Huygens Optics - 2019-12-16
The video shows (hands on) how a nanometer level flat optical surface can be made. It first discusses the principle of the continuous pitch polisher, also known as the planetary polisher or optical lap master. 00:00 Intro of flat surface creation / polishing 00:37 Optical flatness specs compared to general machining results 01:04 Angular machine / continuous pitch polisher explained 07:24 Simplified version of the continuous pitch polisher 10:15 CNC polishing machine construction explained 11:16 Example of polishing 3 objects flat on a plate In addition, I discuss my personal method to make flat optics which is a modified / simplified version of the continuous pitch polisher. This video contains short clips of other videos showing similar continuous pitch polishers in action. Clips at 1:16min and 5:16 min were displayed by courtesy of Sydor Optics: https://www.sydor.com/ Check out their company video at: https://www.youtube.com/watch?v=N3RbCq8Kg5U& Clip at 1:20 taken from Gijs Loning's video (OpPad) on his visit to the Zeiss Factory: https://www.youtube.com/watch?v=9YhsTEOjxtU (very nice and informative video, Dutch spoken)
The true test of whether someone has mastered a field is their ability to explain it to the uninitiated in a clear and concise manner, you sir are a credit to the field.
This is really good, so well detailed. It seems over the years there has been a lot of demonstrations of optical grinding/lapping, lots of "recipes" so to speak, without any detailed explanation as to why it works. I'm coming out of this with a deeper understanding of the process, only took 12 years, but better late than never!
I have been interested in optical engineering for a long time now and yours is the first channel I have seen that covers it well. So thank you for making such excellent videos.
This is the most satisfying and informative presentation I've seen in ages. As a photographer I really appreciate the craftsmanship required to produce high quality optics. My hat off to you Sir! 🎩
I work in the optics industry for a couple of years now and I have to say that your channel is a real treasure! Your videos are both, highly educational and entertaining. Keep up the outstanding work!
Totally counterintuitive. I've done a fair bit of metalwork sanding and polishing, so I naturally assumed that optical polishing would be similar, only using something harder and flatter to grind the surface. It never occurred to me that the rotational grinding process would use something ductile, yet get better results. Thank you very much for the excellent explanation.
In metalworking terms, it would be very similar to using an aluminum, copper, or tin lap (as in watchmaker's "black polishing"). You want your lap to be softer than the material to be cut. Your lap becomes a matrix to hold the abrasive particles in place, and the cutting happens on the material that can't just grab and hold the abrasive. (Tin, by the way, gives absolutely amazing results when polishing steel. It's just really stringy to machine when you're initially making the lap. Save it for your finest - sub-micron - grits.)
You polish silverware with fine cloth which is softer than silver. If you use sandpaper the result would be terrible.
@Gvidas 1 This is great, thanks!
I feel there’s a general misconception when it comes to lapping a polishing that is a result of focusing on the lap material. As the first comment responder noted the lap only hold the cutting media. There are three fundamental rules for cutting to occur, though I only usually remember two. The important one here is that the cutting “tool” (in this case lapping or polishing compound) MUST be harder that the workpiece. The second is that there must be relative motion. The third escapes me.
But in either case it is not the lap that cuts the work piece but the embedded abrasive. Apologies for the lecture comment but lapping and polishing seem to be no different fundamentally than any other metal removal process; hard removes soft.
In the case of polishing silverware presumably there is some residual polishing compound on the cloth that is the effective mechanism for removing the oxide layer.
Also, if I’m glaringly wrong please correct me. 👍
Edited for autocorrect errors.
I used a machine like this in the 90s to flatten hydraulic motor parts. Instead of pitch, the wheel surface was steel, and the surface was kept flat by adjusting three rings which also kept the parts in position on the wheel. We'd check it a couple times a day by washing the abrasive off and placing an optical flat on the wheel. But other than that it worked the same way.
its not the same as true level
@Nathan Reality is poison! I can't live like this!
@stickyfox lol nice answer.
Did you happen to work on pistons and cylinder bores too for a hydraulic piston motor?
@Andrew Crews I worked on Eaton and Sauer-Sundstrand axial piston pumps and motors. We would replace pistons and cylinder blocks and send them out to be resleeved/refinished.
@stickyfox ah very nice. I have an Eaton series 1 pump. 5.4 cubic inch variable displacement model. Installed on my truck. Great pump 👍 wish I had a 11 cubic inch fixed displacement piston motor to go with it but instead I am using a Geroler. It does ok but slightly less optimal.
Flat-out the best vid on making flat optical surfaces! Clearly thought out well, I couldn't pitch in any criticism. It's almost like we're on the same wavelength.
What a cheerfully bright comment! I for one found the video very illuminating, and it seemed to polish out all the rough spots in my dull and hazy knowledge. You could say that it expanded my bandwidth....
@digitalradiohacker makes me wanna leave my daily grind and do something else
Micronically inquisitive mind lapped up the precision explanations.
If y'all don't cease with immediacy I'm gonna jump into a woodchipper.
😂
The principle looks simple, its just a tar and turntable, but those who tried working with glass, especially polishing and making it precise, knows that its extremely hard, takes years of practice and patience. Great video.
One of the most clearly explained process ever seen on YouTube. Beautiful. I feel like building one of these now.
How did I end up watching 12min of "how to polish something to the nm scale?" But you explained it so well that I understood it without any previous experience in polishing glass or anything for that matter
I would have never guessed that you'd use a malleable disc to do the polishing. Really fascinating to see how this is performed, thanks for the video!
Your videos constantly inspire me to want to build my own lenses for different optical projects. Thank you for sharing your designs and knowledge!
Very fascinating seeing someone so specialized and advanced in their field, thank you for sharing.
I've been polishing for a year now. This was super informative. Putting images to techniques helps me understand more of what I do all day long lol
Very clear and detailed explanation, best I found so far (and no irritating background music).
Cool how you built the turntable from a washing machine motor and rollerblade wheels!
Very good stuff. I've done my share of glass pushing, long long hours of manual work. I tried to make 200mm flats but I constantly got into troubles in 1um (two rings) level... Perhaps I return to them sometimes, even though I hardly remember why I started making them LOL (ok it was some cassegrain telescope idea, and another for testing other flats)
I have been polishing precision optics for 12 years, I really enjoyed the video, thank you. I do the final polishing of the optics on a spindle in a zerodur plate with holes, I put planes with weights in them, according to a similar principle. pitch polishing pad for the night I turn over on a plate smeared with Regipol with good flatness
Clear and precise explanations along with fascinating footage. Thank you. Subbed.
Fascinating videos, with plenty of details. Thank you for all this useful info and diagrams!
Thank you for making and sharing this video! Great content and very informative!
At work here in Germany they got mad at me for filing like this....that you work in nm tolerances and do so as well made me really happy. The understanding of why one would do it so they just couldn’t understand. Also an amazing video, very informative. Keep up the good work!
Muito obrigado pela excelente explicação. :)
Another very good and informative video from you! Just a question:how is the bruiser plate hold on position and driven?
Fascinating, and very well explained! Thanks a lot!
Using a Fisher and Paykel motor driven by a VFD is genius! So much simpler than the old belt and pulley reduction.
Thanks for the video, it's very informative. So the polishing table is an aluminum disk with a motor stator attached to it, and you press the pitch lap by using a granite plate, but I was wondering if you could share what the pitch lap substrate is made of? It looks like a few inches thick disk. Is it also granite?
No actually in this particular case it is borosilicate, which has a thermal expansion coefficient that is about 3 times lower than granite (which is an advantage). You can however use granite without problems if you have good temperature control.
Very good explanations with great schematics. Great video overall.
This is very interesting. I read somewhere that for lapping of silicium wafers they use some chemicals instead of abrasive particles. I can't imagine how precise they must polish wafers for 4nm technology.
It's generally a combination of both. If you use a chemical that etches your surface while you are polishing, you can use a very mild (or soft) abrasive agent, which results in a smoother result. By the way, when you use Cerium Oxide to polish glass, chemical interaction also helps speed up the polishing process. For wafers the actual flatness is less important that the smoothness, since modern wafer steppers make a heigh map of the wafer to correct for the total thickness variation when clamping a wafer to the chuck. Modern technology wafers are indeed incredibly smooth and flat (from the dimension of individual components to that of the full chip)
Really well made video! Great job.
I've been having a go at marking crude lenses from polycarbonate , the tyre pattern got me thinking.
I had previously seen brief footage of a lens factory circles on domes and lots of white liquid,
Your explanation has helped me understand the process, I'm not willing to sacrifice my record player or washing machine , but I do have some granet and microwaveable casting rubber.
Thank you, i always wanted to know how it was done. Very clear description.
I immensely enjoyed your double slit video, I would love if you did more quantum discussions - I clicked a lot in my mind, thank you!!
I've always thought there was something almost magical about being able to make incredibly accurate optical surfaces, flat or otherwise, with no precision tools whatsoever. I ground my 6" parabolic mirror by hand, and figured it to 1/20 wave accuracy on a pitch lap, with no references other than the Foucault test.
Very nicely done. Subscribed.
cheers from sunny Vienna, Scott
if you like that; then the three plates to make a surface plate is another example of this principle (though wil hardish surfaces)
@Robert McCabe Indeed. I use this principle to keep my sharpening stones flat. Using silicon carbide abrasive, I grind A against B, B against C, and C against A.
No idea why this is in my recommended, but very interesting. I'm amazed this kind of thing can be DIY with the proper knowledge and materials.
I would consider myself a maker more in the software area, it's always cool to see what other people are working on. Keep making!
"proper knowledge and materials"--including an old washing machine motor and rollerblade wheels.
Interesting, I always wondered how glass in binoculars and optical instruments is made so flat.
It looks like you polished a lot so far. Do you happen to have a shear plate laying around somewhere that you don't need? 😊
This video reminds me of how profound our technological advancement has been. Just think of how many different people had to cooperate and dedicate basically their entire lives to engineering better solutions in the relatively niche field of precision optics. Using a high viscosity fluid as a lapping surface? How the hell did anybody come up with that? Stuff like this just blows my mind.
Very interesting and informative. Thank you!
If pitch is a liquid, couldn't flatness be achieved without a reference flat (like the bruiser or surface plate)?
Enclose the pitch in a container with walls higher than it and heat it up enough to reduce the viscosity so it flows fast enough for the surface to find its level in a reasonable amount of time, then let it cool down. Surface tension would mess with the flatness near the walls, but closer in should be fine.
I suppose you lose the grooves though, darn.
You will have to wait for a long time before the surface reaches submicron flatness. Keep in mind that there is a volume contraction during cooling down. And of course it is not just about getting the tool flat, but keep it flat during processing.
Amazing video. Thanks for sharing such detailed explanation about the process and the tools you use. You got a new subscription from an admirer of the fascinating world of achieving precision from not so precise objects.
Did you make this yourself?! Incredible. This is amazing.
Excellent. Very happy I found your channel. Honestly, as a nerd in training, a good friday night for me includes such terms as nanometer and interferometry. Looking forward to your next video!
Edit: trainings -> training
Great Video!!! Is there a way to make flat and parellel surfaces ?
This is an excellent way to do low speed control with a VFD. Thank you for the good idea.
Excellent vector drawing demonstrating the constant angular velocity.
Fascinating stuff, the explaination is on point!
this is absolutely fascinating thank you very much
That was interesting and well explained. Good job, I will watch a few more of your videos
McCallan - 2021-06-24
I've got absolutely no idea why this video was recommended but I'm so glad it was.
Fascinating. Well done.
RobotSlug - 2021-06-25
Same
Keyfox - 2021-06-26
Same
Booty Yeeter - 2021-06-26
Same
Nathan Trigg - 2021-06-26
It's because your subliminally interested in light & optics.
McPozzm - 2021-06-28
It started when I clicked on a bartender showing how to make optically clear ice cubes for drinks, next day this was in my feed.