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furrysocks

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About furrysocks

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    Scotland
  1. Thanks, Alan. I accept that 6mm and lower is pushing it. I've only been in this for a few months, but have read of a general mag limit for UK skies, mag limits per inch of aperture, min/max exit pupil sizes, massive mags for resolving doubles, etc... There seems to be a balance to be struck and criteria/limits to 'what makes for a good view'. The lunar views in the 6mm were great!!! - the Jovian views through the 6mm on a patchy night otherwise dark skies were some of the best I've had. Going purely on my experiences looking through what I've got, I want to (and I think I can) push the scope a little more. Again, nothing to compare my experience to, really, but on feel alone I'm still tempted to push one more notch - 5mm or 4.5mm. It's a long F/L - 1635mm, 216mm mirror - I've been assuming that that affords me a little more mag and less of a need to go with some of the more expensive EPs. I may have got that wrong. So if it's mainly a scope for planets, lunar, solar and splitting doubles, does that change the advice re: max mag at all, or am I kidding myself?
  2. Or is a 4.5mm Meade 5000 HD-60 a better EP than the 4.5mm TMB Planetary II?
  3. I started back in December with a 3" Aldi dobson, and immediately bought 30mm and 8mm Vixen NPLs. Wow, I thought! Having tried these in my new DIY dob (8.5", f/7.6) I knew I needed a few more EPs. I know I'm meant to be saving up and buying a few good ones, but I didn't - not really. A cheap £15 40mm plossl - in the 3", I can't get rid of the shadow of the focuser in the middle. In the big dob, the eye relief is so large and the eyecup so small that I struggle to look through it. I will try wrapping a small length of camping mat foam or something and zip tie it round the barrel, just to give my eye something to rest/register on. Giving me a nice low mag view at 41x, 5.3mm exit pupil but not much over 1deg TFOV, alright for the money, perhaps. A £38 80 deg 11mm - 149x, ~0.5deg TFOV. Not bad - currently my preferred EP. Good Jovian and Lunar views. Had to let the primary out a few mm as I couldn't focus first time even with the focuser wound all the way in. It's a good 1/2" in from any of the other EPs which is a little annoying. 2nd hand £35 TMB Planetary II 58deg 6mm - 272x, 0.21deg TFOV - what a little cracker. I'm really happy with this EP, lunar at least. Dob az bearing is very stiff and cause me problems using this EP but the lunar views, even over the rooftops - 0.8mm exit pupil, eye floaters starting to appear, atmospherics evident, but nice watching the moon drift across the fov. I thought that the 6mm would be for "exceptional nights, only" but being so pleased with the performance on the moon tonight, I think I'm now after a 4.5mm TMB PII to give 363x with 0.6mm exit pupil, and about 43x/inch. That is perhaps as far as I'll push this scope. We'll see... Don't know if I want/need anything between the 30mm and 11mm - a mate might have an old 17mm but I don't think I'm going to go and buy one. I have no Barlow, not sure I'm going to get one. These are getting me going, though - around £170 spent.
  4. furrysocks

    S&M tools

    Now you can... ;) http://www.smtools.co.uk/shop-virtual-tour.html
  5. One of the best small sites I've been to! Lovely place, top notch facilities! See you all again, I hope. Matt
  6. Should be there in a few hours - one forecast site I looked at suggests clear skies tonight. Who knows...
  7. Nice to find this thread - just what I was looking for! Ordered a copy at around £7 delivered - still one more at that price on Amazon (April, 2013) should anyone else want one. Also ordered a moon filter to save my eyes! Ta, Matt.
  8. Ordered some - picking up in a few days. Thanks for the tip, and good job on your scopes! FLO, for example, do a similar 1mx0.45m material for £7 a roll, which they call "blacker than the blackest stuff" - I wonder how the Wilco stuff compares. Anything should be an improvement for me, though. I may even cut strips and flock my trusses!
  9. As far as standard monocular sizes go, there's 22x32 for <£7 or 22x36 for nearly twice that. I've ordered a 22x32 - see how that goes. I'll need to tape up the end of the barrel a fair bit to get it to friction fit into the filter, but the extra magnification should be good.
  10. As the sun was setting below the rooftops this evening, I just managed to squeeze in my first solar observing session! According to NASA's SOHO site, I've bagged my first sunspots - 1711, 1713 and 1714. I used a 10x40 monocular I got from eBay for about £8 and made up whatever that is that you can see in the picture below... Hankering after a bit more magnification, I've now got a £7 16x40 on the way to use instead - should just be a drop-in replacement. I've got a filter to make up for my dobs (8.5", f/7.6) so I'm in for some finer white light views soon, but a wee "handheld" 16x40 should be a good wee thing to have around.
  11. I've finally mounted one of these to my scope - I had to build the scope first! It's mounted with a couple of stiff springs, two captive bolts and two wing nuts - and a zip tie. It got me Panstarrs last weekend - right down low above a neighbours garage. I'd have never found it in the scope (0.9deg TFOV) and it was not visible to the naked eye. The finder found it and centered it in the scope no bother. I could take it apart again and add crosshairs but I don't feel the need yet. There is at least one other variety of 10x40 monocular on eBay at the moment - completely rubber clad, knobbly body instead of the moulded grip on this one. They're about a pound cheaper but the build quality is not the same, field stop slightly smaller, eyecup poorer, etc. I've currently got that one with a solar filter on the front of it - there's also a 16x40, I think, which would be better for that. If you're getting one, get one that looks like this one. Anyway, just though I'd give this wee update - as a cheap finder scope, it's two thumbs up!
  12. Thanks again, folks! It's not blowing my socks off, but it seems to work ok.
  13. Thanks, folks! It is "original" - that made me and my wife chuckle! It evolved... I began by planning a dirt cheap build along the lines of Toshimi Taki's 8 inch dobsonian - a long dodecagonal tube. I was going to get the tube made from a single sheet of 3mm hardboard around some scrap mdf/laminate ribs but when I mocked up a short tube, I liked the look of it and decided to change to a truss design. I've got another 8.5" mirror too, and had been thinking "binoscope". I've since made up the six tubes for both OTAs from that one sheet of hardboard. The truss design came from Robert Royce's 8 inch truss tube newt. The double truss configuration I believe is called Serrurier and it has the advantage that as each end sags from the middle, they maintain collimation better than single truss designs. With heavy tubes and a long scope, I thought the principle sound. The tubes came out really fragile, so I used 30gsm surface tissue and polyester resin on them all to increase their strength. The middle tube got another layer of 225gsm CSM and resin as this is taking all of the weight. I had been going to put external rings round them all both to hold them together and as something to attach the trusses to - glad I didn't - shoutout to astrobeast on CN for helping me think that one through. I'll spare the details, but after ensuring structural integrity, it's all about geometry. The mirrors came from preloved.co.uk - a guy in the North East was selling them - two primaries and two secondaries for £100-odd. They'd been salvaged from a Charles Frank scope that had changed hands and was subsequently dropped. I've had the secondaries re-aluminized. The primaries will follow but are good enough for now. The finish is just £1shop matt black paint. I'm on my third tin and anticipate finishing the fourth when I re-coat the mount. For the most part, I just wiped it on with a kitchen sponge. I've used an old tin of blackboard paint inside - it needed a bit of thinners and a good stir to get it going. I've got a new tin too, and may re-paint inside if it helps. I was going to make a 2" helical Crayford focuser with some skateboard bearings and aluminium tube, but stuck with plumbing parts and an old cut-down Barlow to make a very serviceable 1.25" focuser. The bearings are running on kitchen chopping board at the moment. I started in December - working with glue, fibreglass and paint in sub-zero is not fun so I've used a fair bit of electric to heat up a curing cabinet. It's been evenings and weekends only, and very bitty - as I had no real plan, I needed to see results before I could move on. A very inefficient way of working - I had six weeks off the project because I was getting frustrated. It did not end up a dirt-cheap build. At every step, I reasoned that I needed to spend more money - I'm not going to add it up. I never will! I do however have pretty much all I need to finish off the next one - perhaps just a sheet of ply and the odd bit of hardware needed. I wouldn't say it's particularly portable - the OTA is >10kg and I've not weighed the mount yet. Vibrations appear settle at 50x in about 1 second. The OTA does come apart into two sections and tomorrow morning, I'm loading it into the van along with the family and heading for darker skies. So that's a little bit on the design and the evolution of the build. I blogged it on here while I was going, for what it's worth. It's all a bit 'stream of consciousness' but the process helped, I think. Anyway, I can put all that behind me now and start observing - you know, as we're approaching summer - ha!
  14. She needs some more paint and smoother az. bearings, but she's essentially finished.
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