Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Restoration of Meade 8" Newtonian

beginner classic DIY dslr Meade mount reflector 3d printing
  • Please log in to reply
7 replies to this topic

#1 Squidink

Squidink

    Explorer 1

  • *****
  • topic starter
  • Posts: 77
  • Joined: 28 Sep 2020
  • Loc: Greater Boston

Posted 22 October 2020 - 09:06 PM

I got a 8" Meade newt off Craigslist. It needs some restoration and I will document it here.

 

I think it's a 1990s vintage F/6. But I can't positively ID it yet.

 

It came on tripod with die cast legs and a 4" tube, like my MTS-6SN. Only on a plywood trolley with casters

 

Features:

 

Battery operated RA motor drive, but no fine adjuster. Appears to take a 9V, but has an adapter for 6x AA batteries. Also has a jack for 12V. It seems to work, but clutch engagement/disengagement is a mystery.

 

Rust. It was stored on a 3 season porch.

 

Pollen. See above.

 

The world's worst focuser- a 2" rack and pinion with stripped teeth.

 

Finder scope: 6x30mm straight through.

 

Thermoformed  end rings on old, repainted sonotube with mildew stains and a overspray of white.

 

A 2nd set of mounting holes for the mirror for (D)SLR focus.

 

What to do:

 

It needs a cleaning and focuser. Just for evaluation. Or at least a cleaning.

 

If it is what I think it is, I will press it into light AP duty with a DSLR.

 

I am wondering about a fiberglass overcoat on the Sonotube

 

Your input is welcomed, this is my first try.

 

IMG_7720 (1).jpg IMG_7721 (1).jpg IMG_7722 (1).jpg IMG_7724.jpg IMG_7714 (1).jpg IMG_7717 (1).jpg

 


  • Bomber Bob likes this

#2 CHASLX200

CHASLX200

    ISS

  • *****
  • Posts: 20,893
  • Joined: 29 Sep 2007
  • Loc: Tampa area Florida

Posted 23 October 2020 - 05:35 AM

Looks like a early 90's Starfinder. I had one and it was very good.


Edited by CHASLX200, 23 October 2020 - 05:35 AM.


#3 Macguyver909

Macguyver909

    Lift Off

  • -----
  • Posts: 23
  • Joined: 04 Dec 2019
  • Loc: North West,WI

Posted 23 October 2020 - 10:16 AM

I agree on the early 90's starfinder. I have a DOB mounted one and the spider is exactly the same as yours.

 

Everything I have read about the early starfinders, is that they have surprisingly good mirrors. I put a GSO focuser on mine and moved the focuser and spider up, and the focuser to the opposite side for right eye dominant viewing. It will reach focus with a mirrorless Sony camera with this setup ( 24mm back focus vs ~ 54mm for a mirror camera). Just a FYI, after the new focuser, I had to shim the focuser base to get collimation to agree between a cap and laser.

 

Also added a RACI finder.  Looks like yours has a better mirror cell. Mine is the RTV to particle board type. 

 

A good coat of bondo skim coat on the tube and white appliance paint will do wonders for the tube, I would skip the fiberglass.  

Put a fan behind the mirror, the mirrors are thick and need all the thermal management they can get. Flock it and Rock it!!

 

I paid $100 for mine and as a total newb, wasn't afraid to hack and wack. I'm glad I did, it turned out to be a very usable instrument. 



#4 Squidink

Squidink

    Explorer 1

  • *****
  • topic starter
  • Posts: 77
  • Joined: 28 Sep 2020
  • Loc: Greater Boston

Posted 23 October 2020 - 05:59 PM

I found a thread noting that the secondary mirror may be undersized on some of these starfinders.

 

https://www.cloudyni...e-starfinder-8/

 

I am not 100% clear on how I determine this.

 

I did find a pollen coated marking on the back of the mirror. If it's an 8" primary, that makes this just shy of f/6.

 

IMG_7736.jpg IMG_7735.jpg

 

 



#5 Squidink

Squidink

    Explorer 1

  • *****
  • topic starter
  • Posts: 77
  • Joined: 28 Sep 2020
  • Loc: Greater Boston

Posted 26 October 2020 - 06:33 PM

I have a crazy idea. I am going to pursue it a bit.

 

I have a 2' x 4' sheet of polypropylene honeycomb cored fiberglass. If I slit it half depth 5 time to get (6) 6" x 48" flats, I could get a hexagon with a 9.8" distance across the flats, inside to inside. (right? 2x SIN(60degrees)) With a little resin and tape, it would have great damping, flat sides and hold an 8" mirror cell. Maybe I can stretch this to 10" ID. I am not sure of the true ID of moldy 10" sonotube is. I will grab some calipers.



#6 rsnuke

rsnuke

    Lift Off

  • -----
  • Posts: 1
  • Joined: 21 Oct 2020

Posted 30 October 2020 - 11:12 PM

The original 2" focuser is garbage, I've had a 8" since '97, and those teeth strip off... I do recommend changing it. 50-100$ for one. 


  • Squidink likes this

#7 Squidink

Squidink

    Explorer 1

  • *****
  • topic starter
  • Posts: 77
  • Joined: 28 Sep 2020
  • Loc: Greater Boston

Posted 02 November 2020 - 09:26 PM

The original 2" focuser is garbage, I've had a 8" since '97, and those teeth strip off... I do recommend changing it. 50-100$ for one. 

I should be receiving one in a week from the classifieds here. Yeah, the teeth are coming off. I was astounded! Good to know the optics are good. That's something I keep hearing. There isn't a whole lot else to recommend, given the construction and condition.



#8 Squidink

Squidink

    Explorer 1

  • *****
  • topic starter
  • Posts: 77
  • Joined: 28 Sep 2020
  • Loc: Greater Boston

Posted 21 November 2020 - 09:52 PM

This has been on pause for a week while other chores get completed.  I now have a focuser and new aluminum end rings. The pollen is off the secondary. I still need to clean teh pollen off the primary.

 

I have a question though.

 

I have a 3.2mm FL Paradigm ED eyepiece. That's still too short a FL for even this scope. It should gather rather more light, but with f/6, the exit pupil will be just over .5mm, right? So It will be not so much fun, I guess?




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: beginner, classic, DIY, dslr, Meade, mount, reflector, 3d printing



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics