CN-212 restoration project

[multiweb]

Couple of progress pics of the CN-212 I'm trying to put back together with the help of MichelangeLewis. :painting: Fred Garcia from takahashi america also helping me with the optics and Matt (kunama) and Phil (issdaol)have been good answering my calls to pick their brain. I'll post more stuff when it's back together and I get closer to using it and hopefully image with it but that's still a fair while away due to weather and drying times.

[Dennis]

Nice looking OTA.:)

So, that's the Tube Holder eh - thanks for the views.:thumbsup:

Loved the laser light show and the rustic pine Welsh Dresser.:)

Cheers

Dennis

[multiweb]

Circa 1995. Old school. ;)

[Dennis]

Hi Marc

Are those rings in Image #1 the standard Parallax Instruments Tube Rings?

Cheers

Dennis

[multiweb]

Yes, parallax rings for my C11.

[Atmos]

Fantastic Marc!

[RickS]

Very cool, Marc!

[LewisM]

Oh, now the publicity photos are up, I am charging more....

Ya could have at least delineated what was before and what was after :lol:

It's amusing to see how Marc's lighting and white balance makes the Tak Green bits look like modern Tak Baby Blue compared to how my iPhone managed to make them look...traditional green (which they are).

I think Marc's green imbalance is genetic :lol:

[LewisM]

OTA Ochre coat No.2 MIGHT go on before Christmas at this rate (poor weather, high humidity). I MAY even have to de-mask it and remask it to avoid the tape glue hardening! Already done that to the masking of the Tak decal to avoid issues.

[multiweb]

I like to think of it as an "attribute".



I have a green sponge if you need it.

[LewisM]

I really don't need to know of your hygiene (or lack there of)

[multiweb]

:eyepop:

[Dennis]

Thanks Marc - I checked the Parallax website and they do not produce a standard set for the M210, although I'm sure they have the specs and would manufacture a custom set if required.:)

Not in that lovely Tak Green though.;)

Cheers

Dennis

[LewisM]

I can remedy that :)

Seriously, I have ordered Parallax rings before, and asked NO paint, or only primer. No felt either (I feel Parallax's biggest drawback is their paint and felt - both easily fixed). I then painted them Tak green with Tak green felt (2 layers seeing Parallax are generally over-sized, making the gap with felt)

[multiweb]

Have you tried Peter Tan? He sells rings, different sizes.

[Dennis]

Thanks Lewis - it looks like the Parallax Rings "may" interfere with the fixed Tak Finder as it rides quite low to the OTA.:shrug:

The rings seem to have quite a thick, flat mounting section, top and bottom.



Thanks Marc, I'll look him up as sometimes it might be convenient to rotate the OTA on the mount.

Cheers

Dennis

[multiweb]

Is this for the mewlon? Might be more cost effective to rotate the camera or buy a rotator of some kind. Parallax make rotating rings but they are quite expensive. I have the standard ones. In my case it was due to the sheer weight of thr OTA after the mods and I needed something very solid to brace the whole tube.

[Dennis]

Thanks Marc, I wanted to have the option to rotate the OTA in rings, just in case I needed to alter the angle/position of the diffraction spikes in the frame, should they be hiding a faint moon of e.g. Mars or Uranus.

Cheers

Dennis

[multiweb]

ha ok. you can still do that with the standard rings by losening the grip and rotate the ota. they're very well built. problem with the mewlon will be the finder. i don't think the thickness of the rotating rings would fit in the gap between the ota and the finder tube.

[multiweb]

Some progress. Can see blue sky and no rain. :)
Secondary spider and tube undergoing polishing at Lewis Paint Incorporated.

[multiweb]

If anybody needs some tak green touch up paint here's the ratios I got that works for me from bunnings after a few trial end error. One is gloss, one is flat. If you want the desired sheen mix 50/50, that's what I do or different ratio to achieve the satin finish you want.

[LewisM]

Problem is Marc, that works for THAT telescope....the green I have works on your CN, but is not close enough on my FSQ.

You need to custom mix EACH time. Or best, repaint ALL the green when you do it.

Fun eh...you need to see the trouble I went to for the CN's ochre tube...insane :(

[multiweb]

For sure but that will get you very close to final tweaking. They can do that at the counter to match exactly. Your mix is a little greener than mine. I can't believe I'm actually saying that... :lol:

[LewisM]

Well, that's the colour your parts are, so you'd better use it :P

[RickS]

I found that a mix of Blyfgoam Glosd, Ice Gray, Stoomy Brown and Snowbonk worked well for me :thumbsup:

http://aiweirdness.com/post/160776374467/new-paint-colors-invented-by-neural-network

[LewisM]

Uber Nerd :lol:

[multiweb]

Snowbonk's on the money and I like the sound of that. :thumbsup:

[RickS]

Not according to my kids :D

[LewisM]

Wet block sanded 2000 grit for 4 hours...lucky I have strong well trained wrists from years of....erm...bachelorhood :lol:

[multiweb]

Slowly filling up my box of accessories. Newtonian corrector, newtonian secondary, Newtonian draw tube, english manual and particularly excited to have scored one of the very last remaining genuine cassegrain focal reducer (f/9. 9) TAK part #KA74580. Brand new. This is like winning the lottery. :cool:

I'm picking up the scope with my daughter on a road trip to Canberra this Saturday so will have plenty more pics to upload when I start putting it back together. :thumbsup:

[LewisM]

Ooops...someone wanted a CN212 tube with clamshell, so I sold it. I thought you'd given up!

I'll go you half.

[LewisM]

30 minutes to handover and I’ve lost the newt focuser base. Je suis screwed

[LewisM]

Yay, it's finally gone! Hope Marc doesn't notice the missing bits appear on eBay. :P

Still got 2 hours before he gets home....

[multiweb]

Well, back home now and I have all the bits and pieces I think. :)

The tube finish looks bloody fantastic. Job well done mate, exceeding all my expectations. :2thumbs:

All the other bits are terrific as well.

I was told not to touch it for another 2 weeks until it cures and hardens so now I can only look at it and drool. :sadeyes:

By then I should have collected all the other pieces of the puzzle, tak collimation tools, reducers, tubes and adapters.

Also found another frog (http://www.marscaper.com/) who has a CN-212, 98 model and we're exchanging photos and information. And he has the same kind of avatar as me.

http://www.marscaper.com/files/marscaper-hdr-froggy-lying.png

Who would have thought! :lol:

To recap. Michelangelewis knows his sh|t and did a terrific job on the paint and resto. Fully endorse him. If you've got any thing to fix send it his way. :thumbsup:

[Lognic04]

Does this guy do MT-160 tubes? :lol:

[multiweb]

Here's Sebastien's blog (http://www.em10-usd-arduino-takahashi.eliotis.com/) about his work on his CN-212 and an EM10 with an Arduino. Worth a read. :thumbsup:

[LewisM]

Taps fingers on desk... :lol:

[Kunama]

Beautiful work by Lewis. That will look superb once back together again. As good as the one I had for half the price !!!

[multiweb]

For sure. He really went to town on this. Attention to details and went beyond a simple paint job, replacing bits with new ones as well. He pretty much approached and executed the job as if it was his own scope. A lot to be said for it.

[Kunama]

I think Lewis told me that he put on 9 coats of paint on the OTA !!!

I think I have a genuine original Takahashi M71>M72 adapter somewhere as well, brand new never used.......

[multiweb]

The whole rig was in pretty bad shape but for the optics that somehow are pristine. Something nasty happened to that tube for sure as all the internal paint was missing on one half. Traces of corrosion and wear out on pretty much all the other components. It is now back to its former self and I am looking forward to first light.

[RobF]

Looks stunning. Thanks for sharing guys. You better make sure she's packed nicely before taking on any bumpy roads to Astrofest next year Marc!

[multiweb]

Yeah I've been re thinking my packing arrangement even with the FSQ on the back seat when driving around. Going to make some foam padded boxes. Right down my list of things to do around the house though. :sadeyes:

[RickS]

Looks great, Marc & Lewis!

[RobF]

Used to pad my Tak in a big doona on the backseat, until one year when the kids were young and they decided to help unpack after a weekend away.....both had the doona by the corner and were tugging it out of the car. Just managed to catch the scope before it came out and hit the garage concrete floor :scared: :scared:

[multiweb]

Alpacalyptic! ;)



:lol: Yeah that would send cold shivers down my spine too.

I have that recurring dream that my C11 falls off the mount in the grass and glass shuttering noises are heard in the dark before I wake up. Maybe I drink too much coffee.

[multiweb]

Tube is now flocked. So will start putting secondary spider back in soon.
And my box of goodies.
Spider is back in. So are all stainless steel fasteners. Touching up all the nuts,bolts and edges inside with flat black paint. Need a bright led torch. It's very dark in there now.

[RickS]

Completely and thoroughly flocked, Marc :thumbsup:

[multiweb]

All smiles for the flash photo. :)

[LewisM]

Flocking hell, that's better! :lol:

Frankenstein rises...

[multiweb]

Finally got the new control wheel delivered from China to fix my broken SONY NEX-5 so I can take decent pics again. :)

The inside is nearly done. Still doing black touch ups on the bolts and will fix flocking tomorrow once it's dry. Still waiting on TAK collimation scope and other bits so won't be able to put the primary back in there for a while still.

I can only look at it for now still. :sad:

[Atmos]

Seeing that makes me want to flock my Mewlon 250!

[multiweb]

I know it's been a controversial subject lately but I've always done it with protostar material and it works for me. Or maybe it's the placebo effect? :lol:
Seriously it helped a lot with my C11 so I ended up flocking my newt then the mewlon then this one. Anything that has a largish aperture or is not baffled. My Mewlon 210 did show and increase in contrast before and after. I was able to confirm with imaging before and after. Just don't put cheap stuff or "velvet" into an expensive OTA. This stuff is for clothing. Socks on lenses is different. :lol:

[multiweb]

Well the inside is all done now with glue and touch up paint. It's as darks as it's gonna get. Much better than what it was. The inner tube was a real dog's breakfast, Lewis can attest to that. I don't know how's he managed to stabilise it in the first place.

[Kunama]

That is a great result Marc, a great restoration indeed. Looks brand new!!! Looking forward to seeing the completed scope.

[multiweb]

Thanks mate. I can't wait to actually look into it. Maybe today. :prey:

[multiweb]

Well it's back together now mostly. Still have to fit the finder which is drying.

I've attached a pic of the serial# plate which was very corroded. I cleaned it as best as I could and sealed it. Very fitting for Frankenstein.

Mostly spent the week finishing off flocking and painting inside but last night I put the spider back in, the secondary cassegrain mirror and the primary cell.

Used the Hotech to align everything and a circular howie glatter pattern to center the secondary. I don't have the TAK collimation tools yet so that'll do for now.

Maybe I can have a look into it tonight and do a quick star test. Will definitely look at some trees and TV antennas today though. :lol:

[RickS]

Dead on target, Marc :lol:

[multiweb]

Indian myna training mate.

[Wilso]

Looks fantastic Marc,

Keeping the tag in original condition is a good idea also!
I kind of like messing with my Astro gear as much as looking through them.
Very rewarding when completed.

:thumbsup:

[LewisM]

Well, that was worth all my blood, sweat and tears (more tears than anything :lol:)

Epic is a very apt adjective for this restoration. From Freddy Kruger to Belle of the Ball.

[RobF]

That last re-aligning pic looks like you're all set to touch down at Clavius Base
(tragic 2001 Space Odyssey reference - skip to 2:45 :) )


https://www.youtube.com/watch?v=RtDS2sI0N50

[multiweb]

Thanks. That's the only ugly bit that reminds me where it comes from. :)

I like frankenstein better, Freddy Kruger scared the sh!t out of me when it came out.


:lol: yeah I remember that scene.

Still watching paint dry for now. Nothing new yet. Might do a star test tonight with an articicial star to check collimation but the tube is still very tender to handle which is a real pita. I have to be super careful. I've learnt a lot about touch ups though and paint resto, polishing, etc... so I kept busy fixing my car bonnet this weekend and bought an orbital polisher. Holding this thing is like riding a hula hoop.

[multiweb]

All set up to check collimation tonight. Waiting for dark.
Artificial star across the reserve is ~30m I'd say direct line of sight from the scope on the table through the garage.
Posting a couple of videos soon taken through the scope with my SONY NEX-5.

Here's the video during twilight of the artificial star at the cassegrain focus.

https://vimeo.com/298821676

[multiweb]

Learnt a few things tonight. My artificial star is just not bright enough to be of any use with the CN-212. 8 ish " at f/12+ doesn't cut it. Even visually with a 4mm eyepiece it's pretty dim once defocused. The NEX-5 at 12800 ISO 5s exposures shows the diffraction rings but I focus and shoot in the dark. Nothing is bright enough for a live view focus. Will have to try with a webcam and the laptop next time. Here's a serie of pics in and out of focus. Collimation is a little out but not by much so as Rob said my 2001 moon landing was pretty close. :P

Here's a GIF sequence (http://www.astropic.net/astro/CN-212_artificial_star_cass.gif) shooting in the dark. Will do a better video with my ZWO when I get a chance and tweak collimation.
Also added what I think is the closest to focus in the few frames I got.

[multiweb]

Here's a video done last night with an ASI 120MM.
I will need to mount the scope to do further tweaking as it is cumbersome to collimate and shift the OTA back on the table to recenter the star.

PS: I measured accurately tonight. The distance from the scope aperture to the star was 46m and the diameter of the smallest inner dark disc where the star sits in the video is 4.7mm across.

https://vimeo.com/299117886

and a focus sequence with Bahtinov mask (http://www.astropic.net/astro/CN-212_artificial_star_02.gif) [7.5MB].

[Merlin66]

Marc,
are you going to set-up both the Newt and Cass arrangements??

[multiweb]

I'm trying to get the cassegrain right first, spider centering, primary tilt etc... I'm still waiting on the TAK collimation tools and accessories to do the newt side of things. The mirror has a hole in the middle so you can't use a cheshire or a laser or even the catseye kit, so I'll do that later. There's a step by step procedure in the manual. I also saw a few posts on CN using a howie glatter.

[multiweb]

It is Aliiive!....:scared:

[RB]

Awesome stuff Marc and Lewis.

:cheers:

[h0ughy]

whats that red bit - did you cut yourself assembling it:rofl:

[multiweb]

Some of Lewis blood and sweat.

Keen for tonight. Not ideal conditions but hopefully can have a look at some real stuff for a change.

[Lognic04]

I think you offended Lewis with that moonlite :lol:

[multiweb]

I need a focuser to image at the back. The moonlite is motorised. Otherwise I'd have to drill the back for a bracket and change the primary focuser to a micro focuser. If I drilled the back Lewis would give me a call for sure.

[Lognic04]

hehe. I think i have to drill my focuser, only way i can mount a stepper properly! Lewis is definitely gonna kill me :lol:

[LewisM]

I gave up on saving that MT160 a long time ago :shrug:

Plenty ways to mount the stepper without drilling. Use the flange screws already there, bend the bracket at right angles. think laterally.

[Lognic04]

Flange screw or screw(s)?
I think i probably might have better luck with manual focusing for the minute anyways, with this focuser...

[multiweb]

My TAK collimation and adapters are posted. Should get them within the week. Scope is on the mount. Everything is set up. Aligned the finder. Sky is still blue. Hope it sticks for a little longer. :prey: I just want to see one star.

[multiweb]

Couple of shots taken with the NEX-5 at sunset tonight. Achernar and NGC104. 15s unguided. The fov looks a lot better than the Mewlon 210. Collimation is still a little out and I haven't touched it. Seeing is not the best. Pretty happy with sharpness and contrast though. Just set up the QHY9 mono with UV/IR cut LUM filter now waiting for the clouds to clear and try some long exposures.

[multiweb]

Achernar single 3min exposure LUM QHY9 guided and very heavily strecthed. Pretty happy with the stars in the field at that FL. Image scale is 0.42asp and fov 24' x 18' . The double diffraction spike tells me what I already knew when I checked visually, the secondary is not quite centered and the spider vanes are not exactly square. When I get the TAK collimation scope I'll be able to tweak that and recollimate. I reckon the scope will perform exceptionally well once I get it right. The FL on this shot is 2.6m.

Added 7x2min so 14min LUM on the trap uncalibrated. Limiting factor is going to be my guiding. :sadeyes: But exciting times ahead. I have now a scope I can't even get the best out of yet. Very sharp and such a nice flat field compared to the C11. It gathers less light but the quality of the data can't compare off axis.

[multiweb]

Final cassegrain collimation tonight looks good.

https://vimeo.com/299853950

Done with a ZWO ASI 120MM. THis time on the mount so it was very easy to recenter after tweaking the secondary tilt.

[LewisM]

Kinda looks like a telescope again :P

[Kunama]

Great work on the collimation Marc. Looking forward to the images to come.

[multiweb]

I knew frankenstein always had it in him, under all that rust, dints and cr4p it was a diamond in the rough.


I received all the collimation kits and adapter this morning in the mail so I will revisit for sure. The scope is cooling outside as we speak, everything is set up for a night of imaging or two, as sunday is looking good too.. :thumbsup:

[multiweb]

Tonight's efforts.

NGC104 8x180s
NGC2070 29x120s

Need to still fix collimation for stars. I can do that tomorrow as I've received all the collimations kits this morning. Field looks sharp and flat though with no noticable curvature or flaring corner to corner.

[Dennis]

Yes Marc - they look very good from edge-to-edge, very nice indeed.:thumbsup:

Cheers

Dennis

[multiweb]

Looks a lot better than the mewlon 210 because it's a classical cassegrain and better corrected. It was fairly easy to collimate accurately today. The newtonian side I did struggle. Got it in the end but it was pretty hard.

[peter_4059]

Looks like a great project Marc. Can't wait to see some images.

ps - no sign of Indian Mynas on those antennas....

[multiweb]

I've had one dropping on the white tube already. No respect...

[RickS]

Test images look good, Marc!

[multiweb]

Getting very close now. :thumbsup:

[LewisM]

White?! White?! It’s not bloody white. I wish it were white... bloody ochre with blue tint...

Oh I had fun with that tube... might send Arief a “Pain and Suffering” claim (joking...kinda):P

[Dennis]

Hi Marc

I don't know where I obtained this "Collimation Guide" but here it is, if it can be of any use for the CN-212.:)

Cheers

Dennis

EDIT:
http://www.alluna-optics.com/Downloads/Alluna_RC-collimation-English.pdf

https://gravitylens.files.wordpress.com/2013/08/takahashi-collimator.pdf

[multiweb]

Thanks a lot for posting all the links Dennis. :thumbsup:

[multiweb]

Some moonage waiting for dark tonight. SONY NEX-5 at the cassegrain focus in live view. With Mynas and all...

https://vimeo.com/300249375



Video at cassegrain focus [F/12.4]

https://vimeo.com/300392505

Video at newtonian focus [F/3.9]

https://vimeo.com/300394937

Some stacked stills from the ASI120MM. All cassegrain. First one is at the newtonian focus.

[multiweb]

Last night was great for testing. I had a couple of hours before clouds rolled in from the west and there was also a thin moon crescent to play with.

I had used the TAK scope the previous day to finish collimating the cassegrain focus. It's very close but still needs a tiny more tweaking which I'll do with the artificial star. I spent some time on the moon visually from 32mm to 24, 9, 6 and 4mm eyepiece. I could still easily snap to focus with the 4mm eyepiece and see some very nice sharp details. A lot more than with the C11. I took a couple of shots with my SONY NEX-5 and ZWO ASI 120MM.

Then I switched to the newtonian side which was a bit of a disaster. Visually the focus point snaps and the image is very sharp as well. The fov is huge. On closer inspection at higher magnification I can see very obvious astigmatism so the detective work is starting. I suspect something to do with the secondary as the primary is ok in cassegrain mode. There is an aluminum cylinder that encases the secondary glass to stop it from dewing up I assume. It was very tight so I've losen that. I think maybe it was pressing against the glass. The astigmatism can be compounded by the fact I still haven't got the newtonian side collimated correctly. But there is definitely some kind of stress in the glass there.

Here' s a couple of shots of the primary collimation push/pull system, centering and locking mechanism. It's well designed and very simple.

[multiweb]

Some good progress. Finally got everything collimated tonight including the newtonian side. The aluminum shroud for the secondary was stressing the glass and causing the distortion. Losening the screw that holds it did the trick. There is a very slight sign of astigmatism when very close to focus but nowhere near what it was. I don't think it will be and issue with the CCD given the image scale as it is so close to focus, might not even notice it. Will see when I do a full fov shot. I also tested the newtonian corrector. Seems to do a decent job. Will post before/after pics later on.

This is the diffraction rings for the newtonian focus IN/OUT. First part of the video with the SONY NEX-5 , second with the 120MM.

https://vimeo.com/300486343

[multiweb]

Here's the uncorrected (1st) and corrected field (2nd) with the SONY NEX-5.

[multiweb]

I did a star test on both cassegrain and newtonian focus tonight taking advantage of the steady skies. Went down to a 4mm eyepiece and I didn't have to tweak either. Spent a bit of time on the moon, saturn, NGC 104, the tarantula, anything bright enough that I could see from my light polluted skies. So I think I'm done and dusted now. As Diego would say, I am happy. :lol:

Video of the moon tonight with the SONY NEX-5 at the Newtonian focus. No corrector.

https://vimeo.com/300710018

[RickS]

Woohoo!

[multiweb]

:cool:

Got the final piece in the mail this morning, the coveted focal reducer to bring the system from F/12.4 down to F/9.9. So my box of goodies is now full.

To date I have finally a complete system. The only thing I don't have is the certificate. Takahashi doesn't make test certificates public but I had a verbal confirmation that this scope serial# had passed as "excellent" by takahashi internal standards from the people who put it together at the factory.

Now I'm tightening my mount and trying to remember how to use the SXV-AO-LF then I should be well on my way to having some long focal length fun and try my luck at some small galaxies. :thumbsup:

[Merlin66]

Any reason you wouldn’t use the New focus f3.9 and a good barlow to get f7.5 etc rather than a reducer on the Cass?????

[multiweb]

Plenty. There's a coma corrector for the newt and a big overhang already. The cassegrain side is also a lot easier to collimate and more rigid with plenty of back focus. Makes sense to use that end. I haven't finalised how I'm going to automate focus yet. At the moment I have a moonlite at the cassegrain end so I don't have to move the primary. For the newt in visual it is very awkward to look into the eyepiece and extend your arm to the back of the scope to focus. That's 80cm away. So if you image in newt mode you need to move the primary. This means in the long term I might have to get a starizona micro-focuser, feathertouch kind of setup and mount a sharpsky pro on it like I did for the C11. But I'm more interested in the immediate to image at long FL at the cassegrain focus. This is why I got the scope and moved away from the Mewlon 210 which had a smaller uncorrected imaging circle. This one is dead flat across 39mm.

[Dennis]

You might need this back focus info.:)

Cheers

Dennis

[multiweb]

You're awesome mate! :thumbsup::thumbsup::thumbsup:

[multiweb]

Trap in Ha 30min with the CN-212/QHY9. Desperate to image so did this in a few sucker holes. Needed to confirm scope was properly collimated and star shapes alright. Looks good all over the field. Happy days.

HD here (http://www.astropic.net/astro/M42_Ha_CN-212_HD.jpg)

Big one (1:1) here (http://www.astropic.net/astro/M42_Ha_CN-212_1to1.jpg)

[Kunama]

That looks good Marc, now that you have it dialled in I am looking forward to seeing what you can do with this scope with good sky conditions.

The restoration was well worth the time and effort :thumbsup:

[multiweb]

Thanks Matt. :thumbsup: Yeah I'm over the moon with that scope fov. It is so good across the whole field. Almost looks like FSQ quality stars at 3m. Very impressive. And it is better corrected than the Mewlon 210 although the fields are very similar. My guiding is the bottle neck so I'm not even close to what this scope can do. This is still 70% of the top performance I reckon.

PS: added final stack with 25x2min and 200% fov center, edges and corners to show correction (big one here (http://www.astropic.net/astro/CN-212_fov_200.jpg)).

Stars would be perfectly round if I could guide under 1 second of arc. I can live with it for now. I just want to image.

[RickS]

Very impressive, Marc! I can probably find you a spare pier at El Sauce ;)

[multiweb]

My astro tent base is 2x2m. I have a tripod and a compass. I'll bring the cheese and wine. :P

[RickS]

And some chips for the alpaca :)

[multiweb]

Some yass grass.