Quote:
Originally Posted by Paul Haese
Yesterday as I started stripping down the Newtonian I discovered some things that might be affecting your dew problem.
See attached images.
The first things is that the primary is fixed with a threaded plug. This is glued into position with that silastic goo they use. I noted that the mirror was flexing with a bit of pressure and that might be contributing to star shapes. It takes a bit of pressure to remove the mirror but go in an anti clockwise direction and it will come off eventually.
Secondary and hence the reason why you need to remove the mirror, is that the fans blow air onto the mirror not suck it down and past the mirror. This would also create astigmatic star shapes early on with cooling and caused partial dewing of the primary too. I reversed mine, so you might want to check the direction of flow. In the pictures the fans are now correctly facing outward and you can see the dust marks on the back of the mirror too where air was being pushed into one spot before.
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Yes, my fans are the same. I noticed this a couple of days ago. I will swap them around.
So there is a bit of play with the silicon goo ? Can you reduce the amount of goo to get around the flexing ?