[HN Gopher] OpenAstroTracker: 3D printed, open source star tracker
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OpenAstroTracker: 3D printed, open source star tracker
Author : trishmapow2
Score : 158 points
Date : 2021-04-25 07:21 UTC (15 hours ago)
(HTM) web link (openastrotech.com)
(TXT) w3m dump (openastrotech.com)
| krisoft wrote:
| If you have a black plastic object, why would you show it over a
| black background?
|
| It's very stylish but I just can't see it.
| app4soft wrote:
| Here is GitHub repo of OpenAstroTech project.[0]
|
| [0] https://github.com/OpenAstroTech
| krisoft wrote:
| Thank you!
|
| Found this video linked from the github page you linked:
| https://youtu.be/9MNLAIyqGoA
|
| Now that I can see it its clear that this is a very
| impressive mechanism!
| trishmapow2 wrote:
| And that was one year ago too! Now the much more powerful
| and precise NEMA steppers are supported, plus so much
| behind the scenes work on improving software / driver
| reliability. Amazing project and community.
| dylan604 wrote:
| Cause it's cool and hip. They wanted art/cinematic look,
| instead of product shots that would be useful.
|
| I felt the same way though. Some of the shots, they used a
| background simulating a blurred out star field which was a
| tremendous improvement over the solid black, but still very
| difficult to see. I did like the red highlight, but still that
| background.
| Scene_Cast2 wrote:
| I think your issue is with the lack of brightness and contrast,
| and not with black-on-black (which, I'd dare say, is not a bad
| choice - see macrophotography, and how they are always looking
| for the blackest background materials)
| TaylorAlexander wrote:
| Looks great! I have long wanted something like this.
| delgaudm wrote:
| Not nearly to the level of this project, but if you want to
| dabble with taking long exposures of the sky: Consider the simple
| "barn door tracker"[0][1][2] to try astrophotography. After all
| was said and done my sky was too polluted for anything
| worthwhile, but the simplicity of it still intrigues me, and may
| be an intermediate step before going all in on the OAT.
|
| [0] https://garyseronik.com/build-a-hinge-tracker-for-
| astrophoto...
|
| [1] https://www.astropix.com/bgda/sample2/sample2.html
|
| [2] https://sites.google.com/view/emvilza/proyectos/star-
| tracker...
| abraae wrote:
| Dangerous rabbit hole!
|
| Must. Not. Enter!
| acidburnNSA wrote:
| Seconded. I got some "great" (for me) shots using a simple barn
| door build of the 2017 eclipse and the neowise comet. Just
| needs 2 pieces of wood, a theaded rod, an esp8266, a stepper
| motor, a hinge, and some bolts
| Aachen wrote:
| The kit costs over 200 bucks. I've been very causally considering
| whether to get into astrophotography, so don't yet know anything
| about it but I'm curious: what makes this so expensive? A printed
| frame is cheap, and the other major component is a way for it to
| automatically move. Are the motors the expensive part then,
| because they have to be so precise?
| elteto wrote:
| If you find $200 expensive for a piece of astrophotography gear
| you are in for a shock when you research actual prices!
|
| For example, the EQ6R Pro mount is a very popular and decent
| goto mount and it will set you back $1600. You will struggle to
| find any decent mounts for less than $1000.
|
| $200 is EXTREMELY cheap.
| sink wrote:
| I think in general your point is correct.
|
| However, this is not a fair comparison. In astrophotography,
| a primary consideration for the price point of a mount is its
| instrument weight capacity. The EQ6-R has a weight capacity
| of 44 lbs. This astrotracker has a capacity of 5.5lbs. The
| difference is, well, massive.
|
| The EQ6-R also has other features, like a built-in polar
| scope and a periodic error correction. Mounts are also a lot
| like cars, in that some consumers purchase them for the level
| of support offered by the manufacturer, and perception of
| reliability.
|
| With that said, I know I'm burying the lead and focusing on
| the wrong subject. $200 is very reasonable to get something
| that will probably provide very good initial results, and get
| that astrophotography addiction started. And I'm really happy
| this exists, at this price point.
|
| I don't want to suggest the parent poster is really
| reinforcing this attitude, but in this hobby (and let me
| stress, it's a hobby), there is an occasional subtext that
| expensive gear is the only way to get great results. I don't
| think that's the case. You can spend as much as you want, of
| course, and money will let you do more things, but at the end
| of the day, we're just making sciencey art.
| elteto wrote:
| I 100% agree with your points. A more apt comparison could
| have been against the SkyGuider Pro (or the SkyTracker),
| which is $400 for double the payload capacity. So, in a
| sense, this mount is priced very well.
|
| My original point was more along the lines of "if you think
| $200 for a mount is expensive in astrophotography then you
| will be very disappointed when you start learning about the
| hobby". I see this high ($$$) barrier of entry as a very
| real impediment to getting started in the hobby. But like
| you said, you don't need to go all in when starting, a
| decent DSLR and a tracking mount will provide countless
| hours of fun (and frustration!).
| jcims wrote:
| I'm DIYing one for radio astronomy, mostly as a learning
| exercise, and have about $400 in it. I wanted to try direct
| drive, which requires larger motors and controllers, and the
| costs just add up unless your entire goal is to keep it under
| some amount (at which point you spend more time engineering
| cost out of it than features into it).
| noir_lord wrote:
| A couple of hundred bucks seems pretty reasonable.
|
| You have to source all the parts, make sure they work together
| properly and assemble the kit.
|
| I mean $200 isn't a lot of money for something you'd
| potentially get years and years of use out off.
| Aachen wrote:
| Sure, but my question is _why_ it carries this price tag, not
| whether I 'll get years of use out of it.
|
| So if I understand your comment correctly, it's the R&D
| (making sure all parts work together correctly) that decides
| the majority of the price here, not one of the actual
| components?
| yreg wrote:
| It seems like there is a lot of human work as well (print
| the parts, pack it, ship it, customer support...).
|
| I wouldn't do this for random internet people for less.
| amelius wrote:
| The entire thing is on GitHub, so if you think you can
| build it for less then go ahead!
| dylan604 wrote:
| Why are you arguing this? Are you really arguing the price
| of the unit because it's made from $2 worth of plastic, so
| why the mark up? Why does a car cost so much when there's
| clearly not $30k worth of parts in it. Why does a house
| cost $500k when there's only $70k of material. Trolls have
| to eat too I guess.
|
| From your continued asking of the "why" question, it makes
| me wonder if you've ever tried to build a DIY anything
| yourself. Developing something like this involves a lot of
| the designer's literal blood, sweat, and tears. There are
| all sorts of levels of DIY from using 2x4s to machine
| precision accuracy. I will say, that precision is what
| astro is all about though. A seemingly innocent +/-1 degree
| accuracy will be okay-ish for something like wide-angle
| DSLR type shots, but once you start using longer lenses,
| you will be wasting your time.
| sink wrote:
| I don't think this person is trying to argue this.
| They're asking a sincere question about a non-intuitive
| aspect of open source company business models, and they
| just keep getting answers that indirectly answer their
| questions in a veil of condescension and sarcasm.
|
| This person is trying to have a discussion, you're trying
| to have an argument.
|
| > Developing something like this involves a lot of the
| designer's literal blood, sweat, and tears
|
| I retain a lot of water so I can see the sweat part. But
| I think blood and tears are an OSHA concern.
| dylan604 wrote:
| If you've ever built a PC from 90s era cases, you'll know
| it is quite easy to get a slight scratch/cut from some
| edge in that case. If you've ever done enough electrical
| wiring, you'll have felt the tickle at some point. If
| you've ever worked with near a stove or anything hot,
| you'll have touched something you shouldn't have at some
| point. There are a lot of oops that happen that are not
| life threatening OSHA violations.
|
| If you've never shed a tear over something so close but
| ultimately not working, then you must be a robot or
| souless. It's human nature. You could just as easily add
| and/or swap tears for curses. Personally, I lean toward
| the cursing as it's more satisfying.
|
| Also: argue: intransitive verb: To put forth reasons for
| or against; debate.
|
| The fact that this word immediately sets forth a hostile
| emotion for you does not mean I am being hostile.
| sink wrote:
| re Argument definition: I don't think this person is
| trying to debate you. That's sort of the core of my
| point. You're giving a really forceful reaction to
| someone I perceive to be asking clarifying questions.
| But, since you are perceiving their messages with a
| different tone, and I'm perceiving your messages with a
| different tone, and we're never going to find any ground
| truth, who's to say who is correct?
|
| And if people regularly bleed and cry at my workplace
| then I think it's reasonable to call that a toxic
| environment.
|
| Since definitions of terms and semantics are now a part
| of this Internet conversation, I think we're done here.
| You can reply once more and have the last word, if you
| like. :)
| trishmapow2 wrote:
| I personally DIYed mine and it took a lot of tinkering to get a
| reliable setup. The kit is very well polished and uses the new
| NEMA steppers. As for pricing, I think it includes 20% VAT,
| which I assume is removed if you are not in the EU. I
| personally have spoken to the creator and they have tried very
| hard to make it as low cost as possible.
|
| If you have a 3D printer and live in a country with decent
| hardware suppliers (not the case for me in Australia), then
| sure go ahead, DIY and save money. But for people who want an
| almost ready to go solution it's very well priced, considering
| commercial alternatives are well into 500+ for the feature set
| that this mount offers (GoTo, optional guiding down to 1"
| accuracy).
| Aachen wrote:
| So if I understand you correctly, it's the R&D that makes up
| the majority of the price, not the components?
|
| Not saying that's bad, just that my question is what makes
| this cost what it does. If it weren't justified, there'd be
| competitors doing it way cheaper (the field is accessible and
| large enough for that), so it's just a question out of
| curiosity.
| polack wrote:
| Have you seen how many parts there are? It would probably
| take most people with a normal day job a week to print all
| parts in the evenings and weekend. And that's if they do
| have a printer.
|
| Add another 20 parts that you need to order from different
| place, make sure they meet the specifications, pay for
| shipping for a lot of different packages and that many
| things must be bought in bulk and not single pieces.
|
| USD 200 is a bargain for this kit. Sure, you might be able
| to save a couple of dollars if you do the work yourself.
| But is that worth many hours of work, and the risk of
| ordering wrong stuff?
| trishmapow2 wrote:
| Not quite - if they priced in all of the dev effort
| required to make the mount software compatible (ASCOM, etc)
| it would be much higher I think. From what I see, ensuring
| the 3D printed parts are up to spec and look good
| cosmetically requires a lot of time, not to mention
| manually wiring and flashing all the electronics.
| dylan604 wrote:
| Of course the R&D makes upt the majority of the price. When
| is that ever not the case? The version that is available
| now is not the only version that was made. This is
| something that has been thought about, made, revised, made
| again, etc. Things like this often go through multiple
| iterations. Hell, there will probably be a OpenAstroTracker
| 2.0 in a year.
| Aachen wrote:
| > Of course the R&D makes upt the majority of the price.
| When is that ever not the case?
|
| Like, pretty much every other product that wasn't an
| entirely new concept in the last few years? Looking
| around me, I think the thing with the highest R&D price
| component is probably the chips in computers (desktop,
| laptop, smartphones), everything else is just mass
| production and low markup with hardly any research
| recuperation in the price (keyboard, lamp, paper, desk,
| floor, beanbag, fridge, IR thermometer, picture frames, a
| spoon, a computer display...). Unless you meant "when is
| that not the case for astro trackers", I don't get what
| you meant because it's rather exceptional to still be
| paying off R&D if you're buying regular mass-produced
| consumer products.
|
| > This is something that has been thought about,
|
| Obviously, but if it's open source (with a free,
| commercial-use license and no big call for donations
| other than a coffee) then apparently recuperation that
| design time is not a goal, they're actively giving it
| away for free and encouraging people to make it
| themselves. That suggested to me that the price must be
| for an expensive component or two. Or perhaps the
| printing time, but since it's mostly unattended and
| filament is cheap, I didn't expect it to be that. And the
| tracking calculations have been long done by people
| decades ago, so it's just buying parts and putting them
| together, where the "putting together" part is done by
| the customer since it's a kit. So yeah I expected the
| price to be mostly an expensive precise motor or
| something.
| oivey wrote:
| Just do it all yourself then? It doesn't seem
| unreasonable that the creators of this want to make a
| little money off of something that almost certainly took
| a lot of their time. If the markup is too high you're
| welcome to assemble your own.
|
| R&D cost is built in to everything you buy, otherwise the
| companies that make this stuff wouldn't be profitable.
| The amount of per unit R&D markup for, say, a thermometer
| just isn't as high due to its relatively low complexity
| and huge number of units sold. This thing is niche and
| not going to sell that many units.
| dylan604 wrote:
| Great, Apple's new M1 based systems now exist on the
| market. Go make one for me for less than what Apple sells
| theirs. Should be easy according you since someone else
| is already doing it.
|
| R&D is everything in making of something. Just because
| someone else made it doesn't mean you get to start
| exactly where they left off (except in cases of open
| source where you get their literal plans). Even in wood
| working or any shop type of work, you often spend more
| time setting up things like jigs or other custom tooling
| than it takes to do the actual work. Is that supposed to
| be a sunk cost to the builder? No, it is part of how the
| builder arrives at the price of the final thing being
| built.
| sink wrote:
| I'm not sure why you're so hostile to the GP.
|
| Their questions are sincere. Your comparison to the M1 is
| not appropriate, and you're not actually paying attention
| to what they wrote.
|
| They wrote that they are surprised that R&D makes up the
| majority of the cost, since this is an open source
| project. This is a fairly non-obvious feature of open
| source company business models. They give away the
| product, and its designs, for free, and solicit community
| collaboration. But it's usually complex or cumbersome to
| operationalize or build, so they then sell a set of
| services or pre-builds around it. Datastax and Confluent
| are two examples of this in the OSS domain.
|
| Woodworkers don't market their plans as open source, put
| them on Github, and accept pull requests.
|
| Don't create arrogant, sarcastic responses to sincere
| questions. It devalues this forum, and it's a bad look.
| dylan604 wrote:
| >They wrote that they are surprised that R&D makes up the
| majority of the cost,
|
| I am as equally as surprised by their surprise about how
| much R&D is involved in making a "simple" lamp. Someone
| had to draw the plans so that the metal/plastic could be
| formed/shaped into the lamp. The parts had to be
| researched on what could suffice and be safe. Some person
| didn't just go "i want to make a lamp" and a lamp was
| created (unless they had Aladdin's lamp first). Research
| can be as simple as internet searching on parts, but that
| is still research even if people with PhDs and white lab
| coats were not involved. The design is still necessary in
| getting the lamp to a shape that is aesthetically
| pleasing enough for someone to want to buy it.
|
| >Woodworkers don't market their plans as open source, put
| them on Github, and accept pull requests.
|
| That's not true in the spirit to the point you are
| making. There are plenty of websites where wood workers
| offer their plans/drawings/instructions, and then allow
| comments where people that followed their plans made
| modifications. So yes, they don't necessarily use Git and
| PRs, but the concept is there nonetheless. Same with
| cooking/baking/etc.
|
| > I'm not sure why you're so hostile to the GP. >Don't
| create arrogant, sarcastic responses to sincere
| questions. It devalues this forum, and it's a bad look.
|
| You're reading into the comment an emotion that did not
| exist when the message was sent. If you read hostility,
| then that's no what I was trying to infer.
| sink wrote:
| > I am as equally as surprised by their surprise about
| how much R&D is involved in making a "simple" lamp.
|
| I think your surprise is justified, especially since
| you've been in this world for a while. But I think there
| is an apparent (but not real) contradiction between
| offering designs for free so people can go and build
| something themselves, and then charging money for R&D.
| This is what is meant by the term trade secret.
|
| re: Woodworkers and co -- sometimes. Room & Board doesn't
| share their designs. Tartine Manufactory probably has a
| cookbook.
|
| > You're reading into the comment an emotion that did not
| exist when the message was sent. If you read hostility,
| then that's no what I was trying to infer.
|
| I'm genuinely really happy that this is not the intent.
| Challenging phrases and Socratic questioning can really
| come off as hostile.
| dylan604 wrote:
| >Challenging phrases and Socratic questioning can really
| come off as hostile.
|
| I think this is an entire new thread that could be
| expanded upon. This is how I was taught. Never given the
| answer directly, but by being asked another question
| designed to create further thought on how to answer the
| orginal question. If being offered a way for more
| critical thinking is considered hostile, then I weep for
| future generations.
| sink wrote:
| I'll add one more thing to my sibling comment. This
| person is clearly unaware of whether there is ongoing R&D
| in the realm of hobby astrophotography mounts. They
| mentioned they're just considering getting into it.
| They're talking about mass manufactured goods. They were
| not aware that this is a field of active innovation.
|
| We could have given someone a warm welcome to the hobby
| by clarifying that politely.
|
| I know when I was getting started, I didn't know what
| made some things more expensive than others. I didn't
| know about doublet or triplet refractors, Strehl ratios,
| Chroma vs ZWO filters, why a MACH2 is such a grail mount
| over a Optron CEM120. Luckily I had nice, friendly,
| helpful people to talk to, instead of a wall of
| arrogance.
| dylan604 wrote:
| >We could have given someone a warm welcome to the hobby
| by clarifying that politely.
|
| If this was Cloudy Skies or some similar site dedicated
| to the hobby subject matter, then sure, let's hold
| someone's hand while they decide to make expensive
| decisions.
|
| HN is not that. It is, as the name applies, a place where
| tinkerers in any hobby gather. As someone that
| hacks/tinkers/plays/circumvents/etc, it is clear that
| research is step 1, 2 & 3.
| spacemark wrote:
| There are other options in this class, such as the Nyx Tracker
| at $125.
| gattr wrote:
| A few fellow astrophotographers have built and used them
| successfully (forum link in Polish):
|
| https://astropolis.pl/topic/71039-monta%C5%BC-wirus-2020/
| withinboredom wrote:
| To whomever authored the title: it should read "open source;
| built with 3D printed parts"
|
| I'm always on the lookout for neat things to 3D print. The
| current title is deceiving in that you cannot fully 3D print the
| whole thing. It looks cool though!
| trishmapow2 wrote:
| Hmm while I see your point, I was going for conciseness and I
| think it's reasonable to assume that extra parts are required -
| we can't quite print stepper motors at home yet! The rest of
| the basic requirements is nuts/bolts (standard kit stuff), and
| a $5 microcontroller[1]. (Things like the aluminium base can
| also be 3D printed, but it's not recommended for stability.
| There are lots of _optional_ components that greatly improve
| usage.)
|
| [1]:
| https://wiki.openastrotech.com/OpenAstroTracker/ShoppingList
| washadjeffmad wrote:
| I think GP's point isn't off the mark here, but also that the
| title doesn't need to be altered. There's no need for any
| additional electronics to construct a Dobsonian and mount
| capable of manually tracking DSOs, for instance.
|
| I say this as someone who uses "computerized" and EQ mounts,
| but I also assumed from the title that this was a completely
| 3D printable project (sans mirrors, I can print my own
| washers and bolts), which is way more exciting a prospect
| than having to buy or put together a fairly complex kit, just
| not all of it if you have a 3D printer.
|
| I just 3D printed a custom IR CCD mount for my CST, but I'm
| very interested in adapting this to some of my designs, so
| thank you for sharing!
| trishmapow2 wrote:
| Oh sure, but in my defence a simple Dob eq platform hardly
| requires any software, so 'open source' would be a strange
| thing to point out ;) A lot of the hard work is the custom
| PC software & getting it ASCOM compatible for autoguiding,
| etc.
| dylan604 wrote:
| You can open source a file for use in 3D priting. Lots of
| work goes into creating those files, so releasing it as
| open source is a concious decision the maker made.
| tpmx wrote:
| https://wiki.openastrotech.com/en/OpenAstroTracker seems like a
| better starting point. The main web site is frustratingly vague.
|
| This wiki start page actually manages to explain what the thing
| does:
|
| _OpenAstroTracker is an equatorial mount which "compensates for
| Earth's rotation by having one rotational axis parallel to the
| Earth's axis of rotation". You can mount a camera (mostly a DLSR
| or DSLM) on top of it and it rotates with the same speed as our
| earth rotation in order to remove stars movement relatively to
| the camera and allow longer exposures this way. The mount is
| being controlled by an Arduino. The Arduino is controlling
| multiple stepper motors which in turn rotate the camera mount._
|
| _The mount provides multiple options for control: LCD Keypad,
| USB Serial connection, WiFi. Latter two enable remote control
| with special astrophotography software based either on the LX200
| protocol, ASCOM or INDI platforms._
| Tepix wrote:
| This is pretty cool. Can the parts also be made with a laser
| cutter?
|
| The astrotracker appears to be a bit bigger than what i'm looking
| for: A DIY alternative to the Omegon Mini Track LX2/LX3.
| Aachen wrote:
| I see that device is mechanical, didn't know that existed,
| that's quite cool! Is there an advantage to it not requiring
| electricity, though, or is it just the cool factor?
| Tepix wrote:
| One less battery to worry about i guess.
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(page generated 2021-04-25 23:02 UTC)