- Sunscan, by the STAROS team : a fully integrated open-source solar imaging kit : https://www.sunscan.net/fr
- Eric Royer's binocular 24" dobson : http://www.astrosurf.com/topic/124758-bino600/
- The Slim400 by Laurent Bourrasseau : https://www.cloudynights.com/forums/topic/920950-the-slim400/
- Astrowl, an electronically enhanced astronomy kit : http://www.astrosurf.com/topic/151807-projet-astrowl-de-visuel-assist%C3%A9/
- The smallest, an open-source 6" portable dobson : http://www.astrosurf.com/topic/176898-un-dobson-150-f5-facile-%C3%A0-imprimer-et-assez-compact/
- A dedicated astrophotography power supply : https://github.com/Antiath/Open-Power-Box-XXL
- Sunscan, by the STAROS team : a fully integrated open-source solar imaging kit : https://www.sunscan.net/fr
- Eric Royer's binocular 24" dobson : http://www.astrosurf.com/topic/124758-bino600/
- The Slim400 by Laurent Bourrasseau : https://www.cloudynights.com/forums/topic/920950-the-slim400...
- Astrowl, an electronically enhanced astronomy kit : http://www.astrosurf.com/topic/151807-projet-astrowl-de-visu...
- The smallest, an open-source 6" portable dobson : http://www.astrosurf.com/topic/176898-un-dobson-150-f5-facil...
- A dedicated astrophotography power supply : https://github.com/Antiath/Open-Power-Box-XXL
I'll share them with a friend who loves astronomy and who loves to organize star-gazing events that he livens up with his Unistellar telescope.
https://stellafane.org/stellafane-main/tm/index.html
How to make a telescope, by Jean Texerau, which was the absolute bible of this field : https://rexresearch1.com/AstronomyTelescopesLibrary/HowMakeT...
Here is a talk (in french, but maybe the auto-subtitling would work?) I recorded that overviews the whole process (2h30 though, and lacks info on the Bath) : https://www.youtube.com/watch?v=Wt7lBLS0ueg
Here is Gordon Waite's youtube channel which actually shows a lot of the moves : https://www.youtube.com/@GordonWaite/videos
Best resource on the Bath (french, but should translate well) : https://gap47.astrosurf.com/index.php/technique/optique-inst...
One question I always think about is how much time and effort a "one-time" mirror maker should plan on making to exceed the quality of a generic 8" or 10" F/5-F/7 available from the Chinese mirror makers.
Zambuto seems to imply that whatever magic happens for his mirrors might be in very long, machine driven polishing to smooth out the final surface imperfections that cause scatter. With his retirement and with few mirror makers in the US, it seems like options for buying "high end" mirrors in the 6"- 10" size are very limited. I have been debating an 8" F/7 and would love to just purchase a relatively high quality mirror, but most of the mirror makers seem more taken with significantly larger mirrors.
Edit : it seems that I now do have one : https://lucassifoni.info/blog/tag/astronomy/rss.xml I just tried it, the links don't seem to be working. I get sent to https://lucassifoni.info/miniscope-tiny-telescope.mdx for example
Too rarely in life are things made better than practical consideration would dictate, just because of dedication to the craft.
I build microscopes instead of telescopes (as a hobby). I can't tell you how many times I've taken a mostly working system and stripped it down to make some important change that affects most of the design to get only a tiny incremental improvement. Sometimes that improvement makes all the difference (for example, being smart when 3d printing a piece that carries something heavy so it doesn't deflect) and sometimes it's just an itch I need to scratch. Eventually, I learned to make two: a microscope that gets built and used, and then a microscope that is a prototype. Then I'm not tempted to take the daily driver and pull the engine.
Although my day job is running compute infra, I have a background in biophysics and I figured I could probably do something similar to Joe Derisi, but lacked the knowledge, time, and money to do this either in the lab, or at home. So the project was mostly on the backburner. I got lucky and joined a team at Google a decade ago that did Maker stuff. At some point we set up a CNC machine to automate some wood cutting projects and I realized that the machine could be adapted to be a microscope that can scan large areas (much larger than the field of view of the objective). I took a Shapeoko and replaced the cutting tool with a microscope head (using cheap objectives, cheap lens tube, and cheap camera) and demonstrated it and got some good images and lots of technical feedback.
As I now had more time, money, and knowledge (thanks, Google!) I thought about what I could do to make scientific grade microscopes using 3d printer parts, 3d printing and inexpensive components. There are a lot of challenges, and so I've spent the past decade slowly designing and building my scope, and using it to do "interesting" things.
At the current point, what I have is: an aluminum frame structure using inexpensive extrusion, some 3d printed junction pieces, some JLCPCB-machined aluminum parts for the 2D XY stage, inexpensive off-the-shelf lenses and industrial vision camera, along with a few more adapter pieces, and an LED illuminator. It's about $1000 material, plus far more time in terms of assembly and learning process.
What I can do: the scope easily handles scanning large fields of view (50mm x 50mm) at 10X magnification and assembles the scans into coherent fullsize images (often 100,000x100,000 pixels). It can also integrate a computer vision model trained to identify animacules (specifically tardigrades) and center the sample, allowing for tracking as the tardigrade moves about in a large petri dish. This is of interest to tardigrade scientists who want to build models of tardigrade behavior and turn them into model organisms.
Right now I'm working on a sub-sub-sub-project which is to replace the LED illuminator with a new design that is capable of extremely bright pulses for extremely short durations, which allows me to acquire scans much faster. I am revelling in low-level electronic design and learning the tricks of trade, much of which is "5 minutes of soldering can save $10,000".
I had hoped to make this project into my fulltime job, but the reality is that there is not much demand for stuff like this, and if it does become your job, you typically focus on getting your leadership to give you money to buy an already existing scope designed by experts and using that to make important discoveries (I work in pharma, which does not care about tardigrades).
Eventually- I hope- I will retire and move on to the more challenging nanoscale projects- it turns out that while you can build microscopes that are accurate to microns with off-the-shelf hardware is fairly straightforward, getting to nanoscale involves understanding a lot of what was learned between the 1950s and now about ultra-high-precision, which is much more subtle and expensive.
Here's a sample video of tardigrade tracking- you can see the scope moving the stage to keep the "snout" centered. https://www.youtube.com/watch?v=LYaMFDjC1DQ And another, this is an empty tardigrade shell filled with eggs that are about to hatch, https://www.youtube.com/watch?v=snUQTOCHito with the first baby exiting the old shell at around 10 minutes.
I've wanted to make this the Openflexure Microscope (https://openflexure.org/projects/microscope/) but it is behind the backlog of all sorts of other things.
I don't like the openflexure design at all. I mean... obviously it works for a lot of people, but I just don't want a flexure based stage. I like real 2-axis stages based on rolling bearings, basically cloning the X and Y parts of this: https://www.asiimaging.com/products/stages/xy-inverted-stage...
UC2 is another cool project: https://openuc2.com/ but I found their approach constraining.
Frankly I think you could just buy an inexpensive 3D printer that had an open firmware, and replace the extruder with an objective, a tube, and a camera, and you'd have something up and running cheaper for less time.
Thanks for sharing the post!
"Exorcise the lattice hoard to siphon the new incarnation."
What we said:
"Purge the web cache to download the new version."
I guess, if/when I retire to that remote mountain hideaway, I might just get into this hobby. The idea of grinding my own mirrors to look at dew on the spiderwebs of the neighborhood is just so appealing.
> Optical Engineer Rik ter Horst shows us how he makes very small telescopes (at home) which are intended for use in micro-satellites.
pictures would be captured by hand held groundstations
https://en.wikipedia.org/wiki/Newton%27s_reflector
Very nice and I might look for one of these mirror kits.
For this specific mirror, I was a bit disappointed, because it was specifcally advertised as parabolic, which made this project suitable, because coating costs trump all other costs for very small builds. Well it was 1.7x too much parabolic, and now I have to pay a coating :)
In my understanding it's gotten considerably easier over the years with better availability of diamond and CBN abrasives, and with more electronic control of the grinding hardware. Slumping glass and bonding a thin sheet to ceramic foam reduced the costs and weight a great deal as well. Mastering these techniques make it easy to start a small business rather than to do a one-off in your garage, though.
As a sidenote: The Celestron RASA astrographs are so effective and so inexpensive of a wide-field instrument that it's a lot harder to justify the DIY activity that existed in the 2000's.
Progress on my 16" f/3.2 is currently stalled though.. a multi-year project indeed.
If you want a working telescope for $small, buy a second hand one.
If you want to mess around with mirrors for hours on end then build one!
Or check your local library. It may have a smaller Starblast table-top dobsonian you can check out - I did that when traveling once.
Whatever you do, do NOT buy a small cheap refractor on some flimsy mount. They are mostly awful.