28 replies to this topic

[Muhammad Arif]

I have the opportunity of buying a Monolux 20-60x zoom 60mm telescope. Is it worth collecting? Any info about this telescope would be appreciated.

[roscoe]

Can you look through it before paying? Perhaps you have a chance at a real gem, however I have a Monolux 40mm zoom with an internal image-erecting lens, and even after cleaning all the glass, it is terrible. (it does look just like a real scope, though....)
Russ

[Muhammad Arif]

unfortunately, I won't be able to look through the scope. I was asking my brother to pick it up for me and he is not too knowledgeable about telescopes.

[Bonco]

Most of the zoom refractors I've viewed thru had poor optical performance. Wouldn't buy one without looking thru it.
Bill

[droid]

At worst you can chop it off and make a richest field refractor out of it, what I did with an old Tasco zoom type, as a zoom scope it was horrible to terrible, as a richest field scope, it rocks.

[roscoe]

At worst you can chop it off and make a richest field refractor out of it,

Yeah, it'd make a great 60mm finder-scope!

[Muhammad Arif]

Converting this to a finder is a great idea and I couldn't resist the temptation of having a 60mm finder. So, I picked it up. Pics to follow.

[Muhammad Arif]

pic 1

Attached Thumbnails

• 

[Muhammad Arif]

Label

Attached Thumbnails

• 

[mdowns]

In the past I collected a stack of spotters. I had several Monolux in the group though I think they were all prismatic spotters. The brand didnt carry any real value though they can be fun and to me,that was always the point.To collectors this model probably wont generate alot of interest.However,it is a circle't',Towa made model, which someone might find appealing. Harder to find american made spotters like Argus and B&L always retain value.

[Muhammad Arif]

I totally agree. "Fun" is the main reason here - I'll have fun converting it to a finder and in the process, I won't destroy anything that's valuable or collectible.

[Muhammad Arif]

Looking through an old Tasco catalog (1968, I believe), this looks surprisingly similar to the Tasco 88TEZ.

Attached Thumbnails

• 

[Muhammad Arif]

Now the fun begins - dissecting this little beauty. I'd like some help/suggestions but before I continue, should I move this to the ATM thread?

[roscoe]

When I dissected a somewhat similar scope, I found an image-erecting lens inside, mounted on a long internal drawtube.
I don't remember if it came apart, or if I amputated it with a fine-tooth blade hacksaw, but away it went! This changed the focal length to something rather shorter, I unscrewed the lens cell, taped it to a hunk of wood, and holding an EP in my hand, found something approaching the focus point. Then, I unscrewed the focuser, set it up like normal (with a diagonal, in my case), and taped it to the stick where I thought it should work.....then moved it around till 3 or 4 of my EP's focused sort of in the center of travel. Then, I measured the space and cut the tube - about 1/2" long just-in-case, tried it with everything in place, and ended up cutting another 1/2 or more off. Then, I had to mark and drill holes for the focuser attachment bolts, and it seems somewhere in there I had to move, and ultimately remove a baffle. I believe I ended up shortening the focuser drawtube some more, too. My focuser was a standard rack-and-pinion, if yours has that twist-to-focus, you'll have to work with what you've got.
I ended up putting a 45-degree erecting prism on mine, and use it as sort of a spotting scope, though it begins to get chromatic over about 30x.

Here's a photo of mine, with a paint job and a photo tripod mount:

Attached Thumbnails

• 

[amicus sidera]

Now the fun begins - dissecting this little beauty. I'd like some help/suggestions but before I continue, should I move this to the ATM thread?

I "dissected" an older Edmund reflector here over the course of about 10 pages, so I think you're safe!

[Muhammad Arif]

Well, I also found an old thread about another Monolux getting converted: http://www.cloudynig...ll/fpart/1/vc/1

I'll be posting some more pics soon.

[Muhammad Arif]

When I dissected a somewhat similar scope, I found an image-erecting lens inside, mounted on a long internal drawtube.
I don't remember if it came apart, or if I amputated it with a fine-tooth blade hacksaw, but away it went! This changed the focal length to something rather shorter, I unscrewed the lens cell, taped it to a hunk of wood, and holding an EP in my hand, found something approaching the focus point. Then, I unscrewed the focuser, set it up like normal (with a diagonal, in my case), and taped it to the stick where I thought it should work.....then moved it around till 3 or 4 of my EP's focused sort of in the center of travel. Then, I measured the space and cut the tube - about 1/2" long just-in-case, tried it with everything in place, and ended up cutting another 1/2 or more off. Then, I had to mark and drill holes for the focuser attachment bolts, and it seems somewhere in there I had to move, and ultimately remove a baffle. I believe I ended up shortening the focuser drawtube some more, too. My focuser was a standard rack-and-pinion, if yours has that twist-to-focus, you'll have to work with what you've got.
I ended up putting a 45-degree erecting prism on mine, and use it as sort of a spotting scope, though it begins to get chromatic over about 30x.

Here's a photo of mine, with a paint job and a photo tripod mount:

Nice spotting scope. I'm aiming for a decent finder at the end. Thanks for the info on how you determined the new tube length - I was wondering about that and I'll try your method. There is a separate tube with moving lenses to change the focal length for the variable magnification (sort of like a variable barlow) that was easy to remove. The focuser is rotating type (helical?) and I want to keep it.

[Muhammad Arif]

Here is the objective. Air spaced doublet? The outside surface has some dust but nothing major. The inside is clean.

Attached Thumbnails

• 

[Muhammad Arif]

Here is the zoom mechanism. Rotating moves the two lenses closer or apart to change the zoom.

Attached Thumbnails

• 

[Muhammad Arif]

The focuser. I really like the feel of it - so, I want to keep it and figure out a way to attach a 1.25" EP.

Attached Thumbnails

• 

[Muhammad Arif]

The focuser has only about 5/8" travel and the drawtube is 1" OD. So, I'll have to figure out a way to attach a 1.25" EP - probably using an adapter.

[roscoe]

Wow, that's a pretty fancy focuser mechanism! If only the scope worked well, eh??

Any chance you could get a .965 tube inside that focuser end?? if so, you could adapt a diagonal to it. If you were planning to use it as a one-EP finder, 5/8" of focus travel would be plenty.....

[Muhammad Arif]

Wow, that's a pretty fancy focuser mechanism! If only the scope worked well, eh??

Any chance you could get a .965 tube inside that focuser end?? if so, you could adapt a diagonal to it. If you were planning to use it as a one-EP finder, 5/8" of focus travel would be plenty.....

Great suggestion. And I did try a .965 diagonal and it fit like a glove

Now I just have to figure out a way to lock it down so it doesn't fall out.

Attached Thumbnails

• 

[roscoe]

I tracked down ths old thread, because today the mailman brought me what looks like a practically brand new 1986  Monolux 4445 spotting scope, which looks exactly like the 'no-number' monolux posted here.

 

I'll resize and post some photos tonight.

[roscoe]

Here, as promised, is a photo of my seemingly brand new 1986 Monolux 4445  20-60 x 60mm spotting scope.  It came with a quite nice tabletop tripod, an instruction sheet, a Halley's guide, and except for a glue-smudge on the tube, appears totally unmarked, even the box is barely scuffed! 

Optically, it's ok, but nothing special, my hope is to keep the twist-focus intact, and add a 45 degree correct-image diagonal to take .965 EP's.