PeterStudz

When I started making my Dob base for a 200p a year ago I did have a look to see if there was anything commercially made in the UK. I couldn’t find anything. And these things really need to be custom made for a particular telescope. It’s not easy to make one that would fit a variety of OTA’s. Even if someone did there would need to be annoying compromises. Of course the whole point of a Dob base is that it could be simply constructed largely from bits and bobs people already have down their sheds. If you don’t have these parts sitting around at home, or can’t pinch them off someone that has, then even just purchasing the parts can add up. I’m not surprised at the price of the Orion Optics examples. Eg - I did buy some quite cheap plywood for mine. I needed two sections of plywood at £18 each. I’ve noticed that these are now £19.90. If I’d added a reasonable lazy susan then this would have cost about £35. That’s about £75 before you’ve even started. Personally I prefer Teflon pads and some sort of Formica or equivalent (which I used) but that’s not much cheaper. Then you add paint, glue, screws, nuts and bolts, washers, rubber feet… You often need to buy bolts in, for example, packs of 10 when you only need one. Fortunately I have a big shed and already had a lot of stuff. If you aren’t careful it can soon add up. And of course time is money so there’s labour. I guess it might be possible to find someone (maybe on this forum) who could make one for you.

Awesome report! I actually prefer spending longer on targets anyway. If something is looking good, at its best or close to, I can spend an hour just observing that one thing. Often you’ll see more as your eyes adjust to what you are looking at. I got this wooden adjustable stool for £10 via Gumtree from a guy in Southampton. Works a charm. I also drilled some holes (what can go wrong?) in the OTA and attached a handle. It’s the best mod I’ve done and wouldn’t be without it - no more slippery “fish”.

I guess it depends on if you find it fun. Personally I would find driving (I don’t like driving) more than 30mins to go to a dark site just for a night of observing all on my own too much like work. But I would if, for example, it also involved camping with a group of friends, family or meeting fellow astronomers. Others might disagree and find it enjoyable. Last year we managed to go to a tiny place in Southern Crete. Bortle 2 and the sky was stunning. But it was all last minute, I had no idea what to expect and the moon was around for most of the time. Although I did take binoculars. We are going back there this year for a holiday. Now I’ve made sure we are going when the moon will be out of the way most of the time, I know what to expect and I’ll do some planning. Might even pack a travel telescope. However, I’m not going there because it’s dark. I’m going there because it’s a holiday with family plus friends, my wife likes the beach and my daughter likes it there too. Incidentally, you can get a direct ferry to a small island not far away thats Bortle 1. But I doubt I’ll bother doing that unless I can get my whole family and friends to go along too - doubtful as there’s not much there. The mention of M44 reminds me. My back garden in Southampton is Bortle 7, although last yr ClearOutside had it as Bortle 8. Bortle 7 is probably more accurate. However, this time last year there were about 3 nights in a row when I could see M44 naked eye. And my eyes aren’t great. Some nights, even with light pollution, are better than others. I do find observing from my own garden fun. It’s a bit of…”wow… I can actually see that from my house”.

Went out with my 10 yr old daughter in order to check out a darker site about 30mins drive. To keep things simple I just took our 8x42 binoculars. If anyone knows the area it’s Bolderwood Deer Sanctuary in the New Forest. Supposed to be Bortle 4 compared to my garden in Southampton which is Bortle 7. Although the gate is locked at night there is access to the top of the track and an adjacent accessible open area. Got there at about 9:45pm. It was cold (below freezing) but hardly any wind. One issue, even after 10pm and even though it’s relatively remote, was the number of cars going past. Roughly one every 3-4 mins, which made it impossible to get truly dark adapted. Still, the sky was obviously far darker than home, but as my daughter pointed out, “it’s not Crete”. You could, after sometime in the dark, just make out the Milky Way, although of course it’s not in a great position at the moment. Did a quick tour with the binoculars and just scanning the sky. Mainly old favourites like the Pleiades, Beehive, Orion, Hyades…. There was far more going on around Orion’s sword than we can see at home. I managed to just be able to see M81 & M82 (which I can’t see in the binoculars at home), although Alice couldn’t make them out. M3 looked brighter too. We also spotted a couple of shooting stars. Definitely possible to take the Dob there, although car headlights would be annoying. And it was obvious that Alice wasn’t comfortable being there just with me. If there was one more person/astronomer(s) it would have been fine. Because of that we didn’t stay too long. Camping in an official campsite would probably be a better option. I also know the head chef at one of the New Forest hotels, but of course you’ve got the hotel lights. Maybe preferable to car headlights. Took a quick snap of Orion with my iPhone at the beginning using the Nocturne app. Not convinced by it but worth experimenting. Interestingly a car drove past with full beam while the app was in the process of capturing the picture. Somehow it’s removed it. All in all worth the effort, yet another late night but better than being stuck indoors. The hoodie that Alice is wearing is great. Warm, fake fur lined and with a large horizontal pocket that’s handy for eyepieces, caps, various bits and bobs. I have an adult version too. Of hand I can’t remember where it’s from as my wife bought them. But if anyone is interested I can find out.

I agree. I have been looking at another pair in the last few days. Alice also likes bird and wildlife spotting so it would be a win all round. And thanks for the nice comments!

I agree with what you say about “best way to get them engaged”. Camping somewhere dark/darker is a must. I thought about doing that last year, but COVID and other things got in the way. Alice does like the outdoors and camping anyway so it wouldn’t be difficult. From a past job I do know Dorset quite well so that’s a possibility. I guess the issue in the UK is going somewhere and finding it’s cloudy, but even then it wouldn’t be a total loss. The New Forest is close to me and at least that’s a bit darker - around Bortle 4. In fact we checked a possible Darker site about a 25mins drive from me on Saturday night. Might write that one up tomorrow. Camping there would be easy although the campsites can get booked up quickly. Last August we did go to Southern Crete. The location is Bortle 2. It was all a bit last minute so little planning. We were also there during a full moon period but had a couple of days at the end without the moon. Then the sky was stunning and there every night was clear. At that time of year you are unlucky if you see a cloud. We are going back this year, again in August, for two weeks. But this time I’ve made sure it’s during the new moon. There’s also a tiny island called Gavdos with a direct ferry link near where we are staying. Apparently it’s Bortle 1 and the southern most part of Europe. However, I have a feeling I/we won’t get a pass to go there for a night!

Thanks Dave. Should do more but often time is against me. I do enjoy reading other peoples. The gaming, it’s annoying, it is something we suffer with too. I think all kids do it these days. But with astronomy she definitely has an interest, although impossible to say if it’ll last. It’s the excuse I had for getting into this. Although as a boy my parents bought me a cheap reflector, I sadly got no further. Until now that is. And I’d completely forgotten how much I enjoyed it. My wife on the other hand has no interest what so ever. Things like the cold, short attention spans and equipment (especially if it’s also new to you) work against kids. One thing I learnt was to try and make it an event, with the telescope just part of it. Eg I thought that summer, due to lack of darkness, would be disappointing for us both. But I was completely wrong. What I didn’t realise was how much she’d be into planets, particularly Jupiter and Saturn. As soon they got high enough for our garden (about mid-June) it was every opportunity. She enjoys camping, so we’d camp out in the garden (no tent), look for shooting stars, sleep, wake up (then it was about 2am), view Jupiter and Saturn until the sun came up. The dawn chorus, foxes jumping our fence, hedgehogs going off to sleep added to the event. It was the first time she’d heard the dawn chorus too. Most of this was in the school holidays so she could lie in. For me I had to work and was often knackered! A while back Alice did a tour of her potential new school. Unusually they do a GCSE in astronomy course there too. When one of the science teaches found out that she’d used a telescope to see Jupiter/Saturn he asked her a few questions. Eg… “Have you seen Jupiter’s moons?”; “Yes and shadow transits”. “Did you see any bands on Jupiter?; Yes and the Great Red Spot”. “Have you seen Saturns ring?; “Yes and the Cassini Division”. I stayed silent. But I could tell from his face it was “what have we got here?” Quite amusing!

Had a 3.5-ish hours session last night from my back garden in Southampton. Bortle 7, 8x42 binoculars, Skywatcher Skyliner 200p Dob. Seeing decent, transparency average. Suffered a little from thin high cloud, that came and went, especially towards the end. Temperature 1C to -1.5C, wind - light breeze. Not a whole lot of targets, but I like to take my time. Started off using the binoculars as the Dob cooled. Also giving my 10 yr daughter a little tour of the constellations. At the same time jogging my own memory of some star names which I still struggled with. It would be easy if they were called names like “Fred”, “Sid”, “Poppy”, “Vicky”. Visited old favourites like the Pleiades and Hyades which to me look their best in binoculars anyway. Also the Beehive which is a little harder to locate. Orion too which is rapidly sinking to the horizon. Interesting how Alice can easily star hop via simple instructions from me. Far, Far easier than using a telescope. Although practically it would be better with a couple of binoculars, swapping one pair back and forth is a bit of a faff. I practiced a few star hops using the binoculars too, before using the Dob, although on that I was also getting the hang of (third time I’ve used it) the PushTo feature in PS Align Pro. Works really well and I should do a little write up. M37, M36, M39 started off with these star clusters in Auriga using the Dob and 32mm 2inch PanaView. M37 is my favourite cluster and looks great in the 2inch. Looks like what I imagined a globular cluster to look like before I’d seen a globular. Mind, I have seen these better. Alice seems to like them too. Swapping between a 2 & 1.25 inch is a bit of a faff but I find it convenient to have the 1.25 inch that I’m next likely to use ready locked into the 2-1.25 adapter. M44, beehive cluster. Obviously much brighter than the above but I prefer M37 & the Auriga clusters in the Dob as they are surrounded by a good amount of black space. My daughter does prefer the beehive. Alice then went back inside in the dark to “play”. Told her that se he could go to bed but she wanted to stay up. It wasn’t a school night. M81 & M82 next up. Easy to see as two smudges. Again I’ve seen these better, with a little detail, when transparency was better. But these are the only two galaxies that I can see from my back garden. Still, spent some time observing and changing eyepieces. Called Alice put to have a look. She wasn’t that impressed! Then ruined all night vision by having a break - toasting marshmallows and drinking hot chocolate. M3, M5 and M13. I do like globular clusters. First up M3 which was now at a good height. I could just make out a sprinkling of stars using a 12mm and above. Then M13 which was now at a height that was doable. I hadn’t seen this since last year. A good sprinkling of stars in and around the core using the 12mm. A 5mm eyepiece filled the VOF but can be getting on for a “glitter ball” at this power even in my sky. Got Alice out from our dark house to have a look. Both spent a bit of time on it and watched as the view improved as it slowly gained height. Alice was getting cold now despite being well wrapped up but it’s difficult keeping children still, outside in the cold, so she called it a night. I finished off with M5 which by now was possible. Again, hadn’t seen that since last year. Could just make out a few stars in and around the fuzzy ball by it was rather low. Finally packing up just after 1am. Had a bit of a lie in! Must go and check some darker sites that aren’t too far from me. On a practical note. Kids do find a 2inch eyepiece easier to use. Looking down an eyepiece is a skill that we can take for-granted.

Managed a quick session this afternoon between the clouds and snow showers. Literally had to grab everything back inside as it started snowing. There’s a lot going on now. iPhone single shot doesn’t do it justice although conditions not ideal. iPhone 12 single shot hand held, standard camera app, Skywatcher Skyhawk 1145p on EQ1 plus cheap motor drive, BST StarGuider 12mm.

That’s what I do for M44. I have a cheap red dot finder and 9x50 RACI finderscope on my Dob. I’m in Bortle 7. Another example is M3. To find that I point the red dot as close to half way between Arcturus & Cor Caroli, the only two stars that I can see naked eye from my garden that are anywhere near M3. It’s quite a big gap. Then look in my RACI finderscope. Most of the time I can see M3 as a faint fuzzy patch of light somewhere in the finderscope. If it’s not there I try again with the red dot. At most it’ll take me 3 attempts but 50% of the time I get it first go.

@Stu I like those! I’ve done a little experimenting with electronic sketches too. I do have an iPad plus Pencil and what I tried doing was drawing over a smartphone image of a DSO (I used one I’d taken of the Orion Nebula) using a very basic/rubbish pencil sketch I’d taken at the eyepiece for reference. The original image does mean I can get the stars in the exactly the right place. Will see how it goes.

If someone thought that my smartphone pictures (well, any single shot picture) was a sketch I be well chuffed! Nice images @Stu. Sketching is something I’d like to learn/be able to do. I have far more interest in that than trying to go full on astrophotography using a PC, software and stacking. It sounds far too much like work Out of interest. I recently asked a friend of mine, who is a very good photographer, mainly nature/landscapes, if he’d considered astrophotography. His reply was “I seriously thought about it but couldn’t be bothered with all that stacking”. It’s not for everyone. I have an interest in seeing what a smartphone camera can do but that’s as far as it goes.

Interesting, I have a similar problem (could be the same) on a similar telescope, a neglected Skywatcher Skyliner 200p Dob which I’ve been restoring. However hard I tried and whatever I measured I could not get the secondary far enough away from the primary. a>b in @Spile excellent article. I had the whole secondary plus spider out at least half a dozen times. For me the centre spring was maxing out (fully compressed) before the secondary holder physically came into contact with the spider hub. The work around was to cut down the spring, just a little, to ensure a bit more travel. I actually have a spare spring but that’s another story. In the picture you can see how little wriggle room I have left. This was after I cut the spring down. At this point it was just roughly collimated, paying attention to getting a=b. I’ve also added the milk bottle mod yet there’s barely room for that. It’s now fully collimated but with the room/movement I have after cutting the spring down I can only just do it. Somethings not quite right but it now works.

I was able to see it from Southampton at around mid-day, although a total cover of thick haze/mist spoilt the view it was still worth seeing. Stood out like a sore thumb and could still tell it was something unusual. I left the telescope out in the hope it would improve but the haze just got worse until it was cloud.

@PeterC65 I’m in Bortle 7, although until recently ClearOutside had it as Bortle 8. I’d say Bortle 7 is more accurate but it looks the same to me. Bortle 4 is a dark sky for me! I’ve got a few likely spots to check out that are about a 30 mins drive from me that are Bortle 4. Still, there something special about observing from your own garden. Here, I find that light pollution is at its lowest from about 1:30am. In the past I’ve set my gear up outside and slept on the sofa downstairs, or, when it’s warmer, slept on an air bed outside without a tent. Then got up in the early hours. Of course sleeping outside can only really be done in the warmer months when there’s not so much to see. But I’ve done this with my daughter who loves camping even if it’s just the garden. We’ve then looked for shooting stars and used the binoculars before sleep. It also means that when she does get up to look in the telescope her eyes are dark adapted. Trying to get a 10 yr old to sit outside and get use to the dark isn’t easy. We also camped in the garden last summer when Jupiter and Saturn were in the sky at around 2am onwards - great fun - she does prefer the planets. One other thing I’ve noticed. I’m sure that there was less light pollution during the lockdowns. Even in Bortle 7 it can be surprising. I know that certain areas of my sky are darker than others and if an object is high in the sky the views are always far better.

That’s fantastic! Seeing has been OK here but transparency poor. Don’t like saying it but I think we need a spot of rain to clear the air.

The best view I’ve got of M31 was with 8x binoculars while on holiday in Southern Crete. The area is Bortle 2. It covered just over half the FOV and I could just make out M32 as well. It was quite low in the sky too. Here, all I can see (so far) is the bright core if I’m lucky.

As has been pointed out by some for me it’s time. And it’s easier to post a quick picture. Eg I have spent a good 5 hours observing in one night, then taken a smartphone picture of something I’ve seen before I pack up, spending around 30 mins taking the images. Then posted one of those images on here. Sadly the observing report gets left. In fact I don’t think I’ve written one. I also find it difficult to write something like this but must give it a go. In fact I have a backlog of things I want to post/discuss.

I know what you mean by great “night out”. My kind of thing too. And from what I’ve learnt it’s always worth practicing and learning. The seeing was poor here but I used the night to iron out some bugs, try my new DIY dew shields in action and finally look at the moon. However, the moon was boiling away and the views somewhat disappointing - to be expected but hoped it might be slightly better! Tonight looks like it could just might be better.

The ISS just made a long bright pass as I was setting up. I must try and see it or even try and take a picture through the telescope.

Nice one @Penumbrella. Here’s my attempt from last year using an iPhone on an even smaller telescope (Skywatcher Skyhawk 1145p pictured here doing some solar) in Bortle 7, although last year ClearOutside gave it Bortle 8. However, I could see it in the telescope as a faint fuzzy patch. Then M3 was high in the sky. My advice is to wait, or stay up into the early hours, when the object you want to view is as high as possible. Then, especially in light polluted sky, it’s darker. I find it fun trying to see what smartphones can do without stacking and minimal processing on the phone.

This is exactly what I do now and wish I’d known - took me several months of trial and error before I worked it out!

I use taxi magnets like these… https://www.ebay.co.uk/itm/x-2-EXTRA-STRONG-RUBBER-MAGNETS-TAXI-CAB-LICENCE-PLATE-HOLDER-ROOF-SIGN-magpad-/254620380154?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=710-127635-2958-0

Nice balance review. Having made a Dob base I’d make another. My experience of trying to strengthen something made out of wood is that you never quite get there and will never be happy. It’ll also bump up the weight. Plywood is lighter and stiffer than chipboard/MDF which I assume is what it’s made out of. I used standard relatively inexpensive 18mm Far Eastern plywood for my base and it turned out as solid as a rock. And as for weights. Personally I prefer to balance a Dob with weights rather than totally depend on tensioning. I like to balance the OTA and use the tensioning knobs so that it moves in both directions with equal force. Having it move one way easier than the other makes tracking a less pleasant experience.

This thread made me revisit this interesting article… https://skyinspector.co.uk/wp-content/uploads/2020/07/SandT-1999-10-Improving-Dobsonian-Motion.pdf I’d seen it about 10 months ago when building my base but at the time couldn’t work out exactly what “Teflon sheet” is. The article is from 1999. However, looking at it now it’s obvious. It’s basically PTFE sheet often used for heat presses and is now easily available and cheap eg… https://www.amazon.co.uk/dp/B07H55M1ZR/ref=cm_sw_r_cp_api_glt_i_YKDS2EN8M1ZV20EK3HG5?_encoding=UTF8&psc=1 Moreover, I might have already used something virtually identical without realising. I experimented with PTFE tape on my Alt bearing and found it good. The construction of PTFE tape sounds very similar to this sheet. It also has a dimpled surface. I’ve attached a closeup picture of the bearing/tape that I used. I’m going to order some of this sheet to see what it’s like and do a few experiments myself.