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Cheap - indi compatible - controller for Losmandy SVM-HT servo motor

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#1 dolguldur

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Posted 14 September 2018 - 06:24 AM

Dear all,

 

I am looking for a cheap alternative for gemini2 motor controller.

 

In the past, I have been working with astroEQ controller based on arduino. However I cannot use this solution for controlling a Losmandy mount with the svm-ht controller.

 

Do you know if there is a similar controller box that would allow for controling a gm-like mount equipped with servo motor ?



#2 orlyandico

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Posted 14 September 2018 - 06:48 AM

SiTech. Not cheap.

If you have a Gemini 2 with a busted board and you don’t want to buy a new board, why not sell the servo motors and do an OnStep conversion (or AstroEQ) with stepper motors?

Trying to find a DIY servo controller isn’t going to be cheap or easy.

#3 dolguldur

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Posted 14 September 2018 - 07:42 AM

Thank you for your answer.

It is a second hand gm8, with new motors, but no control box.

 

I realized that this question had been asked few time here, and the the most common answer was, as you suggested, this one: http://www.siderealt....com/store.html

 

Version 1 and version 2 of Sitech controller look both cheaper than a proper gemini 2. It is alright for me to spend up to 400$/500$ for a good controller, especially given the fact that servo of that torque are not that common. But 1400$/1500$ is too much for a "simple" GM8, that only carries 30 lbs max with around 10" periodic error, or even more.

 

The question is: has someone tried to use one of those controller on a gemini 8 with the new SVM-HT motors? is is easy to setup ? What are the key feature that would make you choose one over the other ?

 

If it is too difficult to find an alternate solution, I might just buy the Gemini2, but first, I would like to assess if the mount worth it.


Edited by dolguldur, 14 September 2018 - 07:43 AM.


#4 benula

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Posted 14 September 2018 - 06:58 PM

If your willing to go the diy route, I think you would be very happy with onstep. I have a g-11 that had the 492 digital drive and didn't want to pay the $$$ for gemini. There are quite a few of us using OnStep with INDI and it works great.

#5 dolguldur

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Posted 15 September 2018 - 09:49 AM

Thank you for the answer. The thing is that I already own the svm-ht servo motor. The onstep project looks nice but it is designed for ... stepper motor, so that would require me to buy a set of old stepper motor for g8 (not available anymore as far as is know ?) and build the onstep interface, am I correct ?

What motors do you use ?

Edited by dolguldur, 15 September 2018 - 11:01 AM.


#6 dolguldur

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Posted 15 September 2018 - 11:18 AM

Wait realize that 1 thing is not clear to me:

Would buying the sitech1 alone controler be enough to control the svm-ht motors from losmandy (from a computer, because I don't need a hand controller) ?

#7 555aaa

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Posted 15 September 2018 - 05:21 PM

I think the answer is yes.

#8 dolguldur

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Posted 18 September 2018 - 05:38 AM

Ok I think I finished the searching phase.
I asked on sitech yahoo group and got confirmation that sitech 1 and 2 controllers are out of the box compatible with svm-ht servo motors for losmandy mounts.

But, sitech is not indi compatible, still expensive for the second version, and not convenient for EU customers.

But... I recently discussed with developpers from freego2, and, although the project is not yet fully in production (beta of ascom driver, indi still in roadmap), it looks extremely promising:
http://campussternwa...de/freego2.html

It is servo AND stepper motor compatible, and... quite cheap and... opensource

Edited by dolguldur, 18 September 2018 - 05:40 AM.



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