Takahashi FS-60 2' diagonal drawtube adapter

[Profiler (Profiler)]

Can someone please help.

I am trying to establish what is the 'correct' adapter (i.e. part number etc) which screws onto the draw tube of the Takahashi FS-60 focuser and allows for the use of 2' diagonals and eyepieces.

I have spent countless hours looking at such adapters for the Sky90/FS-78 etc and other Tak models but can't seem to find the right part number (be it Takahashi or some after market manufacturer)

I know this part exists as there are plenty of pictures online showing both FS-60's as well as FC-76DCs and FC-100DC's all fitted with this 2' adapter on their drawtubes and thus holding 2' diagonals/eyepieces.

Finally, I want to clarify that I am not after the 2' adapter which connects to the extender 1.6Q - which is the only one I can actually find via the Takahashi schematic diagrams

My thanks to everyone in advance who can share their wisdom

[beren]

http://www.optcorp.com/tk-toa0040-2i...ashi-fs78.html

[UniPol]

The only FS-60 model which accommodates the 2" ( Part 69 - TKA21110) adaptor is the CSV version and even then you can only use a 1.25" diagonal and EP's (see : http://www.astronomy-electronics-cen...ystemChart.pdf) Being of such short focal length you need a fair bit of in focus which the CSV version offers. The C and CSB models do not show the 2" adaptors on their system charts for this very reason.

[FlashDrive (Poppy)]

just a thought ....if one could know the ' thread ' size M60 /M72 etc....Baader might make one...

I know they make them for the 2.7" TAK Focuser.

Would anybody know what it is....thread size ....??

Just an idea...

Col...

[Kunama]

The thread is M55.9 and a finer pitch than the M56 used on the Chinese scopes.

@ Richard, be aware that unless you change the tube to the shorter 105mm one from the CSV, using a 2" diagonal might make it difficult to get to focus with the FS60 focuser.

I got it to work with the shorter tube with about 2mm to spare. Some eyepieces would not come to focus at all till I changed to a prism diagonal.

[FlashDrive (Poppy)]

Richard...I don't know how long you intend to keep the FS60, but I have a solution to fix your problem.

This is a FT Focuser with the FS60 Adapter ... screws straight onto your FS60 Draw Tube.

I had this on my FS60 ( since sold ) and I could get any eyepiece to come to focus.

Place your 2" Diagonal in, and away you go.....

Your under no obligation to buy .... just an alternate option.

I will be listing this for sale shortly....

Col...

[Profiler (Profiler)]

Hi Col

I really appreciate the offer - and advice from everyone else - thank you so much for all the help everyone

Just to clarify - I don't actually have any telescope at the moment

I am just doing research into options for a FS60 (which I would like to buy) and the FC-100DC - which also has the same focuser as the FS60 (to my understanding)

[FlashDrive (Poppy)]

All good Richard...

Col...

[sharpiel]

My, my, Col! Is that your cabinet full of focussers in the background..? You do have raaaather a lot!

[FlashDrive (Poppy)]

Originally Posted by sharpiel

my, my, col! Is that your cabinet full of focussers in the background..? You do have raaaather a lot!

Yep ...come in handy they do....

[anj026]

Baader make a Tak adapter which converts the M43 thread to T-2. Then you can add a T-2 to 2" female adapter. I don't know if this will allow you to reach focus using a 2" mirror diagonal on the FS 60.

I have just received these parts and will try them out on my FC76 DC and report back. I also bought the Baader T-2 quick change parts to use on the prism diagonal I already have.

[Kunama]

The shortest way to attach a 2" diagonal to the Tak 2" focuser is to use a Takahashi TCD0015 adapter. This threads onto the draw tube and has a 24tpi SCT thread on the other end. You then remove the 2" nosepiece from the diagonal and then thread the diagonal onto the adapter. An SCT lock ring can be fitted to the adapter to lock the diagonal in any particular orientation.

[anj026]

That sounds like a better solution Matt. I tried the 43mm to T-2 adapter with the T-2 to 2" female adapter and could not get infinity focus with a 2" mirror diagonal (on the FC76DC).

Using the Baader prism diagonal with the T-2 to 2" female adapter I was able to get focus using various extensions. I also found that the Takahashi focuser felt a bit overloaded with a 21mm Ethos and even a 17mm Nagler. It worked ok but it was much smoother with lighter eyepieces such as a 27mm Panoptic and a 40mm GSO reverse kellner.

I think I will mostly stick with 1.25" eyepieces for the FC76. There may be occasions when it will be handy to have the 2" eyepiece option but I think the focuser is generally much happier with lighter loads.

[Kunama]

Originally Posted by anj026

That sounds like a better solution Matt. I tried the 43mm to T-2 adapter with the T-2 to 2" female adapter and could not get infinity focus with a 2" mirror diagonal (on the FC76DC).

Using the Baader prism diagonal with the T-2 to 2" female adapter I was able to get focus using various extensions. I also found that the Takahashi focuser felt a bit overloaded with a 21mm Ethos and even a 17mm Nagler. It worked ok but it was much smoother with lighter eyepieces such as a 27mm Panoptic and a 40mm GSO reverse kellner.

I think I will mostly stick with 1.25" eyepieces for the FC76. There may be occasions when it will be handy to have the 2" eyepiece option but I think the focuser is generally much happier with lighter loads.

I use the Pentax XF8.5 most often with the FC76DC, gives 67x which is nice in this scope. I will also be using the Tak LE24 for 24x and if the TV 40 Plössl is bound to stay with me that will be a finder eyepiece at 14x.

I doubt I will bother attaching the 6x30 finder at all.