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  • Author Author: lokkytron
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ASTROPHOTO mount. (Considerations)

lokkytron

Hello mates.

 

Here I come again...I really continue figuring out how to reach a very mall and continous speed of rotation, with a very high precission.

What I want to make is a mount to put on a camera and shoot photos of the night skies. My original idea was in the line of control the movement of my telescope, but I think this is unreacheable in my monetary conditions.

 

So I am here with this paint schema image

image

 

The mechanism has aproximatelly 30 cm width and 30 cm height.

The structure will be made with plates of alluminium of 1,5 mm wide

You can think the camera is a small reflex camera (like Nikon D3200)

 

I had thought that I could reach this with an Arduino UNO board and a pair of sttepers. But when I have started to play with the Arduino board that I bought, some thoughts have come to me. I dont know how to choice the better options.

  1. Will I be able to make this mecha move with a pair of small sttepers 28BYJ-48 with ULN2003 driver?? I have not got the structure pieces yet, so I have not been able to probe this yet.
  2. What do you think will be the better way to control the movement of motors? Bluetooth, IR, RF?
  3. If I would wish to know the angle where the camera to be pointing, ¿what would be the better way? Would I need any optical sensor? or it would be enough with some variables in the code with which I control the sttepers to know this data?
  4. Whatever the choice of motor type, I need to know how to provide movement in the vertical axis. I mean: it would be better a small gear in motor axis and a big gear in the basis? or a wheel in the axis of the motor and a simple circle as basis?

 

Thank you in advance.

And please, escuse me if I explained it bad

  • in reply to Workshopshed

    True Workshopshed

         But I can see a solution using this:

    Imagine a circle with a point sticking out. When the point turns around and  breaks the laser beam you have hit the zero point!

    Clem

  • The problem with steppers is you don't know where you've started from. So you can either move to a fixed point and then record steps from there or you can use some kind of feedback. I used a slotted optical disk for my clock project and homed the motors on boot.

     

    I did some experiments with a PS/2 mouse attached to a UNO, something like that might work, perhaps with 2 mice?

     

     

    If you move the H axis camera to the right it will balance the weight of the V axis one.

  • in reply to Robert Peter Oakes

    Thank you Clem, I will try then with my small pair of 28BYJ-48.

     

    Thank you Peter, I know about the ecuatorial mount. I have a little CELESTRON PowerSeeker 127EQ

    ... but you are right... I should have searched the words " arduino ecuatorial mount" and in this way I should have found THIS

    It now seems stupid do not have searched in elemen14 at first time or simply let google search it for me..

  • Search for Equatorial Mounts, for years people have been making these for exactly this purpose, with a combination of crafting and some simple motors you can get what you need

     

    The aparatus will need aligning with the north star in order to simplify the whole rig

     

    Let me know how you get on

  • I bet with proper gearing, you could make a precise movement with Arduino/motor...

    Clem