Scope arrives and clouds roll in

[Somnium]

so i finally picked up my AG Optical iDK 14.5 after some serious issues with the logistics company. the scope was packaged well and seemed to handle the trip just fine. it is a 14.5" f6.7 corrected Dall kirkham design with an optec Gemini rotating focuser. i have been preparing its arrival for a while so i had organised a MMOAG and all the appropriate adapters and spacers so as to be able to image ASAP. i laid the imaging train out on the carpet so you can see all the connections i had to make. and unbelievably, it worked. i was able to set it up and achieve focus on the first night. it is also the first time i am running a whole heap of new hardware, the FLI microline and CFW 2-7 is new along with the lodestar autoguider and the MMOAG. there were a few hiccups along the way but for the most part i sorted it out. unfortunately i was only at my observatory last night and will have to wait till next weekend (hopefully the clouds will clear up) to snap some first light images. i still need to do a bit of cable management and i need to sort out 1 driver issue. the only thing that remains an issue is the Thermal control system for the telescope. a dodgy connection means that the cable needs to be in a certain orientation to connect and even when i do the fans are not being driven when i turn them on. i will see what i can do about that otherwise i will have to send it back but at least it is a small component.

Also, i attempted collimation but stopped because i was getting strange results. when i put the laser collimator into the eyepiece holder, the dot bounced back on the collimator slightly off centre at about 5 o'clock. i wanted to make sure this was not the collimator itself so i rotated it and looked back and it was at 7 o'clock. i decided to test it out while having the rotating focuser rotate and watched the dot go from 5 -7 in a straight line. it didnt trace an arc like you would expect if the collimator was out of alignment, anyone with any thoughts on what could cause that???? i cant think of any so i didnt touch the collimation, i didnt want to make it worse.

overall first impressions of the scope and focuser are great, they both are extremely high quality and i cant wait to get some proper first light images.
Next weekend i will go down with some shorter cables to see if i can clean it up. i need to run a pointing model, and PEC and then it is first light !!!

[Slawomir]

Wow! That certainly is a beautiful set-up. Congratulations Aidan.

Looking forward to first light.

[Somnium]

Thanks Suavi. the observatory and Pier were built to house this specific telescope, when i set it all up i was amazed that my calculations were perfect and the roof closes just above the highest point of the scope. i was trying to limit the lost horizon.

[vlazg]

That is sooooo sexy.
looking forward to 1st light :thumbsup:

[Atmos]

Beautiful piece of optical engineering :) Very jealous I am! Not that it is a telescope I'd like to be setting up every night!

Looking forward to seeing what a first light can produce.

[glend]

Very nice scope, congratulations! Re the laser, is it possible that there was slop in the focuser clasp of the laser body, that could cause the straight line shift when rotated. Do you have a centering adaptor (like a Parraliser)? Can't imagine that focuser having slop in it but it's all I can think of off the top of my head.

[Somnium]

Well I do work out :)



I am looking forward to it too :) this whole venture started with me not wanting to set up each night, then I built an observatory and I needed a better mount to operate remotely and then I couldn't put the scope I had on that mount with an observatory. It is a slippery slope but I think I have hit the bottom of the hill :)

[Somnium]

Thanks glen, I am using a baader click lock 2". I was hoping that would be solid .

[issdaol]

Great looking setup......

Interesting point on the laser alignment.......trying to imagine that scenario in my head ......have you checked axial alignment of the entire optical train ??

With everything lined up you should see equally overlapping concentric circles

[Paul Haese]

Nice piece of kit Aidan. I have been umming and ahhing regarding getting a Gemini R&F for the last 6 months. I am sure it will be a beast.

Some thoughts on collimation. I have never had a folded OTA arrive on site that did not need some collimation. So it might well be out of collimation.

Secondly, I would not have thought a laser collimator would have been the best piece of kit to do collimation on that scope. I have attempted this myself several times on the RC12" (just out of interest) and found the results inconclusive. Do you own a Tak Collimation scope? If so, use that to check collimation. If not I would urge you to buy one. This sort of kit you want working at optimum performance and a Tak scope is going to get you so close you will only need to do a star collimation to tweak the secondary at most.

The Gemini would not have any slop so you can rule that out.

How are you going to go with weight on the PMX? I am currently around 37kgs all up on my MX and wonder if you will be close to the line with cables etc on board?

[Somnium]

Thanks Paul , the Gemini is a really good package, given my small fov and the use of an oag I definitely need a rotator and the fact that it comes together with the focuser means 1 less element in the imaging train. It feels and looks really solid, I am looking forward to putting it through its paces.

I do have a TAK collimating scope which I was planning to use for the primary adjustments. I don't have a central dot on the secondary to help with its alignment.

The weight is actually okay. The images I took were with the extension pole in and no camera attached. Once I got all the cables on and the camera and fw I did have to move the weights down a bit but there is plenty of room to go. I will see how it will handle with the tracking next weekend when I get first light but it doesn't appear to be struggling with the weight. However, I wouldn't want to put a bigger scope on that mount.

[DJT]

That's an awesome bit of kit, Aidan. Enjoy.

On the collimating, the centre spot is on the primary not the secondary. The Tak should be fine. Link to RCoptical systems below for collimation with the tak scope.
http://www.rcopticalsystems.com/support/images/rcos_alignment_collimation.pdf

I seem to recall their website has a video tune as well.

Excuse me whilst a wipe the drool off my iPad..

[DJT]

Hi Aiden,
Ignore my last comment on secondary spotting..I just learnt something new about the CDK today.

[Somnium]

No worries David :)

[issdaol]

Hi Aidan,

Although the Tak collimating scope might not help as much with secondary without a centre spot it will still help in making sure everything else is in proper alignment.

So should still be very useful to you.

Cheers
Phil

[FlashDrive]

WOW ... What a beauty that is ....:thumbsup:

Col....

[Astroman]

Very nice setup you have, clouds are going to be hanging around for quite some time looking at the setup involved... Good luck on first light, hopefully all performs as well as it should.

[Somnium]

the only thing i am concerned about is where to make the adjustments. i know the scope is slightly out of collimation Because i am getting a slightly uneven light annulus but if i adjust the primary am i just making it worse because the secondary might have an alignment problem that i am trying to compensate for.



Thanks Col, i cant stop looking at it. i think this is a perfect size for me, sure we would all want a 24" beast but i am really happy with the set up.



absolutely, first light has already been delayed by a week due to clouds, but hey i have waited 6 months another week wont hurt.

[issdaol]

If the primary mounting design is anything similar to a Mewlon 300 then it is very rare for the primary in these type of systems to have moved or tilted.

Unless it has had a fairly severe shock in transit.

I could be wrong but my guess is the problem will be with your secondary being slightly off axis as the secondary mount points are usually more susceptible to change in these types of scopes......especially if the truss section is a bit out.

The Tak Collimation scope should show that type of problem up immediately ... so then you have a place to start.

[Somnium]

i would have thought that the primary would be the thing to shift given it's mass, but maybe that is because i am used to Newts, perhaps these scopes are designed to hold collimation in the primary.

looking through the TAK scope everything looks perfect, just there is a slight difference in thickness in the outer white circle (the light annulus). my understanding is that this is caused by a primary mirror collimation issue but are you suggesting that if i adjust the secondary this might resolve the issue?

[issdaol]

Hmmm now that is interesting.

The mirror mounting on the Mewlon 300 is designed to align the primary in the factory and minimise movements of the primary ... so it is very rare for the primary to move or need adjustment.

While I am no Newt/Dob expert this is very different to the mounting of the primary in Newts which in my experience talking to Newt owners is much more susceptible to the primary moving and needing alignment.

ODK/CDK/IDK are not cheap scopes so I would be very surprised if their Primary Mirror Cell is not as good as a Mewlon 300's

The Tak collimation scope need to be moved in wards and outwards to change focus on the elements you are aligning.

If you focus the Tak scope on the secondary baffle you should see 2 large circles with a thin white circle in between .... all with equal distance on all sides.

If not and one side looks like a darker circle ...... then the secondary baffle or spider needs adjustment.

It's hard to guess without looking myself to see so hope what I am describing makes sense

Cheers Phil

[Somnium]

Thanks Phill, i dont particularly want to be playing around with the spider and the baffles just yet, i think the solution is much simpler than that, it is either the primary or secondary that is just slightly out. i will have a play around with the laser to see if i cant get some consistent results for the secondary and use a TAK scope for the primary, unless anyone can tell me how to collimate the secondary without a laser and without a central dot

[gregbradley]

Beautiful setup. Which Microline did you get?

It appears to be a well made scope.

The CDK comes with collimation instructions and an eyepiece and adapter to set the distance for the primary and secondary although you would expect that to be correct from the factory.

With that much weight on a PMX make sure its well balanced.

If you can you are better off having the counter weights higher up the shaft and no counterweight shaft extension. A possible source of flex.

Greg.

[Somnium]

Thanks Greg, doesn't really compare to yours but i am happy with it :)

i have a microline 8300 with a CFW 2-7. i know it is not perfectly matched to the scope, i will probably end up doing a lot of 2x2 binning. eventually i want to replace that with the 16200 but right now the wallet is a little light.

the primary secondary distance is set with collimation only taking place on 2 of the 3 collimation screws, the scope came with collimation instructions and says to use a laser to align the secondary and then do a defocused star test to check that it is perfect, then adjust the primary by analysing the edges of an image. i think i will get the secondary as close as possible using my glatter then use my Tak to check on the primary and refine based on star tests.

the scope is actually really well balanced at the moment, i am trying to keep the weight distribution simple so i am not adding any piggy backing or off axis weight. i was weighing up the option to use the extension or buy another counterweight. if i have issues with flex i will get another CW down the track. The weight doesn't appear to be overwhelming the mount at all, the scope is actually relatively light, about 25 kgs for the OTA and my imaging train is relatively light too. but i guess all the issues will come out when i try to get some long exposures

[gregbradley]

Sounds great.Looking forward to first light. Feel free to ask any questions. I used a FLI ML 8300 for several years.

Greg.

[Somnium]

believe me i will :) i am chomping at the bit to get down there on Saturday, hopefully i can post first light.