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Showing content with the highest reputation since 30/10/19 in Blog Entries

  1. 4 points
    Hi all Been a while since I added to my blog. To be fair, not really had much to report! I have been out of furlough for over four weeks now, and with nearly 2000 of our Greene King pubs reopening in the space of a week recently, the last three weeks have been manic! We have a reduced team, but have all pulled together and got each site across the line! I would like to say things are slowing down a bit, but that just doesn't seem to be happening! But I'm not complaining - happy to be busy again! All this work had meant I have not been out under the skies for some time now. Sure, the weather hasn't been very cooperative, but on the odd evening where the clouds have cleared, I have just wanted to go to bed! So, I made a conscious effort that this weekend would be different. I had been keeping an eye on Clear Outside all week, and Sunday looked like the best evening. I wanted to see the comet, so decided I would make a trip into the Peak District (I live in Derby), to find some darkness! So, at around 10pm, with a still bright horizon, I hopped in the car and made my way to Thorpe Cloud near Ilam - an area a few miles North of Ashbourne. The car park I used to use when I came here to do some Landscape photography has now got a barrier across it, so I had to park about a mile away and walk back. Note to self: Next time, pack a torch so I don't have to use phone! Here is a light map of the area. Am surprised its Bortle 4 here - thought it darker than that: The 30 minute walk across the side of Thorpe Cloud gave my eyes time to become dark adapted. On the way round, I saw a pass of the ISS. Was as high as I remember ever seeing it, and it was very bright. I checked this morning, and it was -3.4!! I took my time and drank in the Milkyway over head, with Cygnus buried deep in the star clouds. I came round the side of the Cloud and there it was! Nestled just above the horizon below the pan of Ursa Major! I needed averted vision to see it with my naked eye, but when I turned the 20x80's on it - WOW!!! The most amazing site. I have not seen a comet since Hale-Bopp, so this was a special moment for me. I spent a good half an hour on the bins, and then decided to try and take some photos. I will freely admit that I am at the very start of my AP journey. I have a Canon 400D, and a fixed tripod for widefield, while my EQ3-2 is manual right now. Using the 500 rule theory, at 17mm on my 17-55mm f2.8, I worked out I could get 18 seconds exposures before trailing would be really evident. I opened the lens wide, set ISO to 800 to try and reduce noise and set the shutter at 15 seconds and started snapping away. When the first preview appeared I was quite pleased - there was the comet as I had seen it through the bins: Yeah, I didn't nail the focus. Difficult with nothing to actually focus on, and only a small (non-live view) screen to look at! However, if you squint a bit they look ok! The wider shots are better: It was getting late, and I had to be up at 6am, so started to head back to the car. It was then the ISS came over for pass #2 of the evening. Very much the same brightness, and I followed it across the sky. I had put my camera away by this point, otherwise would have taken a long exposure of it going over. Got back to the car, and headed home, getting in at about 2:15am, and went straight to bed. I intend to run these images through Photoshop this evening and try and pull put some more detail. I am also going to try and stack some of the images I took! Thanks for reading all! Nige
  2. 3 points
    After much advice here and thanks to a friend of a friend I took delivery of this today. 1.3 m high, many kilograms heavy! It's been treated with zinc phosphate primer and will get a couple of coats of Hammerite or equivelant before planting. This weekend I'm running Cat6 cable out to the plinth and starting to build the equipment box which will be fitted to the bottom of the mount. Michael
  3. 3 points
    This evening I prepared the tube for all the new parts- filling in old holes and drilling new ones- the end is in sight
  4. 2 points
    I modify my 28BYJ-48 stepper motors to run off the A4988 driver modules, just like the Nema 17. I use these for remote focus for my astro imaging. These motors come with centre-tapped coils with the centre-taps connected internally. We need the full coils without the centre-taps and these need to be separate so the internal link needs breaking and center-taps ignored. This in turn effectively changes a 5v rated motor to one that works fine with 12v. These photos show the coils and connection PCB taken out of the motor, to explain the process. (Don't jump straight in and take the motor apart, it isn't necessary.) The yellow and blue wires are one coil (or winding) and the orange and pink wires are the other. The red wire is no longer used and cut short for safety. At first I opened the motor casing to get at the connection PCB but it was very difficult to get everything back in so I decided to try and cut the PCB track without taking the motor apart. I carefully drilled a hole through the blue plastic connection cover to access the PCB where the strip wanted cutting through. Then I was able to take a very small screwdriver and scrape through the track without disturbing anything else. This is shown in the close-up photo below. As before the coils are orange-pink and yellow-blue. Do not connect the red wire. Note :- Seems not all motors use the same colour wires but the outer two wires are one coil and the inner two are the other. The middle wire is not used and should be cut short and insulated for safety.
  5. 2 points
    Initially I planned to make the focus motor quick release and the magnetic coupling made some sense but I ended up going for a simple screw mounted motor so it makes less sense now But it’s done now and it works really well- better than I’d expected. It allows for lateral misalignment yet is a nice stiff rotational coupling for the sort of torque required to turn the moonlite knob. A ptfe pad keeps the magnets slightly separated so the two plates can move a little easier against each other. The black magnet holder on the focus knob is 3D printed and a press fit on the knob
  6. 1 point
    Telrad fitted. Baader zoom has to be used in place of the 1.25" focuser, straight into the 2" focuser. Had a go at collimating first and managed to mess it up. All I could see after pointing at Vega first was a blob of light. Collimated again and was better, but realised it's too far from the secondary mirror. Removed the 1.25" focuser and fitted straight into the 2" one and that's perfect. Need to grease the focuser. Found Double-Double but was unable to split the 2 stars into 4 at 162x. Jupiter at 162x fitted 4 moons in the fov and shows nice banding. Saturn at max zoom a bit fuzzy but still can see the rings very nicely. Forgot to look for Cassini division but probably need Barlow for that. Was still to bright for Andromeda and was getting late so looked at Mizar but haven't seen the second star, I think. Need to check sky maps. (Turns out my zoom was too big and missed Alcor)
  7. 1 point
    I think I have the design for my latest ASC pretty much finalised now so I'm starting a Blog for it.
  8. 1 point
    A new improved version of my "GinaRep Mini" 3D Printer. The first version used cord for the drives whereas this one will use the standard timing belt for X and Y and trapezoidal screw drive for Z. I also expect to use a stout wooden case of 18mm plywood like my Concorde printer, for maximum rigidity. This is to be a specially accurate 3D printer with option of nozzles as small as 0.2mm. Print bed will be 200mm x 200mm with around 200mm printing height. Essentially this is to be a reduced size, higher resolution, version of my Concorde printer.
  9. 1 point
    This blog describes Installing 3rd Party Drivers into a Raspberry Pi having installed Ubuntu MATE and followed the instructions to run the AstroPi3 script to install INDI and other astro related software. SSH has been enabled so that now the RPi can be accessed remotely from Terminal. eg. ssh gina@rpi where gina is my user name and rpi is the computer name as set up during the Ubuntu MATE installation. This set up process is detailed in my blog :- Setting up a Raspberry Pi for Astro Imaging and Control - Updated Feb 2020 for RPi 3B & RPi 3B+
  10. 1 point
    Finally bit the bullet and knuckled down to wiring the handpiece- really made a rod for my own back though with the very tight space for the wires...it’s going to be really tricky getting the other half of the housing on there without squashing wires But it works-almost perfectly-almost that is except the pwm on the LED isn’t pwming I swapped from a nano to the new Arduino nano every and I’m guessing the code isn’t totally compatible... 0E01F364-3061-4211-904D-1334A76EFE8A.MOV
  11. 1 point
    It's a question that comes up regularly, but what is the difference between a Barlow and a telecentric amplifier (TA), otherwise known as a Powermate, ES Focal Extender. Meade Telextender, Bresser SA Barlow, etc? A telecentric amplifier does give a 2x magnification, just like a Barlow but that's where the similarity ends. A Barlow is a negative doublet (Smyth lens) that causes the exiting light rays to diverge and hence deliver the image amplification. If you move the EP further from the Barlow the magnification increases, whilst taking the Barlow nose-piece off and screwing it onto the EP will [generally] give 1.6x magnification, assuming we're talking a 2x Barlow. In the FE/Powermate/TE/SA Barlow (the latter isn't a Barlow, which is a confusion) the negative doublet is followed by a positive doublet that turns the exiting rays back to parallel - ie, telecentric. Because the rays are parallel, the distance between the EP and the amplifier elements is [broadly] irrelevant as the image amplification was done internally, between the TA lens elements. In practice, this still means that the effective focal ratio of the scope is doubled - It's a common misconception that the EP focal length is halved - but unlike a Barlow, the eye relief of the EP in use is unaffected. In other words, you insert an ES FE in the scope and the EP behaves exactly as it did before and the scope has effectively doubled in focal length. The down side is that double the number of lens elements costs more, but whereas a Barlow (which has other uses because of what it does) tends to feel like a second-best-to-an-additional EP, the ES FE simply feels like you have an extra EP. In visual terms, it's a less intrusive and more transparent solution and a more transparent device. So the Barlow is second best? Well no, not all of the time. For the reason why, you only really have to look at Televue Naglers and the clones thereof. They weren't the first (contrary to popular forum lore, but they're certainly the most successful) to use the idea, but what Unc Al realized was that whilst it was easy(ish) to create a wide field EP, the difficulty was in creating them at shorter focal lengths with an eye relief usable by humans AND with a well corrected field of view, especially in fast scopes like large Newts. Essentially, what he did was create longer focal length wide field EPs and then fit them with a Smyth (Barlow) element in the nose. Thus, you got an EP that acted as a shorter effective focal length, but had greater eye relief than it would have without the Smyth element. Very cool. In fact, this is the source of the reason why Naglers (and there derivatives) are renowned as well corrected in fast scopes. The Smyth element does increase eye relief, but as per a Barlow, it effectively increases the focal length and therefore focal ratio of the scope. As we know, a slower scope is less prone to aberrations, but in this case, it's the EP that is effectively delivering it. Your Nagler is better corrected, because it effects a better correct scope. So, this is also what your Barlow can do. A 20mm EP in a Barlow (and TA) will give a better corrected view than a 10mm EP, all other things being equal. This is handy, especially if you like your Orthos and Plossls which tend to have ever shorter eye relief with decreasing focal length. A Barlow can be partnered with a longer FL EP to give an effective shorter FL EP, without the need to glue your eyeball to the EP it emulates. Whereas a TA uses up it's focal length in the focal path, a Barlow does the opposite and pushes the focal point outward - It adds optical path length. How is this handy? Well if you have a binoviewer that uses up 110mm+ of focal path, the scope (refractors in particular) may not have enough space available to rack the focuser inward to compensate. A Barlow, or at lest the doublet element from the nose of it, screwed into the Binoviewer is enough to push the focal point outward and get you that focus point back. That's just one example. The important point is that whilst a TA is, as long as it has room to work, a generally superior device, there are times when a Barlow has qualities all of it's own. A good example of both will be a one off purchase and both will deserve space in your EP case. Buy right first time and you may find they remain a constant, whilst your prized EPs come and go..... Russell
  12. 1 point
    GOTO Telescopes. Being someone who has had both types of scopes and mounts I can honestly say I have learned more with the GOTO setup than I have ever learned with the manual set up. Previous to my current setup which is a SkyWatcher 200p (8” Mirror) and a EQ5 with SynScan GOTO added I have either manual mounts or mounts with a RA tracking motor for photography. Both Refractors and Reflectors and I certainly prefer reflectors unless you have a very large wallet. Now unless you use your telescope for large bright objects and have loads of free time then I would certainly choose the GOTO every time. If you like me and have a work schedule and family like to slot in around you hobby (should that be the other way around?) You will find a manual telescope very frustrating on anything other that the brightest object in out solar system. I may only have a couple of hours to go out with the scope and I have spent many frustrating hours searching for DSO’s (Deep Space Objects) and getting nowhere, arriving back home without seeing the objects I was searching for. What did I learn from this experience? Space is very big! Now since having the GOTO option I have learned, a lot about Polar alignment, how to set up and telescope correctly, how to align a telescope to 3 bright stars, to get correct alignment. Just learning the bright visible stars is an achievement and if you go at different times of the night and months throughout the year you get to learn all about the local bright stars that you need to know for correct alignment. When I go out these days it what used to take me 10 minutes to set up (Manual) now takes me 30-40 minutes to get everything, balanced, polar aligned, and GOTO 3 star alignment set up, but once set up correctly that is it for the observing session. A full catalogue of objects and planets are at my finger tips, full visual tracking of objects, anyone who has manually found DSO objects in the eyepiece only for a few seconds later is gone? Things move fast out there! The bigger your scope and the higher power eyepiece you use the smaller your field of view and you are constantly adjusting your scope, where as with the GOTO option once correctly set up objects remain the the FOV for very much longer in fact nearly all night if required. I can spend most of my evenings observing session actually viewing the objects I wanted to view from my observing lists, and yes I'm learning more about the night sky than ever before simply because GOTO made it a less frustrating experience and allowed me to spend my time with the telescope doing what I like to do, which is view our vast expanding universe. People who say to me you are not learning about the hobby is rubbish, I have learned more since I went GOTO than ever before, If you want to learn the sky manually that's great get a star map book and a pair of binoculars and enjoy your hobby, but to say to me I know more about the sky than you, could be true? But ask your self this! What did you come into the hobby for? To sit there night after night learning star charts so you could point out to people oh there is M31 or M57? Or did you come into the hobby to view the wonders of the night sky and out planets? Just because I have a GOTO telescope does not mean I'm not learning, in fact I could point out a vast amount of objects and planets in out sky, simply because once GOTO has positioned the scope and cantered the object, that's not the end! I step back from the eyepiece and look up “Oh that's where it is” can I see it in binoculars? What's the nearest constellation? Any bright known stars in the FOV. GOTO simply means you have options, how you use those options depends on the person. For me the whole galaxy is there, and other galaxies as well so don't be an Astro Snob! GOTO is a fantastic achievement for the average astronomer and has released the hobby into the 21st century . My telescope time is no longer a frustrating experience and is more a giant learning curve learning about DSO’s, nebula’s and galaxies and I’ve now moving on to astro-photography this again is another massive learning curve, but now I have the time to learn about the photography side knowing that I can at least find the DSO objects next step is photographing them Ray Gilchrist
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