Tak FC-100 - a few questions :)

[marcus_z]

4 hours ago, Peter Drew said:

It seems to take a lot of aftermarket help to operate one of these Taks satisfactorily.    

That might be, but one would not even think about upgrading the focuser of a 500€ scope with a 500€ focuser. Focusing a 2,4mm eyepiece in a loaded turret which weights 1,5kg is "When only the the best will do!"

[mikeDnight]

Spending a small fortune on upgrading a good focuser to a state of the art focuser, when you're talking about Takahashi, is really testament to just how much the owners appreciate that incredible lens.  If someone gave me an FT to put on my scope i wouldnt complain, but until that day I'll be content with my humble MEF 3.  

[Highburymark]

13 hours ago, BGazing said:

Also amazingly expensive.

Not if you check out end of year sales at camera websites - less than half price

[AstroPhil]

On 5/1/2018 at 11:45, 25585 said:

FLO asked Moonlite on my behalf which focuser of theirs would fit, and was told the 2.7 inch model. Those of course have options on colour, speeds, tube length, finder shoes, motor etc.and are rotatable presumably.

Well I'm happy to report that the MPA-TAK2.7 is now installed and fits perfectly to the FC100DL (2nd run). Silky smooth and very happy with it. And... clear skies! Maybe I try it out as well ;-)

[25585]

On 02/05/2018 at 00:01, Highburymark said:

Not if you check out end of year sales at camera websites - less than half price

Camera Web sites are good places to look for fracs themselves I have found. When astro stores are sold out, photo ones still have stock. 

[Highburymark]

6 hours ago, 25585 said:

Camera Web sites are good places to look for fracs themselves I have found. When astro stores are sold out, photo ones still have stock. 

And eyepieces too. Some great deals out there. Check out Microglobe in London, and Wex. Also elsewhere in Europe. I bought a Leica ASPH zoom for £400 from a Dutch website - at the time retailed for £750- £800 from Leica.

[BGazing]

Has anyone had any chance to test their FC100 DC/F in decent seeing on Mars? How well are they corrected in red?

[GavStar]

20 minutes ago, BGazing said:

Has anyone had any chance to test their FC100 DC/F in decent seeing on Mars? How well are they corrected in red?

mikednight is your man on this - from his sketches he clearly gets great views with his FC

[Piero]

Not yet!

It's known that a more vivid red colour can be revealed using prism or bbhs diagonals. 

[Piero]

Well, I finally decided to upgrade the focuser of my Tak with the MEF-3. The reason behind this move is due to my most used eyepiece, the Zeiss zoom, which is nearly - but not completely - parfocal. The travel required for reaching perfect focus within the minimum and maximum zoom range is very minor, making the micro-focuser a useful option for this little adjustment. 

The parcel arrived safely. Thankfully the instruction for the installation of this accessory includes an image for this step, as I would not have known how to decipher all that Japanese text, otherwise! 

 

The installation is almost done, apart from fixing a couple of small screws completely. Said this, I am puzzling about a ~1 cm long screw and a washer which have been included with the package and it does not seem to be any use for them, looking at the images. Any idea? 

[Piero]

And here is a photo of course!

Edited May 16, 2018 by Piero

[AstroPhil]

And here's a comparison, from me... FT version.

[Piero]

8 minutes ago, AstroPhil said:

And here's a comparison, from me... FT version.

Nice one! 

[Stu]

2 hours ago, Piero said:

And here is a photo of course!

How do you find it Piero? I do wish Tak would redesign their focusers, that metal plate always seems a weak point and comes lose.

Hope it works well for you though.

[Highburymark]

3 hours ago, Piero said:

Well, I finally decided to upgrade the focuser of my Tak with the MEF-3. The reason behind this move is due to my most used eyepiece, the Zeiss zoom, which is nearly - but not completely - parfocal. The travel required for reaching perfect focus within the minimum and maximum zoom range is very minor, making the micro-focuser a useful option for this little adjustment. 

The parcel arrived safely. Thankfully the instruction for the installation of this accessory includes an image for this step, as I would not have known how to decipher all that Japanese text, otherwise! 

 

The installation is almost done, apart from fixing a couple of small screws completely. Said this, I am puzzling about a ~1 cm long screw and a washer which have been included with the package and it does not seem to be any use for them, looking at the images. Any idea? 

Piero - I  remember there were various bits and pieces left unused when I fitted the MEF, so yours sounds normal. I've found it very beneficial for maintaining sharp detail at high mags.

[Piero]

2 minutes ago, Stu said:

How do you find it Piero? I do wish Tak would redesign their focusers, that metal plate always seems a weak point and comes lose.

Hope it works well for you though.

Thanks for your advise, Stu.  

It's clearly too early for me to say whether it will come lose or not over time, although I agree with your point that the metal plate is the weak point. 

The microfocuser seems well built and precise in my opinion. What is not clear from the photos on the Internet is that the MEF-3 is connected to the metal axis of the focuser (the axis having the two knobs at each end) with two micro screws (see red arrows). The metal plate fixes the rotation of the metal component of the microfocuser, but does not hold the microfocuser itself. 

The micro movement is very smooth and should be more than sufficient for the minor focus adjustment that my zoom needs between zooming in and out.

Of course, the purchase of the DF plus this microfocuser can make one wonder whether getting the DC and upgrading the whole focuser with an FT one (which is 2" and includes the micro adjustment) could potentially be a wiser option from economic and functional standpoints. 

[Piero]

56 minutes ago, Highburymark said:

Piero - I  remember there were various bits and pieces left unused when I fitted the MEF, so yours sounds normal. I've found it very beneficial for maintaining sharp detail at high mags.

Thanks Mark. That's what I thought too. I believe the washer and additional screw are meant as a replacement of the large screw with the two micro-holes, which now holds the metal bar. 

Stu is right on the money about the weakness of that bar though. If the two screws loosen a bit, there should be some backslash. Maybe, Takahashi should have attached that metal bar to the microfocuser permanently without those screws. 

Edited May 16, 2018 by Piero

[Stu]

21 minutes ago, Piero said:

Of course, the purchase of the DF plus this microfocuser can make one wonder whether getting the DC and upgrading the whole focuser with an FT one (which is 2" and includes the micro adjustment) could potentially be a wiser option from economic and functional standpoints. 

That was my logic Piero. I had experienced perhaps some older Tak focusers which had been brutalised by imagers and showed their age so I went straight for the FT. Yes, if the two screws come lose then the knob moves around a little which is something I’m not keen on. Hopefully as a new assembly yours will perform nicely though.

[Piero]

Actually, thinking a bit more about that metal plate..........

One weakness I can see are the oversized elongated holes to allow the two screws to be fixed. Here an idea:

1. One could replicate that metal plate and drill just where the screws need to be inserted (therefore two simple holes);
2. If the screws often loosen, one could glue the screws, metal plate, and microfocuser together, so that those three components stay permanently in place. A metal-to-metal glue should do the work just fine; 
3. the modified MEF-3 would now be connected via the two mini-screws (see the red arrows in the above photo), and the central screw with circular flat cap. 
4. The movement of the microfocuser should affect the metal plate at the level of the two screws mostly. Having fixed these, the central screw should be rather stable.

Thoughts? 

Edited May 16, 2018 by Piero

[marcus_z]

1 hour ago, AstroPhil said:

And here's a comparison, from me... FT version.

Phil, there's a gap between the focuser housing and the MPA at the sides. It seems like your MPA-TAK2.7 technically works, but that the MPA-TAK2.5 closes the gap here...

[avtaram]

I use the Baader prism diagonal with focusing eyepiece holder in my FC-100dc which has a nice smooth fine focusing action and it's a lot cheaper than upgrading the focuser.

Avtar

[Piero]

1 hour ago, avtaram said:

I use the Baader prism diagonal with focusing eyepiece holder in my FC-100dc which has a nice smooth fine focusing action and it's a lot cheaper than upgrading the focuser.

Avtar

 

That works fine as long as you do not use 2" eyepieces / filters. 

Edited May 17, 2018 by Piero

[AstroPhil]

14 hours ago, marcus_z said:

Phil, there's a gap between the focuser housing and the MPA at the sides. It seems like your MPA-TAK2.7 technically works, but that the MPA-TAK2.5 closes the gap here...

Indeed! I did get plenty of advice and was told the MPA-TAK2.7 for the 2.7" focuser (which this is). Oh well. It works perfectly though - there are 4 set screws and nylon seats that are adjusted to make the unit fit and mesh properly with the gear and OD of the focuser; the small gap is the same all round - the radius of curvatures match. So all-in-all I'm happy with it.

[BGazing]

17 hours ago, Stu said:

How do you find it Piero? I do wish Tak would redesign their focusers, that metal plate always seems a weak point and comes lose.

Hope it works well for you though.

I also thought it looks weak...but I was not aware that it actually is, i.e. that it comes loose. As I put the scope in the bag, it basically rests on that bottom little metal plate. I thought it was odd but thought that Takahashi knows better than I do.

16 hours ago, Piero said:

 

Of course, the purchase of the DF plus this microfocuser can make one wonder whether getting the DC and upgrading the whole focuser with an FT one (which is 2" and includes the micro adjustment) could potentially be a wiser option from economic and functional standpoints. 

Yup, thought so, too...the only clear minus I can think of is aesthetic...and perhaps not even that.

[Piero]

1 hour ago, BGazing said:

I also thought it looks weak...but I was not aware that it actually is, i.e. that it comes loose. As I put the scope in the bag, it basically rests on that bottom little metal plate. I thought it was odd but thought that Takahashi knows better than I do.

Yup, thought so, too...the only clear minus I can think of is aesthetic...and perhaps not even that.

@BGazing Well, we are not the first ones getting the MEF-3. Actually, the majority of members upgrade the standard focuser with this microfocuser, rather than replacing it completely with a FT one. Over time, it will be more and more clear how effective to us this works.

 

@Stu Out of curiosity, which models of Tak focusers have you experienced issues with? Do you reckon the problem was due to the MEF-3 or the focuser itself (e.g. rotation movements, backslash along the travel, etc) ?