40 replies to this topic

[luxo II]

Hello All;
After several discussions with Martin he decided this was to much for his abilities. Martin forwarded contact info and I am on the road this Tuesday to pick it up. So Peter the scope is going to be rescued!

Another "thunder-road" trip!!

Kevin Medlock

Awesome indeed !!!

[willluk]

Hi Kevin,

 

I have an AstroMak 12" f5 from my late father-in-law.  It's a great scope.  Had several email exchanges with Jim Riffle (he still remembers my father-in-law), and he showed me how to mount the OTA (weight about 75lb) on an equatorial mount.

 

Best,

 

William

Edited by willluk, 08 January 2021 - 03:16 AM.

[gnabgib]

Hello William and everyone else,

    Got back yesterday!  My co-pilot Ridge and myself a little worse for wear.  I have never been to Borego Springs before.  What a beautiful part of our country.  The pickup of the Astromak went well.  It had been sitting outside under a tarp for awhile.  The tarp had deteriorated under the sun so the scope has suffered a bit. Overall it is in savable condition with a lot of TLC.  Good news is the optics are in very good condition with some dried dew spots on the corrector inside surface.  The primary mirror's silver coatings showing some dark spots but hey after 30+ years "not bad". Fortunately the front had its 1/4 inch thick acrylic plastic cover still bolted on.  This is definitely one of the 12ich f/5 models with a roller RA drive.  I will post some picts later today when my own "gyros" have stabilized a bit more.  Right now I am hip deep in the Group 70 telescope build.  There are times when this project overwhelms me and I need to step back, breathe and remind myself "just one bolt, one weld at a time".  This Astromak project will be my sanity check as a diversion in what I call normal telescope building.  It will bring me back into my comfort zone.  Peter Ceravolo is right.  There is something special about large Maks.  It's probably the look of all that glass up front.  Something all the refractor folks can relate to!

 

More to come

Kevin

[Peter Ceravolo]

Congratulations Kevin!

 

I agree, ya gotta inject some fun projects into the stream when you've got a massive job underway.

 

I recall meeting Jim Riffle at the conferences decades ago. He had on display some huge photographic prints taken through the Astromak. His astro-photography was ground breaking then.

 

I'm looking forward to a great restoration thread!

 

Peter

[gnabgib]

O.K.!  I know everyone is waiting for some picts.  So here they are.  The optics were in fair codition with the mirrors showing some of the usual deterioration spots but not bad for 30+ year old silver coatings!  The main concern was the inside of the corrector.  The scope had been sitting outside under a deteriorating tarp and condensation spots were all over the inside surface.  Everything has a fine layer of that ubiquitous dessert "dust'!  Well I contacted Jim Riffle (Astroworks) and he gave me some pointers on removing the corrector.  It involved a 1 inch aluminum bar about a foot long with a 1/2-13 threaded stud on the end.  The front of the secondary mount has a thread hole in it and this is for this bar to screw into.  I followed his directions and cleaned the corrector.  All is well as the last photo shows.  Scope will need much TLC but the optics are in good condition and that was the main concern.  Enjoy the photos.  I will update as I get into this project.

Kevin

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[Bowlerhat]

beautiful, what a score.

[Peter Ceravolo]

O.K.!  I know everyone is waiting for some picts.  So here they are.  The optics were in fair codition with the mirrors showing some of the usual deterioration spots but not bad for 30+ year old silver coatings!  The main concern was the inside of the corrector.  The scope had been sitting outside under a deteriorating tarp and condensation spots were all over the inside surface.  Everything has a fine layer of that ubiquitous dessert "dust'!  Well I contacted Jim Riffle (Astroworks) and he gave me some pointers on removing the corrector.  It involved a 1 inch aluminum bar about a foot long with a 1/2-13 threaded stud on the end.  The front of the secondary mount has a thread hole in it and this is for this bar to screw into.  I followed his directions and cleaned the corrector.  All is well as the last photo shows.  Scope will need much TLC but the optics are in good condition and that was the main concern.  Enjoy the photos.  I will update as I get into this project.

Kevin

Kevin I was confused by the handle in front of the secondary in the initial images. It turns out to be a plexiglass cover? Kind of unusual...

 

Happy to hear that the optics look good. Do I recall correctly they were made by Tom Scott of Fresno?

 

I noted the scopes was equipped with a star diagonal in the Faceplant pics. Any sign of the field flattener lens?

 

Peter

[tim53]

Wow, the optics cleaned up nicely!!

 

I'm jealous!

 

-Tim

[starman876]

Great looking scope.  I bet that mount will handle a ton. Looks really well built

  Thanks for the update.  That is going to be a wonderful scope.

[gnabgib]

Peter;

    Yes the "dust cover" is made out of clear acrylic and has the "T'" handle in the center.  My understanding is Cumberland (spelling?) made the first 6 + optic sets and Tom Scott made the last sets.  Don't know this for sure though.  I have been in contact with Jim Riffle and he is sending me "the definitive set of Astroworks/Astromak literature! I will post more when this arrives.  The star diagonal elliptical flat was trashed and un-salvageable.  The field flattener was not with the scope and may be lost to time.  An inquiry has been made so a search is happening.  We will see what happens although all is not lost in this regard.  Jim says the optical shop that made these lenses is still in business and has the test plates.  So one could be made.  At least there are options. 

Tim;

   Yes the corrector cleaned up nicely!  That was my biggest concern.  I was not going to sleep well until I knew this for sure.  The mirrors will need recoating.  When I get to that part it will be time to obtain some silver wire, fire up the vacuum chamber and once again put my government training to good use.  The years I spent at Lawrence Berkeley National Laboratory as a vacuum deposition tech do come in handy!    I will post photos of the "naked optics set" in the future as I begin to restore the tube assembly.  The r and r of the corrector was to settle my fears of any etching that may have occurred.   If you all noticed the threaded hole in the secondary holder Jim told me how to remove the corrector.  Get yourself a 12 inch length of 1 inch aluminum bar, drill and tap a 1/2-13 hole in the end, thread in a 1/2-13 stud.  Screw this into the secondary holder and use this as a handle to remove the corrector with secondary as a unit.  It worked well!  And YES, I am repeating myself.

 

Kevin

Edited by gnabgib, 09 January 2021 - 07:09 PM.

[starman876]

Peter;

    Yes the "dust cover" is made out of clear acrylic and has the "T'" handle in the center.  My understanding is Cumberland (spelling?) made the first 6 + optic sets and Tom Scott made the last sets.  Don't know this for sure though.  I have been in contact with Jim Riffle and he is sending me "the definitive set of Astroworks/Astromak literature! I will post more when this arrives.  The star diagonal elliptical flat was trashed and un-salvageable.  The field flattener was not with the scope and may be lost to time.  An inquiry has been made so a search is happening.  We will see what happens although all is not lost in this regard.  Jim says the optical shop that made these lenses is still in business and has the test plates.  So one could be made.  At least there are options. 

Tim;

   Yes the corrector cleaned up nicely!  That was my biggest concern.  I was not going to sleep well until I knew this for sure.  The mirrors will need recoating.  When I get to that part it will be time to obtain some silver wire, fire up the vacuum chamber and once again put my government training to good use.  The years I spent at Lawrence Berkeley National Laboratory as a vacuum deposition tech do come in handy!    I will post photos of the "naked optics set" in the future as I begin to restore the tube assembly.  The r and r of the corrector was to settle my fears of any etching that may have occurred.   If you all noticed the threaded hole in the secondary holder Jim told me how to remove the corrector.  Get yourself a 12 inch length of 1 inch aluminum bar, drill and tap a 1/2-13 hole in the end, thread in a 1/2-13 stud.  Screw this into the secondary holder and use this as a handle to remove the corrector with secondary as a unit.  It worked well!  And YES, I am repeating myself.

 

Kevin

Projects like this are a joy.  To take an excellent instrument and rebuilt to its original glory and then get to enjoy it.  Having the original designer and builder still around must be wonderful. 

Edited by starman876, 09 January 2021 - 08:04 PM.

[tim53]

Peter;

    Yes the "dust cover" is made out of clear acrylic and has the "T'" handle in the center.  My understanding is Cumberland (spelling?) made the first 6 + optic sets and Tom Scott made the last sets.  Don't know this for sure though.  I have been in contact with Jim Riffle and he is sending me "the definitive set of Astroworks/Astromak literature! I will post more when this arrives.  The star diagonal elliptical flat was trashed and un-salvageable.  The field flattener was not with the scope and may be lost to time.  An inquiry has been made so a search is happening.  We will see what happens although all is not lost in this regard.  Jim says the optical shop that made these lenses is still in business and has the test plates.  So one could be made.  At least there are options. 

Tim;

   Yes the corrector cleaned up nicely!  That was my biggest concern.  I was not going to sleep well until I knew this for sure.  The mirrors will need recoating.  When I get to that part it will be time to obtain some silver wire, fire up the vacuum chamber and once again put my government training to good use.  The years I spent at Lawrence Berkeley National Laboratory as a vacuum deposition tech do come in handy!    I will post photos of the "naked optics set" in the future as I begin to restore the tube assembly.  The r and r of the corrector was to settle my fears of any etching that may have occurred.   If you all noticed the threaded hole in the secondary holder Jim told me how to remove the corrector.  Get yourself a 12 inch length of 1 inch aluminum bar, drill and tap a 1/2-13 hole in the end, thread in a 1/2-13 stud.  Screw this into the secondary holder and use this as a handle to remove the corrector with secondary as a unit.  It worked well!  And YES, I am repeating myself.

 

Kevin

Kevin.  Useful information.  I have a 16" Maksutov optics set I bought a few years ago with polished primary and secondary, but only generated Meniscus.  Is your astromak corrector coated?  I'm a few projects from having to worry about this (going to tackle some more "mainstream" optics before I'll be brave enough to do the 16), but at some point...

 

-Tim.

[Oregon-raybender]

Good save Kevin. Glad it's in good hands. Looking forward to seeing progress.

 

Let me know when you are back to coating again.

The 6 inch you did decades ago needs to done again, one last time.

 

Starry Nights

[gnabgib]

Tim;

    YES the corrector is coated!  A 16 inch MAK, WOW!  Sure it's not just a crystal fruit bowl?  LOL

 

Kevin

[gnabgib]

Good save Kevin. Glad it's in good hands. Looking forward to seeing progress.

 

Let me know when you are back to coating again.

The 6 inch you did decades ago needs to done again, one last time.

 

Starry Nights

Bob;

   I will let you know about the coating.  "One last time" makes me feel OLD!  I keep wondering who the old guy is in the mirror each morning!

 

Kevin

[dec12252]

This scope is in great hands.  Will be fun to watch this project develop a fine refurbished scope.  Please keep posting Kevin!!

 

Dave