Roy Hughes

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  • in reply to: Materials strength question #630767
    Roy Hughes
    Participant

    James,
    Typing “how much weight can an m4 bolt hold” into Google gave…
    “An M4 bolt’s weight-bearing capacity depends on several factors, including its grade, the material it’s made of, and the type of load it’s subjected to (tensile or shear). However, a general estimate for a common grade 8.8 M4 bolt is around 300 kg (661 lbs) in tension and potentially 150 kg (330 lbs) in shear. This assumes the bolt is properly tightened and not subjected to excessive vibration or impact.”
    from the AI (always suspect, may have the figures the wrong way round!).
    But if the material you are bolting into is aluminium that would fail in tension/pull out well before that.
    Not a lot of use I’m afraid – everything else is above my brain grade.
    Roy.

    in reply to: Interstellar asteroid A11pl3Z #630544
    Roy Hughes
    Participant

    According to the Astroart forum the main site is down for maintenance.
    However the mirror site at https://www.msbsoftware.it/astroart/ seems to be working normally.

    in reply to: Ratchet mechanism for opening slit in dome #626255
    Roy Hughes
    Participant

    First thought.
    You have a square toothed wheel at the end of the shaft.
    How about a simple arm with a matching tooth.
    Pivoted above the wheel, lift to disengage, lower to lock.
    Would need a spring in-line with the pivot to hold it open/closed
    Not as nice as an auto ratchet but very easy to make.
    Roy

    in reply to: Pixel Value and Exposure #623710
    Roy Hughes
    Participant

    Giovanni,
    I was googling around and came upon this article:
    Tips for reading a camera raw file into matlab
    If you have not seen it before, it might be useful.
    The link to the “free Adobe DNG Converter” is broken but readily found using google.
    I hope this link works better!.
    Roy.

    in reply to: Pump spray mirror silvering kit #623607
    Roy Hughes
    Participant

    Nope, seems the link does not work from here!
    Roy.

    in reply to: Pump spray mirror silvering kit #623606
    Roy Hughes
    Participant

    Re Silvering the Hooker 100-inch.
    This link may(?) work better https://articles.adsabs.harvard.edu/pdf/1933ASPL….2….5E
    Interesting exercise, thankfully not one we are likely to emulate.
    Roy.

    in reply to: Dark Side of the Moon #623170
    Roy Hughes
    Participant

    Curiously, I noted that BBC Breakfast used “Far Side” but they had a tame astrophysicist on. So maybe he corrected them. The lunchtime news was correct too. By the evening news they had gone over to the dark side.
    Roy.

    in reply to: The monkey’s telescope – a mystery #622058
    Roy Hughes
    Participant

    It may just be that the tube was painted with a thin wash of some fugitive pigment that has faded over the years.
    I once had an opportunity to get very close (15cm) to a Hieronymus Bosch painting in Washington.
    Much of that painting was ‘transparent’ and the under work clearly visible.
    Roy.

    in reply to: February JBAA #621712
    Roy Hughes
    Participant

    My journal arrived first thing this morning.
    The new paper wrapper however was only just holding closed. The self adhesive seal was only one jolt away from being fully open.
    The stuffing machine is probably not applying enough pressure. Finger pressure was enough to seal it completely.
    Could be worth looking at if there are any other reports.
    Roy.

    in reply to: BAA Calendar #620114
    Roy Hughes
    Participant

    One problem with the Observing Calendar.
    When viewed in night mode (my default) the month and year are Black on Black while the main body of the calendar remains blinding white.
    Otherwise a fine piece of work.

    Roy Hughes
    Participant

    I did not have a clue what this post was about.
    So I googled G4ddk VLNA and came up with a .pdf which included the following.

    Quote:
    Voltage checks
    Connect +12 to +20V to the feedthrough capacitor C18 and the negative (ground) to the
    solder tag.
    Connect good quality 50Ω SMA terminations to the input and output connectors.
    Adjust R14 fully anti-clockwise and then turn clockwise about 30 degrees (not critical).
    Switch on the supply and check that the total current taken is approximately 80mA +/-
    10mA.
    :Unquote.

    It looks like +12v (or maybe +13v from a car batery) at 100mA to me!

    Have a look at the .pdf to see if it ties up with what you are doing:

    http://www.g4ddk.com/VLNASept13.pdf

    Hope the link works.

    Roy.

    in reply to: Pie in the Sky #616879
    Roy Hughes
    Participant

    At the risk of disappearing completely down the rabbit hole.
    Might I suggest Apple Pie in memory of the apple that inspired Isaac Newton.
    Possibly served with a scoop of ISS-CREAM.
    Maybe not that practical in the dead of night, but could work.
    A more apt choice may be a Moon Cake, which is in fact sort of pie of Chinese origin.
    Though even this might be depreciated by deep sky observers.
    Roy.

    in reply to: Pie in the Sky #616563
    Roy Hughes
    Participant

    The main characteristic of Stargazy Pie is the whole Mackerel fish placed in the pie with their heads sticking out of the top “Gazing at the Stars”.
    The BBC has a recipe.
    Roy.

    in reply to: Leslie Peltier video #616206
    Roy Hughes
    Participant

    The Merry-go-round observatory put me in mind of “A PRACTICAL HEATED OBSERVATORY BY E. G. HILL” in the 1962 JBAA V72,3 p102. A similar idea based on a newtonian reflector. No video though. It might have appeared on the Sky at Night as the report predates my membership but I have strong memory of it.
    Roy.

    in reply to: New website – members’ full names #615061
    Roy Hughes
    Participant

    Just fell for this one (I’m an infrequent poster!). Speedily sorted out after an “Oops…” and a second login. But the Web profile page is misleading. There seems to be at least two places that appear to be for putting in a short name / nickname as well as the drop down list at the top (which looks to have done it for me). er…
    Roy.

    in reply to: Journal delays #615060
    Roy Hughes
    Participant

    At last it’s arrived in SW London.

    in reply to: Spiders #613209
    Roy Hughes
    Participant

    Sorry,
    can’t help with the spiders but…
    The self-adhesive copper tape sold by garden centres (and of course the online market place of your choice) may provide a snail free floor.
    Roy.

    in reply to: Publications of JAS #610068
    Roy Hughes
    Participant

    I’m sure you have already spotted these, but just in case…

    https://www.popastro.com/main_spa1/society-history/

    Has a few early copies, scannned at reduced resolution.

    Roy

    in reply to: A Catalogue of Observations of Luminous Meteors #609579
    Roy Hughes
    Participant

    On page 288 onwards in the copy a google search found for me.

    in reply to: Theodorus Blethyn #583889
    Roy Hughes
    Participant

    As you might suspect Tewdwr comes into english as Tudor. There was a good welsh/english name thanslation table available on the Find My Past website. Proved very useful understanding my own family history. Wonder if the ..us ending might just be a latinisation, cf. Kopernik/Copernicus.

    Roy.

Viewing 20 posts - 1 through 20 (of 49 total)