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Mark Henthorne

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Everything posted by Mark Henthorne

  1. Ahh, the Pacman, yes. If the three weights end up at the top of the bar, my head may still need protection if room remains to fit it. Otherwise, it will be gracefully retired to the Home of Rest for Old Pacmen, unless of course it can have a new lease of life in a new home. Any offers anyone?
  2. Well, as we all know every astronomical issue brings with it another £50+ solution. At least on this occasion, it is just a couple of £ over and nowhere near three figures. So the new AZEQ6 GT weight is ordered at FLO and with luck will be in situ in a few days time 😀. I must admit, I won't miss the protrusion loss, with it making navigation around the observatory that bit easier.
  3. Thanks to all for your replies. No negatives with regards going for more weight on a shorter bar, so looks like I am off to get another weight and shorten the counterweight bar. I have to say though that the spit tennis ball will be remaining in place if at all possible! It's a few years now since I lost my youthful protective of cushion of hair. Best wishes, Mark
  4. I have an original Pulsar 2.1m observatory which I currently preparing for the forthcoming season. In this, I have an astro-engineering pier atop of which sits an AZEQ6 with a MN190 mounted upon it. The counterbalance bar has the extension bar attached and the two supplied weights sit just on the start of the extension bar. My question is, what are members opinions as to whether it is better left this way, or should I get an addtional weight and lose the extension bar to gain less obstructed space? Clearly within the confines of a 2.1m observatory, a shorter balance bar would be advantageous, but other considerations may apply that haven't occurred to me. Thanks in advance for anyone's time in responding.
  5. Well, I threw caution to the wind, with nothing I've done appearing to be irretrievable. Four allen nuts removed from the underside, another one to release the dual speed side. With the single speed knob already removed, the entirety of the dual speed side came straight out. Careful examination how it all came apart/went together made for a reasonably easy re-assemble, but with the manual control simply reversed. All ready now to do the final attachment of the EAF tomorrow. Will have to apply power to this before final connection so that the flat on the motor spindle is facing away from the tube in order to be in a position to tighten the grub screw of the flexi-drive onto the flat. Final check that all is aligned and no rubbing anywhere when under power. Hope the above helps anyone else facing this for the first time. Mark
  6. I'm attempting to install a ZWO EAF on my "new to me" 190MN. What I need to do is reorientate the focuser so that the dual speed side is at the front of scope so that the EAF does not protrude at the front with cables sticking yet further out. With this being new to me, I don't really want to find out how this is done by willy nilly undoing bolts to "see what this does". I know on some newts, the dual speed is simply reorientated by removing four screes from the bottom plate, then swapping the focuser controls about and reinstating the bottom plate. Anyone know what is the proper way to re-orientate the stock focuser that comes with the 190MN? Thanks in advance, Mark
  7. Oops.... looks like I deleted a few words in my last post concerning the appearance of the first and last pieces of wood with the cutouts to access the dome support wheels. Also, thanks to Skybadger for the post re BIL castors. I will be taking a close look at them. Mark
  8. Many thanks for coming back to me Steve, and no apologies needed for any delay. We all have lives and family that demand our time and attention. I thought that the "cutout" was how you'd achieved this at the outset, but when watching the video, it seemed as though you'd abandoned that approach. Revisiting the video, I can now see that you had indeed followed that, and there is one just visible at the beginning of the video as well as the one towarddso I thought perhaps you'd dowelled them to achieve that. Top tip that, for plainly we are not talking about the inside sections of the dome as presenting an exactly machined surface. It's tips like these that can make such a difference to the finished job, so again, thanks for coming back to me with the explanation. Offering something back to the group — For anyone else dealing with the older Pulsar 2.1m observatory, when I acquired mine, one of the aluminium shutter guide rails sheared in the dismantling process, the nuts having effectively "welded" themselves to the rods. This left me with one useable rod and one not (both still have in my possession). Visiting my friendly neighborhood stainless steel fabricators, they manufactured two replacements in stainless steel for me. If you are considering this approach, then as a guide I paid about £100.. If you have found yourself in a similar position, I am happy to send the old rods to you (only one of which is useable) for the cost of the postage, to anyone needing these. Hopefully that can save someone something should they require a replacement. Cheers, Mark
  9. Hi Steve, Having long-admired your efforts and the end result in automating the dome rotation on your observatory, I will shortly be in a postion to replicate this process on my own 2.1 Pulsar. I have a couple of questions to ask of you please, before I dive in. Firstly, looking at the shelf construction, did you in any way join together each of the 16 segments to each other or are they simply butted against one another, or was that achieved solely by glueing the drive belt in place, resulting in one unified piece then? (Supplementary question, was it the shelf parts alone, or the inclusion of the belt that made the dome feel more solid/rigid to you?) Secondly, in constructing the shelf and adding the drive belt, this effectively seals off ready access to the support bearing wheels, which should they need cleaning, lubrication, or replacement, poses something of a challenge. I am considering using a holesaw to cut a single hole above the door inside the dome, centred a little higher than axle height, and slightly over the wheel diameter size, so that in theory would facilitate all of the above. The hole, because it is over the door, should allow access by just myself, with spanners either side on both the inside and outside of the dome. Is this a solution that you have used, or have you elected to take another approach. I really want to get the shelf and drive belt arrangement that you have, but without shutting the door on maintenance of the support bearing rollers. As we all know, these are old obsevatories, and as far as I know, the source of the original bearing wheels is something of an unknown to us all. Cheers, Mark
  10. Thankyou one and all for the many words of wisdom. I feel inclined to make the raised floor as suggested by Tomatorbro, but with crossmembers as pmlogg has done (but including cable mananagement), without drilling to the concrete base, for each drill hole will break the sealant barrier. Obviously, there will be four holes required for the pier, and another eight for the four observatory quadrants attached to the floor. I am thinking now that once these are drilled, to "paint" the insides of the holes with a suitable bottle brush with a view to re-establishing the seal. How successful that will be I don't yet know, but it has to be berrer than leaving the bare drill hole, again in the light of experience of JeremyS's initial water ingress. My pier is second hand, and was a little rusty when I got it. Having had it sandblasted followed by powder coating, I'll hopefully avoid any rust recurrence that way. Finishing as I started, thank you one and all for the benefit of your experiences.
  11. Many thanks Tomatobro, for taking time out to come back to me. I had in mind originally to simply seal the surface (thanks for product info) and once the base was sealed to the pad with silicone, tile it with the interlocking tiles. However, there is a deal of merit in having a floor in as you describe, so I intend to pursue that route for better air flow. I was going to use the cable guard used in offices where it has to traverse the top of a carpet, but the raised floor will make cabling internally a lot more flexible. The last owner of the observatory had kitchen carpet directly on the floor with a thin plastic membrane separating it from the concrete. It did look as though perhaps condensation had penetrated, for the observatory suffered condensation internally primarily on the dome. I hope to achieve a rather better air seal between the dome, its sides, and the slot, for I have a descicant dehumidifier I'll be employing to keep the air inside at a reasonable humidity level.
  12. Last week saw the completion of a 2.4m x 2.4m concrete pad to accommodate an old Pulsar 2.1m dome I have acquired. What did anyone who has already trodden this path do to their concrete pad both before and after the dome was fixed in position? I am thinking in terms of sealant to afford protection against both concrete dust and any damp from below. I am probably less than a month away from starting the build. Any advice is very gratefully received, and thankyou in advance for any advice 😀.
  13. Just had the same issue with a recently acquired ED80 and replacing the stock focuser. Skipper Billy's approach was spot on. All I would add to that is that when you get to the screw adjacent to the 'scope description label, I used a piece of metal as a heat shield to protect that from any melting or lifting of the label.
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