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Focuser Upgrade for TV NP101

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#1 ChristopherK

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Posted 15 October 2020 - 11:52 AM

I have a early 2000's TV NP101   (SN 1685) with the stock 2.0" focuser.   Currently I'm using it with TV Binoviewer + 2x Powermate to get to focus with 26mm Panoptics or 13mm Naglers.   That's a lot to hang off the focuser and I'm wondering if I can go better on the focuser.   Also, at high power the 1:1 focus is quite sensitive, and have thought of adding a 10:1 focus mechanism.

 

Is it worth going to something like the Feathertouch 2.0" + TV Adapter?  Its pricey though....    I would be very interested to hear of your experiences with fit, function and performance vs just upgrading the rack mechanism.

 

Clears, 

 

Chris



#2 Jon Isaacs

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Posted 15 October 2020 - 12:12 PM

Chris:

 

I have a similar vintage NP-101.

 

I have the Starlight Instruments two speed retrofit.  It replaces the pinion assembly with a new pinion with a two speed microfocuser. It's easy to install and retains the stock TeleVue focuser.

 

I have two Feathertouch focusers on my Dobs, this one is my favorite.

 

https://starlightins...&product_id=123

 

Jon


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#3 25585

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Posted 15 October 2020 - 02:57 PM

Chris:

 

I have a similar vintage NP-101.

 

I have the Starlight Instruments two speed retrofit.  It replaces the pinion assembly with a new pinion with a two speed microfocuser. It's easy to install and retains the stock TeleVue focuser.

 

I have two Feathertouch focusers on my Dobs, this one is my favorite.

 

https://starlightins...&product_id=123

 

Jon

I have a late 2018 TV 85 2-speed OE, and a brass TV 85 with the FT retrofit micro pinion. The latter is better, and has a brake though it would not work with a TV Focusmate. 

 

Both types work very well and smoothly, the FT retro is a great upgrade if you need 2-speed. They are available for both the chrome & black draw tube models.


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#4 ChristopherK

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Posted 19 October 2020 - 03:45 PM

Thanks, guys.  I see both of you went for the retrofit option which doesn't replace the focuser.  

 

Reading more of the literature revealed to me that the innards of the TV refractor focusers were FT since 2012, so I guess you can't go wrong.

 

I was also looking at doing a complete focuser replacement using the FTF2025BCR and the A20-227 flange adapter. Moonlight also has a similar replacement for a couple hundred less...but I don't quite like the look of the Moonlight ...looks less elegant but probably performs admirably. 

 

I think I'll end up going with the FTF2025BCR and A20-227 path.   Starlight instruments has a FTF2025BCR in the Cosmetic seconds that can save me $100.   



#5 laedco58

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Posted 19 October 2020 - 04:29 PM

Go with the pinion upgrade,  unless you can’t live without the bling factor of a complete after market focuser.


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#6 Spikey131

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Posted 19 October 2020 - 05:40 PM

Starlight did make an entire focuser upgrade, but it is pricey.  The original should handle the weight OK, but the two speed feature is helpful.

 

You can get the pinion directly from Televue.  Call them.



#7 ChristopherK

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Posted 19 October 2020 - 06:11 PM

Ouch!

 

You are probably right.   Thanks for jerking me back to reality!

 

I'll let you know how the install goes.

 

Clears

 

Chris



#8 Jon Isaacs

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Posted 19 October 2020 - 07:22 PM

Thanks, guys.  I see both of you went for the retrofit option which doesn't replace the focuser.  

 

Reading more of the literature revealed to me that the innards of the TV refractor focusers were FT since 2012, so I guess you can't go wrong.

 

I was also looking at doing a complete focuser replacement using the FTF2025BCR and the A20-227 flange adapter. Moonlight also has a similar replacement for a couple hundred less...but I don't quite like the look of the Moonlight ...looks less elegant but probably performs admirably. 

 

I think I'll end up going with the FTF2025BCR and A20-227 path.   Starlight instruments has a FTF2025BCR in the Cosmetic seconds that can save me $100.   

 

Why replace a very good rack and pinion with a Crayford?  A-P uses Feathertouch focusers but they're rack and pinions..

 

Jon


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#9 25585

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Posted 20 October 2020 - 09:09 AM

A Baader Diamond Steektrack might fit?

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  • 2-bds-nt-baader-diamond-steeltrack-focuser-67c.jpg


#10 laedco58

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Posted 20 October 2020 - 11:49 AM

I don’t feel any reason to replace the focuser on my NP127. When I bought mine it came with a two speed Feather Touch pinion and the factory single speed pinion, I like the two speed better so the factory unit is stored away in the Astro cupboard.




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