Laser strain mapper teardown

A look at a highly specialist laser measuring thing

[@cambridgemart2075]

That laser is almost certainly SLM, single longitudinal mode; they are very sought after by holographers and worth a fair amount as a result.

[@SionynJones]

Such a nice end to the day when you get a notification that mike's uploaded a new video. Cheers Mike.

[@KeritechElectronics]

Indeed!

[@WolfmanDude]

Everything made from carbon fiber now just looks like cheap aftermarket car accessories to me. The look has been ruined by tacky "racing" car mods. Almost funny that this device looked expensive and professional at one time

[@tHaH4x0r]

7:13 As someone who works with/designs precision equipment like this, I find the same hex keys all over the place quite convenient. Maybe not so much if all you have are the standard 'L' type sets, but with some T handles or precision hex screw drivers its IMHO superior to screws as you have to really try your best to strip them. (Especially the case if you work with morons who cannot distinguish philips from pozidriv). For my designs I almost always try to default to either torx or hex, and use as many of the same screw sizes in the design as possible (similar to trying to use the same resistor size as much as possible on a single PCB).

[@-r-495]

Absolutely. Also: Cleanliness..

[@tHaH4x0r]

@@-r-495 On that note, personally I prefer to use countersunk/tapered or counter-bored socket screws because of hygiene and less likely to catch stuff on them, as opposed to the button head screws used in this device.

[@-r-495]

@tHaH4x0r in bio labs we had to use those used on this device. I remember a service technician replacing all the screws on the outside of a machine 😏

[@ddegn]

I completely agree.

[@KeritechElectronics]

That's indeed some really nice electronic engineering... Lemo connectors, a thing of beauty. As always, your videos are few and far in between, but always a joy to watch. I love scientific, military or some other high grade electronics teardowns.

[@nixietubes]

You're unavoidable Keri: p

[@KeritechElectronics]

@@nixietubes I'm watching all of ya, haha!

[@pete3897]

That multi-pin connector looks like an old SCSI-III connector at a glance

[@theshannonlimit1114]

Those interlock switches are super common on CNC machine doors, and may be mainly for regulatory purposes rather than actually required for safety, especially if this was destined to be used in factories in the US.

[@moki123g]

Carbon fiber has very low thermal expansion compared to aluminum. The other option is Invar. Interferometers are super fussy about things moving.

[@JFirn86Q]

My understanding is they would probably use the speckle pattern - taking a base image, subjecting the object to a stress, and then taking the new speckle pattern and subtract out the old. Result would probably give a map of strain and make defects noticeable, by showing fringe patterns.

[@freeebord]

Always a good day when Mike does a deep dive video! Cheers!!

[@phcjs]

Interesting! Looks like a hacked together, low cost, scanning Michelson Interferometer. Serious Instruments use chunky Granite and die cast Aluminium structures, stabilized tube lasers for good coherence and optics down to errors of Lambda/40 on sophisticated vibration isolation. This way subnanometer resolutions are achived. My Profile picture is taken from an18" instrument.

[@ciprianpopa1503]

It looks like a student project.

[@aritakalo8011]

Well if you say have to hoist that thing to ceiling to flatscan downwards a big piece of material, granite slab is not exactly optimal material. That or it is field model with light weight being a high concern for customer. Even down to aluminium or so being deemed "hefty" Also aluminium would be suspectible to thermal expansion. Maybe the customers application had special concern for thermal stability and thus most metals outside of very specialty alloys is out of picture. The kit bashed nature makes me think this is custom instrument job for something, some lab or facility. They made like exactly one or two to a very specific need and application. Thus using combination of off-the-shelf parts in combination to make specialty instrument. At which point "did they good job or bad job" is hard to gauge, since we don't know what the asked spec was. What the application peculiarities are. What the actual scanning setup is. Since should this have been for example a lab instrument, it might have been just part of larger instrumentation setup with potentially very custom and experimental instrumentation setup. After all Laser Optical still lists consultation and custom development as one of their business. So who knows what that thing is exactly done for. After all lot of university experimental lab instrumentation is such of. "wait what is that piece there.... you can't seriously be using that thing in your million dollar lab" and some researcher just answers "We needed a thing that does X and needed it quickly, that does X well enough and was available from local hardware/electronics store since it's common item. Plus it was cheap. We tested and verified it. It works to the spec and accuracy we need."

[@chrisellingson123]

Carbon fiber has a much lower thermal expansion coefficient compared to metals. Perhaps this is the reason for their material choice, especially considering the laser assembly and camera are housed in the same unit.

[@christopherleubner6633]

Carbon fiber is used for the dimensional stability. A while back i worked at a place that built large single mode flowing gas CO2 lasers (Eagle 500) and the tube elements with the resonator were supported on a 9 inch diameter carbon fiber tube. All the alternatived were either extremely heavy or even more expensive. When mixed with the right polymer binder carbon fiber composite has very low thermal expansion ❤

[@RooMan93]

Huygens Optics most likely has a video for this kind of thing.

[@busti4552]

😮 Allen Head screws are clearly superior to Phillips head tho! 😢

[@mikeselectricstuff]

Nope. Too many different sizes and both heads and drivers chew too easily - give me a Pozi any day.

[@0xbenedikt]

@@mikeselectricstuff You really need a bit set and an electric screwdriver. I have built so many prototypes with Allen screws. It's so incredibly fast to screw and unscrew if you use the proper tools. Much faster than Philips screws.

[@sparqqling]

@@mikeselectricstuff Pozi and torx

[@mfx1]

@@mikeselectricstuff Torx.

[@mikeselectricstuff]

@@mfx1 Torx is fine, at least you don't have to figure out if it's metric or imperial

[@ciprianpopa1503]

An interferometer in a suitcase.

[@marvintpandroid2213]

Nice meeting you Mike, at the Fully charged show.

[@NiddNetworks]

Ahhh, if I'd known Mike was there, I'd have attended! (I live in Harrogate!)

[@marvintpandroid2213]

@@NiddNetworks ah, he came to the Farnborough one.

[@NiddNetworks]

@@marvintpandroid2213 thought it was a bit of a way out! Still kinda wish I'd gone....

[@marvintpandroid2213]

@@NiddNetworks it was worth going, I went on the friday, more interested in the home tech stuff but the cars were insresting and the rain wasn't that hard.

[@T2D.SteveArcs]

Always military proprietary connectors 😅

[@dcallan812]

It looks like when new it cost a fortune. Very interesting bit of kit to see open. 2x👍

[@christopherleubner6633]

Yup the DPSSL in it alone cost about 9 grand by itself at that time. It's a SLM long coherence length etalon stabilized laser.

[@douro20]

That laser would be very good as an illuminator for laser fluorescence.

[@MrTurboturbine]

I'm curious if this would have been used to measure the modulus of elasticity of some type of structural member? or reference surface?

[@01glenn0101]

I made my first full color laser with a clear housing, so my lsd mates could see it working, so i think they just used carbon fibre because its COOL ..... no other reason

[@danbrit9848]

i love the advanced inter lock switch ...because if im trying to get around safetys 2 screws on the coupler will deff stop me lol

[@NoEff3x]

Post a picture of your ebay purchase history lol

[@mikeissweet]

Keep 'em coming! Can people send in equipment? Or ebay funds?

[@mikeselectricstuff]

I have a backlog of stuff - time is my limiting factor

[@albinklein7680]

I can imagine your basement/garage/attic filled to the brim with absurd stuff no sane person will ever come in touch with! Thanks for years and years of great teardowns!

[@MVVblog]

Good!

[@wolpumba4099]

Would the target be measured in reflection or transmission?

[@christopherleubner6633]

Reflection. Swap the laser out for a Coherent DPSS ring laser and it would be even more sensitive.

[@Z-Ack]

That surface mount cap is comical.. why though? Ha!

[@dw1444]

that looks like a standard SCSI connector

[@IanScottJohnston]

As it's made out of carbon fibre I wonder if it was made for a Formula 1 team. A few F1 teams have factories etc in the UK.

[@fuzzy1dk]

more than a few, six out of ten are UK based

[@cankurt6634]

im still tryin to reach you for handmake thermal vision…how can i reach you?

[@davidf2281]

My guess is that Mike doesn't take commisions from random youtube commenters

[@tinygriffy]

10:08 .. wow these HV MLCCs are 20-30 bucks a pop ...

[@Jeroen74]

It's a PET film cap, not ceramic. Seems to have part number 10606560518820T. No longer available.

[@tinygriffy]

@@Jeroen74 Thanks !

[@mikeselectricstuff]

Couple of bucks at Digikey : SMDTG03470YA00KT00/9449165

[@tinygriffy]

@@mikeselectricstuff I knooowww .. I looked at the wrong parts, I only found 4 - 8kV MLCCs in a very quick search.. but its nice to know , thanks also !

[@palharley]

Thanks Mike, I miss your great teardown videos.

[@bobert4522]

Probably already had the capacity to make carbon fiber enclosures and this was cheaper than doing a low production run case manufacture.

[@skonkfactory]

Maybe it needed to be light for some reason, like someone had to carry it up a scaffold to do strain mapping on an inaccessible part of some large piece of engineering like a reactor pressure vessel or an aircraft tail or something.

[@TheStuffMade]

Interesting, must have cost an arm and a leg. Back in the 90s I think we used to pay something like $500+ to have a few prototype PCBs manufactured, it's understandable they decided to etch their own for a one off/small batch board.

[@TheStuffMade]

I bet you ended up on a watch list somewhere with all these slightly weird high tech ebay purchases

[@cameronwebster6866]

My 2 cents on why the enclosure was made of carbon: the version of the unit shown at 1:26, being in multiple pieces isn't super conducive to quick portability, and so building the unit into one box, like the CF unit would make sense if you had to move it about for in-situ tests, for example. If your company works with a lot of CF, you will often find that they will make things out of CF that don't explicitly need to be made out of CF (take a look at some of the equipment that F1 teams bring to the track for example), I believe this is for a few reasons: 1)Looks/branding, if you sell big things made out of carbon, having small things made out of carbon may be a good way for sales people to show the company's workmanship. 2)Training, if the new guy doesn't have any experience with composites, why not have them learn on something like a toolbox. 3)3 feeds from 2, but if you are making something non critical out of CF, you may as well use as many scraps from regular production as possible. 4)If you already have the infrastructure to make quick turnaround prototypes out of CF, int might be more economical to make something out of CF, even it it doesn't need to be. Going back to my point, I think someone, who uses a lot of CF, and in particular, does a lot of rapid CF prototyping, such as a high-level motorsports team(F1, WEC, etc.), or an aerospace manufacturer, had need of a strain mapper that was more portable than normal, and so either made the CF enclosure on their own(likely with permission), or approached the manufacturer with their need, and said something along the lines of, "we need a version of your product that is all in one enclosure for portability reasons, if you tell us where in space the inner components need to be, we can make the enclosure, and send it to you, and you can install the inner components.” Edit: Another reason I can think of for building the strain mapper into one CF enclosure, what if it was used inside a plane wing, or somthing like that?

[@rtechlab6254]

We used to use Lemo connectors by the ton. Some of our kit would have 4u panels crammed with them

[@JesusvonNazaret]

carbon fiber has next to no thermal expansion, so that's probably why they used it for the construction

[@ciprianpopa1503]

well, it bends a lot and picks every vibration. Strange choice, probably to feed the hype of carbon fiber.

[@theelmonk]

I was going to suggest it was customised for F1 or aero, but then Mike got to the mains power supplies ..

[@silverXnoise]

@@ciprianpopa1503It’s quite famously rigid. Are you sure you aren’t thinking about silicone personal massage devices? They bend a lot and vibrate.

[@ciprianpopa1503]

@@silverXnoise I am 100% sure. I work with optics. Optical benches are made of special steels with very precise and low thermal expansion. If you insist, I can hourly rent you the time on one of the optical benches for your vibrational entertainment. However, I can assure you they are sturdy & the amplitudes will be rather low. Not as low as your dry sense of humor though.

[@paulhawkins6415]

Mike, are you familiar with Optical Flats, used to determine flatness. Maybe this works in a similar way by projecting a fringe pattern, the shape of which determines the flatness.

[@Z-Ack]

It does remind me a lot of optical flats.. maybe the same deal except digital.. brings a different meaning to optical flat if so…

[@cambridgemart2075]

Very similar in principle, it will measure inteference patterns and will be capable of resolving down to 1\4 wavelength or better. It will only work on specular reflection though, the paper just diffuses the wavefronts so will never give a usable pattern.

[@christopherleubner6633]

Yup, except it's for bigger surfaces where a flat would not be practical.

[@SproutyPottedPlant]

I wonder if they used it to help make some fancy carbon fibre road bikes 😀

[@OneBiOzZ]

it is possible that it is made of carbon fiber because they had a weight requirement they had to hit, we have had custom fiberglass cases made when things needed to be attached to a moving carriage and inertia needed to be kept to a minimum

[@unmanaged]

mike needs to make a laser light show

[@NGC1433]

Carbon fiber stuff is not expensive at all if you have the knowledge, skills and tooling for it in house. If you have a supply chain of fabric and epoxy, as well as consumables to make molds and separate your ready parts from the molds - it's just wetting the rags with epoxy and wrapping them around the mold, then putting it into a plastic bag and sucking the air out. Keeping composite layup experts on staff and motivated - that's what is expensive :D Take a looks at tutorials here, for example - www.youtube.com/@easycompositestv composites are really so much easier than metal working or even 3D printing. You don't have to deal with any of the 3D modelling, cnc machining and such - you can literally carve a part from styrofoam with a butter knife, wrap it with carbon fiber fabric, pour some epoxy over it, leave it overnight, splash some acetone to dissolve the styrofoam and have the shape of your imagination in carbon fibre composite - ready. The part will be as precise geometrically as you carve the mold, of course.

[@ferrumignis]

It's very labour intensive compared to an enclosure using e.g. an aluminium extrusion.

[@MrTurboturbine]

It was a pretty big expense 20-30 years ago...

[@k1lmo]

Wow my 16 years of experience as a composites engineer in the space industry summed up in 2 paragraphs 🫣

[@kknull15]

Composites are cheaper for such a small scale production. Injection moulding requires the manufacturer (or usually their client) to invest in moulds. Those cost tens of thousands of dollars per set. Each change in the shape of the product means that you have to trash the moulds and pay for another set. On the other hand, if you order from a local composite shop, you would pay for each item individually. The production of a small batch would take days instead of months, as with injection moulding. Each item will cost more, but nothing has to be paid upfront. I'd estimate the shop charged them $200-300 per enclosure. Which is great considering the overall price of this unit.

[@proluxelectronics7419]

Probably commissioned by a F1 company, they have more money than sense.

[@Zadster]

Or military / space / aviation. Their budgets make F1 look tiny.

[@HwAoRrDk]

Yeah, I was thinking the same. Seems like something an F1 team might commission, having the whole thing made of carbon fibre just because they can. Maybe use it to measure flex of composite parts under load or maybe aerodynamic forces.