Shaking the fiber is all about bending it sligtly in random directions so that the light gets distributed randomly in the different fiber modes, and utimately the speckle that results from the interference of the light that traveled through the different modes changes so fast that it appears blurred on a "slow" detector

Hi Mike! 3:40 The technical term for these is 'flexures'. They are designed in such a way to only couple through the degrees of freedom intended, and release other mechanical degrees of freedom. Currently I am working/doing research in a group specialized in flexural mechanisms. Most important in flexure design, is figuring out what constraints you want. This particular configuration is quite common, and only allows for a single degree of freedom, namely translation 'out of plane' (towards/away from the camera). It is stiff in all other degrees of freedom. They do this to minimize over-constraints in the system. You are right that indeed it is meant to resolve the alignment problem between screw and sled. Personally I am a bit confused why they only care about releasing that 'out of plane' translation alignment axis, but not for example the vertical translational alignment. Ideally you would only want to couple the translation along the screw axis to the slide, and a flexure that would do just that isn't that much more complicated. Seeing the non conventional construction of that flexure, I am doubting whether it was designed by someone that is very familiar with flexures, but I digress. Flexures are very common in high precision mechanisms (think wafer stepper machines like ASML, spacecraft etc). They have a couple of advantages over 'traditional' mechanisms with bearings: - No relative movement between parts, and thus no friction. Friction (combined with limited stiffness) causes a phenomena called 'virtual play' which limits machine precision, thus eliminating this is very important. - No lubrication required (very important for space applications, where bearing grease can cause major headaches with vacuum and temperature fluctuations) - Can be relatively cheap (depending on the materials used). - More flexible in the allowable degrees of freedom (bigger design space). Although this can be mitigated with more complicated designs. If you would like, I have some good recommendations to learn more about them. In particular I would recommend 'Exact constraint: Machine design using kinematic principles' by Blanding. It is not flexure specific, but more on the topic of constraint design, but it has transformed the way I am looking at mechanisms in general (and is quite a fun and light read!). 11:55 I doubt that they would add weight for damping. I would expect that the weight would only shift a mechanical resonance to a lower frequency. Perhaps without the weight it has a resonance peak at the same frequency as another part of the system, thus amplifying each other? Still in such a case, such a massive weight is quite overkill. Generally adding damping to precision mechanisms is avoided, as doing damping without friction is quite hard/expensive (you want viscous damping without friction, most viscous dampers have internal friction).

@MrG-.-

2 ай бұрын

🎓

@KallePihlajasaari

2 ай бұрын

Yes that damping weight was a puzzle I think I saw more holes on the weight and wonder if that was intended for attaching a second weight through a lossy coupling. The flexures may have been a legacy of a different design choice and constraint requirement OR the mechanical system might have adequate play in the other direction and was only binding in the one direction. OR they made a design error or component change that required a change in the spacing of the screw and linear slide that was easiest to compensate with a non-rigid coupling OR there was a thermal expansion issue that would cause binding that was only evident in the one direction. As is typical of these over prices and (comparatively) low volume medical and analytical devices a lot of money gets spent on stuff that might not even need it because of reliability concerns.

I recently had a chance to pull apart a $0.5 M AUD genetics instrument in a 2 cubic meter size enclosure. Aside from the incredible build quality and over-engineering, the most incredible thing is how quickly these kind of equipment go out of relevance. The unit was only 5 years old an no longer supported (critical consumables no longer manufactured) and practically obsolete in terms of performance.

That unbalanced motor fiber jiggler thing just blew my mind. I've never seen that implementation for despeckling done before! It's such an elegant and parsimonious solution! The lengths we have to go to in order to suppress speckle on inertial confinement fusion targets is insane: distributed phase plates, smoothing by spectral dispersion, distributed polarization rotators... all to the tune of many tens of millions of dollars. Of course, we also have to do it on picosecond timescales, so there's that little caveat too.

@Prophes0r

2 ай бұрын

The thing that get's me is anyone trying it in a device like this. I would immediately discount this method because I'd assume we are fighting tooth and nail to reduce any source of vibration. Apparently it's fine?

@chriswalford4161

2 ай бұрын

Well! There you go! Table-top MW fusion generators solved!

@LuckySlevin7

2 ай бұрын

I can totally relate... in my day to day life I also have to put allot of effort into despeckling... the stuff we put up with, the struggle is real...

Fiber is multimode, so by shaking it - you mix modes by physically bending the fiber. So it's nothing fancy. You can test it yourself - project fiber to a wall, bend the fiber - and observe that speckle pattern change as you bend it.

@wolpumba4099

2 ай бұрын

Here is what I remember how shaking a fiber can reduce speckle: This is achieved by launching a mixture of modes into the fiber, each propagating at different speeds. At the fiber's end, these modes interfere, creating speckle. Shaking the fiber alters the relative optical distances between modes, effectively scrambling their interference pattern. Ideally, the fiber length is chosen such that the time delay between the slowest and fastest mode exceeds the laser's coherence length (In your demonstration at 15:39 it doesn't look like intensities are added, instead I think you have to set integration time long enough to contain a few cycles of the shaking motor, I think in the ideal case you wouldn't have to jiggle the fiber). This decoheres the modes, resulting in a more uniform illumination. To understand this further, consider how beams are added for coherent versus incoherent beams. For coherent beams, the fields are added directly (A + B, where A and B are complex numbers). This can lead to high-contrast fluctuations and even zero crossings in the combined intensity. In contrast, for incoherent beams, the intensities are added directly (|A|^2 + |B|^2), resulting in a much more uniform illumination.

@KallePihlajasaari

2 ай бұрын

You must admit that is is cool to see someone shaking a coil of fibre on purpose inside an apparatus though. With the big fan running the sound would not have been noticeable but imagine this in some other equipment like a desktop microscope illuminator, 6dB noise increase when turning on the despeckler. :-)

I think the principle of operation of the fiber shaker is just to continuously shuffle the internal incidences of reflection to avoid hot spots. I think it's mostly just a geometry problem rather than relativistic problem.

@markglover2525

2 ай бұрын

> to continuously shuffle the internal incidences of reflection to avoid hot spots. I do that with my Kelloggs Frosties; otherwise you get clumps of sugary overload.

Might be just me but the birds improved the already fascinating video.

This expensive piece of kit is used to map the dna. It relaxes the whole dna molecule that is fluorescent dye tagged, loads it into a microfluidics chamber stretching it further, and finally cuts the dna in pieces. Dunno if the samples deteriorated, but 18:21 is what it should look like, a unique visible map of the whole dna stretched, cut at various specific positions, with each piece length specific to a cell type, organism, specie.

@TheModernVictorian

2 ай бұрын

Thank you for sharing this knowledge.

Had to pause the video early on once I started hearing the Parakeets, I thought the fan was playing up on my air frier 😂

@awatt

2 ай бұрын

I had to re-read your comment as at first I thought it would answer a question I have had for sometime which is what does parakeet taste like.

@AppliedCryogenics

2 ай бұрын

​@@awattit tastes like squab.

@awatt

2 ай бұрын

@@AppliedCryogenics Haven't had wood pigeon for ages. Thanks.

The shaker on the optical cable operates in much the same way as a galvanometer in that it changes the angle of reflection in the optical cable thereby effectively blurring the speckle effect.

Jboss.. of course. Gotta get that oldschool java monolith energy.

@LongBean7

2 ай бұрын

Yeah it's been awhile since I've heard that name 😂

That is a mode scrambler. Used for making it a pure color of light like a very bright led. These units generally have a 488nm and 635nm laser as well as the 532nm laser. If this one only had a 532nm in it, it was uses for an extremely specific kind of test. That photometrics camera is what was inside a Coherent laser beam mode analyzer with a heavy duty attenuator, they cost a fortune back then. 562nm is the emission peak of florescent green 🪼 protein. 😂

I'm guessing that the custom stepper motor driver was an attempt at implementing something like the new sine wave "silent" TMC drivers which are now commonplace, perhaps. The relays on the output feel like some form of a solution added to ease compliance with some form of certification, since perhaps then they wouldn't have to certify all of the complex electronics as "functionally safe" or something. Definitely feels like there was no shortage of "not invented here" syndrome in this machine, which appears to be common in lab equipment

Yeah that display is perfect perfect. The shaker device would change bounce angles for the light, shifting interference pasterns continously, enabling averaging of interference patterns at high resolution.

8:00 No, there are many conditions that must be followed with medtech equipment and one of them is that if fex a lid is opened so you can access moving parts the moving parts must be stopped immediately, so there is a reason those relays are there.

Despeckling fiber jiggler. Only on uncle Mike's youtube corner.

You get that speckle reduction in laser cinema projectors (with vastly higher powered lasers). It works by changing the path lengths by altering the number of bounces it takes to get around the coils.

Where do you keep getting these unusual teardown items? Is the UK eBay that much better than here in Germany? I might need to relocate. 😅

You should sell the objective with the corresponding tube lens. Even more useful would be the whole assembly with laser, dichroics and possibly camera. I was once in a microscopy course in plymouth. A good way to test a fluorescent microscope with a 60x immersion objective is to place pollen (from flowers) below. You'll need slides, coverslips (0.17mm thickness), immersion oil, embedding medium (you could use the oil as well) and nail polish to seal the coverslip on the microscope slides.

Maybe the motors aren't steppers, but DC servo motors with ultra precise feedback control?

Awesome bit of kit !....cheers.

The crazy complicated driver board might be a case of resume-driven design in an application where costs were irrelevant.

@joseluisgonzalez7350

Ай бұрын

Why not check off some career checkboxes at the expense of the boondoggle which is the US industrial-academic complex

fascinating the way the speckle is reduced with vibration. I like the XY table mechanics but its probably not as usable as one might hope. Great video, very neat stuff

I am quite keen on obtaining such a laser, filters and objective for a DIY fluorescence microscope. And just out of interest, what do you do with the extensive, precision, over-engineered housings? I am a bit of an enclosure junkie and some of the things you tear-down are solidly built and ideal for other projects

I have that PSU from my first PC build in 2008. Still kicking fine all these years later in a crap PC server I use for testing.

I do not have any personal knowledge of optical mapping methods but the Wikipedia article seems to explain the workflow well enough: en.m.wikipedia.org/wiki/Optical_mapping

I used to work with photometrics pvcam in linux 15 years ago. these were 30k USD cooled EMCCDs. Edit: Oh, this is just an interline CCD Sony sensor.

12:12 Parakeets in UK??!!

@mikeselectricstuff

2 ай бұрын

Yes, loads - probably originally escaped captive birds, pretty common to see around London nowadays

@dtiydr

2 ай бұрын

@@mikeselectricstuff Wow, had no Idea that is messed up.

@brandonbutterworth3781

2 ай бұрын

I saw a flock (6+) of green ones near Kenley station a few days ago, must be a lot of them about

@dtiydr

2 ай бұрын

@@brandonbutterworth3781 I had no idea. I looked it up and it seemed like many parakeets was brought in from India among other countries in the mid -90 and then most likely just let let out or many escaped and they seem to thrive there and thus many more of them now, just amazing.

There is nonzero chance they were using same driver board for linear motors stages as well - there the choice of power opamps and DSP to drive it is totally apropriate.

So what is the budget for building this piece of equipment...Yes

Just the laser module would pretty much pay for everything.

They like their lasers shaken, not stirred.

@noahhounshel104

2 ай бұрын

I imagine with all the fiber loops it's more like shaken and stirred ;p

very cool

My favourite is the extreme level of detail in some parts and the semi jank in others. All the high precision machining and then they are using a a couple of standard nuts to space the hanging assemblies. @11:00 I’m wondering if it was just different engineers, the project was delayed or hemorrhaging money so the obsessive over engineering was dropped in favour of just making something work. Even if the product is 300 grand per unit if they were selling in very low volumes or had enough engineers working on the project budgets can get eaten up pretty quick.

@dsfs17987

2 ай бұрын

they probably don't have their own machining capability, they just design, send out, get parts back and then some poor sod (who probably doesn't get enough pay) has to put it all together and get it running see this quite often on lab equipment Chinese these days offer the machines that cost few hundred thousand for free to use, you don't own them of course, but you pay for reagents, and probably they can backdoor and look at any data, killing the competition like they do in all the other fields, and worst part is - scientists DGAF, they get their cut from the reagent sales

@Konecny_M

2 ай бұрын

It is perfectly normal. You try how far you can go with common of the shelf components and solution and switch to custom made only when it is needed. The adjustment mechanism at 11:00 mark is actually very elegant solution - you have the assembly preloaded with its own weight during alignment, fixing it in position without affecting the alignment is simple two step process - first top nut to secure the distance, then the bottom to gain stiffness and stability.

@DMSparky

2 ай бұрын

@@Konecny_M to each their own. I do that kind of thing as an electrician spacing an electrical box off a wall or something. I’m not building $300000 dollar laboratory equipment. I could be mistaken but to me it doesn’t even look like a fine thread screw. I guess if it works, it works, so no need to reinvent the wheel. It’s a short enough stud that there shouldn’t too much lateral movement.

@Konecny_M

2 ай бұрын

@@DMSparky It is not fine pitch thread because it needen't to be - tilt of less than 1mm diameter plane is being adjusted, the location of the mounts from the center axis are effectively acting as reduction lever.

Likley have to watch part 1 to get an idea how you end up with this fellow and if you imported it from the states, where such highly expensive, though dated labgear are being dumped for peanuts.. Though quite a lot of info online for Optical Genome Mapping and how you tolerate these stringent samples for genome sequence mapping. Argus OpGen Optical Mapping System Whole Genome 11201-001 DNA RNA Sequence.. goes for a grand or two in non-working condition, depending on how complete the system is, as its a very specific tool. that been caught by its age / performance, and limited how much you can convert it to other usecases. Thx for the vid Mike, love your content.

I think if one jiggles the fibres, the beam-path & path length would vary / jitter as the cable bends.

The analog stepper drivers could be for emi reduction

thanks!!

Hey Mike I'm after i micro focus xray tube, do you have anything? How can i contact you? TIA Steve ...

I might want to buy that x,y,z stuff, if you're parting it out. The dampeners look ideal for what I have in mind, and as you said IKO is always top notch. That Lunixx root password can be reset by booting into what's called "single-user mode", followed by a simple 'passwd root' and you're good to go.

@mikeselectricstuff

2 ай бұрын

Email me if you're in the UK - would be expensive to ship overseas - the sides are very heavy

@LevonAvagyan

2 ай бұрын

or `passwd username` substituding "username" with the one presented at GUI prompt.

All the budget went into the control panel frame and the Allen screws, so they couldn't get a semi-custom PC power supply without all the useless extra cables sticking out, and find a better solution for those USB plugs 🙄

@dash8brj

2 ай бұрын

Didn't even have the budget to spring for a modular pc power supply :)

@mikeselectricstuff

2 ай бұрын

@@dash8brj Were they a thing in 2011?

@tHaH4x0r

2 ай бұрын

I dont think Allen screws are that much more pricey than phillips/pozidriv. Torx on the other hand...

@dash8brj

2 ай бұрын

@@mikeselectricstuff haha true - never thought of the vintage of the machine you were tearing down :)

@DMSparky

2 ай бұрын

@@mikeselectricstuffyeah I have a Corsair HX750 from 2009 that has modular cables.

I am just curious but where do you find this cook and interesting looking stuff?

@mikeselectricstuff

2 ай бұрын

Ebay mostly

@dr02_schwabe21

2 ай бұрын

@@mikeselectricstuffGreat thanks 👍 do you got any tips and tricks on how to find this stuff or can show it in a video in the future if possible?😅

I didn't expect that motherboard in there

Even the heat sink is totally over-engineered. I mean, at this point why don't get a extruded aluminium heatsink (tunnel) or even a custom heatsink like those in computer PSUs

@Konecny_M

2 ай бұрын

The only custom part there are two sheet metal parts with pressfits - literally the easiest and cheapest solution design engineer should choose as option of first resort. It is job well done.

patiently waiting until you take all the interesting parts that you've collected over the years, and install them into a DeLorean, that can go back and forward in time...

interesting 2x👍

❤❤❤🥰🥰🥰

If you can get the hard disks to me I will try to do some forensic digging on there to see if there is anything interesting.

That's some nice piece of engineering and since it runs on Linux, I could probably hack my way in if I laid my hands on this thing. A nice workstation grade MB there, and he connectors on the brackets at 6:32 are just standard ATX 20+4 and 2x4 power supply connectors for the board, so you can easily disconnect the supply to pull out the platform or test i out of the device. HDDs on the bottom side of the chassis are a nice touch. I'm wondering about the system specs, especially the CPU type. That's definitely a nice laser! That goes on a shark's head. Lovely CCD assembly too. The images at the end remind me more of astronomy or particle physics than biology, but then I'm a chemist and an electronics engineer, not a biologist :)

@Mister_Brown

2 ай бұрын

it's nehalem xeon era stuff so 4 or 6 core 1st gen core i7 type stuff you can always tell from the triple channel ram not useless but not interesting anymore

@BGTech1

Ай бұрын

Wondering about the cpu as well. If it’s Nehalem, I’m guessing it would be a beckton cpu

Centos? no wonder they threw it out ;)

@KD0MOO

2 ай бұрын

😂

@TheModernVictorian

2 ай бұрын

Whats wrong with centos?

WTF Mike, I'm getting old! I watched all of this. Btw, I'm 39, how about the rest of you?

@Muonium1

2 ай бұрын

43

@Potsie

2 ай бұрын

51 and quite annoyed. I usually turn Mike on whilst in bed to stop the billions of ideas rattling round my brain and let me slip into unconsciousness. Was still awake at the end of this. Bum.

@msylvain59

2 ай бұрын

49 here just a few days ago 😑

@thomasguilder9288

2 ай бұрын

40 ;)

@randybb

2 ай бұрын

40

could you get a password just to get it going to show us how it works you could hack it to make it work

when you ask yourself - why this and that, you know the answer already - because you have to pretend to justify the price of the system

@Prophes0r

2 ай бұрын

I've worked in a few places where we did totally unnecessary things because it was VERY important to practice. Then, you have the stuff done, so you just use it. Think of it like...how the Space Shuttle pilots used to manually fly the close approach and landing. The autopilot was perfectly capable of doing it, but they were constantly fighting to keep those skills fresh because there aren't that many opportunities to get real stick time on a shuttle. Maybe the electrical engineering team needed to exercise a bit?

*Abstract* This video provides a detailed teardown and examination of the OpGen Argus system, a large and complex microscope used for bacterial analysis. The video explores the various components of the system, including the microscope itself, the laser and camera systems, and the control boards. While the presenter was able to get the laser operational, the camera remained nonfunctional. Due to the size, complexity, and limited functionality, the presenter ultimately decides to part out the system and sell the components. *Summary by Timestamp* *System Overview (**0:01**)* * The OpGen Argus system is a large microscope with a graphical display and loud fans. * It boots up slowly and runs on Linux. *Disassembly and Initial Observations (**1:13**)* * The presenter was previously able to boot the system to a password prompt and re-zero the XY axes, but this functionality is currently unavailable. * The system contains a PC power supply, a secondary power supply for motors, and a solid-state relay. * A 532nm green laser with a fiber optic output is present. * The system utilizes a PC motherboard with various cards and a camera with custom components. *Microscope Components (**2:42**)* * A shock/vibration mount supports the optical assembly. * The camera is located beneath the optical assembly, and the laser enters through a fiber at the top. * A stepper motor likely controls focus, and a barcode reader reads codes off plates. * A high-magnification microscope objective with an oil channel is present. * The XY motion platform features high-precision slides and a unique motor coupling design to minimize lateral force. *Laser and Speckle Reduction (**4:03**)* * The laser fiber travels through a unique assembly with a motor and offset weight, which shakes the fiber to reduce speckle caused by the laser's coherence. *Internal Boards and Power Supply (**5:06**)* * The boards are mounted on trays and slide out for easy access. * A dual-processor server motherboard is used, likely for image processing. * The camera interface card is manufactured by Photometrics. * A RAID hard disk controller, dual serial port, and graphics card are present. * The system uses a Corsair TX850 PC power supply. *Stepper Motor Driver Board (**7:23**)* * A custom board controls the stepper motors and other outputs. * The board appears underutilized and may be designed for multiple products. * It features powerful outputs for up to six stepper motors, although only three are used in this system. * The board utilizes relays for interlocks and includes an Altera Cyclone FPGA and Analog Devices Digital Signal Processor. * The complexity of the stepper motor driver board is questioned, as simpler solutions seem adequate. *Laser Driver and Optics (**9:53**)* * The laser driver board appears straightforward and easy to operate. * The laser module contains a narrow band filter to ensure only the desired wavelength is emitted. * The presenter demonstrates the laser's functionality and the effectiveness of the fiber shaking mechanism in reducing speckle. *Camera and Magnification (**12:53**)* * The camera is a Photometrics CoolSNAP EZ with a CCD sensor. * A large weight is attached to the camera, possibly for vibration damping or anti-vibration purposes. * The presenter was unable to get the camera working and suspects a problem with the control board. * The camera enclosure is sealed to prevent condensation but does not utilize extreme cooling like other high-end cameras. * Using a DSLR, the presenter demonstrates the limited magnification of the microscope objective. *Conclusion (**17:04**)* * Due to the size, complexity, and limited functionality, the presenter decides to part out the system and sell the components on eBay. * The presenter shares images found on the system's hard drives and asks for help interpreting them. i used gemini 1.5 pro

@Potsie

2 ай бұрын

Once upon a time we had to use VCRs to watch tedious TV programs for us, with that summary I am certain that in the near future Gemini 2.0 will put all the electric monks that still exist out of a job.

@Prophes0r

2 ай бұрын

@@Potsie Not without a major shift in how stuff is done. As a casual ML researcher, I can confidently say that a lot of the "Big" AI stuff is little more than a toy. There are some amazingly useful things we can do. But they are simple tools. Most of the complicated stuff is smoke and mirrors. It's Jesus on Toast. A box of hammers can't build you a house. A rack of wrenches can't fix your car. But they can make it easier for YOU to do it. AI doesn't lie. It doesn't hallucinate. It doesn't make errors. No more than a book does at least. These tools are just too complicated to reasonably comprehend, so we see thing that aren't there. They are also not very good at doing the tasks we assign them. Not because they just don't happen to be good enough yet. They are bad at doing it because how they actually work doesn't allow them to succeed. Seeing Jesus on your toast doesn't make your toaster an artist.

i just bought a printer for 35 quid

I'd like to mention this optical fiber shaker at 4:10 to @HuygensOptics (not sure if this works on youtube and if Jeroen from @HuygensOptics is pinged now)