Getting a Second hand £20 reflector telescope working - a little help please ??

[Mr_Cat]

Quick background - this is not the telescope we want to keep - this is just to see if we can use a telescope on our property or have to drive elsewhere...

I picked up a cheap old jessops telescope from marketplace, I'd done some research and know that these TA1100-102 reflectors are only slightly better than a POS but to test what I wanted it should work fine. The guy selling it said it was his daughters old one and he thought it worked. It looked like it was all there so handed over the cash. 

Got it home and realised it was even worse that I could have imagined - the focusing mechanism was jammed, tripod bolts stripped etc etc.

But me being me I like fixing stuff so happy enough to put some time in and get it sorted. 

Stripped stuff apart and realised an extra focuser had been epoxied onto the original focuser (!) and had jammed it so there was no way it was going to focus. I removed the "extra focuser", sorted out the worm drive on the original focuser and got it working. At this point I realised there were no lenses etc.. Easy enough to get some but the focuser is a 1.5" tube and eyepieces seem to be 1.25" - I dug around and found photos of other TA1100-102s and spotted an important piece missing. There should be an adaptor to attach to the focuser..

I've searched and I can't seem to find anything that would fit  - I can get a mate to make me one but that will take a few weeks. I could just chuck this whole thing in the bin but I'd rather get it sorted and working and then once I'm done with it I can pass it on to someone as a working instrument.

So this is the focuser tube  - any ideas where I can get an adaptor to convert a 1.5" focuser down to a 1.25" eye piece ?

Thanks !

 

[doublevodka]

There is this as an option? Alternatively it's finding someone with an old focuser they don't want to get that part, maybe worth posting a wanted once you've made enough posts to be able to see that section.

[Elp]

For the purposes of trialling I'd just look down the focus tube, you'll be able to see something like the moon through it. You can also pack the external diameter of a 1.25 inch eyepiece to increase its diameter with anything so it'll fit.

[bosun21]

There are 1.25" focusers that can be bought on eBay relatively cheaply that are decent quality (IE metal not plastic). They will undoubtedly cost more than you paid for the telescope though.

[Mr_Cat]

I hadn't thought of replacing the entire focuser mechanism.

Good shout guys - thanks

[Mandy D]

@Mr_Cat You do realise that you are measuring the outside diameter of the focuser tube? You need to turn the calipers over and measure the bore., which will come out much closer to 1.25".

Edited November 21, 2023 by Mandy D
Dang typo!

[Mr_Cat]

3 hours ago, Mandy D said:

@Mr_Cat You do realise that you are measuring the outside diameter of the focuser tube? You need to turn the calipers over and measure the bore., which will come out much closer to 1.25".

While the bore is smaller - the metal is thin and crappy (sorry to mix units) and only .8mm thick so the internal bore comes out at 1.4" - which would make for a very sloppy eye piece fit.

As an example of the poor quality on the telescope stand the friction bolt on the vertical wasn't actually threaded... It had circular grooves that didn't connect up so wasn't actually a thread and couldn't be tightened - I "assumed" it had been bent and cross threaded so cut it short, filed the top, then spent 20 mins trying to work out why a nut wouldn't thread onto it. I have genuinely not seen that in 46 years of spannering stuff...

 

Edited November 21, 2023 by Mr_Cat
mixing units not dimensions. Need more coffee :)

[bosun21]

14 minutes ago, Mr_Cat said:

While the bore is smaller - the metal is thin and crappy (sorry to mix units) and only .8mm thick so the internal bore comes out at 1.4" - which would make for a very sloppy eye piece fit.

As an example of the poor quality on the telescope stand the friction bolt on the vertical wasn't actually threaded... It had circular grooves that didn't connect up so wasn't actually a thread and couldn't be tightened - I "assumed" it had been bent and cross threaded so cut it short, filed the top, then spent 20 mins trying to work out why a nut wouldn't thread onto it. I have genuinely not seen that in 46 years of spannering stuff...

 

Your problem is obviously the missing eyepiece holder which should be on the top of the drawtube.

[AstroNebulee]

They are available on the Internet to buy, just search 1.25inch focuser adapter. A few examples from some online marketplaces. 

PUSOKEI Telescope Accessories Focuser Adapter,1.25inch M35x1mm Reflector Telescope Eyepiece Adapter,Aluminum Alloy Mount Adapter Device https://amzn.eu/d/e2TBI38

https://www.ebay.co.uk/itm/295362508450?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=t7VbWmHDTC2&sssrc=4429486&ssuid=Fo3Iht4XRKy&var=&widget_ver=artemis&media=COPY

From China, both very cheap if you wanted to go that way. 

If you ask on here someone may have one laying about. 

 

Cheers 

 

Lee 

 

[Mr_Cat]

44 minutes ago, AstroNebulee said:

They are available on the Internet to buy, just search 1.25inch focuser adapter.

Cheers 

Lee 

 

Thanks everyone for the great ideas - and thanks Lee for digging those links out - that is really appreciated.

I was randomly given an Amazon voucher by work today so took a mix of the advice on here and got a replacement metal focussing unit - I was very tempted by the Helical focuser but getting the mount 3d printed would have taken a couple of weeks (I have a mate who would have done it but he's mega busy)

Hopefully everything arrives on time and on sunday I'll be trying to collimate it...

Cheers !

[Mr_Cat]

Quick update, one shiny new focuser and a couple of eye pieces arrived today. The draw tube was slightly bigger than the hole in the tube but (after removing the mirrors etc) a quick mark up / dremel session / new mounting holes etc the focuser was in place. 

First test from inside the house with a 20mm eyepiece and there was the moons surface in reasonable detail .. The Mrs had a look and was very impressed. Took it outside and with the 6mm eyepiece I could just see some banding on Jupiter and the bright dots of a few moons around it.

Hopefully tomorrow the collimation tool will turn up and I'll set the mirrors as there is no way what I've just done won't have affected it never mind whatever has happened to the telescope in the past.

So, total bill was about £60 and I proved that I can at least see something without having to drive to somewhere much darker so time to think about a good telescope and mount.

Thanks everyone for your help - today was great 😁

[Mr_Cat]

A quick update is in order.
So the bill now is up to £138 as I bought a old DSLR from ebay (£30 inc postage) a T piece and a couple of adaptors, remote shutter release etc and a cheap barlow.
The Mrs is getting me decent telescope and mount for Christmas so figured I'd put some time into learning how to use this old cheap scope and attaching a camera as if I can get ok results on this POS... 
 

Edited December 21, 2023 by Mr_Cat
how do you resize images here - would rather a thumbnail / clicky link??

[dweller25]

That’s a great image 👍