Eating Oreos while measuring millionths doesn’t seem like it should happen at the same time haha.

I remember one time back in 1973, I set a 100 lb. large cast iron angle plate on the 8x14 ft. granite plate. I turned around momentarily to grab something else, and out of the corner of my eye, I saw the angle plate floating over to the far side of the surface plate. After a quick Oh S#$!, I ran around the other side and stopped it just in time! I had forgotten about this until I watched your cool vid!

Awesome work Lance and Adam! Love the differential levels. Thanks for the shout out. ATB, Robin

Hi Adam, I am a retired film sound recordist with almost 50 years experience. I think that the problem you are having is in the mini connector on the GoPro. There is a switch that is activated in the connector so that when you plug the connector in it disconnects the internal mic so there aren’t two signals going into the camera. The switch is just a metal whisker inside the connector that is very delicate and is easily bent so that there is no connection for either signal. This happens all the time and in a professional situation we just threw them away and got a new one. Is the Hero9 new enough that you can return it for a new one? The GoPros are great when they work but are notoriously unreliable for sound. I would suggest that when you get a working GoPro plug the mini connector in, tape it securely, and leave it plugged in permanently. My dad was a career machinist and watching your videos reminds me of going to the shop he worked in after school and hanging out. Please feel free to contact me if you have any other questions

I love that every few months to once a year we get these kinds of videos of Lance doing things like this or of scraping, etc. Really shows the science behind the machine shop. Lance truly is one of the brightest!

Back probably 45 years ago my Uncle worked at the Fiat-Allis experimental lab & he took me thru the place & they had a surface plate there that was as big as a king size bed of course as a 16 year old kid I didn't really understand when my Uncle told me it was really flat & used to test how flat a part was. But after watching this & your last video I'm amazed with the process of getting such accuracy. Thanks for putting out such informational vidoes.

Enjoyed this video because I worked in calibration for almost 25 yrs and had always heard how they did this but never had actually seen this process. Thanks Adam and Lance.

Thanks Adam for sharing this, really inspiring... I felt like watching Discovery Channel back when it was worth something...

Hellow m. Lance m. Adam. Fantastic.... amazin job. I was working 45 years in machine shops the Last 30 in aerospace industry in Greece I make thousands parts dificault parts with close tolerance this video is near too me Congratulations. John Grizopoylos retired machinist From Greece

@ROBRENZ Getting a mention, I love it. No reason he shouldn't hit a 100k subs by the end of the week. Lord knows he and his knowledge certainly deserve it. If you don't follow him and you value precision, you're doing yourself a disservice.

pretty cool, wish I was born with that kind of patience. Thanks Adam & Lance & John

lol, "air hockey" at the end with what must be a 20-30 lb cast iron lap was pretty cool

Thanks for allowing us to see what has to be done to get a granite plate up to "A" grade. WOW!!

Great episode again. Learn something on your channel very time. Thank you to all

I reckon your surface plates should be in a climate controlled room at 20°C for 7 days before they were measured or worked on. You need 3 flat surfaces to ensure flatness. 2 flat surfaces may be equally curved - one concave, the other convex. The third plate is used to remove that curvature.

Great video! My 4 year old now knows what a differential level and repeat o meter look like! That level setup looks slick! Thanks for sharing!

That stuff is so amazing, the kind of stuff Tom Lipton would drool over. I enjoyed that.

.00008" concave across that much surface, not bad; a well taken care of plate. As a Tool and Die Maker who specializes in Tungsten Carbide, .00008" is a football field in size and can make or break a precision fit, just like thermal expansion plays into the finished Dim. First video I've seen of a surface plate being resurfaced. I always look forward to my annual plate inspec/resurface. It is an old craft, usually passed from grandfather, to father, to son, and it's still done by the decades old process of the flat plate and silicon carbide. Not many companies out there doing this type of Craftsmanship. Of course, although not mentioned in the video, that granite plate quarried in the USA is a much better quality and harder plate than the "import" (without naming the sole source country of origin) plate. Great video Adam!

This is all amazingly fascinating, something I'm lucky to see thanks to you.

This kind of stuff is amazing to watch. I love precision work.

Complex yet surprisingly straightforward process-with the right tools.

Love the content as usual Adam! Always love when you and Lance get together. I have learned a ton from both of you.

Thanks for sharing with us Adam, pretty slick 👍👍👏🏻👏🏻

Who knew there were professionals that did that kind of work. Glad you showed us Adam.

Great job 👏 love when you and Lance get together, I just sit back and say,you gonna learn today boy

Absolutely love your videos dude, I look forward to them because they're not 5 mins long very in depth and I look forward to the little Abom79 notification on my phone throughout the week

This level of precision is amazing. Lance is such an incredible resource for this.

Thanks for sharing this Adam! Awesome equipment Lance. It doesn't seem like much to doing this but the precision of the laps, abrasive used, and most importantly having the inspection equipment to gage the work brings it all together. Robin was able to use his repeatometer the moment he had a proven surface in that optical flat. Great work you guys, Thank you! Phil

Excellent description of what you guys were doing. Thanks.

That is so cool. That plate is flat! I like it. I was explaining to my wife what and why to the best of my abilities of what a plate is for and why it needs to be flat. She understood the need to be flat! Such awesome tools one didn't know existed to make tools so precise. Good to see Lance, thank you John for the shop and Adam for a great video!

I bet Lance takes the fizz out his cokecola so it's flat also LOL

Fascinating look into a process many of us can only partially comprehend!

Thanks for sharing!

I'm not even a machinist or want to be one but the science behind all of this is amazing.

Very cool video. Thanks for sharing

I find this so fascinating, and I'm loving the explanation that goes along with it. Thanks so much!

Thank you Adam I always enjoy watching your videos I am from South Africa

Now that was very informative, thanks!

Fantastically amazing process and knowledge.

What a great team

Really interesting video and learned about new things. Love it

Very cool to watch. It feels like one of those things that's half precision science and half dark art :-)

Very interesting. Blows my mind talking about 80 millionths and 200th of arc second 🤯

Great video and educational. TY

The science of flatness. Interesting!

Wow, amazing how that lapping works.

Hello Adam, Very interesting to see Lance doing the mapping of the surface plate and subsequently lapping it, thanks for sharing. Take care. Paul,,

Man johns shop is so nice so many toys

Nice job Lance!!

I know why it's important to have a reference but I have no idea why getting to it is so fascinating, but here we are 20 minutes later. Thanks Adam and Lance !

Rest your hand on the plate for a few minutes and the flatness will go to he!! All of these measurements at those levels are temperature sensitive. You have to leave that plate in a controlled temperature room for a week (if not longer) to get consistent readings. Place I worked at 40 years ago had a surface plate and all I had on it was a height gauge. I used to measure across drawn stampings and if I'd had geometric tolerancing my best reading was probably 0.020. I was a rookie engineer and really didn't know what I was looking at. Thanks for posting Adam, I learned something new today

Way outta my pay grade,Thanks for allowing us to look over your shoulder🤔

very nice!

Congratz on your new AA plate.

"80 millionths" that's some accurate measurement .

I love lance and abom content

WOW what a great vid

Great content thanks for sharing

Awesome stuff

Excellent video!

OLD GUYS RULE

Wow! That was amazing...:-)

I love the fact that they really use the shop paper and not just throw it in the bin clean. Our shop of 10 men burn through a 50€ worth paper roll in less than a week, i literally get my clean paper from the recycling bin.

So... this is roughly how I've surfaced aluminum heads... only I used 1/2" thick glass and wet/dry 400/600paper with pb blaster as lube. I add 10 then 25lbs (with the 600) to ensure the force is perpendicular to the surface. Everyone says it won't work yet it does. Steel gasket too.

Fun fact: The calibration of the Shars plate cost four times what the plate did lol.

So cool that Robert Duvall is into lapping plates

Love this kind of stuff. Granite is relatively cheap, I can get a 3 x 1 meter slab of granite and have it diamond ground for under $1000. Then you can make a set of lapping plates and go to town.

Thats awesome

Lance should try making telescope mirrors

Like #6 Thanks for the video!

Везде берет!!! Super!!! Thank you for sharing!

Working with stone is fun! Good luck to you!

I work in a lab and I can't wait for our 3 surface plates to be lapped in March!

Oh shoot there’s a high spot right here! Never mind just an Oreo crumb

Super interesting video, Adam! Always wondered how surface plates get lapped back into the proper grade.

Thank you for another SNS Adam!

Now technology advanced. I am retired mechanical engineer.in our days we know only blue matching only.Thank you for your video.I am happy to see advanced instrument for checking granite surface plate.i am from india.

Whole new meaning to flat now. 😲

It really is like that bit from that Rick and Morty episode, except that no one had an existential crisis at the end. Maybe it wasn't flat enough?

Well done!!Well said!! Cheers!:-)!

Learned a lot, I know really nothing about surface plates before watching abom79. What is the price difference between an B surface plate to a AA plate. Amazed as to specialized measuring equipment. Love to learn more about it

Great video, I always wondered how they tested the testing equipment.

Hey Lance old buddy old pal I have a 4x6 plate up here in Kentucky you can come check sometime if you need some cooler weather. :-)

I may have written about this before but at a job I had years ago working for a German Diesel Engine manufacturer (the US operation) we moved to a new building. Our "new" workshop was twice the size of the old one (as was the whole building)! There was a surface plate that I had never seen before. Had to be 4' x8' and five+ inches thick! Or whatever the Metric size was. First time I saw it "Hans" the shop manager was standing next to me and I ran my hand over it and noticed this gouge in it about an inch long and 1/4" wide and 1/8" deep. I said: "I'm glad I'm not the guy that did THAT!" Hans said : "He vas fired!" I was one of the few that was allowed in "his" shop other than the guys that worked there every day...

Johns shop seems like a cool place to work. He's not looking for a close to retirement employee is he? LOL. Great video Adam.

Damn, thats crazy

I would like seeing how the bar that the meters run on is made. Has to be super super precise.

If it's not lawn mowers, it's power tools!! 😂

Nice work if you can get it.

Wow what an informative video that was, especially when he explained the pendulum in the magnetic field. That is one nice plate, pink granite I wonder where that was sourced/mined it sure is a nice plate. One thing I’ve learned in this game is you can always learn something new.

Ya that Starrett Pink Panther Is MEOW!

Need to take this equipment to Egypt!

Of course in an upcoming video, you can link to Robin’s info site so we can watch it and learn form it too? This was a great edu video well worth watching.

That measuring equipment is so sensitive that a fly whisker will change results

well learned something today, there is a measurement smaller than the proverbial gnat's behind!

We have an old plat like this that we heat up slowly with scrap wood and cook steaks . take 10 hours to warm it up and will stay warm for days

Nice flat of granite.

I would love to see the calibration standard for the mapping tool. How it's done and require readings for in spec. operation. Very interesting video. Thanks.

Robin Renzetti (@robinrenzetti) ROBRENZ - KZfaq The meticulous man @Abom79 and Lance mentioned deserves a shout out! He has far fewer subscribers than he should, check him out.

Damn i wanted to see how bad the shars plate is and im sure im not the only one