thanks!

Re: Custom telescope mount using harmonic drives and ESP32

#67

Post by sokoloff »

nancyminusone wrote: post #36
Aurornis wrote: post #29

Earlier quoted context omitted.

Honestly it’s useful enough that I’d pay the several hundred dollars per year if I had to. It’s that much better. The money spent would be well worth it (for me) for all the time saved over using FreeCAD. I’ve used multiple professional CAD packages and I’m just not interested in going back. People sneer and tell me I’m going to get burned some day, but meanwhile I’ve been using it to great effect for many years for…

Unfortunately, those who (used to) use Autodesk Eagle can't say the same, and they were willing to pay.

The irony (or at least difference) here is that KiCAD is way better than Eagle ever was (or whatever the Fusion name is now). FreeCAD isn’t better than onShape, F360, or SolidWorks (and not even close, IMO).

Re: Custom telescope mount using harmonic drives and ESP32

#68

Post by jcims »

waerhert wrote: post #64
jcims wrote: post #61

Earlier quoted context omitted.

I built a small two axis direct-drive mount ( https://mjbots.com/ controllers are great) to track satellites and aircraft with an RF antenna. One of the things that stood out in the article for me was the yolo send to JLCPCB. It spoke volumes about your confidence in the CAD design, maybe one of these days I'll get there hahaha. Great design and writeup btw, it looks as good if not better than most of the commercial…

Thanks for the compliment and links! Can you tell me more about the aircraft tracking? I've been toying with the idea of being able to select a nearby airplane on flightradar24 and instructing the mount to follow it as it comes into view. Not sure how I would even begin building that.

You could actually build a self-contained unit with a raspberry pi and a rtlsdr based receiver. They do a great job picking up ADSB directly from aircraft 100+ miles away.

You'd just need to write some glue code to take the ADSB streams from a given plane (could pick based on area or strongest signal or whatever) and convert that to alt/az from your reference frame to feed the motor controllers for tracking. Your mount would clearly be adequate for optical tracking so you'd want to add some smoothing and likely some kind of tracking corrections/trim but you'd be close right off the bat.

Re: Custom telescope mount using harmonic drives and ESP32

#69

Post by dylan604 »

waerhert wrote: post #59
dylan604 wrote: post #53

Earlier quoted context omitted.

Yeah, in astro, the quality of the lens shows in much more disappointing ways that regular photography. Any softness from the lens can be part of the art in regular photography, but in astro is a lesser image. Maybe I missed it, but where in Europe are you? Are the temps part of your softness issue? I'm in Texas, and during the summer when it's prime time for central part of the Milky Way the seeing is horrible from…

Yeah I didn't expect such a stark difference in image quality from the same lens when using it for day photography vs astrophotography. Just goes to show how incredible a proper astrograph is. I'm located in Belgium: high light pollution and very humid skies. The only targets worth bothering here are close to zenith. It's a fun rabbit hole to be in :)

At my home, it is so light polluted, I don't even bother with attempts at zenith objects. I joke about every hotel in town is a 5-star hotel because you can literally only see 5 stars at night. With a 4 hour drive, I can be in one of the darkest spots in the state. To get to the darkest, it would be at least 8 hours. Either way though, it's Texas, so the high temps play havoc on image quality.

Re: Custom telescope mount using harmonic drives and ESP32

#70

Post by missinglugnut »

nancyminusone wrote: post #23
Aurornis wrote: post #20

Earlier quoted context omitted.

I think it’s great that we have FreeCAD as an option and I’m excited to see it mature. That said, I recommend Autodesk Fusion free tier for anyone who just wants to get quality work done quickly. Some will refuse to use it on principle and that’s fine for them, but it really is quality software free for hobbyist use with trivial restrictions. EDIT: Getting downvoted, presumably for suggesting a non-OSS software to ge…

Those who have bought into "free" closed source software simply haven't been burned hot enough by it yet. It might take a while, but you'll learn your lesson one of these days.

I think I could be burned by Fusion, recreate everything in OnShape, get burned by OnShape, then redo everything on a 3rd software and still be better off.

FreeCAD is just that far behind.

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