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… that the kit was popular. That’s some achievement.
I’ll have a look at Ken’s design if it’s still available. I’m quite optimistic that a Littrow (such as Lhires) could be made but it would take me a year and some investment. (Probably easier to take those parts to a specialist and get them made). It’s down to cost/benefit I suppose. Could it be done cheaper and more accurately than a Lhires? In all likelihood, “no”. Personal satisfaction apart.
Many thanks for your response, very informative.
Tony
Thanks gents very useful. Thinking out loud…
Having read through the the LhiresIII pages I’m comfortable with the plate-work and basic engineering. The lathe-work less so but those skills aren’t beyond me (he says with ease) and the necessary tooling-up would appear to be in the region of ~£700 or so. (I have accurate drilling equipment, etc already). Probably worth it.
I think my first steps would be investigating what components can be adapted from existing or bought ‘off the shelf’ and what then needs fabricating/maching. Let’s assume the bodywork/casing if fairly straightforward, it’s the accuracy of those bespoke mounts that seem the real challenge. I can see why the ‘kit’ was such a success. All the hard bits done.
I’m surprised that all the engineering diags are available ‘to the public’ in the way that they are on the website. Very laudable.
Has anyone tried this from scratch?
Regards
T
Many thanks for the info and the investigative work.
I’ve unwittingly misled the forum into thinking that the ‘negatives’ are part of the atlas. They’re completely separate – but are published by Sky.
They are not bound nor are they photocopies and are printed on ‘heavy’ card as a complete, but loose, set. They are a different scale to the maps. I’ve photographed them side by side.
I was aware of the differing desk and field editions. All my stuff is dated 1969 so not rare in any valuation sense, it’s just that I had not seen unbound maps (or negatives).
Are these unbound ‘card’ negatives a version of the field maps?
Regards
Tony
I’ll post what I find out.
That looked like a great holiday Len! I visited the Czech and Slovak republics many times prior to retirement and I’m kicking myself that I didn’t visit the observatory. It was always “I’m busy, I’ll catch it next time”. What a fool.
Regards
T
Hi Eric, There’s a bit of a tale to it but long story short…
It was fabricated by an ex-mines engineer from Doncaster coal mine. That’s why it ‘looks substantial’ and that’s why it broke my Jeep’s suspension.
It takes three men to lift it. The plates are 15 mm steel that ate three hardened drill bits needed to drill four puck holes. I’ve got no idea what the pipe is but it looks similar.
The fella’s workshop looked as though it had half the old mine’s metal working gear in it.
That said, he was a very talented guy. He only wanted £300 for it and I could not, for the life of me, convince him to make more. I think he’s retired.
It dwarfs my CGEM head and, at a guess, could take anything in the amateur domain. And when I sell it I’ll advertise it as ‘Collection only, bring two mates”.
Regards
T
I’d considered a folding design but my flat roof is approaching 9×9 for which weight is an issue and I couldn’t guarantee rainwater wouldn’t stand without some form of artificial slope. (I didn’t really have the room for (half) a fold-off on neighbours’ sides).
Those ropes must be strong!
Good visibility though.
Regards
T
Andrew, I like anything that automates processes and this is truly impressive.
(I use SGPro for photometry which off the shelf and I like Demetra for its spectro workflow/processing automation).
Any plans to ‘publish’?
Regards
T
Hi Roy,
I’d looked carefully at rubber membrane based roofing options but these were very expensive (£100+) compared to the £3.50 and ten minutes work per covering for the EasyTrim.
Regards
Hi Lars,
The house is North – although what you see is mostly a single story garage.
My views East and West are particularly good. West is the Northumberland National Park (great!) but East is light polluting Newcastle.
South is good above 20*. I don’t miss much North. I can see Polaris and anything circumpolar above 65*.
Regards
T
hi Roy, yes, its limited somewhat by the UV restriction. i’ve mitigated against any mech failure by using exterior varnish on the roof underneath and i now have two layers of poly covering in place. if the first does crack or become porous the layer underneath should hold (and should be UV protected by that above). The weight saving and cheap cost is worth it. It took ten minutes to cover the roof.
there’s some good rubber roofing products out there too so i’ll watch the performance of the Easytrim and keep the forum updated. let me know if you find anything better.
regards
T
Hi Eric,
Yes I looked at those auto gate mechs in case I needed them. A bit expensive for what i wanted. I’ve knocked up a pulley/weight now and it works a treat. Virtually no effort needed. I’d go that route first.
Regads
T
Hi Grant,
Without the need for roofing felt (which would have added another 20Kg!) it’s less than 50Kg including the barge boards. Which I don’t think is bad. The weight was bumped up a bit by extra wooden battens for bracing and, of course, the castors, etc. But nothing dramatic. The roof height was only raised about 3 inches.
The whole thing is easily manageable. I can push it up the ‘slope’ single handed – and I’m 5′ 4″ and 10.5 stone dripping wet. Left to its own devices it’ll roll slowly down on its own. The slope is only about 7 degrees. Enough to avoid standing water but not so steep so as to cause weightlifting type effort to get it back.
I’ve already rigged an old 10Kg counter weight vertically on a pulley inside the shed which almost negates any effort.
Literally 30 seconds to close and secure (once the mount is ‘homed’) and another 30 to close the ‘gates’.
I need to give a bit of thought to the rear barge board which, because of the need for a good weather seal, just clips the rear wall as it goes over the top. I can’t decide on a hinged board or just a rubber trim but since I haven’t yet had any water ingress despite several heavy downpours I might just leave it be.
My only issue is what to do with the water that runs off the front during rain!
Regads
Tony
Hi Eric,
Wow, that area would be a fine weight if felted – getting on for 40kg?
This stuff is called Easy-Trim. Make sure you buy the Non-Breathable (ie fully waterproof) variety. There’s about 20 stockists in Tyneside (such as Dove and Eurocell) so you’ll find it anywhere. It’s in 45m rolls of 1m width and costs about £20 per roll. It’s literally 1/20th the weight of felt.
https://www.easy-trim.co.uk/products/roofing-underlay/breather-membranes/non-breather-membranes/
You’ll get funny looks from the builders when you ask for the Non-Breathable because the norm is to use ‘breathable’ under the likes of tiles/slates.
I hurriedly nailed a covering on the roof at the end of the day just to keep things waterproof and it survived the last ‘hurricane’ without so much as a ‘flap’ or tear. The first covering is still on. I’ve got 30m left!
Not sure what snow and Ice will do but I’ll probably put another layer on and then see.
Regards
T
I tend to agree with Andrew(S) and Nick. I behave like Peter(C). I’m jealous of what Gary can do with regard to visual variable observations. And, I aspire to Grant and Andrew(R) – but family life usually intervenes.
I must confess however that I occasionally get lost (with a pair of binoculars) in the way that David(S) and Peter(M) describe.
And yes, David(A), I definitely don’t do “suffering”. One day I threaten to post a picture of me in my full Parka outfit (with water bottle strapped to my chest!).
From my perspective, the ‘scope, etc are “a means to an end” I’m afraid. The equipment is there to gather data with which to further my understanding and perhaps make a small contribution to the science that is astronomy.
But I think this post shows the richness of, and variation in, an astronomical community, and for me that’s been a great delight too.
Regards
T
I’d thought about ’embedded’ rails to ensure they’re in line and make the opening/closing as smooth as poss.
Have to rethink.
Regards
T
Many thanks. Had considered toothed track, etc but had fallen at the first hurdle with regards availability.
Regards
Tony
The rails are (obviously) the main addition to the construction.
I’ll take David’s advice and double varnish/cover the rail areas and overlap end covers. I’ve got some liquid rubber that I’ve used previously and this has proved effective. Although, I’m using a pent roof shed so would not expect to suffer from standing water. (Hope not anyway!).
Stewart’s recommendation is along the lines I was thinking. In my case I’ll try angle aluminium. (David’s comment on weight being the factor here). Those wheels sound good. I’d identified some similar but I’ll go with the 75mm recommendation. I intend to try six each side.
Thanks for taking the time to help.
Regards
Tony
