mdstuart

Sounds like your hooked on observing galaxies! Mark

WOW. Maybe I will get you to make me some. Mark

Excellent. Looking forward to seeing the built version. Mark

Fair enough. Just something I have pondered after my build. Mark

If you make the base and arcs wide enough you could use embedded rollers like on your az movement. Mark

I have also just come in after a long relaxing session under the stars. Lovely to see Hercules and M13 and Lyra rising again, Summer is coming. I managed to see all my targets tonight so my transparency was good. So encouraged to read everyone's posts about their observing and imaging this evening. Mark

Here is an image showing ngc 5263 at the left and m3 in the centre.

Hope it clears but snow does tend to reflect lights and take the edge off the sky darkness! Mark

Sounds like many of you are as excited as me. My plans include The galaxy pairs ngc 5289/90 and ngc 4227/9 Ngc 5025 with its fake supernova Ngc 5263 right next to M3 A few markarians 431/669/278 So let's see how we all get on. The wind will drop overnight but yes might make astrophotography more challenging so maybe a night for us visual astronomers. Mark

Polar maritime Air over the UK tonight. I could see Dunkery Beacon 60 miles away from Gloucestershire and the moon does not rise till well after midnight. So tonight is the night for trying to see.. That faint spiral arm.. That central planetary neb star.. The variable quasar on your challenge list... The lensed galaxy you keep trying to see Faint nebula or galactic cirrus The asteroid that has always eluded you Go on you know you want to... Mark P.S but not good double star or planetary seeing...

It was lovely here north of Bristol as well Nick. The stars were pinpricks around the galaxies I was looking at. Glad you managed to have a good night as well. Mark

Lovely clear evening, the sky looked reasonable with mag 5 stars visible overhead. I spent a couple of hours to the right of the base of the plough. After a look at M63, lovely and bright! I moved on to the faint stuff. I worked through a list of five galaxies NGC 4837, 4741, 5029, 5112 and 5107. This morning I had a look at them online and it turns out the first three are all relatively distant in terms of what I can observe at around 400mly. Here is in image of NGC 5029. An elliptical galaxy with a high absolute brightness. It turns out the last two NGC 5112 and NGC 5107 are MUCH closer at around 50 million light years. They may be a pair NGC 5107 is an edge on dwarf spiral. In images it is close enough to see star forming regions. Here is a picture of both galaxies from mantrap skies. Both of these were faint and required averted vision to spot with my 20 inch. NGC 5112 was a very faint oval whereas NGC 5107 was a lovely slither. What struck me was that I did not sense that the first three galaxies were ten times further away than the last two. Keep looking up, there is so much to find. Mark

Looks great to me. Mark

And you got the galaxy cluster to the left of the main galaxy. Lovely. Mark

You now have what is called aperture fever.

Got it. The rhombus is easy to see. M52 in my 11 x 70s was just visible with the triangle of stars below that including the nova. Thanks for the charts. Mark

I was out looking at pairs of galaxies with my 20 inch scope last week and came across this pair. In the eyepiece they looked just like a fainter version of M81/82. Both cores were just visible with direct vision. This image does not do the visual view justice. The top left galaxy NGC 5142 is an edge on object in the eyepiece just like M82 and the bottom right galaxy is an oval like M81. Both can be found in Canes Venatici which is rising in the NE at the moment. Both are mag 13 and they are around 240 million light years away. Give them ago and see what you think. Mark

Planetman Sounds like you have someone with experience helping you which is good to hear. Looking forward to more pictures as you progress. Mark

One thing is certain. You will learn so much building a scope like this. Also you will get lots of help/views on this forum.. Mark

My mirror is 51cm and the inside diameter is 53cm. I have not noticed any vignetting etc but then I rarely use any eyepiece with a focal length above 16mm. Mark

Just fir fun have a look at this.. https://www.cloudynights.com/topic/56129-inside-diameter-of-secondary-cage/ Mark

Now you have done it. Its only a matter of time before you buy a big dob. Mark

Make sure the top cage is big enough. Has to be a bit bigger than the mirror diameter to avoid vignetting. Mine is slightly smaller than recommended but to be fair it has not impacted the performance in terms of the faintest stars I can see. Mark

Very low profile

Old fruit My understanding is Teflon works fine for any size as long as you get the angles, size of pads and bearing surfaces right but once you get to 20 inches plus some designs start to include bearing rollers. There are lots of views on the subject. I ended up with Teflon on the front alt bearings as some rollers at the back alt bearing which sort of works. Mark