Old Refractor & Alt Az Mount Resurrection

[Kunama]

Another day .......... another project .............

Don't really know whether to thank Lars or not but the little pile of brass bits he gave me has been sitting in the corner for a couple of weeks, quietly looking at me, jealous of the attention I have been lavishing on the Old Gaunt, pleading for resurrection .........

The clouds have already started to gather in the Snowys as a result of the arrival of the Vixen GP Deluxe II and the completion of the works on the Gaunt Mount.

Might have to start the new restoration tomorrow..........
Here is a list of the bits and pieces and a brief plan for their future:

a: Brass objective cell with what looks to my tired eyes to be a 3.5" F15 doublet lens
b: Brass Alt Az mount/tripod head unit with bolts and brass washers
c: Cast aluminium tube carrier 3.5" ID

The mount will start first with a complete strip to bare shiny brass, followed by cleaning and smoothing of the tube cradle which will be painted black (VHT Crinkle finish should look nice)
The tripod legs will be a triplet sandwich of Mountain Ash, Redgum or Jarrah and Mountain Ash again.

For the scope I will need to set up a test bed to check the focal length then source some 90mm OD tubing etc and an old focuser

Any donations of tube or focuser will be rewarded with red wine and such :P
This will be a slow project as I have to juggle time with my home duties and so on

Here is the first of many pics:

[Kunama]

Little bit more progress on this little project today, I managed to get a bit more brass polishing done with the Alt/Az head now looking more presentable.
The brass washers were also polished and all brass was then clear coated.

The bolts were also cleaned of years of corrosion and coated in satin black epoxy. The tube carrier is now ready for some VHT Crinkle Finish.

Next job will be the dismantling and polishing of the brass objective lens cell.
Then the tripod legs and finally the OTA.

Here is a picture of the head after today's efforts.

[asimov]

Nice work Matt! I simply love polished brass.

[Wavytone]

Not sure if you're aware but someone is mass-producing fake antique refractors in India, more as lounge room ornaments of yuppies (the objectives are usually a single uncoated lens, and don't work BTW). Lots of shiny brass bits that look like they were cast from an original telescope, usually on a badly made (wobbly) wooden tripod.

Just don't make it too smooth/shiny or some will think its one of these !

[Kunama]

Thanks John, brass is a very rewarding material to work with.

Unlike the Indian refractors this is going to be a very solid setup, I have just found some 88mm OD 82mm ID tube that should carry the heavy brass cell with its doublet lens very well, just need to locate a suitable focuser. The tube carrier is going to be painted black (epoxy).

I will have to confirm the focal length once I get a focuser but it appears to be about f15 focal ratio (82mm x 15 = 1230mm).

[Kunama]

A little bit more progress with this project today:

Dismantled the Objective cell
Cleaned the doublet elements and spacer (1.7mm)
Polished the brass cell and retainer
Realigned the doublet (20 degrees out of alignment)
Installed elements and refitted retainer

A little bit of machining to be done on the counter cell before reassembly.
The machined thread needs to be removed and then resized to 89mm to form a slip fit with retaining screws.

Here's a few pics. Not sure how old the doublet is but it has held up well.
82mm clear aperture F15 ......... should be quite nice when completed.

[FlashDrive]

That's nice....waiting for the end product :thumbsup:

Flash....

[Larryp]

Love those old refractors!

[Kunama]

Thanks Col and Laurie,
Just got onto some Aluminium tube of the right size, now looking for a focuser to suit (see wanted ads).
If I can get a brass focuser set up I will be painting the OTA Ferrari Red or High Gloss Black and fitting some polished brass tube weights etc.

Going to Canberra this week to try and find some nice timber for the tripod legs, thinking of Ash-Jarrah-Ash sandwiched together
Cheers,

[Kunama]

Another update:

Managed another couple of hours on this project today :work:

A bit of grinding to remove the threads inside the cell and to take it out to 88mm and then a little bit of elbow grease to shine it up a bit.
The 3 brass screw also got cleaned up so the objective end is ready for the tube which is making its way from Wollongong as we type.

Trying to decide whether to baffle the tube :shrug: might make a 3 baffle cage and slide it into the tube.

Then to work on the focuser :P

A few more pix:

[FlashDrive]

Nice work.......keep going.....will be following this thread :P

Flash.....

[MortonH]

Fantastic work again, Matt. Love following your projects!

[asimov]

Oh yeah gotta love that yummy shiney brass *drool!!* You doing this by hand or on a pedestal grinder with mops?

[Kunama]

Thanks Morton, it keeps me off the streets !

I haven't graduated to machine polishing yet John, all by hand.
This is not museum quality conservation, as the cell is of unknown parentage I am being a bit harsh with it. The process was 400 grit, 800 grit, 1200 grit hand rubbed then Autosol paste handrubbed followed by car polish, then a thorough wash and assembly.

I wanted to remove some of the sharper machining marks but not completely, they can still be seen in the pics albeit much smoother and less distinct. Time will mellow the colour nicely as there won't be any lacquering.

[LewisM]

Matt, kudos to you. Loving every second watching this emerge.

I am a restorer at heart - I love working with my hands. I collected MANY antique firearms in my life, the main object of which was restoration. The thrill of the hunt finding rare and obscure parts, or having to make them, and restoring wood was my favourite. I would admire my work for a while, need a new project, and sell the previous to continue the obsession :)

[Kunama]

Hey Lewis, Thanks, I don't know that I will be able to sell any of these projects once they are completed. I expect I will end up with several of these oldies before long.

Update: StarTrack Express brought my OTA tube today .................. now where to get an F25 objective :question: .... oh well might have to cut the tube down a bit......

2000 mm x 88.9mm x2.4 wall tube $92 including delivery within 2 days !!!

[Kunama]

In all my excitement to build this scope I forgot I already had a focuser that might suit this build.
Rummaging through a box of bits I found an old brass focuser that Sean Cunneen from Cloudy Nights sent to me when contacted by Lars.

I also forgot to photograph it before starting to clean it.
The pics below show the assembled and the parts, the shiny bit was treated to an hour sanding and polishing to reveal the beauty within.

I may still need to source a couple of bits to act as extension tubes due to the short focus range ............................

[bojan]

Fantastic job!

I wish I knew where you found all those old instruments?

[Kunama]

Thanks bojan,

The Gaunt Mount and Pier, Berry & Mackay Refractor and this objective and mount came from Lars Hansen's " Ye Olde Telescope Emporium "
Many of the parts were a gift from Lars, the larger items were sold to me at such a great price they felt like a gift anyway.

When I was looking for a focuser knob of the 'right' period Sean Cunneen sent me a box of brass bits from the USofA gratis.
My thanks to them, although my wife is not so enthusiastic as not much else is getting done about the house.

C'est la Vie ......

[mercedes_sl1970]

Great project! And, I'm impressed with the generosity you've encountered, in all it's forms. Indeed, that's one of the things that has struck me about the astro community - how willing people are to help/assist.

Andrew

[Steffen]

Looks great, but (pardon my ignorance) why did you polish the inside surfaces? Wouldn't you rather blacken them?

Cheers
Steffen.

[Kunama]

Hi Steffen, Good ?, Yes, they will be painted flat black but I wanted all the scale and oxidization removed first so the paint will last. All the 'to be painted' surfaces will be wiped over with 800grit before paint.

I will also assess the internal reflections after painting and if necessary I'll machine some aluminium knife-edge baffle discs.

[FlashDrive]

Coming together nicely.....:D

Flash....

[Steffen]

Yep, looks yummy.

Cheers
Steffen.

[Kunama]

A little bit more:

Still have to decide whether to use a diagonal or not and then cut tube to length, drill tube for finder and focuser, paint tube inside and out, finish focuser renovation and put it all together.

[Kunama]

Considering the colour to paint the tube:

Forest Green
Gloss Black
Bright Red
Takahashi White


Any suggestions welcome!

[gts055]

Hii Matt, Thats a wonderful project. My preference would be a white or red/maroon tube to contrast with the black cradle. Red/maroon might be nice with the timber you have selected for the tripod. Have you seen the brass diagonal that Watson and Sons and Broadhurst Clarkson had as options for their 19th and early 20th century tlescopes. You could cut the telescope tube to cater for a diagonal and make a threaded brass extension for the focuser to allow straight through viewing. Mark

[Kunama]

Hi Mark, thanks for the suggestions. I have just test fitted the tube cradle and am also inclined to go with a red tube and polished brass tube weights etc.
I have a Berry&Mackay refractor from the second half of the 19th century but no diagonal, I might have to make a brass casing for a 1.25" diag.

I have also got a quote from Danny at Crawmach to build me a 1.25" focuser with brass knobs etc.

Here is the tube holder in place.

[gts055]

A Crawmach custom focuser would be very nice. I have attached an image of a Broadhurst Clarkson diagonal (Watsons ones look identical) so you can see the old style. The prism is collimated with the three screws at the rear. Mark

[Kunama]

Thanks Mark, that is the one I have been looking for but they are as rare as Rocking Horse droppings.

I might rip off the design but install a dielectric mirror inside it instead. I can get some brass tube of the right size and silver solder it together.

[gts055]

If you would like dimensions or more images just let me know :) Mark

[Kunama]

The focuser decision has been resolved, Danny at Crawmach is now making a 1.25" focuser with custom brass adapter, brass knobs and screws for me.

In the meantime, I now have a beautiful Carton (Japan) Magnesium Fluoride coated 80mm F15 air spaced doublet in a collimatable cell that will also need an OTA.
(thanks Doug)
You guys really need to stop selling me stuff, you're getting me in trouble with the Boss.