64 replies to this topic

[BarrySimon615]

Continuing from a previous thread and keeping it on topic, here are some photos of a scope that for most amateur astronomers has no real value, when modified it does have some utility.

 

The scope I am talking about is a Tasco 5VTE.  It is a zoom 60 mm refractor that yields upright images and has zoom indents at 15x, 30x, 45x and 60x.  It comes with a small tabletop tripod and at least about 10 to 15 years ago could be purchased very cheaply on eBay, Craig's List etc.  I know because I bought 4 of them.  Why?  The reason being that if you remove the zoom apparatus and erecting elements it makes for a nice relatively fast 60 mm f/7.2 rich field refractor with a 432 mm focal length.  Make you cut right in front of any mark left by the alt-azimuth brackets on the original scope.  Replace with an after market 1.25" focuser for a 60 mm scope and you are done.

 

See photos.

 

Barry Simon

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Edited by BarrySimon615, 11 June 2018 - 08:54 AM.

[Chuck Hards]

Very nice, Barry.  I did the same thing with the same telescope a couple of years ago.  Used the focuser from a classic as well, but with a 1.25" eyepiece holder instead of the .965".  Seen here on a Manon mount.  There's a thread about it buried here somewhere.

 

 

 

 

 

[BlueTrane2028]

I too did this, with a 60mm Jason zoom spotter.  Used a cheapie 1.25" focuser from eBay.

I still prefer to use the scope as a spotter, but the view is WAY better now than it ever was regardless of what it's pointed at.  A 17mm Plossl seems ideal for it most of the time.

[Chuck Hards]

Here's a link to my thread from 2-1/2 years ago:

 

LINK

[roscoe]

I came upon one with this nice table-top alt-az, and a nice helical focuser.  I removed the erector-lens assembly, sawed the tube down, figured out a way to mate a 45-degree diagonal to it, and made this nice little spotter out of it. It's scheduled to go and live on my 6" Jaegers as a finder when that moves closer to reality....

 

[starman876]

Very nice, Barry.  I did the same thing with the same telescope a couple of years ago.  Used the focuser from a classic as well, but with a 1.25" eyepiece holder instead of the .965".  Seen here on a Manon mount.  There's a thread about it buried here somewhere.

 

Tasco 55VTE astro conversion 001.jpg

great minds think alike. i have done the same thing with similar scopes.  they actually have decent optics.  you would not have known it with all those lenses in the zoom assembly

[deSitter]

great minds think alike. i have done the same thing with similar scopes.  they actually have decent optics.  you would not have known it with all those lenses in the zoom assembly

I have two, one with a 1960ish Tasco focuser and the other with a 1.25" focuser. Both are really good optically, I would even say excellent (diffraction limited but rather colorful). They both have key roles in my telescope constellation, one as a rich field cruiser of very wide fields, the other as the side scope on my big Newtonian. Mine have air-spaced objectives that are as well made as other period 60mm Towas. With a porro prism they make fantastic spotting scopes as well.

 

-drl

[BarrySimon615]

The modified Tasco 5 VTE shown in the first post also has a pedigree focuser with a modification.  The focuser is the one sold with the Unitron #145 which is the 3" photo equatorial telescope.  That one has an additional thumbscrew location allowing for a better lock down position for photographic applications.  The one I bought did not have the intermediate interface piece to allow it to attach to the Unitron #142 tube assembly.  As received used I could not use it - too small for a 3" and too large for a 2.4".  However I did have a ruler and measurements indicated that the focuser did have enough wall thickness to be turned down to work in a 2.4" tube.  Having a friend with a lathe the deed was done. 

 

One thing about sand cast parts, the wall thickness on a precisely centered part turned down on the outside meant a wall thickness that varied on the inside - adequately thick in some areas and almost paper thin in other areas.  So out came the JB Weld to the rescue..  I had a piece of brass pipe that fit inside the inside of the focuser without impacting the drawtube and just large enough to create a gap between it's outside surface and the inside surface of the focuser where it would slip into a telescope tube.  Into this void I poured JB Weld and when all was dry I cut flush..  I think the pictures illustrate this well enough for everyone to see exactly what was done.

 

The only thing missing at this point is the rear thumbscrew bracket that goes on the drawtube.  I will probably have to fabricate one of those.  It may not match the Unitron version already on the tube but at least it will work.

 

Barry Simon

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[Chuck Hards]

JB Weld has saved my bacon on more than one occassion!  (Hey, I'm a poet)

 

I found this pic of mine on an EQ-2.

 

Here's the pic I was looking for, back on the Manon mount.

 

I think this focuser was from an Asahi Jupiter that came to me with a shattered objective.  It was parted-out and allowed two other Jupiters to be restored, so all is not lost.  It has sets of adjustable brass rail slides to constrain the drawtube.  I found paper shims under the rails with Japanese typeface on them.  

 

 

 

 

 

[Alen K]

Wow. Thanks for the memories. That original Tasco refractor was the first telescope I ever used to look at stars. I was 14 or 15. I had borrowed it from a friend. My recollection is that I soon settled on using it at 15x, which gave me impressive "rich-field" views; as rich-field as you are going to get from an eyepiece that gave an AFOV of probably no more than 40 degrees, at any rate. 

Edited by Alen K, 11 June 2018 - 09:03 PM.

[BarrySimon615]

At the low end (magnification) I think you would be lucky to get a 40 degree (apparent) field out of the Tasco 5 VTE, so maybe a 2.66 degree (true) field at best at 15x.  With it modified as I and others have done, a 24 mm Panoptic eyepiece will give you 18x and about a 3.8 degree field.  That seemed like plenty enough back in 2009 when I originally made mine.  Today I wonder if I could adapt a 2 inch focuser to one.  I still have two of the 5 VTE tube assemblies left to play with.  Just think, a 31 Nagler would yield 14x with a field almost 6 degrees across.  The exit pupil would be a reasonable 4.28 mm.  Jump to a 41 Panoptic and you would have 10.5x with a 6.5 degree field and an exit pupil of 5.7 mm.

 

The wheels are turning, I might just see if I can cobble one together with a 2 inch focuser.

 

Barry Simon 

Edited by BarrySimon615, 11 June 2018 - 10:30 PM.

[Garyth64]

I have a sawed-off Tasco 60mm on my 10":

 

 

It was a long time ago.  I don't remember the number, but it was a vari-power Tasco.

 

 

[memento]

I also have a sawed-off Tasco refractor:

 

https://www.cloudyni...t-long-history/

[Chuck Hards]

 

 

The wheels are turning, I might just see if I can cobble one together with a 2 inch focuser.

 

 

This 2-inch focuser currently resides on a Manon 60mm OTA but it would slide right onto the cut-off Tasco 55VTE.

 

 

And here is a cut-off Tasco 4VTE.  Top to bottom, Unitron 40mm, home-made 40mm f/20 (old Edmund objective), and the little Tasco 4 VTE freed of it's erector and simple eyepiece.  

 

[Jon Isaacs]

great minds think alike. i have done the same thing with similar scopes.  they actually have decent optics.  you would not have known it with all those lenses in the zoom assembly

 

They must.

 

I had one of these,  didn't know what i had and gave it away .  I guess that tells us who has a great mind and who doesn't. 

 

The 2 inch focuser is intriguing. For low powers , it could be just slip-slide focusing. 

 

With a 432 mm focal length , based on the field stops,  the 41 mm Panoptic provides a 6.1 degree field,  the 31 Nagler , 5.6 degrees. 

 

From a purely practical standpoint , one could stop down an ST-80 to 60 mm and have a similar view . That'll have to do for me .

 

Jon

[Chuck Hards]

True Jon.  And I have a couple of short 60mm scopes by design.  But re-purposing the 55VTE is so much more fun!

 

I have a Monolux 60mm equivalent of the Tasco.  I plan on cutting it down as well, one of these days.

 

This is what you get when you cut-down a Tasco 6TE and use a Meade 50mm bino objective:

 

 

A RA finder, lol.

 

 

[starman876]

True Jon.  And I have a couple of short 60mm scopes by design.  But re-purposing the 55VTE is so much more fun!

 

I have a Monolux 60mm equivalent of the Tasco.  I plan on cutting it down as well, one of these days.

 

This is what you get when you cut-down a Tasco 6TE and use a Meade 50mm bino objective:

 

Tasco 50mm shorty.jpg

 

A RA finder, lol.

starting to look like a Unitron satellite scope

[Jon Isaacs]

Chuck:

 

I definitely like the idea of modding the 5TE.. I assumed it was a 60 mm x 700mm.. I should have figured out what it really was.

 

I had a Parks/Carton 60 mm F/7 for a while but a friend was needing a petite grab and go rig so I parted ways with it.

 

Jon

[walter a]

Jon the pic of your scope inspired me to buy this F/7 Carton.

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[Kasmos]

Nice!

I'm mostly done buying scopes but would make an exception for one of those F/7 Cartons or the SYW version.

 

Walter, Did it come with that alt-az mount?

[Bomber Bob]

I haven't chopped too many Classics, but I'm very pleased with this one -- I converted a Tinsley Saturn 40mm terrestrial spotter into a 50mm right angle finder for my Tinsley 6" Cassegrain.  The spotter's lens was shattered, and the large replacement may be older than the scope it rides on...

 

   

[walter a]

Thanks Kasmos That mount cam with a 60x800 syw kit but I have seen a Carton on one I believe it was Madeline's. Anyone hear from Madeline lately?

[Vesper818]

Sheldon Faworski made my 70mm RFT as an example of what could be done with his splendid Carton Objectives :
https://www.cloudyni...-in-metal-cell/

Use of the rear reflector focuser and internal diagonal mirror addresses problems with cutting down a short focal ratio scope, and vignetting.
It is a solid little scope, lots of fun to use, and foolproof!

[Vesper818]

And this is the second version of my cut-off Swift 818 refractor, a lower budget terrestrial spotter contemporary. of the 838, 839. At 60mm x 550, it has proven capable companion for birding, then on into the night for all around star , moon and planet surfing. The focuser was from someone's parted-out Royal Astro, but the finder and spotting scope tabletop tripod are Swift. 

 

[Kasmos]

It's probably been more than 35 years since I cut down this damaged Mayflower 806 vari-power scope.

I have a better focuser that can use 1.25" eyepieces that I planned to put on it, but I'm not sure the objective is worth using it on.

 

The last time I used it I wasn't so thrilled with the images (noticeable CA/lack of sharpness), past 20x.

Am I expecting too much from the short focal length?

How much usable magnification should I expect from a 60mm x 400mm scope?

 

If it's clear maybe I'll re-test it tonight

Edited by Kasmos, 15 June 2018 - 03:31 PM.