TheSkySearchers

whilst waiting for other things to come together (deliveries and the like), the next small project is to see if I can make a dedicated solar telescope from an old 80mm objective.

next removal of the screws top and bottom of the main section of the lens and we find the objective (85mm) is revealed.

and now we find the (first?) challenge - how to remove the glass?

There is no thread to turn the lens, no screws, no restraining ring, no sign of glue - this is going to be an interesting one.

And, initial attempts to simply turn in either direction does nothing.

well, after several days of scanning the net, sending enquiries with no response, it looks like that another close inspection of the inner tube has a slight black substance around the inner rim where the glass lies. If this is glue then other than heating the inside and risking damage to the lens, I am left with the alternative of cutting the tube 35mm from the front end. Let's see if the Dremel is up to it. It seems to be about 5mm thick. After it is successfully cut, then filing and ready for checking on the test bench. Then to hunt up a suitable tube.

Perhaps a hacksaw instead so as not to damage any coatings from hot sparks?

Lady Fraktor wrote: ↑Tue Jun 25, 2019 6:05 am Perhaps a hacksaw instead so as not to damage any coatings from hot sparks?

that would take quite a while, safer yes. What I intend doing is to cut down to the 4 mm mark approximately and then work by hand with either a sawblade or very fine file. The lens shall also be covered whilst I make the initial cut. Where are the SF lasers when one needs them?

Probably sitting on the same shelf as the ion cannon for shooting holes through the cloud layers...
Good luck with the build.

Lady Fraktor wrote: ↑Tue Jun 25, 2019 10:37 pm Probably sitting on the same shelf as the ion cannon for shooting holes through the cloud layers...
Good luck with the build.

thanks, hopefully all will go smoothly.