johninderby

Maybe could print up a cereal bowl if not the cereal. 😁

They are getting pretty good at making good hyperbolic secondary mirrors now which really helps. All the various designs have different comprimises. The big advantage the classical has over a Rumak or Mak is zero problems with dew. No glass at the front to dew up plus it tracks temperature changes better and less tube currents. BTW coma is equivalent to that of an f12 newt so not much.

Have found that wrapping a velcro cable tie around the handle of a strap wrench keeps the strap in place which makes it easier to use. A nylon cable tie would also work.

Coma and astigmatism don’t seem to ba any problem from the reviews I have read. It seems to be really well corrected. As it’s really a lunar & planetary scope spikes are a non issue but only seem to be present on very bright stars.

Now just to get the Mak sold. 🙏🏼

The problem with this cheap one is that it rotates as you focus which means that it has to go on the top of the diagonal which is a problem if your diagonal doesn't’ have a T2 thread on the top. If it doesn’t you would need to buy a T2 to 1.25” nosepiece to allow the focuser to fit into your diagonal.The eyepiece will rotate as you focus. You would need a non-rotating helical focuser if you wanted to fit it between the scope and the diagonal. Having the diagonal rotate as you focus just wouldn’t work Something like this. Lot more expensive though. https://www.ebay.co.uk/itm/ZWO-1-25-Helical-Focuser-with-T2-Connection-non-rotating-System-ZWO-HF1-25/372784265184?hash=item56cbac77e0:g:lDIAAOSwKRJdjGuA

The 127 tube is 144.7mm dia. See the notes down the page that say the 150mm rings will fit. I didn’t think they did but they say they have checked. Also available from FLO. https://www.365astronomy.com/SkyWatcher-150mm-Tube-Mounting-Rings-for-150mm-Refractor-Telescopes.html If you want to go the CNC route there are the Primaluce ones but £249.00 🙀🙀🙀 https://www.firstlightoptics.com/tube-rings/primaluce-lab-145mm-plus-tube-rings.html

White is “classical” isn’t it. 🙂 OTA has a Losmandy plate on one side and a Vixen on the other. Will be bolting a carry handle on to the Vixen dovetail..

Black or white. 🤔 After double checking the prices find Telescope Express is a few pounds cheaper but shipping is slightly more. Only 3 quid more for the TS but shipping by DPD so I’ll know exactly when it’s arriving.

He he

Interesting review of the TS version. See the second review by Guus Gilein, said he will be doing a shootout with a 210 Mewlon but nothing yet that I can find. https://www.teleskop-express.de/shop/product_info.php?products_id=10753#cs

While googling Cassegrain came across this. Not exactly what I was looking for even if it is a Cassegrain. 😳

Set of micro milling bits in the open case and micro drills in the closed case.

I see than a group in Hawaii has discovered a load of new moons around Saturn and it’s now Saturn 82 v Jupiter 79 ******************************************************* Saturn has overtaken Jupiter as the planet with the most moons, according to US researchers. A team discovered a haul of 20 new moons orbiting the ringed planet, bringing its total to 82; Jupiter, by contrast, has 79 natural satellites. The moons were discovered using the Subaru telescope on Maunakea, Hawaii. Each of the newly discovered objects in orbit around Saturn is about 5km (three miles) in diameter; 17 of them orbit the planet "backwards". This is known as a retrograde direction. The other three moons orbit in a prograde direction - the same direction as Saturn rotates. Two of the prograde moons take about two years to travel once around the ringed planet. The more-distant retrograde moons and one of the prograde moons each take more than three years to complete an orbit.

Manual for the Orion branded version. https://nimax-img.de/Produktdownloads/62478_1_Anleitung-EN.pdf

A cheaper alternative. 🙂 Sort of halfway between the Skymax and the Mewlon? 🤔

Thanks for the link. Confirms my opinion that the 8” cass will be a bit better than the 180 Mak. Sounds like a great all round performer with less priblems with changing temps. 👍🏻

I had some model boat propellers once made with Beryllium which came with dire warnings not to grind or reshape them.

Beryllium is a metal with unusual properties that make it great for telescope mirrors. So why isn’t used instead of glass in most telescope mirrors. Cost is roughly $748.00 per 100 grams and is also a deady poison. 🙀 How and Where the Beryllium Mirror is Made The beryllium being used to make the Webb Telescope's mirrors was mined in Utah and then purified. The particular type of beryllium used in the Webb mirrors is called "O-30" and is a fine powder of high purity. The powder is then placed into a stainless steel canister and pressed into a flat shape. The steel canister is then removed and the resulting chunk of beryllium is cut in half to make two mirror blanks about 1.3 meters (4 feet) across. Each mirror blank will be used to make one mirror segment; the full Webb mirror will be made from 18 hexagonal (six-sided) segments. Once the mirror blanks pass inspection, they are molded into their final shape, polished and temperature tested to ensure they can withstand the frigid temperatures of space. Beryllium is much more capable than glass to handle the frigid cold of space. The James Webb Space Telescope will face a temperature of -240 degrees Celsius (33 Kelvin). Beryllium contracts and deforms less than glass -- and remains more uniform -- in such temperatures. For the same reason, the optics of the Spitzer Space Telescope were entirely built of beryllium metal. It is thanks to beryllium that the James Webb Space Telescope will be able to see further back into the universe and back in time than any other space telescope operating today.

Felt like trying something a bit different. To quote Robert Frost “Two roads diverged in a wood and I - I took the one less traveled by, and that has made all the difference.”

Yes I have. Similar size and weight OTA as the Mak and well just interested me. 🤔

Good article here. https://www.cmog.org/article/reflections-glass-telescope-mirrors BTW glass isn’t actually a solid but has properties of a liquid even though it isn’t really a liquid.

Hi and welcome to the forum.. Haven’t been to New Brunswick in many years. Yes there are people who are clueless and don’t realise astronomy is science and fact and astrology is nonsense and their predictions perform no better than pure chance. But to get back to the subject of a decent finder this one is the most popular for a dob and can be focused by turning the front end. You may be able to find the Skywatcher version cheaper. Most dobs come with a straight through finder and soon get replaced. Antares make a good 7x50 right angle finder as well. https://www.amazon.ca/Orion-07212-Right-Angle-Correct-Image-Finder/dp/B0000XMVE0/ref=sr_1_fkmr1_2?keywords=Skywatcher+9x50+finder+scope&qid=1570416053&sr=8-2-fkmr1

If I went for the Cassegrain would sell the Skymax 180 and if I don’t get the encoders for the AZ100 and the cash from the TS-AZ5 mount would nearly pay for it.