3D printed universal 1.25" bracket (Wannabe Solar/Lunar guider)

[kbrown]

What started as a pondering about how could I keep the object better in the centre of the frame when doing lunar or solar imaging ended up realising as these two prints. They allow me to attach 1.25" things on either a camera tripod or a SW finder shoe holder.

My idea is to try to make the moon and/or sun appear as a star for PHD2 so I figured I'd just use a really wide CCTV lens on my QHY5L-II and try to guide with that.

For solar guiding I will print another adapter for holding a piece of baader solar film in front of the lens.

Haven't had a chance to test any of this yet. It'll be a fun experiment if nothing else 🙂

Edited November 21, 2020 by kbrown

[kbrown]

Today I designed and printed a 2" filter adapter for this particular CCTV lens and a 2" filter housing to have a piece of baader solar white light film in. The adapter accepts any 2" filter so I can experiment with lots of things.

[tooth_dr]

Those look nice!  I’ve been dipping my toe in 3D printing and have been surprised how nicely threads etc can come up. 

[vlaiv]

5 minutes ago, tooth_dr said:

Those look nice!  I’ve been dipping my toe in 3D printing and have been surprised how nicely threads etc can come up. 

Almost everything astronomy related that I want to print has some sort of thread on it - good to know that threads are printable and they work ok.

[kbrown]

5 minutes ago, tooth_dr said:

Those look nice!  I’ve been dipping my toe in 3D printing and have been surprised how nicely threads etc can come up. 

Yeah. That took me by surprise a couple of years ago too. Takes a bit of experimentation on the tolerances as it's (at least in my case) too easy to print too tight fits.

[kbrown]

For higher load threading I just use metal thread inserts like in this case for the tripod adapter thread and the M3 thread for the nylon screw.

[tooth_dr]

I’m only learning to design, have signed up to a course starting next week. Here are some items from thingiverse I printed with threads this week. 
 

Edited November 22, 2020 by tooth_dr

[kbrown]

Took this test image of the sun through my bedroom window. The bright white dot is the sun. The dark rings are probably light leaks and reflections between the solar film and sensor. This is with the above lens set to its widest 1.4mm.

 

This one is with the same lens set to its "tele" end @ 3.1mm.

Haven't tried guiding yet but by the looks of these images I think PHD2 should be able to guide. How useful this will be, I don't know. I calculated that with this lens I'll get about 250 - 550" / pixel so massively under-sampled as expected. I'm only hoping it to be enough to keep the target (moon or sun) in the frame without having to do manual corrections. I'm most likely going to use this with my ZWO ASI183MC Pro on a 500mm refractor which gives me about 1.51° x 1.01° FOV natively and about 21.09' x 14.09' FOV with my Daystar H-Alpha Chromosphere that has a 4.3x barlow built in.

All I need is some time and clear skies to test

Edited November 23, 2020 by kbrown

[tooth_dr]

I had thought about this using type of setup up for tracking but thought it wouldn’t work.  Calibration will require a fairly hefty calibration step for sure. 

[kbrown]

2 minutes ago, tooth_dr said:

I had thought about this using type of setup up for tracking but thought it wouldn’t work.  Calibration will require a fairly hefty calibration step for sure. 

That's probably where it will fail first. Hoping to work around it or cheat it somehow.

[tooth_dr]

8 minutes ago, kbrown said:

That's probably where it will fail first. Hoping to work around it or cheat it somehow.

Keep us updated on the outcome 👍🏻

[kbrown]

2 hours ago, tooth_dr said:

Keep us updated on the outcome 👍🏻

I sure will. Another thing that might tip this idea over is the exposure time. With such bright objects they'll probably be in the milliseconds range. Not sure how the guiding algorithms will like that as I typically guide with about 2s exposures on DSOs.

I like your camera lens and filter adapter 3d prints btw! Is that filter not colliding with the back of any lenses?

[tooth_dr]

8 minutes ago, kbrown said:

like your camera lens and filter adapter 3d prints btw! Is that filter not colliding with the back of any lenses

Thanks.  The filter holder is for using with a telescope only, you are right that a lens wouldn’t work.  I did that print for someone on here to allow them to try existing/cheaper 1.25” filters.