After the 2020 restoration of the 3" Dollond, last November I came across a nice vintage equatorial telescope being sold locally. It was described as in good condition, including no blemishes on the objective.
Here are some original pictures from the seller:
(https://www.cloudynights.com/uploads/monthly_11_2023/post-63207-0-67661600-1699880144_thumb.jpg)
(https://s3-us-west-1.amazonaws.com/groupsioattachments/25007/102729199/52776/3?AWSAccessKeyId=AKIAJECNKOVMCCU3ATNQ&Expires=1713616757&Signature=S7BR%2Fd9sI419y8dthEeJz0VHYh8%3D)
(https://s3-us-west-1.amazonaws.com/groupsioattachments/25007/102729199/52776/2?AWSAccessKeyId=AKIAJECNKOVMCCU3ATNQ&Expires=1713616757&Signature=PpILf5fPNIqhoucydxYNCAvO7wI%3D)
A few days later I collected it and took some pictures comparing it to the 3" Dollond:
(https://astrob.in/pii5d6/G/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/H/rawthumb/regular/get.jpg?insecure)
It is a shorter tube but with very similar focuser. The finder is a lot better in the N&Z. It came with four eyepieces, including what looks like a pancratic tube.
Here are some pictures of the mount in its original state:
(https://astrob.in/pii5d6/N/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/Q/rawthumb/regular/get.jpg?insecure)
The tripod was in worse state than the mount but the telescope was functional and with very, very good optics. I only tested it during daytime and posted about it in the Groups.io forum for the Antique Telescope Society as I had not been able to find this particular model in any of the N&Z catalogues available online.
(https://astrob.in/pii5d6/K/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/L/rawthumb/regular/get.jpg?insecure)
The experts in the Antique Telescope Society forum suggested it may have a Cooke lens (!) and although I could not see any markings upon disassembling it, it looks very similar to a picture showing on page 68 of a History of Cooke, Troughton & Simms telescopes by Anita McConnell:
(https://www.cloudynights.com/uploads/monthly_03_2024/post-63207-0-65815300-1711908592.jpg)
Knowing I had not the weather nor the time to work on it, I put it away until this year.
As the scope was in such good state I decided to work on it only recently and started by disassembling and cleaning the mount:
(https://astrob.in/pii5d6/T/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/W/rawthumb/regular/get.jpg?insecure)
And the worm wheel before cleaning it:
(https://astrob.in/pii5d6/X/rawthumb/regular/get.jpg?insecure)
And after:
(https://astrob.in/pii5d6/BB/rawthumb/regular/get.jpg?insecure)
The patina was nice but the dials and brass work was pretty oxidised so I gave it a good scrubbing with Mothers' polish.
In mid-March there was forecast for a warm early spring day so got to work on the tripod and mount:
(https://astrob.in/pii5d6/BC/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BD/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BE/rawthumb/regular/get.jpg?insecure)
The counterweight was a lead cylinder in a brass jacket:
(https://astrob.in/pii5d6/BF/rawthumb/regular/get.jpg?insecure)
After plenty of elbow grease things started to clean up:
(https://astrob.in/pii5d6/BG/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BH/rawthumb/regular/get.jpg?insecure)
and with the sun still shining there was time to prime the parts for painting:
(https://astrob.in/pii5d6/BI/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BJ/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BK/rawthumb/regular/get.jpg?insecure)
At night there was time to work on the telescope fittings using Renaissance wax using the mototool. I didn't clean it a thoroughly as the mount as the telescope had obviously lived much of its life inside its transit box with the mount spending less time as protected.
Before:
(https://astrob.in/pii5d6/BO/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BP/rawthumb/regular/get.jpg?insecure)
And after:
(https://astrob.in/pii5d6/BR/rawthumb/regular/get.jpg?insecure)
The focuser has a nice baffle with a fixing bracket:
(https://astrob.in/pii5d6/BQ/rawthumb/regular/get.jpg?insecure)
The paint - which was difficult to find a good match for - was between a pale olive green and grey. Both the telescope tube and tripod had the same paint. I stripped the paint from the OTA and saw no clear indication of lacquer on the brass or old patina so I assume it had always been painted. But that's just a guess:
(https://astrob.in/pii5d6/BS/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BT/rawthumb/regular/get.jpg?insecure)
There was minimal damage to the OTA:
(https://astrob.in/pii5d6/BU/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/BX/rawthumb/regular/get.jpg?insecure)
The Easter weekend gave me a chance to prime the telescope tube and paint other parts:
(https://astrob.in/pii5d6/BY/rawthumb/regular/get.jpg?insecure)
Tripod legs and mount parts:
(https://astrob.in/pii5d6/BZ/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/CA/rawthumb/regular/get.jpg?insecure)
At the end of March I started work reassembling the mount after cleaning and regreasing all parts as necessary:
(https://astrob.in/pii5d6/CB/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/CC/rawthumb/regular/get.jpg?insecure)
Here's the mount reassembled in the kitchen:
(https://astrob.in/pii5d6/CE/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/CF/rawthumb/regular/get.jpg?insecure)
(https://astrob.in/pii5d6/CD/rawthumb/regular/get.jpg?insecure)
Well, after having come back from the eclipse trip to Mexico, I worked on the OTA.
First it was primed and painted:
(https://cdn.astrobin.com/thumbs/L7QWOSattlHz_1824x0_3X986N8K.jpg)
I had put all bolts, screws, brackets, parts, etc in separate boxes. The mounting rings for the finder had to be put back in a specific order for the whole thing to fit. It took me some time to get everything together, particularly the front element as I may have sprayed too many layers of paint and lacquer so it was tight fit!
Inside the box (which I still need to work on):
(https://cdn.astrobin.com/thumbs/XKTyiAW6LRds_16536x0_UyysOTOH.jpg)
The fully assembled OTA with focuser (no eyepieces) but with finder and caps weighs in at close to 4.4kgs:
(https://cdn.astrobin.com/thumbs/HvLMBzjz4GC-_1824x0_3X986N8K.jpg)
And here are a few pictures outside in between passing clouds:
(https://cdn.astrobin.com/thumbs/aTzYFL2IAxKO_1824x0_3X986N8K.jpg)
(https://cdn.astrobin.com/thumbs/T2tiWZhfMlsh_1824x0_3X986N8K.jpg)
(https://cdn.astrobin.com/thumbs/6qNXG0dIqlzL_1824x0_3X986N8K.jpg)
(https://cdn.astrobin.com/thumbs/alwSsCRx_MJn_1824x0_3X986N8K.jpg)
(https://cdn.astrobin.com/thumbs/3_9VULPTfHJl_1824x0_3X986N8K.jpg)
Finally, a comparison with the Alt-Az Dollond:
(https://cdn.astrobin.com/thumbs/3HYSAgb1uoMq_1824x0_3X986N8K.jpg)
(https://cdn.astrobin.com/thumbs/ou9D82s65MKA_1824x0_3X986N8K.jpg)
Last ones promise:
(https://cdn.astrobin.com/thumbs/53nFVF451JzS_1824x0_3X986N8K.jpg)
(https://cdn.astrobin.com/thumbs/MonmL-cDmGKm_1824x0_3X986N8K.jpg)
I now need to test it under the stars. A simple comparison with the Dollond on far away branches, leaves and some chimneys implies better optics for the N&Z (potential Cooke). The Dollond is no slouch under the stars so I guess I shall know more when I can manage to test it.
Roberto
That looks like a fantastic restoration job! I hope it rewards you with some fine views when the skies eventually clear. :)
Thank you Rick! Hope to bring it to Ortford one time.
Roberto
It's interesting comparing it with your previous restoration (http://forum.orpington-astronomy.org.uk/index.php?topic=12147.0), too.
What a magnificent piece of equipment! You have done a wonderful job, Roberto, the brass and paintwork really shine. We look forward to hearing how it performs on the night sky.
Wonderful job Roberto
Well done Roberto ~ that's as good as a piece of art!
~ Hugh