3d printed tracker

[Dave_D]

Not sure if this has been mentioned but it looks interesting 

https://www.hackster.io/news/the-nicest-diy-astrophotography-star-tracker-we-ve-ever-seen-0d3632d7347b?fbclid=IwAR02ZPhdAXVgb01DV1fULf1IsW6rvyl68UFlf1zTWOE8_mQ_OSsfeQmcfag

[JamesF]

That's rather neat.  I wonder how accurate it actually is.

James

[Gina]

It would be better if it was EQ.  That gives camera rotation.  Also, one axis looks like friction drive - inaccurate.

[Adreneline]

56 minutes ago, Gina said:

It would be better if it was EQ.

The link seems to imply it is EQ - "3d printable eq split ring style tracking and goto". It also idicates "huge gears that surround the camera. These result in massive gear ratios, which mean the cheap stepper motors that move the camera have to turn dozens of times for every single revolution of the final gears. This keeps movement nice and smooth." - but then I don't really know so maybe it's not EQ. 🤔 Whatever I'm impressed cos' it looks super-cool  

[Gasman]

Looks very Palomarish ! 😋

[Gina]

If it was EQ it wouldn't need both axes running to track the stars.

[Davey-T]

1 hour ago, Gina said:

It would be better if it was EQ.  That gives camera rotation.  Also, one axis looks like friction drive - inaccurate.

Maybe it's simply like a wedge mounted fork, the video is a bit confusing as both axis are whizzing around, presumably when actually tracking only the RA is moving and the Dec making small adjustments, didn't read the whole thing, can it be guided I wonder ?

Dave

[Alien 13]

It looks like a very well designed EQ mount to me, far far far better than any commercial products I have seen for a DSLR and lens..

Alan

[happy-kat]

1 hour ago, Alien 13 said:

It looks like a very well designed EQ mount to me, far far far better than any commercial products I have seen for a DSLR and lens..

Alan

Looks it to me as well.

[Chriske]

Nice looking indeed and nicely done too..
But there are far simpler startrackers that can be printed.
Two printed arms, a hinge, a threaded rod and a stepper. That hinge is the polar axis.

[Adreneline]

THe design is still evolving it would seem.

The current model only works between 45 and 55 degrees North. He's going to release models for other latitudes once he has finalised the design and published it.

Adrian

[Icosahedron]

Definitely a split ring equatorial mount with GOTO capability.

Quite a coincidence as I've just started modifying my version of one this week, abandoned years ago as result of LP where I live. I now need something for my latest project and have decided against getting an EQ6.

I don't see why a friction drive is in any way inaccurate. I regard it as gears with an infinite number of teeth. This does make it difficult to determine the exact ratios, but that is easily sorted with firmware. Unlike gears, worms and belts there is nothing to introduce periodic errors unless something is not round or centred, also easily sorted. IMO, if properly built it can be the DIY'ers 10 micron drive!

Edited January 16, 2020 by Icosahedron

[skybadger]

My, that's fab. Love it. If anything I'd add the third rotational axis and just play. 

Add encoders if necessary and through axis wiring for camera control.

I'll ask the mesu owners about friction drives. Don't know that they are happy enough. 

 

I'd have that on my coffee table just to look at. 

[intercipere]

Just found this randomly, i'm the creator of this tracker. I wanted to do some testing and refining of the design before making it public, but im gonna release the files (as open source) in the coming days. Check r/openastrotech or openastrotech.com/projects/openastrotracker/ for news.

It is a EQ design, the two axis are in fact GoTo, RA and DEC. I have added adaptions so it now works in a range of 15 to 55°N. I also exchanged the friction drive to belts, because yes, that was inaccurate. 

I am getting very good results for 60 and 120s exposures at 300mm, its able to do more but the throwaway rate gets worse. I also designed a guidescope that sits on top, with that i'm getting good 5 minute exposures at 800mm.

I've opted for the cheapest possible components, so it costs around 50 bucks to make this tracker (and another 50 for the guidescope). And 60 hours of printing lol

 

[happy-kat]

Thank you for the post update. Look forward to seeing some images captured with the mount.

[skybadger]

1 hour ago, intercipere said:

Just found this randomly, i'm the creator of this tracker. I wanted to do some testing and refining of the design before making it public, but im gonna release the files (as open source) in the coming days. Check r/openastrotech or openastrotech.com/projects/openastrotracker/ for news.

It is a EQ design, the two axis are in fact GoTo, RA and DEC. I have added adaptions so it now works in a range of 15 to 55°N. I also exchanged the friction drive to belts, because yes, that was inaccurate. 

I am getting very good results for 60 and 120s exposures at 300mm, its able to do more but the throwaway rate gets worse. I also designed a guidescope that sits on top, with that i'm getting good 5 minute exposures at 800mm.

I've opted for the cheapest possible components, so it costs around 50 bucks to make this tracker (and another 50 for the guidescope). And 60 hours of printing lol

 

Hi intercipere, great work. Can you elaborate on your experience regarding friction vs belts? Is it due to the accuracy of the printed surface ?

[MarkAR]

Interesting design and great work so far.

Just wondering if an "over/ under" double dovetail mount would work. That way with the guidescope underneath and the camera above they would feasibly both be pointing along the same axis.

[intercipere]

I have some pictures on my IG https://www.instagram.com/fabianuehleke/  Only the last one is with the belts and autoguiding, dont have much luck with the weather lately. Also, shitty lenses

1 hour ago, skybadger said:

Is it due to the accuracy of the printed surface ?

Yes, mostly. Also two printed pieces dont have much friction, i put some isolation tape on them which made that a bit better, but the mount then started slipping when there was dew. A belt is just more reliable because its a proper mechanical connection. It also makes tiny imperfections in the printed surface more neglectable

1 hour ago, MarkAR said:

pointing along the same axis

What do you mean? They are mounted and pointing the the same axis

[MarkAR]

Difficult to see in the picture, is the scope mounted on rings around the camera lens or a hotshot mount ?

I was just thinking that using some sort of dovetail mounting might have been a possibly more versatile solution that would make it easier to get the scope and lens aligned and maybe more versatile with different lens set ups.

If what you've made works then all is well and good. Keep up the good work and hope to see the final finished piece soon.

 

 

[intercipere]

The lens gets mounted with a ring and the guidescope simply gets clipped onto that ring. That way they always move the same. It works, but its not the best solution as its a little prone to vibrations like this. Might have to change that.

[MarkAR]

Thanks for the clarification. I can see that you might have vibration problems with that set up, good luck in finding a better solution.

[intercipere]

Its public! 

https://www.thingiverse.com/thing:4167783

https://github.com/OpenAstroTech/OpenAstroTracker

[saac]

Thanks for sharing that intercipere, its a really cool project; I may tackle it this summer. 

Jim 

Edited February 24, 2020 by saac