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Orion 200mm F/4 Restoration project


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#1 Starlock

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Posted 08 May 2013 - 08:22 AM

Hi,

 

I noticed the above scope for sale on UK astrobuyandsell going fairly cheap due to its tatty state. It has small dents at the end of the tube where the owner had flocked too far down the tube reducing its diameter for the cell to go back in place. The owner tried forcing the cell back in before realising he needed to remove the excess flock, but by then the damage was already done. Apart from the dents there are a few scuffs on the tube from use but importantly the optics look good! :)

 

I've started this thread to document this scopes restoration and improvement. I will try my best to remove the dents but I might only be able to improve upon them so carbon effect laminate wrap might be an option. I've used this before on a restoration project and its given a very nice result. The scope is already flocked as said and has the sides of the secondary and the focuser draw tube blackened so there might be a limit to what mods I can do, therefore if anyone has any suggestions please fire away, this is partly what this thread is about :)

 

Cheaper F/4 scopes are notorious for collimation issues so I will also be looking at how to improve the mirror cell maybe upgrade the springs and re- silicon seal the mirror in place to reduce flop etc. The tube really needs to be carbon with these fast Newts but I will do the best with what I've got by trying to stiffen up the structure if needed, I can't do anythink about the thermal stability without buying a carbon tube which I'll get a price for incase its feasable.

 

Here are some before pics the guy has sent me, the scope should arrive at the weekend :)

Attached Thumbnails

  • Orion 200mm Silicone on mirror & cooling fan.jpg
  • Orion 200mm Right side.jpg
  • Orion 200mm Primary.jpg
  • Orion 200mm Low profile dual speed focuser.jpg
  • Orion 200mm Left side.jpg
  • Orion 200mm Dents 2.jpg


#2 Starlock

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Posted 08 May 2013 - 10:32 AM

I think its probably going to be a case of undent the tube as much as possible and wrap the tube in either gloss black or carbon effect adhesive vinyl.

 

I think some Bobs ***** for the secondary and stronger primary springs also.



#3 astrodoc71

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Posted 08 May 2013 - 10:35 AM

That's a great project Chris! Is the mirror decent?

Regards

Dave


daveandtelescope.wordpress.com


#4 Starlock

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Posted 08 May 2013 - 11:01 AM

Thanks Dave, I'm not sure what grade the mirror is, I've not been able to find much in the way of specifications for this scope on the net? I should imaging its around 1/4 to 1/6 wave, its Orion so it should be fairly good. The guy said optically its very good :)



#5 DENEB

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Posted 08 May 2013 - 05:22 PM

These are one of the nice Orion (USA) 8" scopes with good results

http://www.telescope...19/p/101450.uts

Correcting the flocking near the primary is so easy !

It's more likely it will be skywatchers 1/4pv grade as they come out of the synta factory but be par on with celestrons quality, as you can see from the build quality of the scope already.

#6 Starlock

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Posted 08 May 2013 - 06:49 PM

Thanks for the link Nadeem, I actually visited that site and missed the spec tab first time round. I've just seen that the tube length is 30" long so I can order the correct amount of carbon effect vinyl wrap now :)

 

The guy who flocked the tube all the way down realised about the flocking and corrected it, but not before denting the tube unfortunately. Therefore I have the not so simple job of trying to undent the tube enough that vinyl wrap will give a smooth result.

 

One thing I do notice about the scope on the above link is that it has 9 internal baffles like the Quattro, I don't know what happened to these on the scope I'm about to receive?

 

I've been on the Bob's "bolts" site (that got round the filters :D) and I've been looking at which secondary thumb "bolts" to get? I think I'll need to wait unitl the scope arrives to measure the existing ones to ensure I order them correctly. The existing secondary bolts look rusty anyway, its a good excuse to fit some of Bob's :D



#7 DENEB

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Posted 09 May 2013 - 06:13 AM

Must be an earlier version then.



#8 Starlock

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Posted 09 May 2013 - 10:36 AM

Maybe Nadeem? I didn't pay a lot for the scope so my expectations are realistic :D

 

I've ordered some 4D carbon Vinyl adhesive wrap 1000mm x 1000mm. It looks quite realistic, its worth a go:)

 

http://www.ebay.co.u...d=320713729466



#9 DENEB

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Posted 09 May 2013 - 01:08 PM

I take it, you did not feel like using Polyfiller then ? :lol:



#10 Starlock

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Posted 09 May 2013 - 02:26 PM

Yes very funny :P

 

I found a second hand coma corrector at a very good price! although, its a SW 0.9 CC so I'd be a bit worried about using it on a f/4 scope as it would make it f/3.6 which might be working too far beyond the engineering of the scope? 

 

I'm giving serious thought to getting one of these for the focuser. It might help critical collimation with my Hotech 1.25" and Cheshire, plus it would help keep my CCD centred to my collimation.

 

http://www.altairast...id=16455&page=1

 

Any thoughts?



#11 DENEB

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Posted 09 May 2013 - 07:39 PM

I thought you had a baader coma corrector.



#12 Starlock

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Posted 09 May 2013 - 09:27 PM

I did have one at one stage but sold it when I no longer had a Newt to use it on.



#13 DENEB

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Posted 10 May 2013 - 12:28 PM

I found the bog standard skywatcher coma corrector will give you Spherical Abberation at F4, thats what i found when using it with a Quattro.

 

The Baader MKII is the best bet, but you will need to get the spacing correct it really is fussy ! Mind you though using that Marmaduke you might not need it.



#14 Starlock

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Posted 10 May 2013 - 12:58 PM

Thanks for letting me know Nadeem, I was also unsure about using it with the f/4 as it would bring it down to f/3.6 which would be pushing my luck I think.

 

I think you might be right about not needing it with the marmaduke although it would be good with a DLSR. Having said this I'm so into using the Marmaduke that I don't think the Canon will get a lookin for a while. Still if and when I do it should work well with the 150pds, and I couldn't turn it down at 49 pounds delivered with all the adpators and original box, brilliant deal! :)



#15 DENEB

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Posted 10 May 2013 - 01:57 PM

Yep agreed for any F5 newt it works well, especially at that price...



#16 Andyfx

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Posted 14 May 2013 - 08:47 PM

OMG Chris what's this you've got now eh lol?! Looks good though and I'm sure you can sort those dents out. The Orion tubes tend to be quite thin so maybe you can reshape it gently, then skim the small imperfections with fibreglass? The wrap will look great (you know you converted me), is it going to be orange though lol......



#17 Starlock

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Posted 15 May 2013 - 07:37 AM

ahah I think the orange tube should stay as your thing Andy :D (well and the classic Celestron C5's). I've now received the wrap I'm going to use and the dents arn't as bad as I thought now I've seen the scope in the flesh, I think I should be able to sort it out ok. I'm off today so I'll get to work on it, I've already stripped the scope down :)



#18 DENEB

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Posted 15 May 2013 - 11:31 AM

There's a baader MPCC on ABS



#19 Starlock

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Posted 15 May 2013 - 04:08 PM

Thanks Nadeem I saw that but I'm a bit low on funds at the moment, I'll hopefully catch the next one that becomes available :)



#20 Starlock

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Posted 15 May 2013 - 04:27 PM

I've made a bit of a start:

 

1) Completely stripped the scope down.

2) Carefully removed the Orion sticker with a craft knife.

3) Gently hammered out the worst of the dents using the tube rings as a mould at the end of the tube

4) Cleaned tube

5) Cut the carbon effect vinyl wrap to size and rolled it onto the tube

6) Spent a good 2 hours trying to get rid of all the air bubbles because the wrap isn't non air trapping with air channels as it was advertised as having :(

7) After finally getting the finish looking reasonably good I heated the wrap with hair dryer to cure it.

8) I then used a craft knife to cut the holes for the focuser and screws.

 

Heres some pics of my progress so far:

 

I'm off to the local DIY store soon to try and find some home made Bob's screws for the secondary mirror :)

Attached Thumbnails

  • IMG_1708.JPG
  • IMG_1711.JPG
  • IMG_1713.JPG
  • IMG_1715.JPG
  • IMG_1733.JPG
  • IMG_1737.JPG





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