Jkulin

Mines a MkII and I haven't collected it yet, but the measurements I have been given the following: -

"The dome walls have a diameter of 2100mm +/- about 5mm. At the bottom of the walls, there's an approx. 80mm flange on the inside - so the internal diameter of the flange is 2100 -(2 x 80) = 1940mm +/- about 10mm. "

I hope this is correct as I have had the concrete and brick wall erected to take it.

2 hours ago, tooth_dr said:

Hi John. Looks nice 👍🏻 So what height is the pier now from the wooden floor?

Hi Adam,

The pier was 1212mm high, so with the wall and floorboards in it will raise the dome by 23cm, thus reducing the amount of pier visible to 982mm, the important thing was that I gained an additional 23cm of clearance for when I go for a 10/12" Newt.

Thanks Ray, I'm a bit apprehensive really as I just hope I have enough clearance for everything to rotate and that there will be enough room to fit a 10/12" Newtonian at a later date, thus the reason for raising the dome higher.

I have built a new computer system that will remain permanently inside the dome (rather than use my laptop), but again am concerned about the clearance for the OTA with gubbins to swing round with enough clearance. I did buy a curved monitor so if needs must the I can mount it on the wall.

Part of me wishes that I had gone for a RoRo Obsy as then I would never have a problem with clearances, but as my garden faces south it does get some savage winds hitting it, so the dome should help improve things.

So, after finishing the tidying up of the cables at the weekend and being plagued with a wasps nest, I finally got that part sorted yesterday and no harm came to the wasps, I moved them down to the bottom of the garden and only got stung once, thus the purchase of a bee keeping suit and gloves as we do get our fair share of wasps, probably due to the fact that we have sown so many wild flowers around the garden that it is a perfect habitat for them.

Today's work or I should say this afternoon, I painfully (due to my back) made up and fitted the joists, they are a really snug fit, so hopefully if it stays dry tomorrow I can lay the flooring as there is no way of doing it once the dome is in place.

Travelling down to Steve's on the 17th to collect the dome, my son and son-in-law are travelling together as they have to work in the same office (so no compromise of social distancing) in a Luton Van I have hired and I will go down separately in my car, so there is no risk of bringing anything back to my wife, we are still in isolation and have been for 12 weeks, I will bring spare PPE for Steve so that we can both respect our families, but acknowledge that Steve will need to get closer to show me the custom software and installation.

Steve mentioned that the Obsy is securely sealed to his concrete with Silicone, so I have bought one of these Car Windscreen Removal Tool Glass Cutting Wire (22M) + Handles as these are designed to break the silicon bond in windscreens so should be able to handle the Obsy silicone.

I have also removed our old Galvanised shed and cut back the Cherry tree to make lifting the fence panel up to get it into the garden from me neighbours garden as that should now allow us to bring the dome in in just two parts and no need to break the panels down (I hope)

2 hours ago, Rainer said:

Hi John,

No, I am not wrong and BTW

 

there is no dealer of iOptron in Mexico so I have been dealing directly with the poor iOptron support in Woburn, Massachussets, USA.  !
 

and

Good for you and consider yourself over all very Lucky. There are many cases of iOptron  CEM 120EC or EC2 mounts which do NOT work. So do not try to cover up the Sun with a finger.

You know the stories very well ...

have a nice day ...  👍

Sorry Rainer I totally disagree, anybody I have spoken to in the UK extols the virtues of the 120EC that includes 3 friends as well, having owned 3 iOptrons now I can only speak highly about them and in the right hands work superbly.

3 hours ago, xthestreams said:

Nice work John - loved to see what you've done to get the system all integrated, inspiring. The work with teh spider was inspired, where did you find a heater that fit between the secondary and the spiders, from what I can see the Kendrick's are too thick to get under.

Also wondering what you've done to Ulitmate Power Box to control the telescope cooling fans, have you had a chance to look at controlling their speed or do they run flat chat the entire night?

Hi,

The Dew heater is a Kendrick and fits perfectly.

I have just used a 12v feed of the UPB to power the fans, nothing special, but the 2.1mm plug was loose so I built it up a bit with solder so that it remains in. Yes the fans run full blast.

On 01/06/2020 at 21:53, Rainer said:

Intelligent decision. CEM 120EC and EC2 still are plagued with encoder problems and that is going on for more then a year. Ask me why I know it. I have two of these CEM 120EC2 paperweights ... and no money to get something decent but that is my goal for next year.Scrap the two CEM 120EC2 and get another reliable brand.

Sorry Rainer, but you are wrong my 120EC is guiding at between 0.18 and 0.29RMS now, I think the issue you had was related to the EC2 and was exacerbated by poor dealer support in Mexico, not something I have experienced with UK dealers: -

Very nicely processed John

Lovely Carole, you have really tamed that Samyang 135mm

Love it, love it, Love it, that is truly amazing Richard, superb processing, the more I see yours and @tooth_dr Adams images, the more you lot are pushing me to save for one!

What temp are you getting the ASI2600MC down to?

Just now, tooth_dr said:

Looks like a good job John, the brick work looks nice.

Thanks Adam, yep my builder is a quality craftsman.

You might want to think about raising you dome as it will give you that extra clearance which is what I wanted.

Builder has now finished the brickwork, all the cables are through ready to connect up to the fusebox, wood for the flooring will be arriving Saturday so I will cut and fit then cover in a tarp until the Dome arrives on the 17th.

7 hours ago, Xsubmariner said:

When I collected my pulsar dome I used a long serrated, flexible kitchen knife to slice through the silicon, it worked well. Later I removed the old silicon with a can of silicon remover. Take care when reassembling the dome quadrants to ensure the bottom mating surface that runs on the side sections is level. My first attempt at rebuilding the dome had to be disassembled and redone. The second time round I used short pieces of wood to bridge the 4 dome quadrant joints. Clamping the wood to the dome across each joint ensured they remained aligned as the bolts were tightened. Good luck with your build.

Thanks, I will take a long kitchen knife down as well, just in case, maybe a bread knife would help?

I've hired a Luton Van, so I am hoping that we can get the dome out in two pieces and won't have to split the base, but will pay attention to what you have said about the alignment, thanks.

The more I kept looking at the image the more I kept noticing that the background was a little red, so a quick curve and I think it is now a lot better: -

What do you reckon?

This is just an example of how many instances I had open to try and get this right, and this was after so many different projects to get it the way I wanted: -

35 minutes ago, tomato said:

Great M101, the Ha has transformed the usual appearance of this galaxy.

Thanks, yes when I added it it went bang, now sussed how to add Ha in PI, which I have failed miserably in the past to add.

Small update today, concrete is finished and setting, he's laying the bricks tomorrow.

He only shuttered half of the concrete as the garden slopes, so he needed to build it up on one end.

Chatting to Steve we were trying to work out how to easily break the bottom seal of the silicone, I then remembered that it is the same problem when people fit new windscreens, so onto Fleabay and they sell Cars Windshield Removal Tool Windscreen Window Glass Cutting Wire + Handles K KY

Using them it should release the silicon quite easily with one of us on the inside and the other on the outside.

2 minutes ago, Allinthehead said:

That's a beauty John

Thanks Richard, much appreciate your comment.👍

Thanks Carole, yes the packing up and putting away at the end of the night was horrible and I was always conscious of making too much noise for my neighbours.

I've kept my kit out side for nearly three years now and it has been a godsend, but as our garden is southerly facing the wind really can howl, so hopefully the dome will reduce that.

I'm also looking forward to drift aligning my PA as that will save time and be more accurate.

My wife is already thinking of what "junk" I can move out of the house into there, I've said not much as its a small dome, she wasn't best pleased, mind you I think I have done well to put an observatory smack in the middle of the lawn any way.

33 minutes ago, Xsubmariner said:

Hi John, 

Good luck with your build, will you be isolating your surrounding concrete base from the pier base to prevent vibrations when you walk around inside. I used flooring screed expansion foam. Looking forward to reading about further progress.

Hi, No, no need as it's less than 1.95m inside, so there is no point as I will control it all from inside my Study, like I do at the moment.

29 minutes ago, tooth_dr said:

Good job John. Capitalise on the good weather 👍🏻 I built my dome yesterday 

Hi Adam, my back was too bad, so my builder is doing it, he's putting the boarding up as I type, then plans the brickwork tomorrow, as I am having a 3 tier brick wall to mount the dome on to give me that little bit extra height. Good luck with yours.

Well work has started, my builder dug the footing out on Saturday and I have spent most of the afternoon running the cabling through.

He's pouring the concrete in the morning and laying the brickwork on Tuesday, I then just need to visit and collect the Pulsar from Steve in Somerset.

My neighbour (the accommodating one) has agreed that we can bring the dome in from his side and we'll lift a fence panel up and bring it through.

6 minutes ago, MarkAR said:

Lovely image John, the 3nm Ha does look good and sharp.

Thanks Mark, out of any of my equipment the Chroma 3nm have proved themselves time and time again, best investment I ever made.

Just now, tooth_dr said:

Superb John, I like this version with the pronounced Ha areas.

Thanks Adam, it was an absolute pain to get the Ha in, as every time I tried it kept saying the stars didn't align yet they all had the same reference image.

I finally closed it all down and recommenced from the RGB and Lum combo and then it worked, it was so bright that I had to reduce the Saturation down quite a bit, there must be so much Ha in that Galaxy.

Just now, carastro said:

That's come out really well John, love the Ha highlights.

Carole 

Thanks Carole, that means a lot to me.

Well I collected a load of data last year and had to throw it all away because I couldn't get rid of some dust bunnies, so this year I was determined to get it right and hopefully have succeeded.

The processing was so critical that I despaired of ever getting an image that I could be proud of, it really tested me to the limit.

Link to more info: - https://www.astrobin.com/r4s23i/

Dates:May 27, 2020 ,  May 28, 2020 ,  May 29, 2020 ,  May 30, 2020

Frames:
Chroma Blue 2" unmounted: 8x780" -20C bin 1x1
Chroma Green 2" unmounted: 8x600" -20C bin 1x1
Chroma Ha 3nm: 8x1200" -20C bin 1x1
Chroma Luminance 2" unmounted: 21x600" -20C bin 1x1
Chroma Red 2" unmounted: 8x696" -20C bin 1x1

Integration: 10.8 hours

GSO/Altair RC 10" Truss, Moravian G2-8300 MkII, iOptron 120EC Mount, Chroma 2" LRGB & Ha Filters, Ultrastar Guide Camera

Here's the bumf: -

The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on spiral galaxy distanced 21 million light-years (six megaparsecs) away from Earth in the constellation Ursa Major. Discovered by Pierre Méchain on March 27, 1781, it was communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final entries.

On February 28, 2006, NASA and the European Space Agency released a very detailed image of the Pinwheel Galaxy, which was the largest and most detailed image of a galaxy by Hubble Space Telescope at the time. The image was composed of 51 individual exposures, plus some extra ground-based photos.

On August 24, 2011, a Type Ia supernova, SN 2011fe, was discovered in M101.

Discovery

Pierre Méchain, the discoverer of Messier 101, described it as a "nebula without star, very obscure and pretty large, 6' to 7' in diameter, between the left hand of Bootes and the tail of the great Bear. It is difficult to distinguish when one lits the [grating] wires."

William Herschel noted in 1784 that "...in my 7, 10, and 20-feet [focal length] reflectors shewed a mottled kind of nebulosity, which I shall call resolvable; so that I expect my present telescope will, perhaps, render the stars visible of which I suppose them to be composed."

Lord Rosse observed M101 in his 72-inch diameter Newtonian reflector during the second half of the 19th century. He was the first to make extensive note of the spiral structure and made several sketches.

To observe the spiral structure in modern instruments requires a fairly large instrument, very dark skies, and a low power eyepiece.