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Posts posted by Mognet

  1. 2 hours ago, Chriske said:

    ok, now I'v got it..!  I thought the upper grey and black part were also printed...silly me...

    That's ok. Perhaps I should have used this photo originally. It shows the whole thing with the camera too


    2 hours ago, Chriske said:

    Suggestion, change the threaded rod with something more stable, as Peter also explained. I'd print a wedge to fill in that gap + a little possible polar tuning. Or is there really need for that long threaded rod..?

    That rod could be a problem. I don't think it needs to be that long either, and at larger angles the mount may not be able to cope with the shifted weight. I'll see if I can come up with something stronger and more stable that can still be adjustable


    2 hours ago, Chriske said:

    That rod btw: nice print, very nice print indeed...!

    Thanks. I used OpenSCad for the design, and the thread uses this bit of code. It creates a 2D shape of the cross section of the thread and the extrudes and rotates it

    module thread(height, outerDiameter, innerDiameter, pitch) {
        threadHeight = pitch / 2;
        outerRadius = outerDiameter / 2;
        innerRadius = innerDiameter / 2;
    	function r(x, z) = [x * sin(360 * z / pitch), x * cos(360 * z / pitch)];
    	input = [
    		for (lp = [0:0.05:1]) r(innerRadius + (threadHeight * lp), pitch * (1 - lp / 2)),
    		for (lp = [1:-0.05:0]) r(innerRadius + (threadHeight * lp), pitch * (lp / 2))
        linear_extrude(height = height, twist = -(height/pitch*360)) polygon(points = input);


  2. 9 minutes ago, Alien 13 said:

    I want one...


    Same here, even if to only experiement with

    I'm curious as to how they perform. I couldn't find anything with a quick search, but if they are going to be using one in a satellite then they must perform well

    • Like 1
  3. 4 hours ago, Chriske said:


    Nice 3D-print project. Could you explain a bit more how this tracker works.
    I can't figure out how you track stars with this device(it's probably me, I know, sorry...😳)


    That's ok. It basically converts the alt-az mount into an equatorial mount, so what is normally the vertical axis (the azimuth axis) becomes the equatorial axis

    Alignment is crude. The camera is set parallel to the equatorial axis using the markers that were already on the mount, and then the mount is roughly aligned with Polaris. After that the handset controls are used to point the camera at the appropriate patch of sky, and the mount rotation should match that of the stars


    3 hours ago, PeterW said:

    I’d have designed it for a fixed angle to avoid flex and possible failure, but seems like yours is delivering the goods!   
    good job!


    Thanks. I did consider creating a fixed angle version, which would have been fine for my use, but I wanted to share it with the community too so opted for the adaptable version. The hinge seems to take most of the weight, so I think it's fairly safe. I wouldn't trust it with anything more than the weight of my camera and 70-300 lens, i.e. less than a kilo

  4. 21 minutes ago, Stargazer33 said:

    Would loading the firmware for an eq mount give you the star alignment option? In effect, your mount now acts more like an eq than an alt-az.  I know Celestron hand controllers can be programmed with either firmware so I suspect Skywatcher hand controllers can too.

    Excellent idea by the way!


    I don't think that's an option for this mount. Certainly nothing obvious from looking at their site and I didn't see anything in the handset menu for it

  5. 11 hours ago, dmki said:

    This is a really nice piece of engineering. I am just starting the 3d printing  and cad journey and to be honest I didn't really think it was capable of stuff like this. something for me to aim towards

    Thanks. 3D printing is quite capable of things like this, and more too. Several members here use 3D printing for lots of things, including clocks, telescopes and rockets for display

    The biggest of the telescopes. Chriske has made several different types

    Rocket for display, also by Chriske

    And one of Gina's clocks


  6. Hoping the skies stay clear tonight so I can test version 2

    I adjusted some of the dimensions and took out the nice curves that fitted the base as they were a bit of a pain to place properly and their positions weren't calculated. The result isn't quite as pretty but it will still work. This version was printed and set up about a month ago and there doesn't seem to be any warping of the PLA so far, unlike the previous version. There is a wobble in the adaptor which seems to be due to play in the adjustment screw and mounts. I might also need to boost the thickness of some parts too



    • Like 3
  7. Have made a minor update to take it to v1.2.6

    This time I found that surplus jpg files were not being deleted before new movies were created. I'd turned off the power here without shutting down the cameras cleanly first and a jpg file wasn't added into the daytime movie that day, but was left hanging around. That meant it kept getting added in at the start of every daytime movie as that part uses a wildcard add rather than named file. The code to clear the surplus files relied on a wildcard which doesn't seem to work with a file delete in Bash, even though it does from the command line

  8. I got the alert on Friday night too. First one I've seen in the four years I've had the app. Went outside to check and it was completely clouded out. As is typical the sky started to clear again once the alert level was back down to yellow

    • Like 1
  9. Looks good. Glad you're getting on with it and you got your MQTT input sorted

    I know what you mean about the clear skies and full moon. Went out to check the skies last night and Jupiter was sparking, but the full moon washed everything else out. Tonight had been promising until about ten minutes ago when clouds rolled in again

    6 hours ago, jiberjaber said:

    I checked the git hub and the version text isn't aligned with the current version (it only goes up to 1.2.4)

    I didn't bother updating the about page with the last change as v1.2.5 only affected the install scripts. They'll be realigned with the next change

    • Like 1
  10. Last night was the first decent clear night here in ages so I took some time to experiment with the wedge. And it does work. Took some thinking about and a little swearing

    The SynScan alt-az software isn't designed to be used like this so initial attempts at using star alignment had to be ditched. Either it wouldn't align, or it would give alignment stars I couldn't see, or it would cause trailing. It seems the way to do it is to set the location to 90 degrees north (or south if you're in that hemisphere) and then skip the star alignment. Target alignment can then be done by guesswork and trial photos.

    The camera stayed pretty much with the chosen star field for the twelve minute period I was shooting in. These are 200x200 pixel crops from the top left corner of the first and last images. For a first test and for my purposes it's acceptable


    This is the result from last night once I'd figured most things out. It's shot on a Nikon D3100 with a Nikkor 35mm 1.8G lens, 22 subs of 30 seconds each, F4, ISO1600, no darks or flats, processed roughly in Sequator and GIMP


    I would have taken more subs, but the camera battery ran out of power after those 22. Which led me on to a problem I was expecting. My print sizing isn't quite correct so the holes in the wedge don't engage with the teeth in the mount and it seems that friction alone cannot be relied on to keep the wedge in place so when I went to change the battery the whole thing rotated. I definitely need to modify that part of the design, and I think I'll just make up an adaptor for my existing one as that piece was a ten hour print

    • Like 1
  11. 14 hours ago, chemistorge said:

    No use to me, but excellent design.

    Thanks. My designs vary between crazy and good, and I think this one could be one of the good ones

    2 hours ago, doublevodka said:

    Looks great 👍 similar concept to the nexstar 4 / 5 mount but yours has better execution with a thread to adjust the angle

    I've not seen one of those before, but it is quite similar

    2 hours ago, doublevodka said:

    As for the mount itself slipping, they are fairly simple beasts, quite easy to strip and regrease and the slippage is likely down the the amount of tension on the bolt for the axis, there's a bit of a sweet spot, not too tight, not too loose, I have the celestron version, but there is very little difference

    I noticed that when servicing the mount a few years ago. I was never quite sure I put the right tension on the azimuth nut when I put it back together. It's possible that I may not have set it tight enough

  12. As I'm being a bit tightfisted economical with my money at the moment, I thought I'd experiment with adapting my old style SkyWatcher SynScan alt-az mount by designing and printing a wedge to enable me to experiment a bit more with astrophotography. I'm not expecting it to be hugely accurate, just vaguely. But if I can get it to follow the same patch of sky to get 30 second exposures with my longer camera lens and without trails then I'll be happy. I seriously doubt it's strong enough to take the weight of a scope though.

    I haven't tried it out yet as I'm waiting on a clear sky, but I have mounted a camera and rotated it using the controls. There is some slippage in the mount in a couple of places which isn't unexpected as the balance is off, and there is some flex in it as it's only printed in PLA with 30% cubic infill



    I'm not publishing the plans yet as it's still a prototype. I know already there are some small changes that need to be made. The teeth on the original mount don't mesh with the holes in the print so might cause further slippage, and I need to tidy up a few other dimensions


    Hoping that this is actually a practical idea instead of one of my usual bonkers ones!

    • Like 8
  13. That's brilliant.

    The space clearance/empty directory problem should be fixed in this version along with a little problem in creating new periods that one of mine was having issues with.  It looked like it was just a timing thing between the capture and new movie scripts. Space clearance now happens three times a day; twice for the new periods, and a third at noon when the timings are regenerated. And that third one also reports to update.log in ~/Mognet-All-Sky-Camera/back-end/ This latest version should be stable. I've had it running for about three weeks and haven't managed to break it yet

    I'll update I've updated the instructions so that removal of the downloaded files and installer directory are included, and added version messages to the autodeploy and update scripts too along with a version history in the README.md too

    2 hours ago, jiberjaber said:

    Good luck on the job hunting...

    And thanks. Job hunting is tedious. Twenty years experience in IT; 3 as a dev and 17 as an automated software tester, and I've only managed to get one interview out of 80+ applications so far.

    • Thanks 1
  14. 1 hour ago, jiberjaber said:

    Yep - I think mine hasn't actually updated based on that!

    I've managed to break the main page, the SD ran out of space so I did a "sudo find /var/www/html/history/ -mindepth 1  -mtime +42 -delete" which now means it reports a missing directory and no about link is there anymore.. 


    I'll give the update another go



    The error trapping on the main page isn't great, so the message of "couldn't open info file" means it's looking in a history subdirectory and not finding that file. I wouldn't be surprised if the directory is empty too, but the directory itself hasn't been removed. It was a problem I was seeing on one of mine before some of the recent fixes (v1.2.2 I think fixed it). The directory in question looks like it's /var/www/html/history/1623186661-night/ There might be others too, and they will probably be the oldest ones

    The find command is new to me. I'll have a play with that tomorrow in between job hunting and learning Python

    57 minutes ago, jiberjaber said:

    Think I might have spotted an issue or 2?

    Looks like the new about.html doesn't get copied as part of the update?

     I also note "no crontab for root" which might be why the file clearup isn't happening?

    Y/N is case sensitive so needs a lower case 'y' to work 

    Just checked the update script on GItHub (https://github.com/MarkGrimwood/Mognet-All-Sky-Camera-install/blob/main/update) and it should copy the entire contents of the front-end directory to /var/www/html/ while preserving the history. (Just seen your update) It should handle Y or y too

    Not sure about the "No crontab for root" message. I think I've seen it on some of the clean installs


    I realise that 'works for me' doesn't mean it works for everyone else. Might need to see what messages are actually coming out of the update script. Might also be a good idea to add version number reporting to the update and autodeploy scripts too in the next update

  15. The Datyson image looks good

    There does seem to be a glow with the Pi cameras. This is from a V2.1 NoIR showing the same glow across the top. It's the second one I've had as the first one, while fine during the day, had an horrendous glow across the image at night that made it unusable



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