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Meade-Vorce "Polaris" 90mm f/10 Achromat OTA

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#26 tony_spina

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Posted 22 September 2018 - 04:08 PM

Alan,

Another option that I have used to fill in holes from removed dovetail bars and finderscopes are the plastic hole plugs.  They come in flat black, in various sizes, and snap right in. The local hardware store carries them by me



#27 Sky Muse

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Posted 23 September 2018 - 12:22 AM

Alan,

Another option that I have used to fill in holes from removed dovetail bars and finderscopes are the plastic hole plugs.  They come in flat black, in various sizes, and snap right in. The local hardware store carries them b

I'm aware of them.  Yes, there is that, and good enough I suppose.  One thing that I was particularly excited about in this acquisition was that it came with a metal focusser; although without a metal objective-cell.  In other words: the less plastic, the better, if I can help it.  In this case, the holes were threaded, and without having to maneuver and install nuts on the inside; much easier. 

 

Incidentally, I just now tested the heads in relation to the tips, of the tube within the tube rings, and they catch...

 

old holes3.jpg

 

...so the heads will need to be ground down a bit to clear.  No problem; however it could slide, the issue that is, as it shouldn't prevent a proper balancing of the tube, but do I really want to find that out upon the event...



#28 Sky Muse

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Posted 23 September 2018 - 01:54 PM

I ground down the heads of the filler screws, but not all the way down flush with the surface of the tube, and still they would not completely clear the tips of the tube-ring bolts, so I took out the bolts and shortened them, and removed the flat-washer for each, retaining the lock-washers only.  Afterwards, I spray-painted the heads of the fillers with gloss navy-blue, the colour close enough, and to weatherproof...  

 

old holes4.jpg

 

old holes5.jpg

 

It takes 24 hours for the paint to cure.

 

All's well now, and with the mounting aspect of this achromat completed.



#29 tony_spina

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Posted 23 September 2018 - 02:21 PM

If the holes were threaded wouldn't grub screws give you that flat look?



#30 Sky Muse

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Posted 24 September 2018 - 02:13 AM

If the holes were threaded wouldn't grub screws give you that flat look?

I had thought about that, and as I was falling asleep one night.  The goal was to simply seal the holes, after all.  But each hole had a dimple surrounding it, and from the drilling and tapping; cheap-looking.  Then I started thinking about...Bondo...gaah.gif .  Bondo is quite good actually, but only if you're planning to paint a piece entirely; not spot painting.  There was sprue from the tapping on the inside as well...

 

sprue.jpg

 

I need to edge the doublet next, and before I correct, blacken and flock the focusser, tube, objective-cell, and the dew-shield...

 

doublet marks.jpg

 

I want its paint to harden, to cease off-gassing, and before I put it all back together.  The dew-shield is one piece, and friction-fit...

 

dew-shield.jpg

 

The finish reminds me of those old Fisher cassette-decks and turntables I had repaired back in the mid-to-latter '80s.  I'm going to paint that dew-shield, for certain, and whilst it's still relatively warm outside.


Edited by Sky Muse, 24 September 2018 - 03:51 AM.


#31 Sky Muse

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Posted 24 September 2018 - 05:14 PM

The edges of the doublet are now blackened, and with their new and permanent marks...

 

doublet3.jpg

 

The next step will be to install the new spacers.


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#32 Sky Muse

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Posted 26 September 2018 - 02:25 AM

I went to Home Depot, then to Lowe's, then back to Home Depot; Lowe's wanted about 50¢ more for the same can.  Yeah, I probably spent 50¢ in gas returning to Home Depot, but it's the principle...

 

paint.jpg

 

paint2.jpg

 

That's for the one-piece dew-shield and its faux objective-cell flange.  Afterwards, I'll apply a clear-satin, possibly a spray-varnish.

 

I had narrowed it down to that, or a satin "claret wine" or "cabernet"...

 

Want some cheese with that whine?



#33 Sky Muse

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Posted 26 September 2018 - 11:30 AM

The new spacers ready to install...

 

spacers.jpg

 

Ahhh, yet another before-and-after...

 

doublet4.jpg

 

Note how the blackening gives the illusion that the doublet is much less there, as though its physical presence has been reduced in the light-path.


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#34 tony_spina

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Posted 26 September 2018 - 04:27 PM

Looking good


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#35 Sky Muse

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Posted 27 September 2018 - 02:13 PM

Certain surfaces of the objective-cell and retaining-ring were roughened with steel-wool, then the components washed, de-greased with 91% rubbing-alcohol, and tack-clothed...

 

objective cell.jpg

 

...then masked for the ultra-flat black...

 

objective cell2.jpg

 

...then the masking altered for the metallic, matte nickel...

 

objective cell3.jpg

 

The retaining-ring for the lenses was blackened as well.  The objective-cell is now complete

 

objective cell4.jpg



#36 tony_spina

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Posted 27 September 2018 - 05:56 PM

Love the color scheme 


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#37 Sky Muse

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Posted 28 September 2018 - 02:49 AM

Love the color scheme 

This is the only instance in which I've seen a "grey" combined with the Meade-blue...

 

https://www.bhphotov..._refractor.html

 

Incidentally, compare that "Infinity" dew-shield assembly with that of this Celestron...

 

https://grovers.biz/...ster-102-az.jpg

 

hmm.gif

 

The last thing to paint is the dew-shield/flange, but I'll need to re-blacken the interior beforehand, then wait until later today, this afternoon, when it will climb up to a toasty 78°.  I just went through a LOT of overcast and random showers for the last week or two, but it's going to be relatively clear for the next week, and with the high topping out at 84°.  The warmer it is, the better to paint outdoors.



#38 Sky Muse

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Posted 28 September 2018 - 12:48 PM

The interior of the dew-shield has been blackened(only the slim, forward-facing surface of its inner rim), and clear-satin applied in preparation to flock the inside...

 

dew-shield2.jpg

 

Yes, I'm going to flock its interior instead of painting it.  Also, the outside of the dew-shield has been prepared for the metallic, matte nickel.  Once the nickel has been applied and sealed with clear-satin, the flocking will be the final step.


Edited by Sky Muse, 28 September 2018 - 12:57 PM.


#39 Sky Muse

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Posted 28 September 2018 - 02:43 PM

It turned out very nicely; gone is that cheap, black-plastic appearance...

 

dew-shield4.jpg

 

dew-shield3.jpg

 

Now, the finish isn't quite flawless, as it was done via rattle-cans, and on the front porch.  Thankfully, there were no insects flying around.

 

Admittedly, it now sports a cheap, silvery-plastic appearance, but improved nonetheless.


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#40 tony_spina

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Posted 28 September 2018 - 06:15 PM

I like the silver dewshield 


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#41 Sky Muse

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Posted 29 September 2018 - 05:19 AM

I like the silver dewshield 

That's what it's all about; making it your very own.  I just now took some #0000 steel-wool and furniture polish and smoothed out the finish; now to flock it.  

 

Incidentally, after nine long years, I placed another order...

 

Protostar.jpg

 

Protostar2.jpg

 

The fixed width in 2009 was 30", and I had ordered a length of 75" at that time.  You can still see that fixed-width mentioned when you're in the process of placing your order, however it also states a 24" width, and on the main page prior to clicking on the specific item...

 

http://www.fpi-proto....com/hitack.htm

 

This time around I ordered a 48" length; otherwise the same fixed length and width(24") as that offered by ScopeStuff...

 

http://www.scopestuff.com/ss_flok.htm

 

In the end, I received the same width and length from Protostar, as if I had ordered it from ScopeStuff; although Protostar does offer bulk lengths up to 500" in the 24"-width. 

 

I could've saved $3.40 had I ordered it from ScopeStuff; but is theirs the same; much mysterious goings-on there. In any event, I have a new, albeit shorter, roll of genuine Protostar flocking; unique in all the world, nothing else like it.



#42 Sky Muse

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Posted 29 September 2018 - 08:37 PM

Here, I am about halfway around with the flocking...

 

dew-shield5.jpg

 

Here, I'm down to the last strip, however it will end up being trapezoidal in shape...

 

dew-shield7.jpg

 

Incidentally, I will have no need of the new roll of flocking for this achromat, as I have enough left of the old roll to complete it; more than enough.  Also, I will illustrate how I will, and by then had, cut the last strip to fit, practically precisely, and in my next post, so stay tuned...



#43 Sky Muse

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Posted 30 September 2018 - 11:53 AM

The dew-shield is completed...

 

dew-shield8.jpg

 

The customised piece fit so well in fact that perhaps only I could tell you where it's located exactly.  There to the left are the two slips of copy-paper that were taped together once they stopped into their positions as I spread them apart.  Each strip is narrower than the space itself, of course.

 

Now for the optical-tube and focusser...



#44 Sky Muse

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Posted 01 October 2018 - 10:05 AM

The tube's masked, and for blackening and flocking...

 

tube masking.jpg

 

The end edges of the tube had an uneven build-up of paint, and the lack of paint.  I placed each end face-down onto a sheet of 220-grit sandpaper and sanded them smooth, after which the thin edges, that of the objective end at least, will be blackened, as I can see most of the tube's edge beyond the doublet as you peer inward.

 

The sanded edge can be seen here, along with the three baffles.  I'm still impressed by the number of baffles within this entry-level specimen.  I will re-blacken the runs amidships, along with the baffles themselves, and flock the fore and aft runs...

 

baffles2.jpg

 

The factory(Sunny Ningbo?) used a blacker paint than what I've seen from Synta and its "Synta grey".


Edited by Sky Muse, 01 October 2018 - 10:09 AM.


#45 Sky Muse

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Posted 02 October 2018 - 07:12 AM

The interior of the optical-tube has been re-blackened, but only the surface of the run at the objective end satinised, and for the flocking.  After the blackening of the two inner runs, between the three baffles, I decided not to flock the focusser end after all, so I went ahead and blackened that run, sanding/roughening its previously satinised surface just before...

 

baffles3.jpg

 

I had read of someone having flocked that end, but I see no practical need or benefit.  Once the refractor is closed up, there at the back, it will be as dark as an unopened tomb of antiquity, and with no real chance of any extraneous light intruding. 

 

However, the forward-facing area of the focusser will be flocked, and as I had done to that of the Antares achromat...

 

drawtube cavity9b.jpg

 

I'm a flocking fool, but there is such a thing as temperance.  


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#46 Sky Muse

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Posted 02 October 2018 - 09:56 PM

The objective end of the optical-tube has been blackened(edge) and flocked(run)...

 

flocked objective.jpg

 

The edge is not white as it appears there, but ultra-flat black.  The camera's flash is responsible for that.  Part of that edge can be seen through the doublet, and was therefore blackened.

 

Now for the focusser, and the last stretch...



#47 Jaimo!

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Posted 02 October 2018 - 10:10 PM

Lovin' this thread.  I keep clicking on the ebay link to buy one, but talk myself out of it... I need another scope, and project, like I need another hole in my head.  Although, I did order some flocking.

 

popcorn.gif waytogo.gif

 

Jaimo!


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#48 Sky Muse

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Posted 03 October 2018 - 08:34 AM

Lovin' this thread.  I keep clicking on the ebay link to buy one, but talk myself out of it... I need another scope, and project, like I need another hole in my head.  Although, I did order some flocking.

 

popcorn.gif waytogo.gif

 

Jaimo!

Oh, give it a go.  Go on, do it...

 

https://www.youtube....h?v=TVH3IBr_Ipk


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#49 Mr Onions

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Posted 03 October 2018 - 01:55 PM

It's looking really good.

Great read and photos!


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#50 Sky Muse

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Posted 03 October 2018 - 08:42 PM

Anatomy of a modern, imported, metal 1.25" focusser...

 

focusser.jpg

 

It's entirely of metal, save for the plastic knobs of course.  I have no idea who made it: Synta, Sunny Ningbo, GSO, although I suspect Synta, and from what I had found within.

 

The drawtube is certainly impressive...

 

drawtube3.jpg

 

The chromed rack led me to believe, at first, that it was of plastic, and because of that certain something I encountered later.  But it's of brass, and after having tried to gouge it with a knife.  Now, I've seen a brass undercoating under a chromed plastic surface before, so I gouged it again to make certain...

 

brass rack.jpg

 

I would not have been surprised in the least had it been of plastic.

 

The pinion, and with a glob of glue-like mystery grease...

 

pinion.jpg

 

Down the drawtube's housing we go...

 

focusser housing2.jpg

 

I was appalled; not one of the three bearing strips for the drawtube were of PTFE...

 

bearing strips.jpg

 

It's those two white, corrugated strips that leads me to believe that Synta made this focusser, for they're the very same strips that once inhabited this mostly plastic Synta focusser that I have...

 

coffee cake.jpg

 

Here, the housing has been emptied and cleaned, including the strip's bases in preparation for the PTFE...

 

focusser housing.jpg

 

Everything has been cleaned at this point.  Given the rather small opening of the baffle at the rear of the optical-tube...

 

baffles4.jpg

 

...I don't really see the need for a flocked baffle for the housing after all, therefore I will merely blacken the inside of the housing instead.


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