Inspecting & Lapping a Granite Surface Plate


89tn visningar17

    My friend Lance brought along his electronic differential leveling system so he could do some inspection on a few granite surface plates at our buddy John's shop during the week of the scraping class. The granite plate in this video is a 36"x36" that John bought at an auction. It was not bad but still needed some attention. I'll have some more of this working on my own granite place coming up pretty soon.
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    Publicerades den 3 månader sedan


    1. u rothe

      eating/contaminating, not realy proffesional !

    2. John Smith

      Those inclinometers, how on earth do they work inside, like to measure a few millionths of a thou out of level. I can't imagine how it works, and why the need for two?

    3. Josh Beauchamp

      Other than the lap-ability why are surface plates made out of granite?

      1. Steve Sousa

        Besides temperature stability and hardness, If you ding or scratch it you get a divot, which is much better than a bump..

      2. John Smith

        More temperature stable that cast iron I think. heat a cast iron plate up by a few degrees and it would warp slightly I imagine.

    4. Ryan Hogan

      Well how many arc seconds is “a blonde one” ?

    5. Mario Perron

      I see people commenting asking Adam to use metric instead of imperial, why? If that’s the system that Adam uses and is comfortable with then let him speak that language. No need to change just to suit others. That’s like saying instead of English i want you to speak Greek for me. Lol

      1. Ratty Woof

        It just seems odd that the most technically advanced nation on the planet is the last one using the bizarre measurement system of their erstwhile oppressors from whom they gained their independence over 200 years ago, when the rest of the world has moved to a simpler system.

      2. Gunhaver

        metric and imperial are exactly the same and interchangeable. the inch is defined as exactly 2.54 cm. you just use what you are comfortable with, and it is often very convenient to have a number with lots of divisors (12) and sometimes its more convenient to work with multiples of 10.

      3. Boots

        All the people who spout off how superior Metric is, seem to have problems with very basic math(s). Never see anyone talking metric complain like babies to convert to Imperial, most likely because Imperialist know how to google and do simple math(s)...... Screw em.

    6. morningstaR x

      I'm not 100% positive because its hard to see without a closeup but that plate looks more like a synthetic slab made with a mix of epoxy resin and granite stone filler. I ran 3 and 4 axis cnc machines as well as was a fabricator in the granite/marble universe for about 15 years and that is what my eyes are telling me. Real granite tends to be much less consistent in its coloration and in the sizes of the specks within the stone. The man-made stuff is a bit more brittle, prone to burning where granite is not, and prone to scratching where granite is not, unless by diamonds or metal infused with diamonds.

      1. Sebastian Nurkowski

        it looks like royal cream granite from India but true , it can be epoxy granite , it is common to make surface plate for cheap using mold made out of surface plates , then u just pour epoxy granite on it and u ready to go after it is hard without need to lap it etc the downside is cure time and soft surface in comparsion to pure granite. But cheaper and fast to make

    7. Ed 007


    8. RMR57

      Bring Pop and Grandpa back in the outro.

    9. Ibrahim Deniz

      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.

    10. jake

      How do you even transport something like this, or is this something that gets checked where it lives and stays there? I can't imagine the granite would handle being moved down a bumpy road too well.

    11. Jsedjen

      Need to take this equipment to Egypt!

    12. Janus Szakazu

      Adam in the name of ABOM79 i know it is hard for you , can you remember people who love your videos and all the time wait for ..... METRIC not INCHES. PLEASE !! THAT VIDEO WAS AWESOME . RESPECT. Wojtek from Poland.

    13. chiefsilverback

      For those who work in Canuckistani measurements, how many blonde ones are we talking here?

      1. Bart Youngblood

        Paging AvE....

      2. Mopar Stephen

        Pretty sure this is well with a "one BCH" tolerance.

    14. michiel 1

      Nice video shame it is all in inches... does not ring a bell with me in mm

      1. Rich Evans

        Don’t care.

      2. MCKSys AR

        0.00015" == 0.00381 mm

    15. Joshua Cowan

      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.

      1. Tony Wilson

        I've seen a few people use wet/dry paper on glass, but never for something like a head. Thumbs for the solution. 👍👍👍👍👍

    16. Muahmed Bnmmddah

      I hope for your help

    17. Pytha Goras

      Is it a good idea to potentially breath in diamond dust?

      1. ECM

        Diamond is made of carbon ... Carbon is the basis of organic chemistry, the organism will use it with. a nutrient ....

      2. Gunhaver

        its not good to breath anything that isn't 80/20, but with varying degrees of badness. in general its a high particle count that will get you. you could breath a few diamond particles and probably be ok (your immune system will handle any that makes it into your lungs). If you are standing in a blendtec cloud of diamond dust, you might end up coughing blood.

    18. Robert Kohut

      Wow! That was amazing...:-)

    19. 348 Loaded Lever

      Where I work some guys use them for workbenches. And if I told you where I worked you would never believe it

      1. Bart Youngblood

        @Lucas Cole Yup, I’ve worked at one of those places before. When the minutes are measured in hundreds of dollars, or more.

      2. Lucas Cole

        maybe getting them relapped is cheaper than your losses from downtime trying to find or get a new table to work on, I am guilty of doing this

    20. J boone

      Inspect it again in the summer time.

    21. Tom P

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

    22. cubonenineO

      thats incredible whats the granite plates for anywwho

      1. Rich Evans

        Reference surface for machinists. Some other videos on scraping from abom you’ll see them using the plate.

    23. Fabio th

      Measuring by levels is the best for check plate...

    24. Bruce Anderson

      Time to change to rumble!🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸

    25. Allen Hale

      Much to do about very little

    26. ROBRENZ

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

    27. Denny S

      I love lance and abom content

    28. Jasper Janssen

      If it’s basically only a couple hours work to get the plate back to AA grade, which is what it looked like, is it really not worth it to them to finish it properly?

      1. John McCoy

        Oxtoolco has a video where his surface plate was lapped. The guy told him that it's common for them to do a lapping and the plate will fall within AA spec after lapping, but they'll certify to A to save time and money. It's a worthwhile video to check out!

      2. Music Bro

        When you say 'properly' what do you mean exactly? It is finished to the required precision. I think the main objective is to get the surface mapped so it's 'known' where it's reliable and where it's not and to what degree the reliability is and to what degree the unreliability is. Not to entirely resurface it.

      3. Yorkiepoocharlie

        I’ll state the obvious. Time is money. So if they finished it better, then it would be more expensive. And then all plates would be ultra flat. And more expensive. If you don’t need ultra precision why spend the money? Many folks don’t use 0.0001 or 0.00005 indicators. Not everybody uses Suburban tooling because it’s too expensive. It built to much higher standards but not everyone needs that.

    29. Lvx Leather

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

    30. Alan Svanes

      Adam I’m not on Facebook or Instagram. I saw an older video with a picture of big monarch. I have some questions about the big boring bar holder. Don’t know how to connect you. Thanks Alan

    31. Michael Bradley

      how much would the inspection and lapping cost to a granite plate?

    32. old magician

      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!

    33. dmadere1

      Awesome stuff

    34. liaschinko

      Hi Adam . My quastion is not for this video . What happen with Keith Fenner Facebook Channel ?

      1. David Wootton

        He has moved to some other media platforms, he did a video on it.

    35. Srinivasan Santhanam

      Now technology advanced. I am retired mechanical 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.

      1. Janus Szakazu

        Adam is the best ,and new technology today is that what we can dream about 30 years ago.

    36. Shadetree Mechanic Racing

      I only have a B grade plate and nowhere near that size.

    37. Amos Backstrom

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

    38. schummiehugo

      nice work... ( mister flat ) hahahaha

    39. Kaedenn

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

    40. OneSquirrel

      As a member of the Flat Earth Society, I approve of this.

      1. tippy dog

        I love all things flat, well almost all things flat

      2. Ibraheem Al hadede

        Hahahah.... really?

    41. Bears Rod Shop

      Darn, Lance's electronic leveling system mite have cost more than our total property cost in 2014 (@@)?? Great learning video, thx for sharing, Bear.

    42. Cecil Brand

      The channel of the (not sure of spelling ) "Robin Rosetti" channel? can someone point my in that direction?

      1. Sub Human


    43. Double Dare Fan

      You are probably not going to get it much flatter without clipping the tops of its atoms.

    44. MisterMakey

      Surface plate grades also need to account for the plate's rigidity as well. Meaning that your plate could be too thin to actually call a grade A, even if it's flat enough. It's a product of thickness vs longest length.

    45. Shawn M

      What would you use this for? Yeah you got a large granite rock thats really really flat but the space it takes up just to have a really flat surface?

      1. Shawn M

        @Jeremy Sawatzky Thanks guys, total machining noob here as you can see. Thats why I watch and learn.

      2. Jeremy Sawatzky

        Having a flat reference surface that you can depend on is a very critical item to rely on in high accuracy components. its an extremely important tool.

      3. Daniel Helfrich

        It's a really important tool for every machine shop. If you have a surface that needs to be super flat, you spread dye onto the plate and put the surface on it. The dye marks the high spots.

      4. Paul Copeland

        Shawn M ....You need to shut your ignorant comments and learn basics before you sound like a dumb shit!

    46. Mark Snyder

      When you do a lapping pass, running the cast iron plate over the surface, about how long did it take? I'm curious how long this whole process took.

    47. freephoenixas

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

    48. Dima Minko

      3.8 microns amazing

    49. Bob Vines

      Adam & Lance, in at least one of Robin's videos on lapping, etc., he moved a "counterweight" (my word, not necessarily his) from side-to-side to balance out his Renzometer, I think. Why doesn't Lance do something similar when making these measurements? I ask because I'm confused, not to be a PITA!

      1. chronok

        If you look at professional lappers, they also don't do that. It's just an extra that Robin did.

    50. FreightDawg

      WOW what a great vid

    51. Brad Thayer

      Complex yet surprisingly straightforward process-with the right tools.

    52. douro20

      The inclinometers are a lot older than the readout.

    53. Dixie Normis

      whats it for, why granite

      1. Bob Vines

        It's hard _and_ stable.

    54. Joe jeans

      Subbed over here from then and sam cooking guy

    55. Frank Rodriguez

      Lance reminds me of John Malkovich on con air

      1. Frank Rodriguez

        @Mike yes! Looks just like him.

      2. Mike

        Cyrus the Virus!! lol

    56. Felix Mueller

      Sorry Adam , for me this was like watching concrete set . I'd much rather watch you make chips . Hell ! Make anything . What happened with that Stoker Engine ?

      1. Paul Copeland

        Go away. You’re just trying to start shit.

      2. Felix Mueller

        @Ben Hollis thanx Ben , I guess I need to relearn "How to read" lol thanx again

      3. Dixie Normis

        too hard basket

      4. Ben Hollis

        Stoker engine update is here:

    57. Jacob Hayward

      That's cool don't know why you need it that flat but cool.

      1. Jeffrey Lee

        To inspect precision parts.

      2. fubar totale

        If you are working to sub tenth tolerances, that's why. I did it for fourty years.

    58. wayne galvin

      Wow, amazing how that lapping works.

    59. felixar90

      I think the no-good part is actually the repeat-o-meter hitting the "no-good" sharpie residues.

      1. felixar90

        @robert bownes Yeah he even checked the different colours

      2. robert bownes

        Tom Lipton actually measured the thickness of Sharpie at one point...

    60. fishingsgreat

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

    61. felixar90

      Why are surface plates rectangular tho? Wouldn't they work better if they were equilateral triangles? On 3 legged stands? Of course it would be kind of less efficient use of the space.

      1. fubar totale

        @J boone Three points describe a plane, elementary geometry. 😉👍

      2. J boone

        Yep our cmm's surface-plate at work sit on three adjustable pads which are also isolators

      3. Larik

        @hippy chip yes

      4. fubar totale

        They generally are set on three pads.

      5. hippy chip

        Is your kitchen table a triangle?

    62. Michael Whinnery

      Why does he need a perfectly flat table ?

      1. Connah Jones

        @hippy chip im a chemist by trade so we have to take the same principles as we need to be super accurate with our measurements and if a machine is inaccurate then may as well throw any readings out of the window

      2. Bob Vines

        If I remember correctly, in order to accurately measure something, the measuring instrument needs to be an order of magnitude (10X) more accurate than what you are measuring, at least in industry & labs. An uneven "table" will make these measurements inaccurate too.

      3. hippy chip

        @Connah Jones This will not make sense to most people---only machinists.

      4. Connah Jones

        So you can make measurements on that plate so if there is any deviation in height you know its the part not your reference surface. Like if you made some parallels, you can make them identical so then the part you put on the parallels doesnt have an error put into it due to the parallels. Hope this made sense

    63. Chris Dockman

      That shop looks awesome.

    64. Chris Leech

      forgive my ignorance but that Starrett looks like reconstituted granite , as per terrazzo.

      1. Chris Leech

        @fubar totale thank you for the heads up! Much appreciated. I live on a sand pit - near many quarries - have never seen this in my virtual experience

      2. fubar totale

        Its called "crystal pink" its coarse grained with a lot of quartz and its very hard. The black granite is fine grained and can be made very smooth, but it's much softer than the pink.

      3. Erik Larson


    65. John Gerken

      Hi Adam. I've got a cast iron table saw that is no longer flat. What would the procedure be to flatten something like that back to a tolerable spec?

      1. John Gerken

        @J boone Yea, for a table saw that is plenty flat enough I'd think. Now to find a machine shop that will do that for me without breaking the bank. Thanks again!

      2. J boone

        Yep. Around .001" "flatness" for Blanchard grind I'm guessing that would take the table saw back to oem specs.

      3. fubar totale

        @J boone Blanchard would be quicker, Mattison would be flatter.

      4. J boone

        Def Blanchard grind

      5. Yorkiepoocharlie

        How not flat is it? That is the question.

    66. Tim Shelton

      How is the granite block supported on the underneath by the metal stand. Is it around the edges or 100% of the under surface?

      1. felixar90

        @spankeyfish Airy points are used for end standard. They don't minimise sagging, they make the ends parallel, for precise length measurement. But a surface plate isn't a length standard, it's a flatness standard. The Bessel points would minimise sagging, but it's a plane, not a line, so it doesn't have Airy points nor Bessel points. (It would mean supporting it only on 2 points anyway) I'm not sure what the 3 points that minimise the sagging of a plane are called.

      2. Tim Shelton

        Its obviously a heavy stone so I wondered if it distorted (saged) in areas that were unsupported

      3. Jeffrey Lee

        Probably the only common factor is 3 points, if you purchased the same size plate from 3 different manufacturers you would likely see some variation in the chosen locations of the points. Not all companies use the exact same rules to determine the locations. The most important thing is to use the 3 points the manufacturer used, use those same points when inspecting/refurbishing the plate, and use those same points to support the plate in use.

      4. spankeyfish

        Usually it's at the Airy points.

      5. Erik

        Usually it's at 3 points.

    67. WreckDiver99

      The real reason vets charge so pay for their expensive hobbies. yea.....LOL.

      1. douro20

        @WreckDiver99 Repeatometer is $1700 without the indicator. The Mahr Supramess millionths indicator is another $1400.

      2. WreckDiver99

        @Paul Copeland His expensive toys....gotta have money to afford those toys. Where I live, those machines they are "playing with", go for $15K+ easy. The Differential Levels are $4500 easy, the Repeatometer is $2000+ without indicators. Those lapping plates can go up to $2500 for them. The "cheap" part is the diamond dust as he said ($25 off Amazon). I don't know about you, but ~$10,000 in equipment for reworking surface plates is a chunk of change in my book. Now then, I know Lance is doing more than just his plates, but the fact is, he also isn't doing this as his "job", $10,000 to invest in a "hobby" and only one portion of said hobby is a chunk of change. Again, I really shouldn't have to explain it, but apparently I did...oh well...

      3. Paul Copeland

        @WreckDiver99 ...Yes, I know he is a vet. I have commented on that several times. Now that you have edited your comment, we can tell (sort of) what you had in mind. I still do not see what this has to do with the content of the video.

      4. WreckDiver99

        @Paul Copeland Lance is actually a Veterinarian. He does machining and all this as a hobby to de-stress. As I you know why the really charge so much. The vet we use has a an exotic car collection...I always tell them "Yea, does he ever drive the same car twice?"...they laugh and say "we think he did once"...LOL. Hey, the guy owns the practice (and its a massive practice with 6 or 7 locations and at least 25 vets among them all)...

      5. Paul Copeland

        WTF are you talking about?

    68. bcbloc02

      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. :-)

      1. Jeffrey Lee

        @bcbloc02 I guess Keith probably can’t hurt it to where you can’t fix it.

      2. bcbloc02

        @Jeffrey Lee Keith hasn't asked and I think he wants to give it a go on his old Lucas. I offered to do it last year when I bored the cylinders but Adam wanted to do it. I am sure if Keith has trouble with it it likely will end up here. Usually only the lost cause stuff wanders thru my doors. LOL

      3. Jeffrey Lee

        Bcbloc, why don’t you cut that stoker engine for Rucker?

    69. Kristian Taylor

      What's this used for?

      1. J boone

        Generally a micro flat plate is for inspections

      2. Paul Copeland

        I suggest you watch this video

    70. Peter Bishop

      How would someone be able to contact you? I’m an avid viewer who is looking for a lathe for our dairy and crop farm, I do welding,mechanical repair and due to the company’s leaving NY because of taxes ,machinist tools are few and far between.

    71. Larry Martin

      Tool & Die maker over 40 years we had this old German man who came and lapped our plates they had to be on zero our normal tolerances was plus or minus .0002 sometimes 50 million if we had stack up of inserts whose total tolerance was +/- .0002, depending on thickness of stock punch clearance could be .002 per side or seven percent of stock thickness, we stamped stock as thin as .004 at 600 spm.

    72. Alexander W

      Those who want to delve deeper into this subject may want to check out Robenz's channel he goes into the into the principles of flatness.

    73. steve shoemaker

      So what is the point of all of this ?? ?????????????????

      1. steve shoemaker

        @Paul Copeland lol You must have had a bad day shithead....You missed the point...The guy in the video is my friend down the road from me here....It was a joke,not that l need to tell you this but people like you need to get a life....Grow up a little and put away your toy's cause it is a small world out there lol lol lol lol...!

      2. Paul Copeland

        Watch the freak’n video!!!

    74. Tom Parker

      Truthfully now is there any real need in having other than the lens on Hubble telescope to ever be 80 millionth of an inch accurate. Do these granite tables have any use in a small machine shop...will it just sit around and collect dust before a real use is found? I use to truck parts in and out of machine shops from small to world wide companies like Cameron Iron Works and never saw one of the tables much less seen one in use.

      1. I Don't Know

        Most likely, every single professional machine shop on the planet has *at least* one surface plate, if not more. And many home shops are likely to have one also, even if smaller than that Sterrett. You would have never seen one because they are kept in temperature controlled rooms, and not out on shop floors.

      2. Fakename Realguy

        I am a fool, but I think it has a lot to do with toolmaking as well. All the inaccuracies carry downstream so it's important to start strong. For making parts to spec vs parts to fit

      3. Jeffrey Lee

        Depends on what you are doing in the shop.Many shops just depend on their machines to give them results, “good enough” and don’t check, say flatness of a surface, parallelism, runout, squareness, etc.. Keith didn’t check flatness of his mill or grinding work on the straight edges. He could have on the surface plate using 2 parallels, and test indicator/stand. If hand tools such as micrometer, caliper, or scale can check what you need you won’t use the plate much. The surface plate is the basis for doing a great deal more inspection than can be done without it. Like anything else in a machine shop, inspection tooling such as indicators, stand, v blocks, angle blocks, gage blocks, gage pins, height gage, etc are needed to enable use of the plate. Check out Starrett, Brown&Sharp, Federal catalogs or books on gaging for various general use tools used on a surface plate. In many cases custom designed/built gages are used on the plate for specific part inspections. Some very simple inspection can be done on a plate simply by setting the part on the plate. Keith could have placed his straight edge on the plate and checked around the perimeter with a feeler gage for any gap or bow in the surface.


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

    76. Klaas B

      Nice job Lance!!

    77. Chris Hoover

      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.

    78. Jeffrey Lee

      I wonder what ancient man came up with first, the straight edge, or the surface plate🤔

      1. Aussie Boy

        the straight edge, which turned out to not be that straight, hence the surface plate to correct the not so straight edge.

    79. George Geller

      How much does the flatness change with temperature?

      1. Mike Farwig

        @Matt Reilly You are correct. The south leg of the St. Louis Arch had to be cooled with water from fire hoses because it was expanding more than the north leg. Great analogy! Thanks for sharing that.

      2. Johannes Linkels

        @Matt Reilly Why would the middle be colder than the edges? When the room is at constant temperature, eventually the whole block will have the same temperature. On the contrary, when the temperature is falling from a higher value, like in autumn or during a cold night, the edges will cool faster and are definitely colder that the middle part.

      3. Corby Cobb

        @Matt Reilly Around than 0.00018" if the center to edge varied by 5 F.

      4. Matt Reilly

        As molecules heat up they expand. I suspect the middle will always be colder than the edges and thus be slightly denser and “smaller”. A story I’ve heard is that the St Louis had to be cooled to put in the keystone a piece cause the metal expanded too much in the sun.

    80. John McKenna

      I am disappointed in you Adam, You are very good at what machine work that you do but you are unwilling to try something new and possible fail and the willingness to have a big public failure is what separates the good from the great. Elon Musk proved that you can land rocket boosters when everyone else was afraid to try. He had many very public failures before he was successful. Most of you youtubers just edit out your failures. As the old saying goes " no pain no gain". I don't have the correct tool is no excuse for not trying.

      1. Jorg Jorgensen

        Calling out someone in their own public comment section is rude as hell. You should be ashamed. If you are talking about Keith's part, it wasn't just Adam's call.

      2. felixar90

        What are you even on about?

      3. arfon jones

        Adam, we all agree, is a manual machinist par excellence. Toolmaker? maybe not so much his forte. Otherwise, I would not have expected him to pass on this one.

      4. Jeffrey Lee

        It did take a little too long to realize the shaper was not a good fit for the task. I can’t say I’m disappointed with the final decision.

    81. Blake Crawford

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

    82. mike williams

      Been watching for a while,, Came across a crazy Russian, He made a bi directional bolt and nuts, absolutely tricky.

    83. Dave Perala

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

    84. Rob Field

      How about a 2d frame around the slab. A gantry with a micrometer runs across it, in increments of whatever you want... Turn the slab into a grid.. Measure at every point, however accurate you want to do it.

      1. felixar90

        Because your frame and gantry will very likely be less flat than the surface plate to begin with, so you can't use them to measure the surface plate. The surface plate is already the flattest thing in the shop. The differential levels and repeat-o-meter technique measures the flatness of surface plate in reference to only itself, which is the only reliable reference. Checking that small areas of the plate are as flat as the plate as a whole, and that spots aren't higher or lower than spots immediately next to them.

    85. Trevelyn Brown

      That one looks just like the one we have at work .

    86. Gary Paudler

      What size (grit? grade?) diamond powder did you use? Does the iron lapping plate remain abrasive after using it? Is there a way to un-charge it or remove imbedded diamond or granite dust? Thanks for the informative video.

      1. felixar90

        @Andrew Delashaw You replied to the wrong comment dude. But you're right.

      2. Andrew Delashaw

        For it to be anywhere near as accurate as this, you'd need A VERY expensive system. Building an extruded aluminum frame around it, and using CNC router rails and steppers/servos won't cut it. Your basically need a CMM, without the table, to go around it.

    87. Phil Grindle

      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...

    88. paul bragg

      See you later trump, I bet you're all super happy about that👍

      1. a man

        @Pliash Muldba Yep the acid from your fingers enters the porous granite and will affect it in whatever way, also a precision stone isn't a workbench and certainly not for setting warm laptops on.

      2. Pliash Muldba

        I was taught scraping during my first education, though in the late 80ties not many did that by hand. But a good way to learn what flat mean :-) You also see granite slabs like that on measurement machines, and the QC room guy will go mad if you even touch the granite.

    89. Aaron Belknap

      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!

    90. petemclinc

      Unless this plate is used in a temperature, humidity & vibration controlled clean room, I don't see the point in lapping it beyond "A" grade. Good video though, I appreciated seeing the difference in surface haze dullness during the lapping.


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

    92. BluetoothSensei


    93. Jim F

      I can't figure out what this granite surface plate would be used for. Anyone care to enlighten me?

      1. Jeffrey Lee

        By itself the surface plate has very limited use. By definition, the surface plate represents a very flat reference plane. Countless additional precision tools are available for use on a surface plate. Probably the most basic tool used on a surface plate would be a test or dial indicator stand. Vee blocks, angle plates etc can be used on the plate. Custom designed gages are used on the plate to hold parts for inspection. Precision height stands are used on the plate. On and on. Lance and company here use the plate along with straight edges to enable inspection of their scraping efforts. We don’t often see Abom or Keith inspecting their work by means other than micrometer, vernier caliper or scale. In a production grinding shop or milling shop, custom gages are often designed and built to inspect parts very quickly and efficiently using a surface plate and other basic tools on the plate. The plate can also be used to enable precise layout of parts made in a tool room or model shop.

      2. Bluegrass 23

        Most are high priced work bench's/storage/catch all

      3. Pliash Muldba

    94. Patrick Colahan

      I thoroughly enjoyed this, always wondered how they got the surface plates so true. A lot of skill and patience involved. Thanks very much for sharing this. I assume the rotating of the cast iron plates as he goes over the surface is to allow for the irregularities of that surface.

      1. Alexander W

        Check out Robenz channel as to how to rotate and move the plate

    95. Russell Erney

      Fantastically amazing process and knowledge.

    96. John McCormick

      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.

      1. felixar90

        They're levels. So you can put them on any 2 points. Then you turn them 180° around and you check if you hit the same value. I guess.

    97. Do RC

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

    98. De Montalvo

      Thats awesome

    99. Tim Mallard

      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!

    100. eric hoff

      What is used to clean the plate? Eric

      1. Perinne

        Probably alcohol