11.8.24

11.08.2024 Back to hutch one: Calfotel XL-2?

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  Sunday 11th. Warm, sunny and breezy but with rather a lot of cloud.

 During the night I worked out how to provide inverted, raised rails. For two calf hutches to roll apart. I clearly saw two calf hutches separating in my dreams. To provide the observation slit for the twin enclosures. 

 Then I woke up. To realise that these enclosures are poorly designed. To join each other, face to face. Which is only fair. They weren't thinking about idiots like me. Dreaming about making ridiculous observatories out of them. 

 So then I had to start worrying about interfacing them for full weather protection. Only to realise that the two would be over four meters long when conjoined. Longer still when separated. The greenhouse would never see the sun! 

 Which was a bit of a shame. Because I was already laminating Baltic birch plywood reinforcement at their intersection in my daydreams. 😳 

 So I must make do with one hutch and do it sensibly. Just for a change. Size matters, but they all taper inwards at the top. The same headroom but less likely to blow over. Greater stability. Not to mention reduced material consumption. It also makes for an attractive appearance.

 The CalfOTel XL-2 is interesting. L= 226cm x Width 166cm x Height 155cm. Larger and designed to house two calves side by side. It provides enough enclosed space to be able to enjoy greater wind protection. Provided it can face south. 

 Rolling it off to the west would immediately expose the telescope to the prevailing wind. Though the hutch might offer some protection by its sheer bulk. It would make the housing of the telescope easier. Though now at £1000 equivalent. 

 Morning imaging with the sun to the east. Would mean the hutch need not be rolled back so far. Offering a useful advantage. Which is lost when imaging to the south or west. When one of the narrower hutches would do just as well. 

 Rolling the larger XL-2 hutch off to the north might cramp the nearby drive. Or it would soon run into the greenhouse! I have just 4m to play with. Depending how harsh I am with the hedge clippers on the beech hedge.

 I am imagining twin doors covering the open front. Now facing south. Though the design of the existing hood is a problem. It severely limits the altitude to which a housed telescope could point. Summer around mid day means 55º. 

 Which would mean taking a jigsaw to the front of the hutch and then reinforcing the enlarged opening with laminated plywood. To which the doors [shutters] would then be hinged. Doable? Needs further thought.

 XL-2 raised on rails? Make the headroom of the hood [say] 2m. Roll off the enclosure back by 1m? It would mean a scale drawing to be sure but summer mid day is the worst case scenario. The rest of the time the telescope would have enough shoulder and headroom. 

 The downside is the telescope is now invisible if I want to sit in the greenhouse. I would have to have a security camera and screen to check for collisions and cable tangling. Or, I could sit in the back of the enclosure. With the imaging monitor mounted on the pier. As I have been doing for several years in the 3m dome. I'd move my chair to the east or west side. Depending on the angle the telescope is pointing. 

 Whoops! Doing a Meridian flip could be an absolute disaster! Unless I provide enough headroom! The telescope usually goes vertical during the flip. A flip could be carried out manually. Without the telescope trying to lift the entire observatory off its rails! Now imagine it does an automatic flip while unattended. Setting limits on a mounting may cause further problems. Can I allow enough clearance for the telescope to go vertical? By rolling back the enclosure enough? The mounting must be clear of any overhang. 

 The obvious solution is not to have meridian flips. A fork mount and a bent [astrograph] pillar both avoid the problem. Turning something like a CEM120 into a fork is rather pointless. The declination axis isn't designed to be somewhere else entirely. Can the CEM120 be fooled into working with a bent pillar or pier? That's not an everyday question for Google. 

 I used Perplexity AI to discover that the XL-2 weighs 135kg. Or 287lbs. No lightweight then. Yet a YT video shows it being moved, tipped and lowered manually by an elderly gentleman. ChatGPT suggests the XL-2 weighs only 69kg. That better matches the effort the YT "actor" was putting into it. 

 I emailed the CalfOTel company. Only to find my contact on leave until the end of the month! I'll try asking one of their dealers.

 

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