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FLI focuser or feathertouch motor for autofocus?

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#1 wolfman_4_ever

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Posted 25 March 2013 - 03:27 PM

Question.

Which way would you go? My NP127is has the feathertouch focuser. I can add the feathertouch motor and go.. Or is the FLI focuser the way to go for repeatability and remote operation? I take it the FLI's are absolute focusers while the feathertouch is not?

Let me know. Thanks.

#2 blueman

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Posted 25 March 2013 - 07:08 PM

I have used the NP101 with a Feathertouch focuser and a Microtouch focuse system (same motor as FT).

It worked very well with great focusing.I used a FLI ML8300, filter wheel, reduce/flattener and adapters for about 6.5-7 lbs load.

The FLI focuser is more accurate, but it has less movement of course as far a total movement. It is a great focuser expecially if you have a heavy load. But the cost is very high in comparison.
Blueman

#3 wolfman_4_ever

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Posted 25 March 2013 - 10:27 PM

Thanks. I can get a used FLI PDF pretty cheap. Figure i can lick down the FT focuser and go the FLI route.

Any other opinions are welcomed.

#4 Jared

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Posted 26 March 2013 - 08:38 AM

Only 7mm of travel with the PDF. You can forget visual if you go this route--it assumes a custom spacer to get your camera at the right distance. It is really aimed at dedicated astro graphs. That being said, it won't flex under quite heavy loads and is repeatable.

#5 bilgebay

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Posted 26 March 2013 - 08:47 AM

Here is what I did to test the repeatability of the Microtouch system on an FSQ106 EDXIII.

I think this performance is quite satisfactory for most of us.

#6 wolfman_4_ever

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Posted 26 March 2013 - 02:03 PM

Hi Sedat.

A google search brought your post up. Thanks for that info.

I have noticed repeatability to be an issue. If I go from an L to an Ha, and back and forth and back and forth, focus will change. That micron focus change, over time, becomes a larger error.. Like PE! :p

Hopefully my indicator will be here soon and I can get back to the drawing board of getting my backlash setup correctly. Eyeballing the focus change is a PETA..

#7 bilgebay

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Posted 26 March 2013 - 03:50 PM

You're welcome Dave.

Backlash makes all the difference. I have extended the test to 100 iterations later on and every time it was dead on.

Cheers

Sedat






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