Hi All [Note, I have no scientific background, it’s late on Friday and this is written by a human]
It is complete! My latest video “I made Super Sonic Whip Launcher”
So my goal was basically a “whip launcher” so to speak, ie. Something for specifically cracking a whip in a target-able manner, for perfect, consistent sound barrier breaks every time with zero prior whip cracking skills.
[I will update this post with some additional photos on Monday that arn’t shown in the video ]
As simple as it looks in the end, I thought I might have to abandon the idea midway (a couple of times) as it wasn’t looking like it was going to work. But ultimately it works better than I imagined. It can be aimed to almost millimetre accuracy by hand and supersonic crack in a very consistent way… and damn, it is so fun to use – especially for gardening… & also for winding up the neighbourhood dogs 😅.
So making the smallest, yet loudest tapered whip possible (without braiding), was quite tricky. Rope weight, size and especially the connection between segments needed close attention. Then working out a way to store the whip in a “ready” position was a pain as it doesn’t take much to interfere with the whip flying correctly and whether it will actually crack or not.
Apart from having fun with it and making some noise, having a whip in a compact, repeatable and “target-able” format seems like it would be pretty ideal for experimenting or educational use. It reckon it could quite easily be made to be adjustable between transonic and supersonic speeds. Then the “skill free” repeatability means the cracking can be very accurately targeted for capture on a high speed camera or with a Schlieren photography setup.
Unfortunately my high speed capture limit is fairly low resolution 1000fps (compressed 1080p). My Wife and I also tried for an hour or so to capture a high resolution still using a strobe flash but capturing something traveling at at over 1230km/h is pretty challenging – we were always too early or too late. I reckon I would need an adjustable laser shutter trigger with my DSLR if I was ever going to achieve it. Having said that I still managed to capture some frames of video that are quite interesting.
I couldn’t include everything in the video but here I can nerd out a little more: As Destin of the Smarter Every Day Youtube channel demonstrated in his 2018 video on whips; The sonic boom actually happens a lot earlier than you would expect. Knowing what to look for from his video, I feel like you can just see it in these tests – maybe? Just before the lash gets to the 180degree turn there is notably a significant acceleration. I noticed any dust or moisture on the lash is very rapidly atomised before it enters the turn. I’m not sure if this is pressure at the transonic phase, or it it’s simply drag during that rapid acceleration everything behind, but either way…it looks cool.
Destin’s video really helped me get my head around how whips actually work otherwise I probably would have given up after the first few failures. For example a couple of stitches out of place on the whip seemed to be enough to prevent that good energy transfer – and no crack. But the whole thing really has me curious about how much earlier in the whip’s deployment could you get the sound barrier to break. I feel like this setup could open up a bunch of variables to play with for people experimenting, ie taper, material weight, adding rigid segments, elastic strength. But most importantly seeing how high can it reach to trim your neighbours overhanging trees while their dogs bark frantically at you.
Capturing the sound of a whip is crazy hard, especially in a way that the audience can appreciate it. It clips the mic almost every time. Ultimately a good echo is the only way to appreciate it in a video but my backyard and particularly my shed is quite dampening to echo. I did a few tests at a friend’s backyard which sounded better – lots of hard surfaces. Ideally I wanted to go and get some recordings in an echoey industrial area…but with the final form factor and sound of the whip launcher – yeah, I reckon that would pretty quickly get some negative attention – so I wouldn’t advise anyone to do that.
Safety wise, to be honest in the end it actually seems a lot safer to use than a normal bull or stock whip (in unskilled hands) and it behaves very predictably. I made a small stock whip first which we all managed to whip ourselves with (as seen in the video). In the video my wife legitimately achieved the millimetre accurate flower stem slices in her first attempts. And my candle snuffing with the whip launcher is as shown – first attempts. But like with any elastic or spring under tension you should always be cautious, kind of the same as elastic hook straps on a car roof rack.
I think the main safety note is making sure the anchor for the shock cord is as solid as possible with backup knot and crimp, and no sharp edges. Otherwise I imagine the whip could could pull a “uno reverse card” on you and hit you in the face. Wear safety glasses, but also the built in acrylic shield is good backup too – 5mm would be best. Also -I didn’t have time – but Ideally I also wanted to make a sailing style jamb cleat hovering just off the end of the roller on the bottom side. So If the elastic did fail somehow it would capture the elastic flying in the opposite direction. A simple bar might even be enough to dampen it too . [hmm I might actually test how it behaves if it did fail and report back]
But still overall – like all my videos – don’t actually attempt to replicate this, it’s just for entertainment don’t take any of this as advise on actually making it, doing so would be at your own risk.
Enough banging on from me, it is Friday, and this has been a surprisingly loooong shoot and video edit. I hope you like the video. I will likely expand on this in the future.
Thanks heaps for the support!