30.04.2021 AR12818-20 are leaving.

 *

Friday 30th 46F, Bright but milky sky. 

I was playing with cross-axis building geometry while half asleep. Lot's of interesting ideas to consider. I really want to limit the space it takes up on the ground floor. Not because I plan to play field sports down there. Just to avoid accidental collisions between myself and the structure. Particularly when it is dark. Or when I am thinking hard about something else. What my wife calls "child proofing" my environment. 

09.15. I started imaging. Very milky sky with thin, high cloud. The complex spot system AR12818-20 is now very close to the SW limb. Not that my image remotely does it justice thanks to the poor seeing conditions. I'll keep trying and hope for better things.

09.46. Added a 1.6x GPC for slightly better result. Lots of cloud now added to the milky, white sky. Thermal agitation and wobbling. The former is rapid or higher frequency image displacement. Wobbling is much slower than the latter but the image is much more distorted laterally. Clouds are crossing the sun's image now.

Trying a 2x GPC. Much softer. Smaller field of view. Dimmer.

10.00 Too cloudy to continue.

Went back to fixing cladding on the observatory level at the back. Only one left to do, at the back by lunch time. In retrospect I should, probably, have done the upper panels first for easier access with the ladders. The ladders can't be in the same place as the panel being fitted.

A light shower at 12.45 and a much heavier one before 6pm. The "tan" on the lower panels is obvious here. In contrast to the freshly exposed, upper panels from the dwindling stack.

The last, upper cladding sheet was applied over extra, made to measure, cross braces. I want the connection between old and new buildings to be really solid here. The two eastern posts of the octagon will be remaining. 

The last, lower panel at the back will follow tomorrow. Leaving the new door and two, lower panels are still left to do at the front. I have been using the original, double doors for access and security. The octagon has remained intact inside the larger footprint. The new dome needs to be in place. Before the old and weathered, octagon panels can be recycled to decorate the insides of the larger observatory.

*

29.04.2021 The hideous reality of building a cross-axis mounting!

 *

Thursday 29th 52F max and overcast.

I brought a 3.2m length of 50mm PVC pipe up to the observatory to represent the cross-axis, polar axis.  It was quite a struggle to get it inside the dome!

The northern bearing support would be fully 3m [10'] above the observatory floor. The south bearing would be at floor level. Not far from the south wall. This would allow the Dec axis to be at the same height as the present DIY GEM. 

Finding suitable donor materials for such a long polar axis would not be easy. My scrap, aluminium tubing stack has two lengths of 1.60cm. Twice that makes a polar axis. 

The downside is that the tubing is rectangular 100x200mm. [4"x8"]  So I can't use the 50mm bore flange bearings from the big GEM. The square flanges are 145mm on a side. 

Not that this is a serious problem. I could use smaller shafts and smaller flange bearings. There are no, heavily cantilevered loads, of the GEM, in the stubby shafts of a cross axis. One could even use a cylindrical, plain, northern bearing resting in pads for light, applied friction.

50mm shafts and bearings can still be used in the declination axis. Though it would require a sturdy construction to join the lengths of 4x8 solidly together. While allowing the declination shaft to be mounted at right angles.   

A better [?] alternative might be a tubular, square cross-section,  plywood, polar axis. Tapered to taste, from centre to ends, in truly classical, observatory style. Easily made to any desirable dimension.  Mitred longitudinal joints for cosmetic acceptability. No exposed laminations on the edges to give the game away. Low thermal mass while subjected to hours of sunlight. So no thermal convection currents rising across the field of view.

The declination axis junction is also easily arranged in plywood. The weight and solidity of plywood would enjoy the natural damping of most, wood-based materials. Tapered, tubular sections of the PA would enjoy immense stiffness. Particularly when subjected to the modest loads of my few, amateur sized telescopes. 10" f/8 on the opposite side of the PA balancing the 7" f/12 and the 6" f/10 solar H-a telescopes.

Do I have a plan? 😎

*

29.04.2021 Is procrastination a serious hobby?

 *

Thursday 29th 44F, overcast and breezy with spots of rain. 

I tidied up again and moved the last of the self-compacting gravel to the edges of the raised pad. 

Having had another look at the warehouse ladder I realised that it can be moved a whole metre to the west. This leaves the handrails resting against the outside panel. Just as it does with the smaller octagon. While the pyramidal pier [if I keep it] only moves 50cm to the west. That difference of 50cm makes the hole in the floor seem much less menacing. Though still present.

I looked at lots of alternative angles for the ladder orientation. Nothing works without major surgery to the existing joists. Most of which are now tied into the larger building timber work. 

The ladder covers 170cm along the ground. This is too much to lose within the new building footprint. I had earlier plans to skew it along the south west walls but there is no room for its 60cm width. I could build a stair there but wonder whether it is really worth the effort. A small landing or semi-winding stair would be needed. This would be likely to add a considerable delay. Time better spent getting the project completed to basic functionality. Leaving the "little luxuries" for the future.

Which is where I find myself with the cross-axis mounting. I have a choice to build the new mounting. Or move the existing pier. Which still involves digging up four foundation blocks and moving them into newly excavated holes. The cross-axis would require the same amount of groundwork. Except that it has the potential to carry much greater loads. 

If I simply move the pier and plop the mounting back on top it gets me imaging much more quickly. The danger is procrastination rapidly setting in and the cross axis is never properly started. The present big, DIY GEM does not lend itself to rapid instrument swaps. Otherwise I would have completed the 10" f/8 lunar and planetary Newtonian by now. The 7" refractor would also have enjoyed much more exercise than it so rarely does these days. Which is a complete waste of useful, optical resources. 

The bigger dome gives me more headroom for lifting these telescopes onto the existing mounting. The problem is standing on a stepladder to change the heavy counterweights. There are no positive axes locks. Simply the friction of the wormwheel clutches on their shafts. Once the cross axis was loaded with all the instruments it could be left that way. Or, I could cross drill the axes for screw in locking. A really solid clamping system, for each axis, would be an alternative.

Time to build a full sized mock-up of the cross axis to see how it looks? Why not?

*

28.4.2021

 *

 

Wednesday 28th 37F, sunny, but lots of thin cloud. Easterly breeze will blow into the dome. The breeze made it feel cold and blew the telescopes around.

9.00 45F, dreadful seeing conditions and then it clouded over!

Later that afternoon: Still cloudy with gaps. The spot group is nearing the SW solar limb. The large prom on the NE limb is still present.

16.08. Seeing conditions are dreadful. Captured a wider field than usual but cropped to remove etalon image boundary issues. There is ringed sweet spot. My usual practice of imaging narrow fields of view hides the worst of these issues.

16.32 Better seeing so used 800x600.

Cloud and more cloud.

 

 

 

 

 

 

 

 

 

 

18.53 A few captures before the sun sank into the trees.

 

 

 

 

*

27.04.2021

 *

Tuesday 27th 28F, overnight frost then sunshine. I'll try early imaging as soon as the sun clears the trees. That should offer the best chance of favourable seeing conditions. 

Despite steady seeing conditions  have struggled to tune the etalon. For over an hour the results have been too sharp without showing the magnetic lines. This image is beginning to show the detail. 

Now the processed images are looking artificial in ImPPG. Despite using default settings.

10.56 48F, rather more cloud but the seeing conditions have really improved. Far more thermally mobile but sharper detail.

11.26 50F Changed to 1.6x GPC to favour the unstable seeing.

 

 

 

 

 

Blogger is having another breakdown. The text has changed and wont revert to normal.

 11.55 Discovered a nice prom at 11 o'clock NE on the limb. Just as a large cloud intervened. Swapped to the PST blocking filter for more light throughput. Needs re-tuning and refocusing. Strong thermal agitation. Coarse result from processing.

 

 

 

 

 

12.36  Last image before lunch: No GPC.

 

 

Afternoon session: 17.50 Seeing poor so removed the GPC.

 

 

 

 

 

 18.16

 

 

 

18.52

 

 

 

 

 

18.55 Sun lost behind trees.

*

26.04.2021

 *

Monday 26th 33F, overnight frost, bright start but becoming rather cloudy. 

My poorly and swollen knee is improving. Lesson learned. Don't crouch on a roof ladder all day long! I am supposed to be having a second rest day from building work so I am imaging. I am breaking in an inexpensive Logitech wireless keyboard after the Deltaco died.

11.00 43F. Waiting [and waiting] for the clouds to clear. So I can check centering and focus.

Will Autostakkert AS!3 let me see the processed images today? I never did find them yesterday.

Nor today after I stacked one of yesterday's videos. When I selected another image in ImPPG it opened as ridiculously over-sharpened! 

I kept trying and found AS!3 images were being saved today. 

11.30 Finally a glimpse of the gorgeous spot group in the southern hemisphere. I captured some videos through thick cloud and full frame. Complete waste of time! I should have set a smaller window in SharpCap.

11.50 Cloud cover getting worse! 

12.50 Still waiting to capture a video without constant streaming cloud crossing. The seeing is so soft it is very difficult to focus.

12.52 First image worth processing. The seeing is settling and clearing at times. Though the sky is very white and glowing around the sun. 

13.10 46F Lunch! Despite the down jacket I am freezing! Usually the sun comes out during lunch. Today the sky has gone black!

15.50 47F, cloud has partially cleared.

16.06 49F,  continuing but the seeing is mushy and the image moving bodily. Were it not for ImPPG's almost miraculous ability to draw out detail it would be hopeless to even try to image today. 

I shall continue for as long as I can. In the hope of better seeing conditions.

 

18.07 The sun has appeared form behind the clouds. Seeing still
mushy and mobile.

 

 

 

 18.13 46F  The cloud is back!

That's the end of today's efforts.

  

 

 

 

*

25.04.2021

 *

Sunday 25th 34-44-51F, full sun but cold. Imaging extended AR in southern hemisphere.

AS!3 is hiding its output files!

I have been searching everywhere but still can't find any processed images [stills] coming from AS!3.

It is 53F in the dome but I am freezing even in a down jacket and fleece.

I was glad to be allowed to come back indoors for lunch!

 

 

 

 

 

 

 

 

 

 

*

24.04.2021 Limping wounded!

 *

Saturday 24th 40-53F, another sunny day but cool and breezy from the north. 

I obviously overdid it yesterday because I can hardly walk on my right leg. Probably due to crouching on one leg from the short roof ladder for hours on end. Sensibly, I decided to avoid too much exercise for today. So I tidied the observatory of all the accumulated detritus, bits of timber, screws, etc.

Then I measured the outside diameter of the building's 2"x6" top ring with the surveyor's, fibreglass tape. The largest measurement was 4.18m over opposing points. Average around 4.15m. All safely within the 4.30m of the dome. Though without the danger of being too small. A laminated plywood top ring will be added on top of the 2"x6" timber ring for reinforcement.

The centre of the new dome will be at the present, westerly pier edge at obs. floor level. The new, westerly, "2x6" is 100cm beyond the octagon's matching top timber ring. Suggesting that the huge, pyramidal pier needs to move 50cm to the west. [If I keep it!] 

As mentioned earlier, I plan to build a very large, cross-axis mounting. With the hope of mounting my three refractors, 180/12, 150/10 and 90mm f/11. All balanced by the 250mm [10"] f/8 Newtonian. Or some other instrumental combination to achieve balance. 

The cross-axis mounting allows large and long instruments to be used on opposing ends of the Declination axis. Without their being obstructed by the [now completely missing] central pier. There is also no need to do meridian flips unless desired for greater viewing comfort. 

The image shows a better geometry than earlier attempts. The north and south piers are based on timber A-frames edge on in the image. I want to maintain maximum clear headroom downstairs to avoid head injury. While still resisting thrust loads on the south PA bearing. Meanwhile the obs. upstairs needs clear floorspace [in the south] to move past the telescopes without having to duck under anything. Though it should be possible to walk under or behind the telescopes at many pointing angles.

* 

23.04.2021

 *

Friday 23rd 34-55F, sunny but another day with a cool northerly wind. 

I shall continue to add cladding. What a struggle! Access is very poor next to the shed. I am using a short roof ladder on the shed roof but it is difficult to reach across the gap. Lifting the upper cladding panel into place was a nightmare. It is impossible tom sue a ladder between the buildings. So I could not be in front of the observatory to lift the panel into place.

The short roof ladder is too long to be moved into position and I don't want o cut it. I have securely tied the ordinary ladder to the roof ladder to avoid them separating. At times I was hanging out of the dome's observation slit to reach down to place screws.

The second image shows the final result at 8pm after a fourteen hour working day. I am aching all over again but at least the panels are in place. With the flashing fixed between them along the horizontal joints.

The next job is to lift and fix the panels in the NE at the rear of the building. Which will mean removing the original octagon panels before the screws become inaccessible.

*

22.04.2021 Door post reinforcement.

 *

Thursday 22nd 40-54F. Mostly bright, but cloudy, with gales. 

I decided to beef up the intended doorway section with at least one 2x4 post. To leave the area unsupported left rather a big gap. I have a spare foundation block which could be buried under the post. Not that I am ever in the mood for digging deep holes. Too much like hard work. Particularly when I am already aching all over! 

The new door will be hung from the octagon posts. Which are well inboard of the overhanging structure of the larger footprint. Which will be taking over as the support for the dome rotation rollers. Any downward flexure will lighten the load on that roller. Throwing more weight onto the others.

The new woodwork is a bit "belt and braces" but I will feel happier for the extra supporting post. I moved the spare foundation block over to lie under the new upright post. Then added cross braces to tie it all together. The cladding can now be carried to the edge of the inset "porch" with full support. 

I can't add the cross braces to the two empty frames on the left of the new door yet. Because the much larger, octagon panels would be trapped inside the new framework.

*

21.04.2021 More cladding ply.

 *

Wednesday 21st 44F, heavy overcast with 40mph gales from the NW forecast. It has quickly become broken cloud and sunny periods. What to do today? Perhaps I should fetch enough cladding plywood sheets to complete the job? That would give me more of a rest than continuing on the build. 

I was able to get help again loading the trolley with plywood. The shops have reopened. The car parks were full. Mask and gloves and spirit hand wash. I am having a rest before unloading the plywood at home.

I enquired of the machine hire company if they had any "tame" Manitou drivers for the big lift. It seems not.

The last of the cladding plywood is safely stored in the expanded lower building. I fiddled with the doors in the afternoon to make them better sealed against wildlife. 

I am looking forwards to having a normal sized door instead of two narrow ones. I never opened the second half of the double doors anyway. The problem is [re]moving the pier before a normal door will open. Major lifting work upstairs to get the heavy and bulky instruments and DIY mounting safely down.

*

20.04.2021 Doors ajar.

 *

Tuesday 20th 34-62F. Sunshine all day.

I reinforced the SE post connection to the new building with 2x4 and 2x6 cross bracing.

Now I am trying to temporarily fit the original double doors to the SE face of the octagon. They fit, of course, but one door strikes the foot of the pyramidal pier as they open inwards. As mentioned earlier, I shall be building an English Cross-Axis mounting. With separate [different] piers standing against the new, N&S walls. 

After lunch: Now the doors open both ways. I just need to temporarily extend one, or both, in width. The plan was to make a new single door opening inwards. Not possible until the old, pyramidal pier has gone. Or, rather, its 4x4 legs are repurposed.

I need more cladding plywood. I have two sheets left and need six in total for the exterior. Probably two more sheets to make a single door. There are lots of offcuts standing in the new, lower building.

*

19.04.2021 Fitting the last few panels.

 *

 Monday 19th, bright and warm. 54F at 9.30.

Today, I plan to fill in the gaps in the plywood cladding. And so it was. It took far longer to remove all the screws from the old panels. Than to place and fix the new panels. 

I temporary fitted tarpaulin over the naked octagon in case wet weather tries to get in at the top. Two top panels fitted. The last still to go. 

Access for fitting and fixing may be quite a problem. I might have to use a short roof ladder on the shed next door. Which is what I did for working on the octagon a couple of years ago. The roof ladder proved vital to reach the SE area to add cross braces and remove the old ones from the octagon. Both easterly, octagon posts will continue in their supporting role on the new building. So they had to be well tied into the larger footprint. 

I had used some inferior Torx screws from a discount DIY chain in the absence of named screws. These have proved a nightmare to remove. The star shaped socket has stripped on all of them. I shall have to saw the timber close to the screws. Then split the timber to use Mole grips on the screws. Not an easy task when there is not much room to manoeuvre. The quality screws have all unscrewed without a problem.

*

18.04.2021 Observatory level cladding continued.

 *

Sunday 18th 40-58F, a sunny day is promised. I am aching from yesterday's exertions. Hopefully my morning walk will untie the knots.

I tried imaging again but the seeing conditions were poor. Neither of my keyboards would work normally. 

So I gave up and went back to building work. Another two, upper, cladding panels fixed in the NW before lunch. Warm sunshine but a cool, northerly breeze again.

60F at 16.00. Back to work in the afternoon. More panels fixed at the rear. North side. Not a great picture as I was facing into the sun. Too many trees, to the west, to allow a decent picture. 

The last two frames at front and rear are too near the octagon. I would never be able to remove the old screws if I fixed new panels just there. 

Or, I could remove the closest octagon panels and fix temporary tarpaulins in their place. There would be plenty of protection from the new panels lying just outside them. That would also allow me to complete the last frames at front and rear. I couldn't attach the cross-braces without removing the octagon panels. To give access to the original, upright posts for screw fixing the horizontal timbers.

Seeing the "tiny" 10' dome on top really shows the scale of the new building and dome. The second image shows the increased space available towards the west. The new observatory wall is over 1.5m or 5' tall. Just like the last one. Ignore the temporary, plywood flooring bridging the gaps in the former veranda planking.

*

17.04.2021 Top tier cladding.

 *

Saturday 17th. 40-54F. I made a start on the upper tier of cladding. Slightly awkward to fit because the ladder can't overlap the panel being fixed. The northerly wind doesn't help!

13.00 Lunch: Three panels fitted. Getting into a routine. Cut a 30cm strip from one side. Then plane that edge smooth. Mark the 89cm width on the other side.  Saw off the narrow strip and plane the edge of the remaining board smooth. Measure down and saw off at 151cm. Push the cut up against the top of the frame and close the gap against the last panel fitted. Fix the cladding panel with 40mm screws. 

3.20. Stopped for a rest. All this staring upwards is making me dizzy!

Later I added another panel at the front. It all looks a lot more solid now. The lighter, lower, plywood panel on the right is the reminder of where the new door will go. Still need to add the frames where they join old and new buildings in the NE and SE. That means removing existing cladding. Which is premature.

I still can't add the new, lower panels yet. Because they would block access to the old and new buildings. I can't remove the inner [octagon] panels. Because I would lose their weatherproofing, vermin proofing and security. 

This high level view shows the considerable increase in girth of the building. The new panels have yet to take a tan. They darken quite quickly in bright sunshine.

At some stage I need to remove the instruments and huge DIY mounting. Then the weather doesn't matter. I can remove the weathered, octagon cladding. Then trim to size and line the new observatory walls with it. Add character and save painting things black. 

I need to dismantle the old dome and prepare for the new. Move the rollers over to the new perimeter and add the new. 

The new dome needs laminated rings and ribs to be added. The cold, spring weather hasn't been right for glue. I am still waiting for the tool store in the city to send me the router bits I ordered. For trimming accurate ribs and rings to size.

 

*

 

16.04.2021 2x6 top ring material.

*

Friday 16th 32-52F, white frost, sunny and calm.  My wireless keyboard has died! Luckily I had a wired one spare. 

AR on eastern limb. AR12814 progressing towards western limb.  Seeing too soft to bother with
processing.

Back to rebuilding the observatory. Fitted the flashings ready for the upper series of cladding plywood.

If I add a ring of 2x6 [45x145mm] timber to the top of the building. Then I only need a 2x12mm, laminated plywood ring on top to match the level of the original top surface of the octagon. What a coincidence! 😏

I decided to fetch the 2x6 timber before the weekend rush. I also bought more 12mmx120mm coach bolts and 40mm square roofing washers. These are to bolt the lower frames firmly together. Luckily I picked a quiet time when there was nobody else there. 

Later I mitred 12 lengths of  2x6s to 90cm for the building's top ring. The sliding mitre saw is an amazing tool for speed, accuracy and repeatability.  

*

15.04.2021 Afternoon imaging session:

 *

An afternoon waiting for cloud to clear.

Images soft on the screen.

Disturbed region near the centre of the disk.

 New AR has come around the eastern limb.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*

15.04.2021 Morning imaging session.

 *

Thursday 15th 30F, white overnight frost, bright start, becoming cloudy. 

My G9 camera won't download today's photos. Wasted ages on it.

11.30 Back to imaging just in time for the cloud to cover the sky. 48f inside the dome. Grabbing 500 frame videos, when I can, between cloud.

Screen mages a bit soft and dull. No real definition.

Caught one video and processed it. Now it looks 'overcooked' to me:

 

 

 

 

 

12.10. 49F. My hands are cold! 

A brief clearing of the sun produced another image:

The etalon is badly tuned and the lighting still very asymmetric. 

More detail through the clouds than without them.

12.20 Solid cloud now. Moving quite slowly from the NE.

12.27 Another brief clearing.

 

 

 

 

 

12.38 50F.

 

 

 

 

13.02 Prom

 

 

 

 

*