takahashi fsq 85 - best mounting system?

[steve2310]

Hi guys

Well, it looks as if I've managed to save enough pennies for a Tak FSQ 85 (so happy) but I'm wondering how others mount theirs? I have a NEQ6 Pro that can use either vixen or losmandy type mounting but I'm not what the Tak comes with?? I intend to hang an ATIK 383L+ and FW and OAG off the end so I'm also worried about weight/balance etc.

Any advice or recommendation would be really appreciated.

Thanks in advance,

Steve

[ollypenrice]

Before committing to the OAG bear in mind that backfocus might just be tight if you decide to try the excellent reducer for the Baby Q. It might be possible but do check. The chip distance is about 73mm from memory.

The Tak comes with precious little! Everything is an extra. I opted for the clamshell and offset foot because the Petzval is very rear-end heavy and needs to sit far forward on the mount. I just bolted this foot to a Losmandy dovetail. For a scope this size a Vixen would do, though.

I used a guidescope mounted via a Baader mini saddle plate on top of the clamshell. This allowed me to quick-change the guidescope for a solar scope, as in this pic.

Good choice of scope. It is the only scope I can think of which has no rival.

The NEQ6 will be fine. Indeed, an HEQ5 would cope easily. You'll be using smaller pixels than I did so will need slightly better guiding but that should be easy enough to ensure.

Olly

[Stephen]

I use Parallax Rings (95mm) onto an ADM Los plate, then an ADM dual saddle

Metal back on the reducer is 72.2 (just to be Sheldon about it) and I can just manage it with 460ex / SX FW / SX OAG / CA35

Base model comes with nothing Though the more expensive version comes with the clamshell as mentioned by OIly

[steve2310]

Olly thank you so much - that is really appreciated. I was hoping you would see the topic as I knew you are a 'Baby Q' admirer and have been using one (with superb results) for a while now. I have been looking at this scope for a long time myself so I'm extremely excited to be finally getting one.

Thanks again Olly.

Steve

[steve2310]

Stephen:

Thanks for the 'Sheldon TBBT' measurement. I'm not sure I'm gonna make it with ATIK FW AND OAG - I'm just off to try and find out. Thanks for the alternative set-up.

[Stephen]

I just lucked out as the 460 (13mm) + SX FW/OAG (42mm) is bang on 55mm (or a DSLR/wide t-ring in Tak system chart world)

You've got +4mm on your CCD back focus and +7mm on your FW/OAG ... it's going to be a fair way off unless you can get something small custom made to go from OAG to reducer (leaving out the CA35)

[steve2310]

Stephen: Can I just ask what a CA35 is??

I have just found some notes on my camera spacing which is:

Atik 383L (17mm) >>> Filter Wheel (22mm) >>> OAG (24mm) = 63 How accurate and true these figures I'm not sure?? With an adapter I think it might be possible....

[Stephen]

Those figures are accurate - the CA35 is a Tak adaptor that connects to the reducer and exposes an M54 thread - have a look at the system charts on the Tak website and it might be a bit clearer what I'm rambling on about

[Stephen]

If you can get something made up that's 9mm in length and connects to OAG and reducer (M56 I think) then you're sorted

Sorry typing from phone so not terribly coherent I know!

[steve2310]

Thanks Stephen - that information is really useful. Why is nothing ever straight forward eh? Time to do some research.

Thanks again.

[steve2310]

If you can get something made up that's 9mm in length and connects to OAG and reducer (M56 I think) then you're sorted

Takahashi Update: Scope arrived early last week and I ended up going with the Parallax Rings with the ADM Dovetail plate. The Tak is superb and although I have yet to complete an image set, the early subs look good. I have a few stars that are stating to curl in the top and bottom left of the images which is a bit puzzling but I'll deal with that as and when.

With regard to the above and the focal reducer spacing with my atik OAG etc, it seems I can get a custom made adapter. However, although I am looking at between 8/9mm for this, the least they can make for me is 11. This means the reducer would be out by 2-3mm. For those that have experience with this TAK focal reducer does this difference make the focal reducer redundant for my current setup? Would 2-3mm make a huge difference?

Steve

[swag72]

I found that parts of a mm made a significant difference - Saying that though, for me the 72.2mm stated Tak distance didn't work and mine is working at 74mm. But whether that would be the same for you I can not say.

[steve2310]

Thanks for your thoughts Sara. It seems that the spacing is certainly more critical dependant on the size of the camera chip i.e., if the chip is large then spacing IS critical. I have an Atik 383L and I have just received a message from a Stargazer whose spacing is a little out (he has a 460) and he has no problems.

Focal reducers and spacing - it's certainly not easy.

[x6gas]

Takahashi Update: Scope arrived early last week and I ended up going with the Parallax Rings with the ADM Dovetail plate. The Tak is superb and although I have yet to complete an image set, the early subs look good. I have a few stars that are stating to curl in the top and bottom left of the images which is a bit puzzling but I'll deal with that as and when.

With regard to the above and the focal reducer spacing with my atik OAG etc, it seems I can get a custom made adapter. However, although I am looking at between 8/9mm for this, the least they can make for me is 11. This means the reducer would be out by 2-3mm. For those that have experience with this TAK focal reducer does this difference make the focal reducer redundant for my current setup? Would 2-3mm make a huge difference?

Steve

I am pondering the reducer too - can you post or PM the supplier of the custom made adapter (which I guess is a male M72 to male M54)? I have more or less the same kit although the backfocus on the 460/490 is 4mm shorter than he 383L...

[x6gas]

I found that parts of a mm made a significant difference - Saying that though, for me the 72.2mm stated Tak distance didn't work and mine is working at 74mm. But whether that would be the same for you I can not say.

That's interesting Sara. May I ask how you manage to reliably make sub-millimeter adjustments? Are you using delrin rings between threads or something?

[ollypenrice]

These guys seem to make most things adapter. http://www.precisepa...main/index.html

Texal Nautical Repair are, despite their odd name, great Tak experts too. My adapter came from them. The European Tak importers, despite their name, are somewhat less expert than might be desired... When I asked how to connect my Atik 4000/FW to the Tak reducer they said they didn't know. Noted.

At F3.9 the light cone is steep, the depth of field shallow and the need for orthogonality high, especially on large chips. (One side in focus, the other not. Were your curled stars without the reducer? If so it is likey to be chip tilt.)

Whatever adapter you order I would build in a little adjustability from the start. Things like filter and chip window thickness have unpredictable effects so calculating from pure theory, as Sara says, is a bit of risk.

It's all worth it in the end...

Olly

[Earl]

Oh the joys on no true standards!

[kirkster501]

I am thinking of getting a TAK as well  Sod it - you only live once!

Sara, how did you build the distance from your 460 to the FR?  What parts did you use please?

If I skip the FR, what parts are used to get the ATik connected to the focuser?  I am new to these 3 inch focusing thingys........

Thanks, Steve

[ollypenrice]

Without reducer you don't have to respect a chip distance, you just focus. (Bliss!) Tak do an extender to ensure that most systems can cope. You can even use a nosepiece and EP holder. I did that without issue when un-reduced, though getting the screw fit bits is best.

I have heard a most unwelcome rumour that there may be two lengths of CA35 adapter. Groan. Beware.

FLO have a link with a guy who makes custom adapters. Tim told me recently that he's very good.

Olly

[kirkster501]

I am a big believer in screw fit if it is possible.  Nice and secure.  I probably won't bother with the redcuer for a while.  Its my finding from playing around with sky/FoV emualtors that few objects truly need the FR - Rossette, M31, Veil and California perhaps.

[x6gas]

I have heard a most unwelcome rumour that there may be two lengths of CA35 adapter. Groan. Beware.

No rumour, I am afraid.  Looks like Takahashi have at least three versions of the CA35 - the CA35 #30 (TKA35201) and the CA35 #35 (TKA31201) the CA35 #60 (TKA00205) and it appears there is also a CA35 with the part number TKA23201.

Confused?

[kirkster501]

Before committing to the OAG bear in mind that backfocus might just be tight if you decide to try the excellent reducer for the Baby Q. It might be possible but do check. The chip distance is about 73mm from memory.

The Tak comes with precious little! Everything is an extra. I opted for the clamshell and offset foot because the Petzval is very rear-end heavy and needs to sit far forward on the mount. I just bolted this foot to a Losmandy dovetail. For a scope this size a Vixen would do, though.

I used a guidescope mounted via a Baader mini saddle plate on top of the clamshell. This allowed me to quick-change the guidescope for a solar scope, as in this pic.

Good choice of scope. It is the only scope I can think of which has no rival.

The NEQ6 will be fine. Indeed, an HEQ5 would cope easily. You'll be using smaller pixels than I did so will need slightly better guiding but that should be easy enough to ensure.

Olly

Olly, I have struggled to find where one would buy the offset foot to attach to the bottom of the clamshell.  I use my mount for other telescopes and not keen on removing the saddle completely. Where did you get your foot from?  I could call Ian King - top bloke - but asking here out of curiosity.  I quite like that blue Losmandy plate as well  Sorry if I am being a numpty and off colour as a google search ninja....

Also, how did you mount the mount scope to the top of the clamsell?  I thought the clamshell only had one hole on the top which made me think the clamp would tend to swivel?

Many thanks, Steve

[steppenwolf]

I'm in the process of setting up an FSQ85 for both native and 0.73x reduction so I have two of the (several!) CA-35 adaptors. For reference, I thought it might be useful to post their dimensions here along with some additional spacing details. Takahashi are woefully poor at explaining what is required here so I hope this helps!

Native:-              CA-35 (TSA-102) TCA 1030   20.0mm deep

You then need a 72.0mm male to 72.0mm female 50.8mm deep extension tube from the CAA to the CA-35 plus a male 54.0mm to male 'T' adaptor from the CA-35 to your camera/filter wheel/OAG. Actual spacing here is not critical as this is a Petzval design, provided you can achieve focus! With a 20.0mm deep 54.0mm to 'T' adaptor, my QSI 683 WSG-8 with a backfocus of 50.2mm reaches focus comfortably.

0.73x Reducer:-  CA-35 (SKY-90) TCA 1020    16.0mm deep

You then need a male 54.0mm to male 'T' adaptor from the CA-35 made to the correct length to allow another 56.2mm to the camera's sensor (allowing for the refraction of the filter and the sensor chamber cover glass). I had mine made by FLO's machining contact to my own specification.

For mounting the FSQ85 on the mount, I used a pair of Parallax Instruments 95mm tube rings and an ADM 11" Losmandy profile dovetail bar with the rings set in the slotted portion of the bar towards the front of the telescope to achieve balance yet retain plenty of surface grip in the dovetail bar. The Focus knobs are pretty darned close to the sides of the ADM bar but they do clear it and that is what matters!!

[x6gas]

The Focus knobs are pretty darned close to the sides of the ADM bar but they do clear it and that is what matters!!

Pretty easy to fettle this, Steve.  Plenty of room on the shaft to loosen the grub screw holding the focuser knob and ease it away from the dovetail bar a little...

[kirkster501]

For mounting the FSQ85 on the mount, I used a pair of Parallax Instruments 95mm tube rings and an ADM 11" Losmandy profile dovetail bar with the rings set in the slotted portion of the bar towards the front of the telescope to achieve balance yet retain plenty of surface grip in the dovetail bar. The Focus knobs are pretty darned close to the sides of the ADM bar but they do clear it and that is what matters!!

Steve where did you get the Parallax rings from please?  Did these come with the screws to attach to the ADM dovetail?