The Charlie Bates Solar Astronomy Project is proudly sponsored by the following fine companies:
ImageImageImageImage
Image
Image
Solar Analemma. This outstanding image from Alexandra Hart taken over a period of 4 years charts the midday position of the sun in the sky throughout the year. The north–south component of the analemma results from the change in the Sun's declination due to the tilt of Earth's axis of rotation. The east–west component results from the nonuniform rate of change of the Sun's right ascension, governed by combined effects of Earth's axial tilt and orbital eccentricity.

Merry Christmas, Happy New Year and looking forward to a great solar cycle 25!

Welcome to Solar Chat! The best forum for Solar Astronomy
Moving forward from solar cycle 24 to 25

Motorized Etalon Tuners

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
User avatar
Martin_S
Ohhhhhh My!
Ohhhhhh My!
Posts: 131
Joined: Sat Mar 16, 2019 12:34 am
Location: Brisbane , Australia

Motorized Etalon Tuners

Post by Martin_S » Sat Nov 16, 2019 8:01 pm

Hi everyone. here's my latest solar mod , motorized etalon tuners.

I got fed up having to keep walking outside and tune my scope.

I do all my Solar Imaging inside the house ,so fitting motorized tuners was a logical solution.
I was inspired by Ken's Vegemite tuner

A small geared motor is housed inside a nylon block, the 4 height adjusting screw are nylon and the unit is held firm with an adjustable
elastic strap. A small piece of rubber sheet protects the telescope and gives a nice firm base to mount the tuners on.
Clipboard.jpg
Clipboard.jpg (96.8 KiB) Viewed 495 times
Total cost for 2 units , under $10AUD and about 4 hours in the shed on a cloudy day.

The main nylon motor mount could be 3d printed, I used a milling machine as I'm a hobby machinist.

Here's an Image from today's solar session
Sol.jpg
Sol.jpg (98.65 KiB) Viewed 495 times
Martin

User avatar
Merlin66
Librarian
Librarian
Posts: 3414
Joined: Tue Dec 13, 2011 1:23 pm
Location: St Leonards, Australia
Contact:

Re: Motorized Etalon Tuners

Post by Merlin66 » Sat Nov 16, 2019 9:50 pm

Martin,
Well done!
A very elegant solution...
I'm sure it will make your life a bit easier - and your images even better.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

User avatar
marktownley
Librarian
Librarian
Posts: 26656
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Motorized Etalon Tuners

Post by marktownley » Sun Nov 17, 2019 11:46 am

That's a great solution Martin that's quite clearly producing excellent results!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Rusted
Ohhhhhh My!
Ohhhhhh My!
Posts: 110
Joined: Fri Jan 19, 2018 11:00 am
Contact:

Re: Motorized Etalon Tuners

Post by Rusted » Mon Nov 18, 2019 12:33 pm

Congratulations on your neat execution.

Being able to adjust these things without physically touching the telescope is a real boon.
Probably one which is grossly underestimated by those who have never enjoyed such "remote control."
With this facility, it often comes as a complete shock to discover how the tiniest variations can have a very real effect on the image on the monitor.
Imperceptible changes in rotation can make the difference between fuzzy, perfect clarity and back to fuzzy again.
BTW: Software and control boxes are available which can slow gearbox motors to a near invisible crawl.

User avatar
Martin_S
Ohhhhhh My!
Ohhhhhh My!
Posts: 131
Joined: Sat Mar 16, 2019 12:34 am
Location: Brisbane , Australia

Re: Motorized Etalon Tuners

Post by Martin_S » Wed Nov 20, 2019 11:01 am

Rusted wrote:
Mon Nov 18, 2019 12:33 pm
BTW: Software and control boxes are available which can slow gearbox motors to a near invisible crawl.
Chris, thank's for your comments. I am in the process of making a multiple function control box with speed control for focusing and etalon tuning.
It consists of a control box with multiple functions that will be inside the house,connected to a junction box at the telescope by means of a RJ45 cat5e cable. I've managed to source some pre-wired RJ45 panel mount sockets on flea bay so when it is all finished there will be just 3 cables running from my study to my scope mount. Power, USB for my camera's and the RJ45 cable, the mount is controlled by WIFI.
At the moment my setup time is about 7 mins till I'm Imaging I just wheel my scope out on a trolley ,line it up to some marks on the ground and connect all the cables and I'm all set to go.

Martin

User avatar
Rusted
Ohhhhhh My!
Ohhhhhh My!
Posts: 110
Joined: Fri Jan 19, 2018 11:00 am
Contact:

Re: Motorized Etalon Tuners

Post by Rusted » Wed Nov 20, 2019 12:50 pm

Hi Martin, it all sounds very sophisticated!

As I have everything in my dome I rely on commercial add-on boxes with control software within ASCOM.

Rather than take up space on your thread I shall return to my own thread with my PST etalon drive, progress report.

christian viladrich
Almost There...
Almost There...
Posts: 573
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Contact:

Re: Motorized Etalon Tuners

Post by christian viladrich » Fri Dec 20, 2019 11:00 am

Well done !!
Christian Viladrich
Co-author of "Astronomie Planétaire"
http://www.astroplanetes.com/
Co-author of "Astronomie Solaire"
http://www.astronomiesolaire.com/

User avatar
rsfoto
Almost There...
Almost There...
Posts: 1138
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México

Re: Motorized Etalon Tuners

Post by rsfoto » Sat Dec 21, 2019 5:28 pm

Hi,

Having made this many many years ago, to be exact it was December 2012, with my Coronado etalons I recommend using stepper motors not DC motors ...

Coronado are easy to modify but Lunt filters, as far as I have seen, is not that easy and I think there is were the producers should put an eye on and redesign their silly adjusting wheels ... Sorry ...

And yes, I have a huge reduction of 5120 steps : 1 revolution at the output and with a screw pitch of 32 (32 threads per inch) I have noticed changes down to just moving 64 steps and calculating the angle that is impossible to adjust it by hand.

If the Etalon producers would incorporate such adjuster for maybe an additional price of US $ 200.00 - 400.00 They for sure would sell it without any problems. They have much better possibilities to incorporate it before then we afterwards. Nowadays there are such tiny stepper motors that everything is possible.

The stepper motors you see in the images are 10 mm in diameter. Look here is a 6 mm diameter stepper motor https://www.micromo.com/media/pdfs/DM0620.pdf


Coro-Step-01_CN.jpg
Coro-Step-01_CN.jpg (94.52 KiB) Viewed 274 times
Coro-Step-02_CN.jpg
Coro-Step-02_CN.jpg (133.42 KiB) Viewed 274 times
regards Rainer

Observatorio Real de 14 San Luis Potosi Mexico

User avatar
Rusted
Ohhhhhh My!
Ohhhhhh My!
Posts: 110
Joined: Fri Jan 19, 2018 11:00 am
Contact:

Re: Motorized Etalon Tuners

Post by Rusted » Sat Dec 21, 2019 6:19 pm

An incredibly neat solution and you are quite right about using stepper motors.
Except for the greater complexity and expense for those not gifted in electronics.
I agree about the gentle adjustment being a revelation in tuning. Remote, or otherwise.

I'm struggling to see the actual drive interface on your mod. Is there a gear wheel involved?
I can't imagine a friction drive wheel on the "knurled" ring would be accurately repeatable?

User avatar
rsfoto
Almost There...
Almost There...
Posts: 1138
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México

Re: Motorized Etalon Tuners

Post by rsfoto » Sat Dec 21, 2019 8:44 pm

Rusted wrote:
Sat Dec 21, 2019 6:19 pm
An incredibly neat solution and you are quite right about using stepper motors.
Except for the greater complexity and expense for those not gifted in electronics.
I agree about the gentle adjustment being a revelation in tuning. Remote, or otherwise.

I'm struggling to see the actual drive interface on your mod. Is there a gear wheel involved?
I can't imagine a friction drive wheel on the "knurled" ring would be accurately repeatable?
Hi Rusted,
I'm struggling to see the actual drive interface on your mod. Is there a gear wheel involved?
No, there is no gearwheel. The motor is fix and when the screw turns then the angle changes. That is all.

It is just turning the screw in or out and so it gets in or it gets out.

I added three more images so you see better how it works

Coro-Step-Up_Down.jpg
Coro-Step-Up_Down.jpg (309.24 KiB) Viewed 268 times
CoronadoAdjust-02.jpg
CoronadoAdjust-02.jpg (1003.47 KiB) Viewed 268 times
CoronadoAdjust-03.jpg
CoronadoAdjust-03.jpg (27.42 KiB) Viewed 268 times
regards Rainer

Observatorio Real de 14 San Luis Potosi Mexico

User avatar
marktownley
Librarian
Librarian
Posts: 26656
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Motorized Etalon Tuners

Post by marktownley » Sat Dec 21, 2019 9:32 pm

I do like a bit of homebrew engineering. Well executed gentlemen!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Rusted
Ohhhhhh My!
Ohhhhhh My!
Posts: 110
Joined: Fri Jan 19, 2018 11:00 am
Contact:

Re: Motorized Etalon Tuners

Post by Rusted » Sun Dec 22, 2019 7:06 am

Thanks for the excellent images Rainer.

A very clever solution! I had imagined rotation was required.

User avatar
rsfoto
Almost There...
Almost There...
Posts: 1138
Joined: Mon Jun 18, 2012 8:30 pm
Location: San Luis Potosi, México

Re: Motorized Etalon Tuners

Post by rsfoto » Sun Dec 22, 2019 7:31 pm

Rusted wrote:
Sun Dec 22, 2019 7:06 am
Thanks for the excellent images Rainer.

A very clever solution! I had imagined rotation was required.
Hi,

The famous little golden wheel has a left and a right handed thread and this is what defines the angle. No less no more. As I do not know the how the lunt is build I can not say anything but I guess it is the same system as they also have a golden wheel for tuning, but the mechanism is hidden by an outside barrel.

Merry Christmas
Last edited by rsfoto on Wed Jan 15, 2020 6:01 pm, edited 1 time in total.
regards Rainer

Observatorio Real de 14 San Luis Potosi Mexico

User avatar
Rusted
Ohhhhhh My!
Ohhhhhh My!
Posts: 110
Joined: Fri Jan 19, 2018 11:00 am
Contact:

Re: Motorized Etalon Tuners

Post by Rusted » Wed Jan 15, 2020 8:46 am

Thank you Rainer.

A belated Merry Christmas and Happy New Year to you too.

Sorry I missed your post.

Post Reply