One Tube Ring Short of a Mount

[dick_dangerous]

Hi All,

So we were down at my parent's at the weekend and I've been working on my ongoing project to refurbish my old telescope so my Dad can use it - a Tal M from 1994 (!). Here's a picture of this vintage 'scope:

As you can see everything is fine except for the fact that one of the tube rings has shattered in a fall. I need to replace the second tube ring but have no idea how to go about it. The rings are cast iron, and here is a picture of the broken ring for reference:

What I want to do is either:

• Mend the broken tube ring
  
• Replace the broken tube ring
  
• Find some other way of attaching the telescope to the mount.
  

It's an 88mm / 3.5'' reflector. Really nice 'scope - we gave it a whirl to check the optics and got it pointed at Saturn and it still shows a lovely clear picture. My Dad was careful to keep the tube somewhere the dust wouldn't get to it. Which of the above options would be the best solution to fixing this fine telescope for my old Dad?!

DD

[Bizibilder]

I would try making one up from aluminium bar to match the original. it is quite easy to work with hand tools and any joints could be rivited. You may be better off buying a pair of tube rings and finding a way to attach them to the saddle - maybe a dovetail or "adapter" would need to be made up. The picture doesn't give enough detail. (You can weld/hard solder cast iron but this is a professional job and probably quite expensive).

[laser_jock99]

Large Jubilee clip.

[LukeSkywatcher]

FLO sell sets of Skywatcher tube rings. Same kind of metal as yours i'd say,so you keep the vintage look. I'd say its an easy enough job to mount them on the footplate. It might involve a drill at most.

[dick_dangerous]

Thinking about it, a Skywatcher tube ring, say for an 90mm refractor, would probably do the trick. It's a bit hard to see from the photo but the rings are attached to a rather solid black slab of cast iron - nowhere for a dovetail bar to go! So the rings are just half rings that bend to clasp the telescope. The Jubilee clip may possibly be a cheap solution. I know people who may possibly be able to weld it back together but I have no clue when it comes to metalwork so I don't know if that would be possible with the iron.

Here's a closer view of that beast of a mount...

When it's whole it's as solid as a rock. Do Tal do spares?

DD

[AndyH]

If you were to put up a 'wanted' add in various places, for a ring for a Tal 100 refractor, I think, the top piece of the latter could be unscrewed and fitted to the M mount. I don't have an 'M' mount, so can't say with certainty that the ring dimensions are the same as on a std Tal tube ring.

I have an 'M' scope and have a set of 100R/RS rings that fit the ota.

To be honest, that ring is in so many bits, I don't think welding will be an option. I could be wrong of course.

[AndyH]

This scope was looooong ago discontinued.

Zero chance of getting parts for it from the factory.

[AndyH]

Are the parts on the mount, where the ring screws/clamps to undamaged. ie: just the top part of the ring that's knackered?

[AndyH]

Scratch the above 100R/RS ring idea.

Found this pic, that shows the top piece of the ring system to have a much longer circumference than a std Tal tube ring.

About 3/4 of the way down the page.

http://www.teleskopfreunde-bayern.de/html/tal-m.html

I think the way to go is to make up a new piece. A wee bit ricky and a bit time consuming, but do-able.

[dick_dangerous]

I'm not surprised it was discontinued - this telescope was from 1994. It was pretty much made from recycled bits of spy satellites after the fall of communism. The rings are longer than they should be - when you screw them in they bend to hold on to the tube firmly. The stand fell over, mercifully, without the tube on it, so it was only that one tube ring that broke.

I think it's going to have to be making up a new ring somehow. I have some contacts who might be able to help with this, but it's beyond me and probably my Dad. My wife suggested some kind of arrangement involving old belts and shoelaces. I guess this could work...

Thanks for all the advice on this one - I'm keen to get the old scope working for him!

DD

[LukeSkywatcher]

Its the big black hunk of a base plate that is a concern. I'm sure that can be removed and a modern set of tube rings and plate could be put in its place. The damaged tube ring is in too many parts really to be repaired.

[Gina]

That would certainly be easiest, I would think.

[sungazer]

I have had one of these very underated scopes, in my opinion the easiest method is a metal jubilee clip with some soft felt underneath to avoid scratches and allow the tube to be rotated as required. Spares are not likely as these were discontinued in 2000 approx. Good luck with your repair.

[Astrobits]

The chance of spares from the factory are zero.

I remember back in the early 90's, a rep of the U.K. importers told me that they could not order anything from the factory. The factory filled a container with whatever they were producing at the time, shipped it to the U.K. and the importers only found out what they had to sell when the container was opened!!!!!!

I had contacted them to enquire about supplies of their eyepieces as a separate product and the response from the factory was " we supply all of our telescopes with eyepieces, why would you want any more?".

Now there's a marketing genius!!!

Your best bet is to use any of the suggestions in the posts above and if you want to restore the telescope to 'original condition' go for the cheapest and advertise for a broken one to use for spares.

Nigel

[dick_dangerous]

The chance of spares from the factory are zero.

I remember back in the early 90's, a rep of the U.K. importers told me that they could not order anything from the factory. The factory filled a container with whatever they were producing at the time, shipped it to the U.K. and the importers only found out what they had to sell when the container was opened!!!!!!

I had contacted them to enquire about supplies of their eyepieces as a separate product and the response from the factory was " we supply all of our telescopes with eyepieces, why would you want any more?".

Now there's a marketing genius!!!

Your best bet is to use any of the suggestions in the posts above and if you want to restore the telescope to 'original condition' go for the cheapest and advertise for a broken one to use for spares.

Nigel

It's kind of the post-Soviet way I guess. I assume Tal might have become a bit slicker in recent years. The 'scope is built like a tank at any rate. I'll go for the Jubilee Clip option most likely - this seems like the simplest method of restoring it to working condition...

DD

[Bizibilder]

This might be the way to go: http://www.tooled-up.com/product/draper-12mm-wide-jubilee-hose-clip-set-3-meters-long/17221/ Not used them myself but I have the product flagged just in case!