Mr H in Yorkshire

Was that river coming in, or going out of the patio area? If out, do you need to be concerned where it's going (before you disappear into the sink hole). Here's a cheery thought suggested to me by a police detective, if you dug up all the patios how many bodies would you find?

@Nigella Bryant I have a neighbour who is a meteorologist (good enough to be a Beta station for the Met Office) and I was talking to him about this dreadful spell of weather. Here in Yorkshire has been awful since summer. He still says that over a 10/20 year period spells such as this are nothing out of the ordinary, although his monthly summaries almost always have an 'exceeds the (whatever value) since records began' entry! I have a photo taken at Christmas last year of our grandchildren - all up a massive tree in bright sunshine and a brilliant clear blue sky, as it was most of that week. Contrast that with the howling gale and incessant rain of this year.

GOTO and tracking, that is impressive. I think I explained that my efforts are towards an actual ride on Alt/Az binochair. Even with the integrated balancing that I have worked out the Alt and Az drives will need a lot of grunt and I don't think I can afford the gear that would be needed, at least not just yet. I was wondering what f ratio those objectives are, the rig looks quite short so low presumably. Mine are f/5 and there is quite some CA present so I a pair of Baader minus violet filters that I expect to mount permanently in the EPs. You have used some seriously thick ali plate and other stuff so I can appreciate the materials cost, as I have just spent £300 on ali and steel. The ali (square tube and plate/sheet) is for the binoscope and the steel tube is for the binochair ALT/AZ drives and rider cage. I am limited in tooling, I do have an ancient lathe and a bench drill, plus hand tools so I have to design for what I can achieve. My rig is thus very simple compared with yours, basically a flat platform on which are mounted the moveable objectives in their ali housings and the primary mirrors and on a pair of movable platforms (to adjust IPD), the secondary mirrors and EPs. I will post about it in a couple of weeks when I have got a bit further with the binoscope and when I know it works! I suspect I will then have to revisit the alt/az drive arrangements. All good fun and something to do while the weather is keeping me off my bike, at the moment I do wonder if I should be making a tornado proof ark rather than ATM stuff.

We have just had 55mph winds, do you plan to add something to hold the obsy box down?

Honestly, can't the younger generation do ANYTHING without looking at a phone screen!

I see you have a control box of sorts but is that just for focus and IPD? Are you considering GOTO or 'drive to' as I call it (the motorised equiv of push to') using encoders. I have encoders (from astro-gadgets, a Ukrainian company) on my binochair and they are great, they work with Stellarium or Skysafari? I'm still working through my binoscope project but my 'engineering' is so rough compared with yours I'm actually sufficiently embarrassed that I've gone back and cleaned up some really rough bits. I can't help it, I once did a personality exam and it turned out I was an extreme pragmatist/analyst type, it's the pragmatist bit that allows me to get away with scruffy work, but I have always admired the patience shown by real engineers.

My bet: the mirror appears to be attached only at the centre - so some sort of expanding sleeve or other device to to hold the mirror securely, collimation is obviously by the three peripheral push/pull units that move the whole cell. That's an interesting mirror casting, I have an ancient Russian Mak MK65 with a shaped mirror (thinned towards the periphery) but I've never seen cast ribs like that, any idea what the material is? I only ask because reading around most attempts at ribbing result in 'print through' effects when grinding the mirror. I was just thinking, imagine if that was a traditional full thickness mirror, trying to make a lightweight version would be a lost cause, in fact you'd probably get a hernia using it!

It looks like a very minimalist design, surely a lot of engineering cleverness must have gone into it. As they say, if it ain't broke...

Looking excellent (and expensive).

I am similarly inclined (and as a result have done for a number of things by misadventure, live and learn) but the problem might be that at maximum hinge width as supplied, the two optic's axes and the hinge axis are already on a straight line. The old Apogee binos I use with my portable binochair certainly have room to spare, so some judicious filing would work. It will clearly depend on the construction detail of the binocular.

A question for manhole cover owners - doesn't the green felt leave unwanted fibres on the glass?

I reckon my local agricultural merchants have everything, maybe not the kinder egg though.

We have a couple of those type of displays near us, when we travel with our grand children they ask 'can we go via crazy house?' What I'm amazed at is one property that is really small but has a massive display even covering the roof - where do they keep for the rest of the year?

I was initially looking for a plough, duh! Beautiful scene.

It's been a bit chilly up here in Yorkshire so a bit of zillion degrees plasma wouldn't go amiss, especially as we'd all be carbonised crisps from the Sun's proximity!

There is a good chance you can download this for free straight onto your new PC. I looked briefly and the omens were good.

Or just strap a puppy to your scope, that'll do it till the Animal Cruelty people come looking.

Hi Tomato, here's another one off CN. https://www.cloudynights.com/topic/743145-roels-16-f4-ultralight-traveldob-propdob-mega/#entry10698873

I just idly googled Albert's book, a mere £690 on Abe books, or a real bargain on Amazon, £397. I thought it was steep at £40 and that was second hand! Maybe I'll rent it rather than loan it 😕 I reckon I've got an heirloom for the grandchildren. PS The offer still stands.

Hi again, I have both books concerned, my only comment is that while both are well written and detailed, the Albert Highe book is more modern in the sense of ultra low base units. The Kriege and Berry book is still in the era of large boxy base units. There is even a lighter design called a flex-rocker, which may appeal as you are going to want to shed as much weight as you can. https://www.cloudynights.com/topic/268199-my-flex-rockeruc-16/ All the best with your endeavour.

The gear looks fun, now you know why you need the optional accessory dehumidifier.

I was thinking clouds = moisture, these modern gizmos can work wonders, 1/2 hour an the whole sky sucked dry and clear for the night and all on one charge.

Dehumidifier?

Re smoking, I remember as a young boy being 'shusshed' in a library by the smoking librarian! Also as a primary school boy our sadist [removed word] alcoholic (sorry teacher) also smoked constantly. I'm glad times have changed, and I say that as an ex-smoker (stopped 40 years ago, best thing I ever did).

Yeah that's the right way. As you say, not 100% accurate. To be exact this is the SPECIFIC GRAVITY, but using water there's practically no difference, other inaccuracies would be greater.