Thermal Issues and Fans Successes
Posted 01 May 2013 - 09:17 AM
Posted 01 May 2013 - 10:27 AM
I was going to weigh it when I finished but I got carried away and forgot, but I did weigh it just before I cut out the middle hole for the fan and it weighed slightly under 2.5kg , so with the middle cut out and the fan added it would probly still be 2.5kg ish, before I made the baffle I was using six 1 kg dumbbell weights attached where the locking knobs use to be and it ballenced perfect wherever it was pointed ( even just before zenith) and it stayed put and was very smooth to move. I'm now thinking that I will probly use three 1 1/4 kg weights instead , but in a few months time I will be getting a thinner lighter mirror so I may be back to using the original six 1 kg weights , which is good because without the metal baffle I probly would have had to of added more weights.
Nevy, how much did the rear baffle for the Lightbridge weigh when you got it done?
Posted 10 May 2013 - 07:18 PM
And all I can say is that I'm chuffed to bits with it.
Normally when the seeing is good I see a white Saturn with a hint of a belt and nice sharp looking rings with a nice Cassini division , the actuall planet is pretty featureless , now with the fan running it looks a bit different.
The seeing wasn't particularly good the sharpest views were at 142x with a TV 10.5 smoothie, I had the fan running for about an hour to cool the mirror while I went inside and waited for Saturn to rise.
The first thing I did was to turn the fan off & the view of saturn was not really that sharp , it was shimmering quite a bit through bad seeing and it would steady now & again and the rings were ok ish Cassini division coming and going , I then switched the fan on and after a few seconds I could see a real difference , the shimmering calmed down quite alot , the planet & rings got alot sharper with the Cassini division there all the time but the main differences was on the planet itself , I could see two bands and I could see a bit of detail in the polar region , I think the reason for this is that for the first time I could see a bit of colour instead of just white and this made the bands more visible , it was like a beige creamy colour on one band and the next band was a slightly darker ( browner ) shade & there was a subtle colour difference coming and going in the lower polar region , I switched to the tv clickstop 8-24 zoom and I was getting just as good views from it even at the 8 mm setting.
So on first impressions its made a huge difference , I can't wait to try again in good seeing , when I first put the fan on the scope it did make for a sharper image but after the sealed baffle system was installed I was surprised to be able to see colour which in turn made bands more obviousness.
So it was well worth doing and I'm looking forward to trying the lightbridge out as that gives even better planetary views with just the standard fan with no baffle so I have high hopes for it now , can't wait.