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OOUK VX16 refurbishment


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Well, all the awful weather we've had lately has driven me to take the opportunity to take my VX16 apart rather than wait for summer.

The primary really needed a clean - which was the main trigger for this - but there's a bunch of other problems I want to resolve to make this scope a really reliable "daily driver" for my use, which is purely visual observation with little setup time in quite a humid area. The scope lives outdoors all year round under a cover.

Things I'm going to try and do:

  • Mount the Telrad base properly with screws (the adhesuve strips don't actually suffice on their own, hence tape below)
  • Replace the finder shoe for compatibility with the finders I have
  • Remove the tube rings and renew the felt lining
  • Repaint all the scuffed and chipped bits on the scope mount with new Hammerite
  • Renew all the PTFE bearings on the mount
  • Drill and tap the mount for encoder mountings so it's ready for that (if Astro Devices ever get back to me!)
  • Finish flocking the inside (it was part-done by a previous owner)
  • Fit the primary fan properly in the primary cell (part-done but can't finish it properly without taking the mirror out of the cell)
  • Renew the spider and secondary hardware with stainless steel thumbscrews to avoid corrosion issues from condensation, after finding them rusting after some wet months
  • Fit dew heaters for the primary, secondary, Telrad, and eyepiece
  • Fit screw-mounted cable tie anchors down the length of the tube to properly manage dew heater and other power cables
  • Paint all remaining exposed surfaces with heavily pigmented black paint (Stuart Semple's Black 3.0)
  • Replace all the tube edging (it's cracked and failed)
  • Make a non-fabric tube cap out of wood with some simple quick-release retention mechanism

I've also got some tidying up to do on the secondary which was flocked around the edge for some reason, and cleaning of all the mirrors.

Dew heating is definitely going to be a big upgrade - by far the most common reason I've had to stop play when using the scope, even with the fan. I've got a set of Lynx heater straps and a 4-channel controller to make it all work.

Should be fun.

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The assembled scope after demounting from the cradle for mirror removal.

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Inside of the tube, looking from secondary down, after mirror hardware removal. It's a bit dusty and only part-flocked!

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This is a bit concerning - where the rolled tube is formed together it's flattened out quite severely. Going to try and bring this back to a vaguely circular profile. This is after removing the tube edging - which just kind of fell apart in my hands as I took it off. Only glued on in about two places with a tiny dot of glue, but the material's also very brittle - I've got some rubber-and-steel edging trim to replace this.

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This is the primary, still in cell (which is quite an early OOUK one, I think - it's not their modern cell design for sure). Lots of large debris on this, as well as some regions where it looks as if the coatings might be failing - I'll inspect this in a bit more detail once I've got it out of the cell and the crud off. Definitely needs a clean, either way!

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Spider came out (with a bit of careful bending!) and the secondary looks fine, though also like it would benefit from a gentle clean to get some dust off. The main purpose of taking this out is to get the secondary mounting out for fitting of the dew heater, painting of the vanes, and replacement of the screws with stainless parts.

Will post updates as I go for anyone interested - I'm curious to know if any other OOUK dob owners have noticed the flattened section of tube above or if this is a damage/defect.

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1 hour ago, Second Time Around said:

No flattened edging on either my 8 or 10 inch OOUK Dobs.

I'll give that a bash out then! Must've had a bump at some point in its life.

Primary has had its first rinse in distilled water (about 2L) to get the worst debris off, though still a way to go clearly.

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The mirror cell came apart readily, though the big screws on the mirror clips required some persuasion and one refused to budge (note the precision engineering tool on left of photo!) so I left it and slid the mirror out instead, and have applied some lubricant to the reticent one.

In moving the mirror cell around I snagged the half-fit fan and managed to damage the wiring so am going to get a replacement rather than risk installing something that'll short when it's a bit dewy - or will replace the damaged wiring, soldering job looks trivial. The fan I got was from OOUK but the DC jack they've supplied won't actually fit the hole in the plate, so I'll need a thinner one of those or to drill out the hole a bit.

20220108_143626.thumb.jpg.95e6f3b5c44eaadca8c1e8984e56ff4c.jpg

The new edging worked a treat, though has left the joint of the tube exposed - I'll apply some Plasti-dip or something to protect this bit. The new edging is steel reinforced rubber and is much more elastic, should actually protect the end of the tube!

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Little bit worried about the state of the primary, but have only just started on cleaning, so will see how much of this comes off easily. Worst case it'll be back to OOUK for a recoat I guess!

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I managed to get in touch with John at OOUK and he's confirmed this is a very old mirror for them, likely polished to 1/4PV, so starting to think that recoating the primary is going to be a sensible path.

Started cleaning with 99% IPA today to try and shift some of the organic contaminants - currently still looking fairly grimy.

I think I'm going to get a couple of discs of plastic laser cut, with one sized to fit in the tube and one to fit over. The one to fit within the tube I'm going to have cut with some ports for 120mm 12V computer fans and mount in the base over the top of the mirror cell like I've done for my current imaging scope. The one to fit over the top I'll put some dowels in around the edge to let it just rest on the tube without slipping off which should work OK as a "lens cap"!

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On 08/01/2022 at 15:13, discardedastro said:

I'll give that a bash out then! Must've had a bump at some point in its life.

Primary has had its first rinse in distilled water (about 2L) to get the worst debris off, though still a way to go clearly.

20220108_141740.thumb.jpg.22c39cd1d0d798c7d3e5f80ac23032bb.jpg

20220108_140340.thumb.jpg.955e3108c36d2f6618437c3a9b4668d4.jpg

The mirror cell came apart readily, though the big screws on the mirror clips required some persuasion and one refused to budge (note the precision engineering tool on left of photo!) so I left it and slid the mirror out instead, and have applied some lubricant to the reticent one.

In moving the mirror cell around I snagged the half-fit fan and managed to damage the wiring so am going to get a replacement rather than risk installing something that'll short when it's a bit dewy - or will replace the damaged wiring, soldering job looks trivial. The fan I got was from OOUK but the DC jack they've supplied won't actually fit the hole in the plate, so I'll need a thinner one of those or to drill out the hole a bit.

20220108_143626.thumb.jpg.95e6f3b5c44eaadca8c1e8984e56ff4c.jpg

The new edging worked a treat, though has left the joint of the tube exposed - I'll apply some Plasti-dip or something to protect this bit. The new edging is steel reinforced rubber and is much more elastic, should actually protect the end of the tube!

20220108_142222.thumb.jpg.215937801999013421d6cf2aaeb0ddf3.jpg

Little bit worried about the state of the primary, but have only just started on cleaning, so will see how much of this comes off easily. Worst case it'll be back to OOUK for a recoat I guess!

Try cleaning site hard in a small area and see what you are dealing with. That looks rather like the coating has 'gone'.

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4 hours ago, AstroKeith said:

Try cleaning site hard in a small area and see what you are dealing with. That looks rather like the coating has 'gone'.

The good news is I don't think the coating's gone!

I gave the whole mirror a bit of IPA 99%, then washed with water. Then using some Sticklers fibre optic endface cleaning fluid - which is just a slightly more sophisticated IPA style solution for optics and glass fibre, so should be safe on SiO2/Al - wetted a lint-free cloth and with very light force dragged the fluid over a square inch or two of mirror and then rinsed with water. What's left below is a perfectly clean mirror surface with no apparent coating damage - I'll get some magnification on it and take a close look before I go further.

Definitely streaking/smearing of the contaminants, which makes me think organics of some sort. I'm going to try some dilute acetone tomorrow as a rinse and see if that helps to break down the organics without damaging the surface - my risk now is that if the contamination smears and doesn't lift with cleaning wipes, I'll have to do quite a lot of repeated dragging across the surface and risk damaging what's left. I really want to avoid damaging the glass at all costs - I'm quite sanguine about the prospect of recoating the mirror at OOUK given it's quite an old thing, but if the glass is damaged then I've got no chance.

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That is good news.

IPA can be remarkably obtuse! Sometimes it shifts stuff perfectly and as you have found there is some stuff it wont touch.
Also perhaps perversely, an IPA/Water mix is better sometimes that pure IPA.
Did you try soapy water first?
I've never used acetone on a coated mirror myself - if the coating is in fact weak then I'd really go carefully. Good luck.

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Great restoration project👍
 

Most of the Orion Optics Newtonian tubes I’ve seen are not completely round with a bit of a flat area at the seam. However yours looks more flattened so a bit of fettling required. Of course a slightly out of round tube won’t affect the views. The standard end trims have a lip, if you measure the diameter of the trim aperture it’s only just larger than the primary mirror. I’ve never really liked that feature- builders of truss tube Dobs always make the inside diameter of the upper tube assembly larger than that to avoid vignetting. So I think the trim you’re fitting is better than the original.

The main issue will be the condition of the mirrors. I’ve seen dire looking coatings still giving acceptable views, not ideal but fine to start with and see how you get on with the scope when it’s in action.

Good luck with this, and do come back with updates 😁

Ed.

 

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I've only just cleaned my OOUK 12inch mirror which is 15years old. I just used water with a little washing up liquid. I read about using cotton wool balls so tried that but didn't shift some of the gunk. I'd read somewhere it was ok to use your fingers with the solution to lightly rub the area after washing off any contamination. That worked a treat.

IMG_20211219_150228.jpg

IMG_20211219_145945.jpg

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39 minutes ago, Nigella Bryant said:

I've only just cleaned my OOUK 12inch mirror which is 15years old. I just used water with a little washing up liquid. I read about using cotton wool balls so tried that but didn't shift some of the gunk. I'd read somewhere it was ok to use your fingers with the solution to lightly rub the area after washing off any contamination. That worked a treat.

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That looks brilliant Nigella, sparkling!

I use the finger tip method too, it does work a treat as you say. I just make sure I soak my fingers for a little while so they are nice and soft before touching the mirror.

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1 hour ago, Stu said:

That looks brilliant Nigella, sparkling!

I use the finger tip method too, it does work a treat as you say. I just make sure I soak my fingers for a little while so they are nice and soft before touching the mirror.

That's good to know Stu, I was a little worried about it but it's a good method.

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Looks great!

I've used the fingertip method when cleaning my 200PDS and thought I'd give it a try after an experimental bit of cleaning with dilute IPA and a water rinse. I kept running distilled water flowing above my fingertips and slowly worked my way across the mirror. There's quite a lot of stuck-on debris still, but this got rid of all the pollen and organics - mostly. Still looking much better than it was!

This is the surface covered in dilute IPA:

20220110_211451.thumb.jpg.55709e8111928b1705e9d832bd052f9e.jpg

It's still fairly clear to see some of the debris (white spots middle right, etc) and some of the "dusty" appearance (bottom left). And yes, all the tools above on the shadowboard are secure! I've got nowhere else to put anything.

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Still one or two bigger bits of debris, too:

20220110_211532.thumb.jpg.dabd4cffacf2bb7d049f2466c428c154.jpg

Just going to try rinse+soak a few more times for now and then it'll be on to the wipes - but it's already dramatically improved from where I started!

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18 minutes ago, discardedastro said:

Looks great!

I've used the fingertip method when cleaning my 200PDS and thought I'd give it a try after an experimental bit of cleaning with dilute IPA and a water rinse. I kept running distilled water flowing above my fingertips and slowly worked my way across the mirror. There's quite a lot of stuck-on debris still, but this got rid of all the pollen and organics - mostly. Still looking much better than it was!

This is the surface covered in dilute IPA:

20220110_211451.thumb.jpg.55709e8111928b1705e9d832bd052f9e.jpg

It's still fairly clear to see some of the debris (white spots middle right, etc) and some of the "dusty" appearance (bottom left). And yes, all the tools above on the shadowboard are secure! I've got nowhere else to put anything.

20220110_211456.thumb.jpg.fbab7dee76983dcdb120451e88735570.jpg

Still one or two bigger bits of debris, too:

20220110_211532.thumb.jpg.dabd4cffacf2bb7d049f2466c428c154.jpg

Just going to try rinse+soak a few more times for now and then it'll be on to the wipes - but it's already dramatically improved from where I started!

Brilliant, I thought my mirror needed to be re coated until I cleaned it as it was getting on in years, lol. 

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3 minutes ago, Nigella Bryant said:

Brilliant, I thought my mirror needed to be re coated until I cleaned it as it was getting on in years, lol. 

15 years is pretty good going! I'm not sure quite how old this one is, but from a bit of internet sleuthing I think this was a "OD400 De Luxe" model with 1/4PV optics and Hilux coating:

https://web.archive.org/web/20090417025321/http://www.orionoptics.co.uk/DOBSONIAN/dobsonian400delu.html

That was gone from the OOUK website by 2011, replaced with the VX16 with 1/6PV optics as standard, so at least going on for 10 years!

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2 hours ago, discardedastro said:

15 years is pretty good going! I'm not sure quite how old this one is, but from a bit of internet sleuthing I think this was a "OD400 De Luxe" model with 1/4PV optics and Hilux coating:

https://web.archive.org/web/20090417025321/http://www.orionoptics.co.uk/DOBSONIAN/dobsonian400delu.html

That was gone from the OOUK website by 2011, replaced with the VX16 with 1/6PV optics as standard, so at least going on for 10 years!

Yeah, mine still had the original sticker on the side of the mirror stating ref number, year of manufacture, 2006 and 1/6PV . Forgot nearly 16 yrs now, lol. I bought mine second hand, changed the focuser with a moonlite, added a rear 12v fan, secondary heater, new losmandy plates top and bottom and internal temperature gauge. 

IMG_20211101_120425.jpg

IMG_20211101_132126.jpg

Edited by Nigella Bryant
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5 minutes ago, Nigella Bryant said:

Yeah, mine still had the original sticker on the side of the mirror stating ref number, year of manufacture, 2006 and 1/6PV . Forgot nearly 16 yrs now, lol. I bought mine second hand, changed the focuser with a moonlite, added a rear 12v fan, secondary heater, new losmandy plates top and bottom and internal temperature gauge. 

IMG_20211101_120425.jpg

IMG_20211101_132126.jpg

That's looking great :icon_biggrin:

My OO 12 inch F/5.3 is a 2006 vintage as well.

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I used to stress with mirror cleaning. Of course great care is always necessary, however-  a few remaining spots or streaks won’t affect the view. Actually a lot of remaining spots or streaks will hardly make any difference to the vlew.  
 

The only measurable effect will be to make the owner unhappy if he/she is prone to anxiety 😊

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57 minutes ago, Nigella Bryant said:

Yeah, mine still had the original sticker on the side of the mirror stating ref number, year of manufacture, 2006 and 1/6PV . Forgot nearly 16 yrs now, lol. I bought mine second hand, changed the focuser with a moonlite, added a rear 12v fan, secondary heater, new losmandy plates top and bottom and internal temperature gauge.

Absolute goals!

This has already had a focuser upgrade to a lovely Feathertouch which I've further upgraded with the Really Big Fine Focus Knob. Not sure how the default OOUK focusers are (or were!) but having gone from the default Skywatcher dual-speed focuser to a Steeltrak to a Feathertouch I'm now officially ruined!

Rinsed the primary once more with water this evening. Looking better. I'm probably going to leave the really hard to shift spots if I really can't get them gone, but am a tad nervous they may damage the coating if left in situ so will give removing them a gentle go.

Annoyingly the handles I'd ordered aren't going to ship for another month so will have to get some other ones. Just simple plastic ones for shoving and pulling the tube around to point, so not the end of the world and they'll find use on another project in due course. Going to drill out the holes in the tube for cable anchors tomorrow.

Finishing up the CAD for the tube caps/fan holder this evening but dithering over attachment methods for the bottom plate - ideally want something easy so I can drop it off to collimate. On my 200P I removed the locking bolts for the mirror cell and used those threads in the mirror cell plate as the anchors for the back plate I added, and given I don't tend to use the locking bolts here I might repeat the exercise (with cutouts for the collimation nuts), just have to see how the clearances look for the fans!

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6 hours ago, discardedastro said:

Absolute goals!

This has already had a focuser upgrade to a lovely Feathertouch which I've further upgraded with the Really Big Fine Focus Knob. Not sure how the default OOUK focusers are (or were!) but having gone from the default Skywatcher dual-speed focuser to a Steeltrak to a Feathertouch I'm now officially ruined!

Rinsed the primary once more with water this evening. Looking better. I'm probably going to leave the really hard to shift spots if I really can't get them gone, but am a tad nervous they may damage the coating if left in situ so will give removing them a gentle go.

Annoyingly the handles I'd ordered aren't going to ship for another month so will have to get some other ones. Just simple plastic ones for shoving and pulling the tube around to point, so not the end of the world and they'll find use on another project in due course. Going to drill out the holes in the tube for cable anchors tomorrow.

Finishing up the CAD for the tube caps/fan holder this evening but dithering over attachment methods for the bottom plate - ideally want something easy so I can drop it off to collimate. On my 200P I removed the locking bolts for the mirror cell and used those threads in the mirror cell plate as the anchors for the back plate I added, and given I don't tend to use the locking bolts here I might repeat the exercise (with cutouts for the collimation nuts), just have to see how the clearances look for the fans!

Be great scope when it's all up and running, well done.

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10 hours ago, discardedastro said:

Looks great!

I've used the fingertip method when cleaning my 200PDS and thought I'd give it a try after an experimental bit of cleaning with dilute IPA and a water rinse. I kept running distilled water flowing above my fingertips and slowly worked my way across the mirror. There's quite a lot of stuck-on debris still, but this got rid of all the pollen and organics - mostly. Still looking much better than it was!

This is the surface covered in dilute IPA:

20220110_211451.thumb.jpg.55709e8111928b1705e9d832bd052f9e.jpg

It's still fairly clear to see some of the debris (white spots middle right, etc) and some of the "dusty" appearance (bottom left). And yes, all the tools above on the shadowboard are secure! I've got nowhere else to put anything.

20220110_211456.thumb.jpg.fbab7dee76983dcdb120451e88735570.jpg

Still one or two bigger bits of debris, too:

20220110_211532.thumb.jpg.dabd4cffacf2bb7d049f2466c428c154.jpg

Just going to try rinse+soak a few more times for now and then it'll be on to the wipes - but it's already dramatically improved from where I started!

Excellent progress.

That 'dusty' appearance is to me the classic aged coating. Have you looked with a high power magnifying glass? Those white specks may be pin holes?

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13 hours ago, AstroKeith said:

Excellent progress.

That 'dusty' appearance is to me the classic aged coating. Have you looked with a high power magnifying glass? Those white specks may be pin holes?

I've not yet but am going to once it's dried after tonight's wash.

Tried doing half the mirror with acetone neat as a last-ditch measure to move some of the organics, so we'll see how that goes. It's allowed me to gently move off one of the bigger bits (the one in the last photo), so some progress! Rinsed down thoroughly with dilute IPA and then distilled water and we'll see how it goes.

Had a bumper delivery of wipes to try today - the Kimwipes did well, but the CERNATA critical wipes were better at removing material with less force. Kimwipes had a tendency to "adhere" lightly to the mirror so were hard to drag off whereas the critical wipes had enough rigidity to just rest on the surface lightly.

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Well, I'm pretty sure it's coating damage...

Took some better photos with a macro lens on the D1x after all the cleaning - not quite done yet, as you can see some streaks below - along with a lot of what's definitely starting to look like coating damage. The streaks in this area were a last-ditch drag with a cleanroom-grade lint free wipe, which failed to shift anything. I've fingertip washed this area twice now, too.

DSC_6876.thumb.JPG.aed450de4fa59216cf377108ae46f95d.JPG

Here's the whole thing. Interestingly, one edge appears to have been spared and cleaned up readily, top left through to centre. No idea why. Storage position?

DSC_6900.thumb.JPG.6bb0257a6178eca6a93b64b885acb822.JPG

Still a few bigger particles I've been unable to shift here and there.

DSC_6913.thumb.JPG.ee38cb1594d7081b0004ed14ab348d2c.JPG

 

DSC_6921.thumb.JPG.d052090135a1a4bf521d271c1eb94ffd.JPG

So I think the right course of action is to ship this to OOUK for recoating. But I've not got that sort of cash floating around at present - so for now, I'm going to leave it and focus on mechanical repairs and improvements.

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