What to do with a 114mm Tasco Newt?

[stringscope]

Hi all,

I have been away from IIS while we have finished building an apartment onto our house for my mother. All finished now so I am back to astronomy. BTW her front courtyard has turned out to be nicely sheltered spot for observing!

Next ATM project to to refurbish an old Canberra Astro Soc Tasco 114mm Newt on a wobbly GEM mount into a more robust unit that can be used by "little people" at public viewing nights and as a hire scope for the intoductory group.

Progress to date:

Mount has been removed in disgrace and will be returned to the CAS equipment officer for burial.

0.965" focuser has been replaced with a cut down Celestron 1.25" unit I had spare.

Tube cradle and altitude bearings fabricated.

Tube internal flocking completed. Exterior covered in a patterned cloth and waiting Estapol coating. Getting the cloth smooth was a bit tricky.

About 2 hrs work so far.

Second hand eyepiece set has ben acquired, in part through IIS. Many thanks Darren. These are Synta WA ep's suitable for use while wearing glasses and do an excellent job @ F7.8.

To do:

Red dot finder.
Dob rocker box and base.
Eyepiece box.
Star Atlas holder. Also convert "The Southern Sky Guide" star atlas from glue to wire binding.
Write Instruction Manual.

I will post some pics when I get a chance.

Cheers,

[janoskiss]

Ian, you've answered your own question and then some. A Dob mount is the key to getting some use out of these cheap Newts. I presume your Tasco has the thick contrast killer spider vanes. If so then tossing them out and replacing with something more delicate might help improve the views a lot.

[iceman]

Hi Ian, welcome back!

SOunds like another nice project to keep a DIY'er like yourself busy!

btw, why aren't you coming to Lostock with Anthony and Markus? :poke: :)

[Astroman]

Hmm gives me an idea for my little TAL-1 OTA.

[toetoe]

Sounds like your having fun there Ian. You just taught me something about the 114 Tasco's, i didn't know they had a smaller focuser, i thought they all had the 1.25". how old would the Tasco be that you are doing up.???

[Orion]

Good to see you back Ian.

It's always nice to hear someone starting a new ATM project and if it is any indication from your last project this one should turn out great!

[Astroman]

A mate of mine "Stargazer" has a Tasco 114 that has a .965mm barrel. Reasonable views through it too for a 4" scope.

[toetoe]

Any idea how old it is Andrew.?

[mickoking]

I once owned one of those 114mm Tasco's. One you use descent eyepieces on them they are actually good performers.

[33South]

Would Stargazer like a .965 eyepiece - Swift 6mm Triplane - not the best but good in its day (for the price) Only 5$ for p&p donated to IIS.

:prey: I've been dying to find it a good home.

[Astroman]

Not sure, will ask him 33s.

Peter the scope is about 20yrs old

[Twokids]

Ooh, is it one like this? If so, I have the same scope and was thinking of converting it to a dob for my 5 year old. The mount is a nightmare to use. I'd love to see any photos you have of what you've done with it :) . I've always found that apart from the mount, it's a suprisingly nice telescope to look through.

[toetoe]

Do you have a picture of it before your mods,??

[toetoe]

That would be just the right hight for a little dob to suit a 5 yo Jodie. :)

[stargazer1969au]

http://www.cloudynights.com/ubbthreads/images/graemlins/slap.gif What??? ... Four and a haaaaaalf!!! :P


:confuse3: Hmm ... I haven't got a 6mm (got a 4mm & a 9mm). More info? I'm interested ...


Yep ... 'cept mine goes faster ... it's a RED one! http://www.cloudynights.com/ubbthreads/images/graemlins/woot.gif

________________
Hey ... I think this is my First Post in this forum! :welcome:

[iceman]

Hi Paul!

We've chatted on email, nice to see you making your first post :)

[Astroman]

Sorry Paul I stand corrected 4 and an half tiny inches :D

[33South]

Probably made in the 60s by Swift, similar ones were also made by Vixen technically its a modified Kellner or achromatic Ramsden. I think it was designed down to a price.....

But its got a shiny barrel and light grey domed end that holds the lenses.
The eye lens is about 6mm in diameter. Good condition no fungus or scratches on what little glass there is, Ill post a piccie over the w/e.

Ive also got an adapter for it to be used with even older style focuser that took threaded eyepieces that screwed into a separate push in drawtube. - collectors item honest :lol:

[stringscope]

I wonder how many of us started out with one of these scopes? This is the same as my first scope of 30+ years ago.

I believe this one I am moding was donated to CAS. I have no idea how old the scope is but it has had a hard life with plenty of bumps. I shoud have taken a "before" photo but I have been so pushed for time I missed this step. However, before I started, it looked the same as the one in Twokids photo (except somewhat bumped and bruised).

The limited star testing I have done to date indicates is quite OK up to 100X or so. I am doing this rebuild on the cheap so I am leaving the secondary spider alone. Having said that, if cost were no consideration, I would love to fit a Protostar curved vane secondary support just for fun.

WRT focuser size, I have noted later model versions of this scope are fitted with a 1.25" focuser. Anyone know when the changeover occured?

Progress to date.

I have applied 2 coats of Estapol to the cloth covering the tube. The first coat soaked right into the fabric, however it is so humid here at present the second coat is proving very slow to dry.

I will probably get the mount well under way this weekend and hopefully some pics.

The ep height should be just over 1 metre so it should be just the right size for little people.

Cheers,

[stargazer1969au]

Cloth? ... Fabric?
:confuse2:

We talking about the same scope here? :confuse3:

[stringscope]

Yep......same scope. The tube is made from rolled steel painted gloss white on the outside. The tube had quite a few dents and scrapes and really needed refinishing. I contemplated repainting it but I have wanted to try this technique I have read about where you cover the tube in the cloth of your choice and then cover with clear finish.

I first knocked the dents out as best I could then sanded the gloss white paint exterior to provide for better glue adhesion. I then used a specialist spray on glue that promised to stick fabric to metal. I found it needed a minimum of 4 hands to apply the fabric to the tube.

Once the fabric is in place it then needs to be covered with protective covering. In this case I am using Estapol (turps cleanup). I have now applied 3 coats of matt finish Estapol without sanding. I did not sand between coats as I was concerned about going through the thin layer of Estapol and contacting the cloth. Now that I have 3 layers in place I try some light sanding this afternoon and if all OK, apply 2-3 layers of high gloss Estapol, sanding between coats.

Why am I doing this?

1. I have wanted to try this technique for a while.
2. I wanted this scope to look appealing and interesting.
3. This finish should be more robust than enamel paint on steel.
4. This external finish, combined with internal flocking should slightly insulate the steel and so reduce the potential for "super cooling" and therefore primary mirror fogging. I still remember this happened to me with my new Tasco in its first night out ( and regularly after that) on a cold September night in the Victorian Central Highlands 30+ years ago......I thought it was broken!!
5. It fun!!

Cheers

[Astroman]

You could using this technique make it look like a patch work quilt, might go well with Mikes scrapbooking :D Ooops don't want to give his wife any ideas, he might end up with quite a colourful 10" scope on a quite colourful EQ platform hehehe. Seriously though, this is similar to using fibreglass I would assume, would make quite an interesting looking telescope. So wheres the pics :D

[stringscope]

This it for the minute..........got to the the dogs to the vet for their shots.

More later!

Cheers,

[Astroman]

well done, looks great, I was expecting a nice floral pattern on the tube though :)

[ausastronomer]

Not surprising :) A lot of the Tasco reflectors sold in the 80's were made by Vixen in Japan, as were a lot of the Celestron reflectors. Change the mount and focuser, stick in a decent eyepiece and they are a very good telescope.

CS-John B

PS: Vixen and Towa Optical (Japan) produced a lot of optics for Tasco in the late 1970's and 1980's. These products are of very good quality, including some of the small refractors, reflectors and binoculars.

[stringscope]

Rocker box and ground board fabricated. Lazy susan azimuth bearing not yet attached. Colour will be blue with silver trim. Whole thing is just under 1 metre high when pointed at the zenith.

Cheers,

[Astroman]

What are the Alt bearings made of? looks great btw.

[johnno]

An Extremly good looking Job,Very well done.
Regards.
John

[Twokids]

What a great kids scope :) . You've got me really thinking about how to modify mine now.

One question though. How is the tube staying inside the box? What is holding it in there?

[stringscope]

Thanks for the comments guys.

Andrew, altitude bearings are 150mm PVC pipe endcaps. BTW, I like your motorised dob, really nice.

Twokids, the tube is held in by friction. The box dimensions provide for a tight fit with the tube. You cannot slide the tube into the box, you have to assemble the box around the tube. In this case the box separates into 2 halves that are held together with screws.

Cheers,

[stringscope]

Finally finished. Summary of mods:

1. GEM removed from scope and retired.
2. Replacement dob mount fabricated from scrap timber, 300mm lazy susan bearing for the azimuth bearing and 150mm PVC pipe endcaps riding on felt floor protectors for the altitude bearing.
3. Tasco optical finder retired and replaced by a red dot finder from Andrews Coms.
4. 0.965" focuser replaced with a spare 1.25" Celestron unit. Focuser body and drawtube both shortened 10-15mm to provide correct focuser travel.
5, Tasco optical tube interior flocked and baffled. All exposed nuts/bolts, secondary spider etc blackened.
6. Tube exterior covered with patterned cloth and coated in clear gloss finish.
7. Tube end rings repainted.
8. Optics cleaned and recollimated.
9. Old attache case fitted with cut packing foam to hold star charts and 4 WA LER eyepieces.

Weather has been unsuitable for observing. What little star testing I have done indicates it should be quite suitable for beginer use.

Eyepiece height/angle is OK for seated adult use. Sub teenage kids could use standing.

It has been a fun project :)

[RAJAH235]

Looks great. Kids will be happy. :2thumbs: :D L.

[astrogeek]

Nice

[stringscope]

Just got back inside from the first decent observing session with this little scope.

Seeing was only just average. Reasonable transparency. Mag 5 visible naked eye @ zenith. Mossies were ferocious!

Mirror is spherical with a little astigmatisim. I used all eyepieces 20/15/9/6mm (45-150X)

Trapezium, A-E visible, F hinted only. Pleasing views of surrounding nebulosity.
Eta Carina, Homunculus hinted only. Pleasing views of surrounding nebulosity. I was surprised I could not see the Homunculus more clearly.
Saturn, a bit low in the sky, Cassini division clearly visible, several cloud bands hinted only.
PN (2438) in M46, Pleasing views of M46 and M47. PN visible with averted vision no filter.

The dob mount gived reasonably smooth and balanced motions in both altitude and azimuth. The lazy susan altitude bearing does allow a little vibration when focusing, however I found this acceptable at 150X.

At 100X and up you certainly notice the spherical mirror when trying to achieve focus. I got the impression 150X is about the limit for this mirror.

In summary, quite acceptable performance for a new starter. Should be a good scope for kids at public viewing nights and a suitable hire scope for CAS.

Cheers

[stargazer1969au]

Looks like a nice little Dob there Ian, like the texture on the tube!

Was your impressions of a limit of 150x due to the mirror or seeing conditions on the night?
I ask this as I've used my 4mm (225x) on Jupiter on good seeing nights with some surprising detail showing up.

Here's a couple pics of my red Tasco 114mm (4.5") reflector ... :)

:astron:

[janoskiss]

Yes, but yours is a "450x POWER" scope Paul. It says so on the tube! :lol:

Beautiful job on the little Dob, Ian. Looks a $1m!

[Astroman]

Mine doesnt say anything on the tube :( Easily seen M104 and Comet Hyakutake (8 days after discovery) Not a very good planet scope though.

[stargazer1969au]

http://community.the-underdogs.org/smiley/misc/musicboohoo.gif Ohh ...

Here Andrew, give me a big white texta and I'll write anything on your scope's tube that you wish! :innocent:


:P

[stringscope]

Thanks again for the comments guys. It has been a fun job and I am really pleased with the result. Didn't take too long (probably 6-8 hours total work, tops) and I got to try out a new tube finishing technique. If I have to refurb another steel tube scope I would use the same technique again. I suspect it is more robust than standard gloss enamel paint and I hope it will assist with thermal issues.

Interesting question about limiting magnification Stargazer. I admit I was probably being a little premature.

In my defence, weak though it may be :P, I did find a significant drop off in image quality when stepping from 100X to 150X and I felt this image quality step was greater than could be justified by the seeing. When you combine this with a spherical mirror @ F7.8 and an accepted reasonable limit of 50X/inch for a parabolised mirror, I made an assumption that the 6mm eyepiece was about it.

Gee I like your motorised focuser on the red 4.5" Tasco............wow! At least I think that's what it is. I guess you need that to focus @ 450X :lol:
There must have been a factory somewhere in Japan that churned out a zillion of these scopes in the 70's and 80's, both red and white. I do like to look of your red scope Stargazer, the next solid tube scope I do will be metalic deep red with gold trim :D.

I suspect that if these scopes had come out with a reasonable dob mount as opposed to the "wobbletronic" they would probably have a better reputation as they do appear to be quite OK as a basic scope. I certainly recall becoming very frustrated with the mount on mine all those years ago.

For a small scope using generic Chinese eyepieces, I was impressed with its performance on the limited DSO work I gave it. Seemed to show quite good contrast with various emission nebulae and open clusters showed a nice dark background between the stars. If the weather is OK I will probably take it to the CAS DSN tomorrow night just for fun just to see what it is like under a dark sky.

BTW, just for fun I have attached an couple of images of the other small CAS scope I refurbished a while ago. This one has been out on almost continuous hire since it went back "on line", I haven't seen it for the last 6 months, I just hope the focuser hasn't fallen to bits yet. Note the signature on the underside of the tube saddle!

Cheers,

[janoskiss]

Love the all-wood Dob! I think I've seen that signature before on Ken's 12". :)