This is a really interesting video from a craftsmanship and engineering point of view. I have been tempted to try to build a crossbow for decades now. I will probably never do it, because of time, but it is a challenge I would like to take on.
Crossbows are, of course, weapons, and as such, they are subject to some regulation in most civilized countries.
In CZ, any crossbow can be bought, built, and owned by anyone over the age of 18. Crossbows with a spanning force under 150 N can be legally openly carried and fired anywhere without any regulations. They are still considered a weapon, though, and if someone gets hurt, there are appropriate consequences. Crossbows with higher spanning force, such as this one, can be owned by anyone, but they can be transported only unloaded, in an enclosed container, and they can only be fired at a range or a fenced-off area inaccessible to the public and in a way that there is no danger to the public.
Open thread, talk whatevah, just don’t be an *hole.
But can we mount this fully automated crossbow onto a Ukrainian combat drone?
Silent running!
Bruce @1: 8-)
I would oppose such a thing that targets Trump’s birthday parade, although a non-lethal drone that just scares everybody would be fun.
Charly if you do ever make a crossbow I’m sure it will be a lot more elegant than that one.
@1 Bruce: Recoil would make it very difficult. The Ukrainians prefer to drop grenades, less recoil and they don’t need very precise aiming.
Interesting looking thing. One of the features I always appreciated about the classical crossbow design was that the wielder had a chance of surviving intact in the string broke. That did happen but obviously the operators were pretty cautious about the condition of the string (more like a hawser!) This design inverts that principle and he’s using a modern kevlar string. I hope he remembers not to leave that out in the sun, etc., kevlar care, etc.
I find the sideburns in the thumbnail quite convincing.
@Marcus, there is a commercial crossbow with the same arm position on the market. And on this specific one, the string actually did break during testing (he shows it in the video, right at the start around the 0:19 mark), and not much happened. With a circa 230 N spanning force, it is not exceptionally powerful. And due to the cams, the actual displacement of the bow tips is very small. So even when the string breaks, it is not that dangerous. Probably less dangerous than an angle-grinder and definitely less dangerous than a wood lathe.
On a classical crossbow, I’d be personally more worried if the bow broke on one side and whipped me around the ear with the broken-off piece. I think Tod Todeschini mentioned in one video that this might be one of the reasons medieval crossbows had huge spanning forces but fairly short strokes, and thus were actually not as powerful as the force-reading might imply.
I haven’t watched the full video, but I did see the guy drilling titanium and getting the workpiece stuck on the drill bit.
How is titanium to drill? I find aluminium to be fairly easy to drill, (mild) steel is kind of ok, but I hate drilling copper. While copper is soft, it is also tough and sticky. The only way I’ve found for copper to work is using low revs, drilling with increasing diameter drill bits and using slow feeding speeds.
Update to my previous comment, buried at the end of previous thread.
I saw the ISS again last night, passing moderately close to the nearly full Moon, which was in due south but relatively low at the time (about 15-25 minutes past 11 PM). Since it was evening twilight, the ISS was illuminated as it rose from the southwest, and flew well past due south to the left before disappearing into Earth’s shadow.
I also went out to see the next round, an hour and half later. This time, however, the ISS apparently went dark shortly after rising above horizon, and I couldn’t see it due to some low hanging clouds. The prime observation window is now rapidly shifting from near midnight to earlier in the evening, and the optimal viewpoint for observation is moving from high northern latitude to lower latitudes where the twilight is earlier at this time of year.
Another update: Last night, one ISS flyby was at ca. half past ten. I went out to see if it’s visible in early twilight, when the Sun is stil only a few degrees below horizon. It was, though relatively faint and not too easy to spot. But it also flared briefly at one point, looking much brighter. Now I want to see an ISS flare in darker conditions -- it could be quite impressive.
(see my post on previous page and the Wikipedia link on satellite flares)
Hello.
It’s been a lovely start of summer here. I usually complain about the weather, but now it’s my favorite season, and the’re’s been a rather balanced mix of rain and sunshine. I had feared for an early drought, since the spring started extremely early this year, and there was no normal snowmelt whatsoever.
On a related note, I was just idly wandering in the local park, going to inspect one of the new fruit tree saplings the city has recently planted. The tree was surrounded by a wide area of tall grass. At one point, while wading in the grass, I stepped on something soft that crunched a little. There was brief movement, and a couple pitiable mewing sounds.
It was a baby rabbit, or possibly hare. Hares are generally much more visible in this neighborhood, but I think feral rabbits might be more numerous, and more likely to nest in a place like that. Or do rabbits keep their pups in underground lairs? Anyway, I rationally understood I’d better kill the animal, since it was apparently too much injured to be viable, but not enough to die quickly on its own. But kill it with what, my bare hands? My first thought was that I’d have to rip the head off body to produce a decent coup de grace. I once did that to a small sick bird years ago, but then I had garden gloves at hand, which made the task less squicky and less unhygienic.
I hesitated for a minute or two, considering various excuses to not do anything. I contemplated the situation to a couple of people who were hanging out nearby, since they’d already heard my sudden utterance of a swearword. I intuitively wanted to make them responsible for my decision. They didn’t comment.
I then decided that stomping the rabbit with my shoe would suffice, despite not being very dignified or efficient as mercy killings go. In the end, however, it turned out surprisingly easy to not only break the animals’s spine, but actually turn it into mush. These things are difficult to estimate without experience. I then waded in the grass some more to wipe the blood off my sneaker.
The body might be picked up by crows, or perhaps more likely by someone’s dog as they walk by (apologies to the owner, whoever that might be). Years ago, I happened to witness as someone’s dog caught a rabbit and happily munched on it. On further thought on today’s events, I think hiding in a place like that was going to make the rabbit pup highly vulnerable to both passing dogs and the city’s lawnmower. Oh well.
@lumipuna, that took a dark turn :-O
Here, the weather is rather cold for this time of year, and we even had a night temperature of just 5°C. The rain was sufficient but not overabundant, but the cold temperatures mean that nothing really grows. Essentially, we now have the same weather we had in April. I am impatiently waiting for the pumpkins to grow a third leaf so I can plant them in the ground.
I had been taught to kill and butcher small animals as a kid, so technically, I know how to kill small mammals and birds quickly. I had to do some mercy killings in the course of my life, too, and it is not a pleasant experience. The last one was this very spring when I was planting strawberries, and I dug out a wintering lizard whom I, unfortunately, injured with my trowel before I spotted it. It did make me sad. I do not enjoy killing pests, but I really hate killing useful animals.
Baby rabbits are very susceptible to being stepped on because their instinct when danger approaches is to freeze and rely on camouflage. I’ve seen a few during my walks in the forests, and luckily, I never trod on any.
I also encountered an adder once. Did not tread on that one either, and it did not even bother to rear its head, although I was quite close -- when it spotted me, it just quietly slinked away.
Happy (slightly belated) solstice, everyone!
This week turned out more rainy than I dared to hope for. I love the relatively cool weather and extremely lush greenery in summertime. I love that wild berried are getting enough moisture for once -- it seems there’s going to be a bumper crop.
(That said, it’d also be nice to have clear skies more often, and enough warmth for swimming at some point in July)
I have been that dog owner, with several of our previous dogs loving rotting carcass above all other possible things to roll in, even badger shit.
We’ve got a huge number of berries starting, but they’ll need a lot more rain to fruit successfully. It’s been, and is still at 11pm, very hot for here so watering has been essentialm but we really can’t water all the blackberries. Decca is unsure what she thinks of the hose alternatively playing in the spray, and running away from it. She is such an easy dog, especially compared to our last boy, she really is very pretty, we’ve even had people run across the road to comment on her and ask if she is a specific type of dog. So far Belgian Malinois and Chinese Red Dog seem to be the favourites, but I think she’s slimmer built than either. Fortunately she is great with people as long as they aren’t wearing hi-vis, so they get to pet her and tell her how beautiful she is, while she gets to preen and politely accept a treat.
Time for an update. It’s been busy.
The weather here turned out remarkably rainy and cool around the Midsummer weekend. Finnish people, those who celebrated Midsummer in the countryside, were able to have the traditional bonfire. In recent years, the bonfires have been often prevented by dry weather and fire hazard.
This summer, we seem to have the jet stream or whatever stuck in a position just south of Finland, so that the rains travel along this route and all the hot air accumulates south of the weather front. The news of this week’s heatwave in southern/central Europe have been scary. The edge of the hot air mass just briefly touched southern Finland, and now it’s back to cool and raining. Finnish media is full of stories contemplating that the summer weather here in the homeland is too cold and wet for most people’s taste, while those who have gone to the usual Mediterranean tourist destinations are facing brutal heat. There is little appreciation that cooler-than-average weather is a rare luxury in a world that generally struggles with excess heat.
I love the cool rainy summer weather. So do the frog tadpoles (which may have already walked out of the local ditch), slugs and snails and most plants. The greenery is more lush and beautiful than it’s been in years. Mosquitoes were oddly scarce in early summer, but now the second generation is booming. In the last few weeks, I’ve seen numerous hares, one fox, a couple broods of mallard ducklings in the tiny local stream, and an unusual number of adult mallards.
I’ve been able to remain more physically active than I’d be in a hot weather. This year, I decided to seriously try and fight a war against the most infamous invasive plant species we have around here: the feral garden lupin (Lupinus polyphyllus). It’s ubiquitous in the meadow areas of my neighborhood park, and the city has long encouraged the public to volunteer to pull it up. Or rather, people are asked to just remove the inflorescences before they bear seed, because weeding the entire plant, with its deep perennial root system, from the clay soil would be unfeasibly difficult. Almost nobody seriously participates in this effort. However, I have found that pulling the mature flower stalks will often bring up some of the root system, and sometimes the whole taproot, when the soil is wet and soft (like it is this summer, unlike most years). While the weather was briefly sunny, I exhausted myself pulling up thousands of lupin plants and cleaning one limited meadow area in the park. If nothing else, it seems to be very useful exercise for my hand and upper body muscles.
@lumipuna, I wish you could send some of the rain my way, we have officially a severe drought -- again. The weather forecast seems unusually unreliable this year, too. Several times, they predicted several mm of rain, and then there was essentially none. Like for today, the forecast was 3 mm of rain, we got 0,3 and that was it. Currently, the forecast is that we should get some rain over the course of this week. I hope it is so, I am running out of water in my rainwater storage and my sewage cleaning facility, too. Without some rain, my garden is fubar.
Good luck with the lupin. It is a beautiful plant, but a terrible pest. Maybe hori-hori would help with getting it out of the soil with the taproot and less effort? I have a gardening tool from a piece of pipe with a t-shape handle on it that I use to lever deep roots out of the ground, too, so maybe something of that kidney would also be helpful.
I too wish the rain was more equally distributed. Between different regions and different years in the same region -- that’s basically the same thing all over. It seems like the weather patterns are becoming increasingly likely to get “locked” in certain positions for months on end, while temperatures increase, resulting in more intense droughts in some areas/years and heavier rains and flooding in others.
(Oddly enough, some parts of Finland are also suffering from drought. The rains seem to be concentrated in fairly small areas, though the amount of rainfall isn’t so extreme as to produce flooding here.)
(I’ve also sometimes noticed the pattern you mention, that on dry summers the weather forecasts seem to consistently overestimate the amount of upcoming rain, for months on end.)
Since the sky cleared again yesterday, I went out at midnight to look for the International Space Station. It’s again the prime time for those of us in the higher northern latitudes to observe the ISS, since the flybys occur at night. This cycle seems to repeat about every two months. For most of the year, you’d need to observe the ISS shortly after dusk or shortly before dawn, but near midsummer it can be seen all night (provided it’s at least slightly dark at your latitude), because it catches continuous sunlight while passing on the north side of Earth’s shadow.
The night was very beautiful, with almost fully clear twilight sky and some mist forming near ground level in the open areas of the park. I saw a nice ISS flyby, complete with a brief bright flare of reflected sunlight from its solar panels.
After that, just when I was about to head home, I noticed the first glowworm I’ve seen this year. I’ve seen them in the park before, but only very rarely despite often looking for them. It’d be really cool to have actual fireflies, or at least abundant glowworms to make the meadow sparkle on summer nights.
(I recently saw Twitter discourse where some US folks were surprised that not every place -- even in the US -- has fireflies.)
Hi there. As always, I resurge. We had a nice holiday and are now catching our breath before the next school year starts.
Hi, Giliell.
Hello!
Hello, rq! Long time, no see.
It has been a while, hasn’t it. It’s been quite a ride, too.
I’m glad to see there’s still an outside world out past my bubble. Trying to stick my head out a leetle more often.
<3
Hi rq.
Hi rq!
I’m basically doing the same. We really owe Charly and his garden for keeping this place alive.
Hi rq! Hi, all!
I’ve been mostly lurking and I’m glad that people still do post and comment.
Hi rq!
I’ve been thinking far days about writing an update. I’m just too lazy and distracted.
At the midnight of 12-13 August I went out to look for the Perseid meteors and early autumn stars, as usual. Visibility was limited by the bright Moon and a slightly hazy sky. I saw a few of the biggest meteors, a few stars and at least one satellite. A special treat was seeing the two bright planets Venus and Jupiter rise very close to each other. Saturn was faintly visible near the waning gibbous Moon, in different direction.
Shortly after that, I finally managed to swim a few strokes (the only time I swam this summer) in the freezing, muddy river after taking a long, sweaty urban hiking trip across much of Helsinki. I’ve harvested a lot of wild berries in recent weeks, and finally found a couple bolete mushrooms.
In the wee hours of August 20, I was again out to appreciate the waning (now crescent) Moon, Venus and Jupiter. The planetary conjunction had passed, but now the Moon and two bright planets were all moderately close to each other, while Saturn was all alone in the other direction. I even saw Mercury very faintly, barely above the twilight horizon.
On the evening of last Wednesday, I went to look for the stars after nightfall, when the Moon and planets were all down. I didn’t see many stars either, because the sky wasn’t properly clear. Instead, there was something I’d never seen at the local park before. A two-person fire dance group was practicing their routine at the edge of a large, dark lawn area, with stage music and live torches. It was very nice to watch from a distance in the dark, when the park was silent and the music was quiet and almost all I could see was the dancing flames. Mesmerizing.
Tonight, there’s alert for a high chance of auroras.
The Moon is waxing again. Next weekend there will be full Moon, with a total lunar eclipse visible on Sunday/Monday night across the eastern hemisphere. In Europe, it will be right at or shortly after dusk/moonrise on Sunday evening. Saturn will rise at the same time, just a little to the left of Moon, and the darkening of Moon should make it more easily visible.
Update: I saw the lunar eclipse, but only faintly in a misty sky. The weather has been again obscenely warm and humid, with copious mist and fog at night.
I went out shortly after 8pm, when the Sun had just set, the Moon was just rising and the total phase of the eclipse was about to begin. It was still a bit too early too view the Moon over the trees at my local park, but I also realized it was too all misty to see the dim eclipsed Moon near horizon in the twilight sky. The situation would only start to improve well after 9pm, when the sky would become reasonably dark, the Moon would be some 10 degrees above horizon and the total phase would start brightening near its end.
I walked to another park several kilometers away, since my friend wanted to meet me there, but I had no particular hurry. Inasmuch as I could see the eastern sky from between trees, there seemed to be clouds gathering. Eventually it was 21.43 when I arrived in that open park area, 10 minutes before the end of total phase. The Moon was now immediately visible, though only faintly, since my view to southeast was unobscured. The clouds had disappeared, but the thick mist remained. Saturn was also just barely visible, as were some stars higher up in the sky. My friend and I stood there until about 22.40, when the trailing partial eclipse phase was nearing its end. By the time I got home it was well past 11pm, and the Moon looked like a normal very bright full Moon, surrounded by a large bright ring of mist glow.
I missed the eclipse but I did see the full moon rising and it was beautiful.
On the early mornings of 16 and 19 September, there should be an opportunity to see waning crescent Moon close to Jupiter and Venus, respectively. These bright planets may be visible almost til sunrise, but they look best when it’s still dark. The closest approaches with Moon occur when it’s early morning in western hemisphere, so this opportunity is especially for those in Americas and thereabouts.
When the conjunction with Jupiter occurs, the Moon will be a substantial crescent and they both will rise soon after midnight. Three days later, the Moon will be a very thin sliver and the conjunction with Venus will be only visible in the low eastern sky as they both rise just before dawn.
Also, the ISS should be again visible in the evening skies of northern middle latitudes.
I completely missed the eclipse. Too busy again
The weather has turned overcast and heavily rainy. Lately I’ve seen only glimpses of the stars and Moon between clouds, and a brief glimpse of the ISS.