SCT primary mirror fogs up on my EdgeHD !? Generic equipment discussions · Arny · ... · 51 · 1517 · 9

JanvalFoto 4.51
...
· 
·  Share link
***Was your scope new or used? No way would it come from factory with lLoctite on those screws. If new those screws are Allen screws. Many people, including me, replace them with thumb screws. In any case they should only be finger tight.  When collimating  you slightly loosen one or two screws before snugging opposing one or two down. If Loctite was used you can use a soldering iron to heat the screws a bit and soften the adhesive. The secondary mirror won't be affected.***


No it was bought second hand and "practically unused". I can't say for sure that it is loctite, but there was clearly traces of something blue in the threads from what I could see. The grub screws could not be screwed out of the black ring that holds everything together. Maybe we are talking about different screws though, as I mean those that hold the corrector plate, not the collimation of the secondary. Those I've replaced with Bob's knobs a long time ago

Good news though as I ran this telescope last night. Brought it outside from 25 degrees to -10 degrees and not a single sign of dew or any sort of issues. Ran the fans straight away and added the dew heater ring a bit later on at about 40%. The insulation kept warm and nice for several hours until I headed back inside. Collimation went pretty well and I got some planetary imaging done. Seems like the upgrades and cleaning was a success.
Like
RKBerta 0.00
...
· 
·  Share link
***Was your scope new or used? No way would it come from factory with lLoctite on those screws. If new those screws are Allen screws. Many people, including me, replace them with thumb screws. In any case they should only be finger tight.  When collimating  you slightly loosen one or two screws before snugging opposing one or two down. If Loctite was used you can use a soldering iron to heat the screws a bit and soften the adhesive. The secondary mirror won't be affected. If blue that is blue loctite which is not as permanent as red loctite. You can try the soldering iron on the screw head trick. But sounds like previous owner did it ;-(  ***


No it was bought second hand and "practically unused". I can't say for sure that it is loctite, but there was clearly traces of something blue in the threads from what I could see. The grub screws could not be screwed out of the black ring that holds everything together. Maybe we are talking about different screws though, as I mean those that hold the corrector plate, not the collimation of the secondary. Those I've replaced with Bob's knobs a long time ago

Good news though as I ran this telescope last night. Brought it outside from 25 degrees to -10 degrees and not a single sign of dew or any sort of issues. Ran the fans straight away and added the dew heater ring a bit later on at about 40%. The insulation kept warm and nice for several hours until I headed back inside. Collimation went pretty well and I got some planetary imaging done. Seems like the upgrades and cleaning was a success.

*** Those outer screws shouldn't be loctited in place. Unless they do it at factory now. I have had or have a 14", 2 -11", and 2- 8" and removed corrector screws and corrector on all of them. I thought you were talking about collimation screws***
Edited ...
Like
 
Register or login to create to post a reply.