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Talk me into or out of the Takahashi FC100-DF

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#176 YAOG

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Posted 19 January 2020 - 12:27 PM

My advice is not to go that path.

 

Either use the Tak stock focuser, which is fine for many, or upgrade and swap it out for a fitting full Starlight R&P focuser to your liking. Expensive but worth the cost if you need it's functionality and/or are in love with it's feel.

 

Just use it a couple of months under the stars first, then decide if you need to change anything. Chances are you will be happy with the FC-100 as is.

 

I foolishly "upgraded" my 2.7" Tak focuser on my FS-102 NSV with the Starlight Feather Touch Micro Pinion Assembly. It is definitely not the same as a Starlight focuser.

 

A better upgrade for just your focuser pinion assembly would be the Tak micro focuser, if any. Or go all the way with a FT R&P focuser.

 

Just my 2 cents.

Erik,

 

What did you find less than ideal with the Feather-Touch micro pinion? I have had a few FTF focusers and they are excellent focusers for visual work, extremely fine focusing with minimal shift off axis during focusing. Not as true running as a Moonlite but very good. My big Moonlite refractor focuser runs the entire 4.5" of travel with virtually zero shift over an 80' laser run. The FTF with 2.5" travel was not even close but in practice there is so little travel used it doesn't matter. 



#177 Erik Bakker

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Posted 19 January 2020 - 12:44 PM

I have no issue with FT focusers and have one on my 16" f/5. A very fine focuser indeed.

 

It's just that I do not consider the Feathertouch focuser pinion option a great upgrade for a Tak focuser. If I would want to upgrade the smaller Tak focusers, I would advice paying the premium and go all the way for a FT 3035 or the likes for photo-visual use on a Tak. That said, a well adjusted Tak 2.7" focuser is a joy to use and great for visual use and light photographic work.



#178 rkelley8493

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Posted 19 January 2020 - 01:33 PM

I have no issue with FT focusers and have one on my 16" f/5. A very fine focuser indeed.

 

It's just that I do not consider the Feathertouch focuser pinion option a great upgrade for a Tak focuser. If I would want to upgrade the smaller Tak focusers, I would advice paying the premium and go all the way for a FT 3035 or the likes for photo-visual use on a Tak. That said, a well adjusted Tak 2.7" focuser is a joy to use and great for visual use and light photographic work.

Would a FT 3035 fit on a Tak FC-100D? I have the same model on my 5.1" Stellarvue, and it's a beast of a focuser.

The main reason I want to upgrade to the Micro Pinion is bc it is more of an "accent" than a full on "upgrade". I don't want to get rid of the Tak Blue sand-cast focuser housing that goes with the sand-cast tube ring. I also think the focuser itself is pretty smooth with just enough tension. I'm just missing the fine focus knob that I'm used to.


Edited by rkelley8493, 19 January 2020 - 01:33 PM.


#179 barbie

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Posted 19 January 2020 - 03:32 PM

I have no problems with the stock focuser. It is buttery smooth and achieving precise focus is never an issue. I won't be upgrading my DF to any kind of micro focuser.


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#180 YAOG

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Posted 19 January 2020 - 06:14 PM

I have no problems with the stock focuser. It is buttery smooth and achieving precise focus is never an issue. I won't be upgrading my DF to any kind of micro focuser.

Same here on the DL I bought locally which I was told was never actually used. It seems very firm to me, very different from the Starlight R&P and Crayfords and the Moonlite Crayfords I have but my hope is that it will break-in as I use it though that has not been the case so far though I've only got maybe seven or eight sessions with it so far. 


Edited by YAOG, 19 January 2020 - 08:32 PM.

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#181 Daniel Mounsey

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Posted 19 January 2020 - 09:09 PM

Would a FT 3035 fit on a Tak FC-100D? I have the same model on my 5.1" Stellarvue, and it's a beast of a focuser.

The main reason I want to upgrade to the Micro Pinion is bc it is more of an "accent" than a full on "upgrade". I don't want to get rid of the Tak Blue sand-cast focuser housing that goes with the sand-cast tube ring. I also think the focuser itself is pretty smooth with just enough tension. I'm just missing the fine focus knob that I'm used to.

 

Here are a few suggestions. Many have a tendency to change focusers automatically but I'm definitely not one of them. Others are welcome to choose whatever focuser they like but you may want to consider afew matters first. I myself will never change a Tak focuser unless I absolutely have to. Half of my Taks have aftermarket focusers while the other half don't. Erik offered some wisdom and I'd take heed of of it. First I'll explain why the FT retrofit focuser may or may not work. If you were to look carefully at a Tak focuser from the rear side of the optical tube, you will see a square gap or groove in the sand casting of the focuser. This gap allows the teeth from the rack to slide forward and backward. The issue is that the gaps are sometimes too wide in the sandcasting. As a result the drawtube has a tendency to twist like a cork screw depending on which direction you rorate the rack. This is what causes the image shift in some of their focuser. I have discussed this with Hashimoto when he visited our store recently. So, even if you add an FT retrofit, you still may have this issue. The other problem too is if they are not set correctly, they can have a mushy feel. This is not what FT focusers are knows for. It's just the challenges of getting all the srcrew tensions just right. 

 

Now, if the issue is that you just really want fine focus, remember that these optical tubes are very light and hardly tax the load capacity of any decent mount. That means you can man handle the coarse focuser without worry of vibrations, making the stock focuser perfectly fine and they are buttery smooth. Personally I would never change the focusers on these little FC's at all. They are consistently excellent. There's still another method though that does not take away from the originality of the stock focuser. You only need to make two modifications to them and if you can find one on the used market somewhere, you'll be set. I have two of them and I highly recommend them. Where focus is really more critical as far as fine focus is concerned during higher magnifications on fine multiple stars and planets where shorter 1.25" eyepieces are being used anyway. 

 

https://www.telescop...ter/p/13025.uts

 

Ths remarkable adapter only needs two modifications which I have done myself. One is a nylon screw to prevent damaging eyepiece barrels which in turn preserves their resale value and two, some red grease. You will need a 2" diagonal to accommodate this and even though it's only for 1.25", remember too that higher magnifications is where fine focus matters more anyway. Once the red grease is caked in there, it prevents any oscillating due to slight thread tolerances. The read grease also does not react to temperature. As a result, it's ultra butter smooth and that's your fine focuser and very little cost. They work amazingly well and I have two of them myself.

 

Steady skies! 


Edited by Daniel Mounsey, 20 January 2020 - 11:43 AM.

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#182 payner

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Posted 19 January 2020 - 10:01 PM

Would a FT 3035 fit on a Tak FC-100D? I have the same model on my 5.1" Stellarvue, and it's a beast of a focuser.

The main reason I want to upgrade to the Micro Pinion is bc it is more of an "accent" than a full on "upgrade". I don't want to get rid of the Tak Blue sand-cast focuser housing that goes with the sand-cast tube ring. I also think the focuser itself is pretty smooth with just enough tension. I'm just missing the fine focus knob that I'm used to.

Based on your post, and respecting that you want fine focus, though it really is not needed on these scopes used for visual imo, I recommend the Takahashi option. Get yourself the Takahashi's MEF3 "MicroEdge focuser. These come from the factory on many models and think you'd appreciate the "original" effect with a 7:1 fine focus wheel.


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#183 m9x18

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Posted 19 January 2020 - 11:31 PM

… There's still another method though that does not take away from the orginality of the stock focuser. You only need to make two modifications to them and if you can find one on the used market somewhere, you'll be set. I have two of them and I highly recomend them. Where focus is really more critical as far as fine focus is concerned during higher magnifcations on fine multiple stars and planets where shorter 1.25" eyepieces are being used anyway. 

 

https://www.telescop...ter/p/13025.uts

 

Ths remarkable adapter only needs two modifcations which I have done myself. One is a nylon screw to prevent damaging eyepiece barrels which in turn preserves their resale value and two, some red grease. You will need a 2" diagonal to accomidate this and even though it's only for 1.25", remember too that higher magnifications is where fine focus matters more anyway. Once the red grease is caked in there, it prevents any oscillating due to slight thread tollerances. The read grease also does not react to temperature. As a result, it's lutra butter smooth and that's your fine focuser and very little cost. They work amazingly well and I have two of them myself.

 

Steady skies! 

This is a very useful accessory. I purchased mine quite a few years ago while they were still available. There were two production versions. The early version had helical screw threads that were more openly spaced and the later version had threads that were more finely spaced. Mine was of the later-variety. In any case, regardless of the version, Daniel's suggested modifications certainly do help make this nice to have accessory even nicer to have. 


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#184 rkelley8493

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Posted 20 January 2020 - 12:18 AM

Had my first light tonight laugh.gif  This is a beautiful little scope.. so beautiful in fact, I am changing its name to *Bella*. That seems to fit much better.

I spent the first part of the night on star clusters. I started off in Cassiopeia/Perseus [with 31T5 Nagler]. The Double Cluster was very vibrant and colorful, and the field of view was extremely rich at 24x. I swept around the area, taking advantage of the wide field of view, and the field felt like it was flatter than it is in my Stellarvue Apo. I'll pay more closer attention to that next time. Anyhow, I had some really good views of the rich star field where part of the Milky Way banner stretches across the sky.

Next target, the Pleiades. I was surprised at how much nebulosity could be seen surrounding most of the Seven Sisters. I normally don't see that much cloud detail from my light polluted back yard. However, the sky was pretty dark tonight, and the Pleiades was near zenith. Scope did a good job of framing the entire cluster [still using 31 Nagler], and there wasn't any false color. Beautiful applause.gif

Next up, the Orion Nebula [I changed eyepieces to the 17T4 Nagler, and later used the Pentax XW's]. It was surprisingly bright for a small 4" scope. There were even parts of it that I hadn't noticed before in my other scopes. I usually can see the "wings", the glowing core, and some billowing clouds that the wings envelop. But with this scope, I could see the faint bottom part of the "bass mouth". I can now see why they say "Doublets for visual, triplets for photo." The fewer elements between the eyes and the sky really does make a difference. 

Overall, I'm very impressed with the performance of the Takahashi FC-100DF. The light grasp was right there within range of my 130 f/7, but in a much lighter and more compact package. I'm still missing the fine focus, but I think I'm starting to get the feel for the single speed. After all, the fine focus knob is an expensive accessory to add. I'd rather have something like a nice case for the scope instead.


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#185 Erik Bakker

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Posted 20 January 2020 - 05:20 AM

Wonderful first light report!


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