Prinz 660 76mm F/16.4 refractor

[dweller25]

Just bought my dream telescope - well from when I was a teenager in 1974 !

It is complete and barely used but a previous owner had the lenses apart to clean them.

It now only has one foil spacer and two glue marks where the other foil spacers should be !

I would like to put three new spacers in, but what thickness should they be ?

Please let me know if you know, if you know what I mean 🙂

[DaveL59]

Any way you can get a micrometer on the one that remains to see what thickness it is?

Next issue of course will be to obtain a suitable replacement that matches...

[Albir phil]

Hi if you do take the lens apart make sure you mark the side of the lens so you get back in the right position. 

[dweller25]

33 minutes ago, DaveL59 said:

Any way you can get a micrometer on the one that remains to see what thickness it is?

Next issue of course will be to obtain a suitable replacement that matches...

Sadly not, the one remaining is glued on and will not come off without damage 😕

[Albir phil]

1 hour ago, dweller25 said:

Sadly not, the one remaining is glued on and will not come off without damage 😕

Try alcohol it might loosen it without damaging 

[catburglar]

Could you check the gap adjacent to the remaining spacer with a feeler gauge? I had one from Halfords about 40yrs ago when I was tinkering with engines…not sure if you can still get them?

Edited June 7 by catburglar

[dweller25]

24 minutes ago, catburglar said:

Could you check the gap adjacent to the remaining spacer with a feeler gauge? I had one from Halfords about 40yrs ago when I was tinkering with engines…not sure if you can still get them?

Good idea 👍
It’s 0.03mm

Edited June 7 by dweller25

[Debo]

Why not remove the remaining spacer and replace all of them with new ones made from kitchen foil. I'm sure the thickness is not critical but of course they should all be the same.

[dweller25]

1 hour ago, Albir phil said:

Try alcohol it might loosen it without damaging 

That would be a waste of good Whisky 🤣

[dweller25]

21 minutes ago, Debo said:

Why not remove the remaining spacer and replace all of them with new ones made from kitchen foil. I'm sure the thickness is not critical but of course they should all be the same.

You are right, they have all been replaced with kitchen foil at 0.03mm thickness 👍

[Roy Challen]

4 hours ago, dweller25 said:

Just bought my dream telescope - well from when I was a teenager in 1974 !

It is complete and barely used but a previous owner had the lenses apart to clean them.

It now only has one foil spacer and two glue marks where the other foil spacers should be !

I would like to put three new spacers in, but what thickness should they be ?

Please let me know if you know, if you know what I mean 🙂

A fine achro you've got there! I've had mine for nine years, during which it was sent to Richard Day aka Skylight telescopes for some cosmetic work. I use it as often as possible and other than a very small amount of CA, it lacks for nothing imo.

As suggested, do mark the orientation of the lenses. 

Post some pics please!

Here's mine in white light solar mode, although I now have a wedge rather than film.

Edited June 7 by Roy Challen

[davidc135]

If the whisky doesn't remove the cement, I expect acetone will. eg nail varnish thinners. Bits of postage stamp or memo pad could also be used at this f#.  David