Fan mount for Skywatcher 200p 8" dobsonian newtonian telescope mirror

thingiverse

I have an 8" Skywatcher 200p Dobsonian telescope and wanted to add a fan to speed the cooling of the mirror and help reduce frost build up in use. The Skywatcher doesn't have any easy way to attach a fan and I wanted to use a USB charger rather than have to carry around a big 12v block (I'm not there yet in my astronomy journey). Solution: + 5V [Noctua fan with USB](https://www.amazon.co.uk/gp/product/B07DXNT9J9?ie=UTF8&psc=1&linkCode=sl1&tag=kidmunication-21&linkId=1915ebfc7e6fa2c430687b4e20eb3a77&language=en_GB&ref_=as_li_ss_tl/) connection. It also includes rubber anti-vibrarion mounting pins. + 3M [picture mounting velcro patches](https://www.amazon.co.uk/gp/product/B07DXNT9J9?ie=UTF8&psc=1&linkCode=sl1&tag=kidmunication-21&linkId=1915ebfc7e6fa2c430687b4e20eb3a77&language=en_GB&ref_=as_li_ss_tl/) (which I cut in two as they don't need to be so strong) + 3D printed mask to mount inside the bevel of the telescope. It's 1mm thick, so I added some ribs to make it stronger. The result is this model which includes holes specifically for the Noctua fan and sits with a 2.5mm gap all the way around the edge so you can easily get to the velcro patches when you need to remove it and collimate the primary mirror. Mounted, it works like a charm and you can easily feel a breeze coming out of the eyepiece mount at the top of the telescope. Now, just need to wait for some clear skies... In the photo, you can see that I need to calibrate the Y axis on my printer as it's flattened the back edge. Not that it affects the effectiveness of the mount.