Tube cooldown

[Cartman]

When the tube of your Newtonian scope is cooling down before observing, are you supposed to leave the cap on or does it go off allready? What's best?

[NGC 1502]

It will cool faster with the cap removed, as this allows air to circulate more easily. You can observe at low power while the scope is cooling, but it won't give of it's best at medium to high power until it's fully cooled. Some add a fan to speed up the cooldown.

Regards, Ed.

[umadog]

It's really the mirror you're cooling rather than the tube. The mirror is heavy and hold heat for quite a while. As Ed says, stick a fan behind it. Even a slow one will massively shorten the cooling time.

[Cartman]

Does that mean that pointing the tube upside down (mirrorside upwards) makes the tube cool faster? In that case, the warmth from the mirror would escape faster since it doesn't have to travel all the way through the tube...

How do you install a fan on the mirror? And how to provide power for the fan?

[swamp thing]

Have a read through this :

http://www.garyseronik.com/?q=node/69

This should give you a few pointers

Of here

http://www.fpi-proto...r/fanselect.htm