Gina

Doesn't PI do layers?

Hmm... I'll be 90 then or moved on to pastures new...

Too much rain and cloud here!

Next door's cat made my jump this morning as I went out through the back porch and she jumped down and ran out the door! 🤣

Galvanised steel will be very heavy. MDPE rubber would be lighter. That's what I use on my build.

The rain is now almost continuous and haven't seen the sun for some time.

Good news...

Frequent rain showers here surrounded by cloud. Brief sunny intervals but probably not worth setting up - scope not even in the observatory,

We all love to see build threads on here - me included. Love that curved roof.

Be aware that Velcro looses its grip after a lot of use. Should be fine if you keep the handle on though. Not a criticism, just a friendly warning.

Yep!!

Interesting and worth watching

Watching...

OIC - though that was what you used - my mistake - sorry...

There are lots of threads and Blogs on here describing various things people have printed. Plenty by me too - astro stuff and clocks as well as making 3D printers themselves.

I see no reason to cut the green out. It's false colour after all. Why chuck data away?! I like Pixel Math in PI.

A nice low-cost solution Chris

Reminds of when I smashed the fisheye lens for my all sky camera. Didn't cost that much but a replacement was just not of the same quality

What colour pallet did you use on that? EDIT - Oops you said - SHO. Just reread the thread...

I would hope to get tighter stars but it depends on so many things that it's hard to say. I'm going for a wider field version of that target so will be interested to see what I can get. I won't be using a reflector though.

Unless you're doing wide angle, you need a very rigid support.

Don't know how I missed this thread before! That is absolutely wonderful Sara. That's my target for when we get the weather. But I don't think I'm likely to get anywhere near the beauty of your image!

Agreed!!

More calculations :- A ratchet wheel with 64 teeth and 160mm OD will fit nicely in the space This will need 13 revolutions so a total of 13x64 = 832 - comfortably below the 900. Total time to wind is therefore 832x2 = 1664s = 27.73m This gives minimal force needed to wind the strike mechanism yet taking a reasonable time. The winding sequence can be started at 12:15 and will end just before 12:43. Seems like a plan - just need to design the parts now.

A calculation for winding every 12 hours :- Weight would descent by 1+2+3+4+5+6+7+8+9+10+11+12 = 78 times the amount for one strike (revolution of the big wheel). Distance from bottom of hood/clockface to floor = 1.3m, less height of weight and pulley of 200mm give 1m clear so 2m travel of the cord. Amount of cord for one strike = 2000/78 = 25.64mm If this were on the same shaft as the strike wheel the drum diameter would be 25.64/π = 8.16mm - which is far too small. With a 4:1 gearing from the strike shaft this would become 32.7mm. 5:1 gives 40.8mm - better. 78 factorises into 2x3x13 so at 6:1 the drum would turn 13 times to wind up the strike system giving a 50mm diameter drum. Seems OK. I will have a lever pushing the pendulum every 2 seconds and I think it could be used to wind up the strike mechanism. This could take half an hour or more giving up to 30x30 = 900 strokes.