14 replies to this topic

[lumos]

When I added the Takahashi FSQ 85 to my Esprit 150 I duplicated all the equipment, i.e. new tripod, mount, Eagle 5 computer, Primaluce Esatto 3 focusser, flattener, OAG-L, guide cam, ASI2600MM, Filterwheel and Antlia 3nm filters. 

 

I now want to add a Takahashi TSA 120 and I am pondering the best approach. 

 

Level 1 would be put a Primalucelabs saddle on top of the Eagle 5 XTM and swap everything above it

Level 2 would be buy the dedicated Esatto adapter for the TSA 120 (300 Euros for just the adapter), buy a new Esatto 3, new 86 to 72mm female adapter then replace everything behind it (flattener back)

Level 3 would be break it apart each time so just buy a new Esatto 3 adapter (did I mention that this costs 300 Euros?), buy a new Tak flattener, buy the appropriate spacers to give me the back focus and use my existing equipment from the camera, filter wheel and off axis guider.

 

I did not mention option 0 which is to buy another Eagle 6, then why not a third mount - for god's sake someone start an intervention.

 

Much of this will depend on how often I might swap between them. Also there are some very stuck elements in the imaging train.

 

My plan had been to shoot all spring and summer from France with the FSQ and the Esprit, running both rigs every night. I have left the Esprit and the 10Micron in France and used the Tak and the Warpastron WD20 this winter in England. However, my horizons at home are limited but a large number of protected trees in our garden so I do not have many nebulae to image and the Tak is reduced to 330mm focal length so not ideal for galaxies. Thus adding the TSA 120 to also travel between France and the UK to allow me to image more targets in winter.  

 

How do you manage this. Are you less of a wuss and are confident you can label that 0.2mm spacer to give the Tak its correct back focus?

 

There is a joy in being able to drop the full imaging system into the saddle and start imaging. But surely there comes a point when we hit rock bottom and start to be sensible.

 

I would really appreciate your advice and Filippo is pacing anxiously as he waits to find out  whether or not he can buy his second yacht.

[Nipkinz]

I feel like your question is not serious, Lumos. If you are unable to figure out which direction you want to take based on your "levels" above, I'm happy to offer my consulting services to assist you. My fee is modest and fair; one Eagle 6 XTM.

[lumos]

I feel like your question is not serious, Lumos. If you are unable to figure out which direction you want to take based on your "levels" above, I'm happy to offer my consulting services to assist you. My fee is modest and fair; one Eagle 6 XTM.

I am now embarrassed as I was being completely serious. Have I missed something obvious or does everyone just reconfigure their equipment for each assignment?

[airscottdenning]

It's a perfectly reasonable question! 

 

I also have a bunch of imaging trains that share a lot of component parts. Unless there's some kind of imperative for running two at a time (like one up at my dark site and another in my back yard), I do indeed disassemble and reassemble the systems over and over again.

 

Of course, if you're dedicating equipment to a remotely-operated observatory you can't be cannibalizing it for a quick weekend trip to a local dark site. In that case you need to purchase redundant components. 

 

In the end, remember that this is a "good problem" to have: an embarrassment of riches, so to speak. It's nice to have choices, after all!

[lumos]

It's a perfectly reasonable question! 

 

I also have a bunch of imaging trains that share a lot of component parts. Unless there's some kind of imperative for running two at a time (like one up at my dark site and another in my back yard), I do indeed disassemble and reassemble the systems over and over again.

 

Of course, if you're dedicating equipment to a remotely-operated observatory you can't be cannibalizing it for a quick weekend trip to a local dark site. In that case you need to purchase redundant components. 

 

In the end, remember that this is a "good problem" to have: an embarrassment of riches, so to speak. It's nice to have choices, after all!

I always image locally; in France I tend to leave both rigs set up under Telegizmos, in the UK I am usually setting up for the night. I loved shooting at 1047mm and 330mm at the same time, sometimes on the same target, but I could equally see myself shooting at 1047mm and 900mm at the same time. The Esprit set up ironically would be the easier one to disassemble (It even has an OAG and guide camera still  installed from the pre-10Micron days). 

 

How do you keep track of the components for each orientation?

[airscottdenning]

I always image locally; in France I tend to leave both rigs set up under Telegizmos, in the UK I am usually setting up for the night. I loved shooting at 1047mm and 330mm at the same time, sometimes on the same target, but I could equally see myself shooting at 1047mm and 900mm at the same time. The Esprit set up ironically would be the easier one to disassemble (It even has an OAG and guide camera still  installed from the pre-10Micron days). 

 

How do you keep track of the components for each orientation?

I have a spreadsheet that I maintain for each imaging train. The hard part is that not only must components thread together, but the optical distances are critical: for example the distance between a reducer and the imaging chip or the pick-off prism in the OAG and the guider. 

 

When I build a new instrument, I keep careful track of each component and measure using calipers if I don't know the precise optical lengths involved.

 

I add ⅓ of the thickness of a filter: for example a string of components that are 60 mm long have an optical length of 61 mm if there's a 3 mm thick filter inline.

 

Also, I take closeup photos of fully assembled imaging trains and save them in the spreadsheet because I frequently get confused later when I'm trying to reproduce them. 

 

I use white tape and label components to help me keep track of whaat goes with what.

 

And I take notes in the spreadsheet as I use things: radial or saggital distortions in the corners of my images that indicate a need to add or remove spacers, default focuser positions for certain combinations, etc.

 

For me, the careful assembly and reassembly and experimentation is as much a part off the hobby as collecting data or processing images. 

Edited by airscottdenning, 23 April 2025 - 12:08 PM.

[lumos]

This is just what I was looking for. I know that if it was going to be a complex process (is this my 0.2mm spacer for the Takahashi or the 0.5mm for the Esprit) I would be reluctant to change over very often. Maybe if I am now certain of my back spacing I order a Precise Parts adapter that replaces some of the spacers and diameter adapters. Maybe if the parts all unscrewed easily I would be less reluctant to touch it.

 

Thank you so much for taking the time to respond.

[lumos]

I suspect from the replies that the notion of duplicating equipment to avoid breaking rigs down is too silly to contemplate. How far would sensible people take this? The FSQ85 and TAS 120 both take the Esatto 3, would you go so far as to remove this to swap scopes? Actually Primaluce Labs make that the easiest interface at it is just three thumbscrews.

[dswtan]

I suspect from the replies that the notion of duplicating equipment to avoid breaking rigs down is too silly to contemplate.

Those of us who are silly and just duplicating are just not replying? But my personal limit is three active (DSO) rigs.

[lumos]

Those of us who are silly and just duplicating are just not replying? But my personal limit is three active (DSO) rigs.

Are there meetings that we can go to?

[Jose_Salcedo]

I have and use two rigs, one based on a Tak TOA-130NFB and the other based on a FSQ-106EDX4. I fully built each rig to maximum rigidity, tilt optimization and alignment, so I never swap imaging trains between them. The only exception is that I have an alternative filter wheel + color camera that I can switch easily when I want to change from a MM camera/filters to a MC camera/filters on the FSQ. For the TOA, I have two preassembled imaging trains, one set for  990mm and the other for 1500mm; when I switch them, filter wheel and camera remain.

[Rasfahan]

I have a fixed dual setup. In addition I swap a full-frame colour cam and a APS-C mono cam between a variety of telescopes ( Tak 76DCU, Askar FRA300, FSQ-85, TS Photoline 130). I‘ve mercilessly culled all parts that would lead to tilt and have standardized on 56mm backfocus from M54 on all OTAs. Switching from ZWO to QHY and Baader (UFC) spacers was very helpful for that. Changing the image train is a quick and easy affair that way. For a different quick-exchange solution, you could try the Baader M68 or M54 changers - I‘ve heard they also don‘t induce any tilt.

[lumos]

I have and use two rigs, one based on a Tak TOA-130NFB and the other based on a FSQ-106EDX4. I fully built each rig to maximum rigidity, tilt optimization and alignment, so I never swap imaging trains between them. The only exception is that I have an alternative filter wheel + color camera that I can switch easily when I want to change from a MM camera/filters to a MC camera/filters on the FSQ. For the TOA, I have two preassembled imaging trains, one set for  990mm and the other for 1500mm; when I switch them, filter wheel and camera remain.

That is really helpful but I just want to make sure that I fully understand. For the FSQ you unscrew the camera and filter wheel together and screw on your colour camera and other filter wheel. I assume that you do not use an off axis guider, or if you do it is not like the ZWO one that needs to be disassembled to be unbolted from the camera and the OAG.

 

For the TOA 130 I think I understand that you use it with an extender or a reducer (1500 and 990mm respectively). To swap these you unscrew the flattener, replace it with the extender then screw the entire imaging train bock on. Does your back focus position stay the same?

 

How are you focussing these OTAs? On my FSQ 85 I use the Primalucelabs Esatto 3 however this has half the focus travel of the original Takahashi focusser. Thus I bought PLL's spacer that makes up the other half of the travel in case I needed it. Unfortunately my Tak reaches focus at exactly the outer limit of its native travel. This led me to the situation that I could use the spacer and have NINA and Hocus Focus fail whilst trying to move the focus in, and without it it would fail trying to move it out. I have the reducer so I am shooting at 330mm. When I swap in my 2600MC for colour I do not use a filter and the back focus change means I now can only focus with the spacer back in and the 0.2mm out. The whole thing is a faff.

 

Thank you  so much for your help; I really love your work by the way.

[lumos]

I have a fixed dual setup. In addition I swap a full-frame colour cam and a APS-C mono cam between a variety of telescopes ( Tak 76DCU, Askar FRA300, FSQ-85, TS Photoline 130). I‘ve mercilessly culled all parts that would lead to tilt and have standardized on 56mm backfocus from M54 on all OTAs. Switching from ZWO to QHY and Baader (UFC) spacers was very helpful for that. Changing the image train is a quick and easy affair that way. For a different quick-exchange solution, you could try the Baader M68 or M54 changers - I‘ve heard they also don‘t induce any tilt.

I looked at the Baader UFC spacers (I assume that you do not mean to use the actual filter carrier part of the Universal Filter Carrier). I really like the way that they are made, and they have holes in which my filter removal tools could fit if they get tight. I have one M42 to M48 adapter that has none and always gets stuck. I am insanely tight for back focus using the OAG-L and filter wheel. I am seriously contemplating buying the 2600MM Duo so that I could get rid of the OAG for the FSQ85 and allow me to install better spacers like you suggest. However, this would mean that the FSQ could stay permanently together but I would swap between the Esprit 150 and TSA 120.

 

Your comments have been really useful, now I wonder if I need any off axis guiding. In the summer I could use the 10Micron for the Esprit or the TSA 120 (unguided as usual) and the FSQ could continue to ride on the WD-20. If I wanted to shoot the Esprit and the TSA I could put the duo camera and filterwheel on the longer Tak and use that for guiding. 

 

This way I would avoid buying another filter wheel and a full set of 3nm Antlas.

 

This has been really helpful as I work through this.

[Rasfahan]

I looked at the Baader UFC spacers (I assume that you do not mean to use the actual filter carrier part of the Universal Filter Carrier). I really like the way that they are made, and they have holes in which my filter removal tools could fit if they get tight. I have one M42 to M48 adapter that has none and always gets stuck. I am insanely tight for back focus using the OAG-L and filter wheel. I am seriously contemplating buying the 2600MM Duo so that I could get rid of the OAG for the FSQ85 and allow me to install better spacers like you suggest. However, this would mean that the FSQ could stay permanently together but I would swap between the Esprit 150 and TSA 120.

 

Your comments have been really useful, now I wonder if I need any off axis guiding. In the summer I could use the 10Micron for the Esprit or the TSA 120 (unguided as usual) and the FSQ could continue to ride on the WD-20. If I wanted to shoot the Esprit and the TSA I could put the duo camera and filterwheel on the longer Tak and use that for guiding. 

 

This way I would avoid buying another filter wheel and a full set of 3nm Antlas.

 

This has been really helpful as I work through this.

For the mono cam I don‘t use the UFC, it is a QHY image train. I‘m using the UFC+spacers only for the OSC. I‘ve found the bolt-on QHY train consistently better than ZWO (regarding tilt - the ZWO EFW is much more reliable). That said, the mono cam for my permanent RC setup is an ASI2600MM. I‘m on my second filterwheel and third OAG and those are finally straight enough for f/8.

Edited by Rasfahan, 27 April 2025 - 02:43 PM.