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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.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.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.
RoyGiovanni,
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.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.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.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.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.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.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.
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.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.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.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.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.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
