#GD

In this video I will discuss the basic rules of setting up a part using geometric dimension and tolerancing and to read a control frame. We discuss the definition of datums, the 3-2-1 rules and how a part is set up and inspected or machined. #gd&t
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[@infinitymfg5397]

For other videos on engineering and manufacturing subjects: Strength of Materials: kzbin.info/aero/PLAXJqmuqGEr7QjsVVyl5jFY6HQTqw6Bfq Metal Casting: kzbin.info/aero/PLAXJqmuqGEr4wiY6xroSK67CXeTu0Otmk Quality: kzbin.info/aero/PLAXJqmuqGEr4LQvNzKHGO9l00gEN4gmSP Design: kzbin.info/aero/PLAXJqmuqGEr706zgRtnwgQiFC5FYLvaTr Automation: kzbin.info/aero/PLAXJqmuqGEr6O_nQ-n08qmrtNnAUruj3b Calculus: kzbin.info/aero/PLAXJqmuqGEr7Ayo18H7tknyQAJu1OcoUW

[@TeW33zy]

Explanation is good. But its 2018 you should always show a live inspection vs alot of taking. Do a live video checking tru pos of that hole instead of talking. Talk less show more.

[@will1603]

@@TeW33zy Comment is good. But its 2022 you should always talk with an appropriate attitude vs being condescending. Be more polite instead of commanding. Rude less kind more.

[@birkanalismibulamadim]

do you plan to update your video according to ASME 2018?

[@63Ducati1]

The 3-2-1 rule doesn't restrict movement in all directions. No one can machine the part with those constraints only. The worst part of your example is that you have three datums and two basic dimensions that are from feature planes that are NOT the datums. You have no idea where the holes are located with respect to the datums because you are lacking the width and length of the part. If you are picking datums, you should probably use them for your dimensions, especially basic dimensions. Part of the problem with every GD&T lecture that I've attended or listened to is the fact that the prints are not complete. I want to see how you put EVERY dimension on the print for the people in the shop who must make this part. If the basic dimensions for the hole must be from a side that is not a datum, should the width and length of the part be basic as well, so that basic dimensions to the hole from the datum are ALL basic? Show me the print as it needs to be, not partials. Even Lowell Foster, arguably the father of GD&T, did this, and it drives me crazy. Datums on a post look stupid and take up valuable print space unnecessarily. I specify 14.5-1982 in my title block so I don't have to see the concessions made to the ISO community by the GD&T committee on my prints. What purpose does the post serve? Further, I would like to know the differences between 14.5-1982 and 14.5-2009. As far as I can tell, they are the same. Symmetry went away in 1992 but came back - I don't know exactly when. On the other hand, unlike the guy who said he is "dumber for watching this," even though I do not agree with everything, I did learn something from the video. I didn't notice the "snap, crackle and pop" of the sound.

[@infinitymfg5397]

Thanks for watching and your feedback!

[@MoharSingh-wk7qd]

Sir plz provide hindi vedio

[@173roberto]

I just didnt undersstand. With respect to datum A, how would I inspect the tolerance? actually that's something I want to know. How would I inspect that part if I had to measure it?

[@mithuns4302]

When you give 3 datums... it shows the inspector how to place the part while measuring THAT dimension. Rest on A align to B , anti rotate w.r.t C

[@eddcraft2260]

WHY are None of the dimensions given in relation to Any Datem?? The "A" has no relevance to the hole position, the "10" is on the far side from the "C" and the "16" is on the far side from the "B". Makes no sense to me.

[@ronmuse276]

I agree completely with Edd

[@somebodyelse6673]

First thing, that most of the information for that part is left off. I assume that was done to leave only the symbols that the Prof. wanted to focus on. My understanding of how "A" applies to the hole position, is that because the hole is actually 3 dimensional (a cylinder), the axis of the cylinder is to be perpendicular to plane "A". It made no sense to me until I got away from the idea that the view was a 2 dimensional drawing.

[@Fabtekcnc]

Edd is spot on. Terrible example "Professor" shame on you for adding to the confusion of GD&T. The primary "A" datum controls perpendicularity of the holes (cylinders), the "10" and "16" should be located from the datums B & C (or the datums need to be on the opposite sides where the dimensions are located from). it's fine that the "10" is not "Basic" and therefore it would be the drawing block tolerance which would apply not the positional tolerance, but for this basic lesson it probably should have all been basic dimensions located from their respective GD&T datums. It then would have been a worthwhile lesson . In the real world as presented it would force a call to the engineer and drawing change.

[@SS-lt7lk]

A,B,C in respect to What??

[@hellosweetheart3350]

Why am I choosing today to learn when I have a splitting headache?

[@obsidian9998]

Please continue giving more video. I like having the video's available for refreshing my ME major knowledge.

[@guillaumevincent716]

321 is amazing I am still in shock its a revelation I can understand now the order of datum and why they are so important

[@MeansOfProduction209]

To all the engineers out there. Please for the love of god, try to make the datum point something that's intuitive and easy to find with conventional calipers. Pleqse please please please, whatever you do, do not locate your datum off the theoretical center of a hole or radius Sincerely: a contract manufacturer

[@guillaumevincent716]

the 321 rules is a new concept to me its like if the clouds have moved and the light shined on my face.

[@thompsonolorede959]

This presentation on basic GD and T is great. The explanations are so clear, thank you so much

[@JoeyandAbby]

I’m in metrology and I’m having so much trouble trying to understand it. 😂

[@yourevolution7850]

Please remove that tik tik sound from background it is hurting to ears.

[@markcinco8405]

Just awful. Datum targets. No modifier? No diameter specified (or tolerance)? BOTH HOLES TO DATUMS, BUT NOT EACH OTHER? 20 years in Quality Engineering I've had to retrain engineers repeatedly in GD&T. Nearly every automotive, aerospace, and military drawing I've tried to use has blown it, primarily because of the extinction of EXPERTS in design known as Checkers.

[@infinitymfg5397]

Thanks for watching!

[@davidlourensz4822]

Hi, thanks for this video that you have put together. I have a few questions for you regarding it if you don't mind - I know little about machining and my questions might be a bit basic: 1. Why would the basic dimension of 16 not be measured from B, as B would be a sure reference to measure from? Why would basic dimension of 34 not be measured from C, as C would be a sure reference to measure from? 2. What importance in terms of tolerance would 10 play, it doesn't seem to have any mention? The surface that it is measured from might be rough and inaccurate when compared to the other official Datum sides (AB & C). Is it not important as to the position of the hole set (the two holes) in relation to the boundaries of the rectangular block it goes through - maybe that block doesn't need to mate up with an adjacent component accurately, but just for it to be attached using bolts? 3. The slide with the 3-2-1 Rule at time 10:02 for example, shows the Right Hand Rule and the 6-axes of freedom. The axes don't coincide in those diagrams (although I can mentally rotate them and see what's going on)...generally speaking, the z-axis is the vertical axis (elevation view) isn't it - thought I would mention this as I think most machine set ups would be with the z-axis vertical (is this the case in industry standards)? Additionally, I know this might not matter, but do you have a preference to which axis has the 3, which has the 2 and which has the 1 restrictions for movement? 4. Why is the term 'counterpart' used, what does this mean in this context - I would imagine it means equivalent part? 5. At time 14:51 it shows the ABC Datums in the control frame and you mentioned that A-Primary, B-Secondary and C-Tertiary need to go in that order and that set up, so even though, some other arrangement of the stops to hold the part in place on the machine would ensure it does not move and all freedoms of movement have been stopped, why would this order be important? Is it related to axis preference or some other preference? AB&C would all be trued up and equally suitable for datums (or are they not?) - is it to do with their specific machining tolerances? 6. The (2x) indicates the two holes I would expect. 7. To achieve a diameter accuracy of 0.001 for example instead of the 0.06 for the holes, would this mean using a more accurate drill bit/chuck/more expensive machine in practical terms - which would make the manufacturing of the part a lot more expensive? Thanks for your help. Kind regards. David.

[@SpaceValveGuy]

I don’t think your example at 5 minute mark is dimensioned correctly. Basic dimensions need to tie back to datum’s in some way. So you really should be dimensioning the “16” dim from datum B surface and and “10” dim should be also basic and from the datum C surface.

[@pabs000]

Correct, a basic dim is tied to a datum's feature of size tolerance.

[@MdubFrederson]

This is awesome, please keep making these videos. There aren't any good GD&T resources on the net and you're doing a great job of conveying the information.

[@infinitymfg5397]

Thanks a lot Mike Walling. Its great knowing that people are getting something out of these videos. Don't forget to share this video.

[@MdubFrederson]

No problem. Definitely got a lot out of it and I would love to see more. I've been struggling with setting up datums, especially when the important features are holes and are angled to one another. There doesn't seem to be enough info out there on using holes as datum features which is crazy considering how many things bolt together. It's far less common for me to want to use 3 surfaces as my datums. Anyway, keep up the good work!

[@seenasrinivasa.r9191]

Mike Walling

[@martingaribay8199]

Great training, could you upload GD&T tolerances for assemblies interaction.

[@houmadi2012]

I love your videos! Your delivery of the material is crystal clear which makes it relatively easy to understand the concepts. Please, please, please post more GD&T and engineering drawing videos. I'm struggling at work understanding engineering drawings and GD&T. Thanks!

[@infinitymfg5397]

Hi Sherri, I'm glad that my videos are helpful. Its people like you why I started this channel. I am planning to put up more videos, but the best way to make sure that you're not missing anything is to visit my new website www.theengineersreference.com/ You can get all of my updates and I will also start making my slides available to my subs.

[@marbrydav9698]

Your videos are excellent. I'm a Canadian Mechatronic Systems Engineering student reviewing GD&T, and you did a much better job in 22 minutes than my profs did in hours. Please continue to make more GD&T videos!

[@infinitymfg5397]

Thanks! I appreciate the feedback!

[@AnthonyClay]

3-2-1 had me scratching my head! I've been so used to CAD doing my constraints, I always assumed that I would never need to specify part orientation. I spent a few minutes confused by the datums but it finally sunk in: A references the back plane, which 3 points don't particularly matter. B References a (single) line along the top of the part, and C is any point along the right side. This opens up a better way to not just describe and manufacture my parts, but also the documentation/use of assembly jigs and part handling, thank you!

[@infinitymfg5397]

That's awesome!! Thanks for watching and the comment. I like that this video made something clear for you.

[@dilbertdude1]

One of the best, easy to understand descriptions I have ever seen! Thank you!

[@infinitymfg5397]

Thanks for watching!

[@JohnPaul-gh1fh]

Thank you for making this easier to understand..! Sure beats reading the flip book..!

[@SunnyKhan-zw1wh]

Very good explanation. If I can understand then anyone can understand which means the content is great. Thank you

[@parijatprabhudesai]

How come the dimensions do not start from datum planes? They're all from the opposite plane. Don't all dimensions have to originate from or be traceable to datums?

[@vythinathanduraiswamy3430]

Great introduction to GD&T. Please keep them coming. Thank you.

[@austinomonuwa8585]

Totally broken down! Thanks!!

[@soundevents7316]

Basic dimensions to the 2X hole features must originate from the datum features. Not an option, major fail for an instructor to present this. Explanation of the 3,2,1 part indexing / degrees of freedom indicates datum target simulation, this is misleading. The drawing requires planar datum simulation.

[@tonyderywosh136]

Cmm programmer here , wish i had seen this video when i first started. Well done!

[@infinitymfg5397]

Thanks! That's quite the compliment!

[@theantichrist6524]

I'm a WELDER by trade but have worked with CNC In the past milling parts I like the video would like to see everything related to topic thanks

[@infinitymfg5397]

Thanks! Its great that you got some value in the video.

[@darshanshanbhag7332]

Kindly prepare video lecture on complete Gd&t and tolerance stack up analysis. Its my humble request to you

[@orurenopapito]

Thank you so much, very helpful 😊

[@infinitymfg5397]

Thanks for watching!

[@marjokusormin570]

need tutorial GD&Tvideo implement to CMM program.

[@ssubashme]

Video AT 4.43 SEC, why basic dimension is not given from the datum. I believe the basic dimension to the hole should be given from the datum

[@infinitymfg5397]

Hi Subdash, You're very observant, the drawing is not perfect, but my hope that there is enough information to help people to understand how the datums are applied to the control frame.

[@ssubashme]

Thank you for the reply.

[@ObelixCMM]

They don't have to be dimensioned from Datum Feature. If the other side had basic from Datum Feature you could just subtract it.

[@DavidBrown-xe9mk]

GD&T cleans up linear dimensions. Thats the idea.

[@VivekAnandJ]

I have such doubts too. For example in the control frame, when tolerance is mentioned and later 3 datums are shown, doesn't it mean the tolerance is for the dimension w.r.t. the three datums? Sorry if I sound foolish. I''m learning

[@tjvanderloop1686]

Good Job with the 12-modes of motion or the 6-degrees of freedom...DATUMS are the key to any tooling set-up. Thanks! Thomas J. Vanderloop, Author, Technology Instructor & Manufacturing Contractor, CMfgE & LSME

[@thevegg3275]

Hi Professor Cummings at minute seven you talk about the 321 rule and you have 3A, 3B, 3C. you seem to refer to them as three datum planes…when actually they are the same datum planes… so why would you call them ABC when they’re all co planer?

[@jayosborne1565]

all your drawings seem to be in 1st projection. 3rd projection is a little more common here in north america

[@robertshreffler6155]

whatever it is called, his orthogonal projection doesn't follow USA standard. It is flipping to next view the opposite way we are used to. So I agree with you but we will just leave it alone to focus on his teaching GDT I guess.

[@Eyoutube99]

.06 tolerance on a machined component??? Yikes. Not a very reasonable example but appreciate you making the video. Maybe a video comparing an engineering drawing with GDT and one without so that people will have a direct line to understand benefits of GDT.

[@navib8845]

i love this, helps me to undersatnd gd&t better. thank you!!!

[@danaschoen432]

Please forgive me, but, since when is the "Z" axis not vertical, the "Y" out and in as viewed by the operator and "X" not right and left as viewed by the operator?

[@user-gj8ss2rv7f]

Ty Mr.Cummins 😎

[@infinitymfg5397]

You're welcome and thanks for watching!

[@johndickinson4600]

The part is not drawn correctly, according to Std. Drafting Procedures. Can't machine something if the part is not drawn correctly! Front and Top view are incorrect! However the video was very good.

[@thanhnguyen-lw6bd]

Part drawn in 1st angle projection! move top-view down & right-view to the left you will have 3rd angle projection.

[@sandeephasija8604]

Great Video thanks

[@thevegg3275]

One other thing that minute 951 you said that putting the part on the three points eliminates the ability to go up and down it actually only illuminates the possibility of going down you can still go up, so could you explain that please

[@potatoboris1534]

This is good content, but the audio... lets just say the quality could use improvement...

[@mattmelissaschwartz3854]

I thought a leading zero before the decimal point designated millimeters ( 0.01)

[@johnmchugh8088]

232 dislikes? seems like some people are salty.

[@infinitymfg5397]

Can't please everyone. LOL!

[@toolman95]

Surely the actual dimensions need to originate from the Datum, A,B not the opposite side as indicated ?

[@adelelamrani9245]

Amazing why cant you be my professor mines suck do you teach at any cuny schools in ny like the way you teach is so intresting catches my attention and goes straight to the point

[@infinitymfg5397]

Hello Adel the turtle! Thanks for the compliment! I currently teach in Cincinnati, Ohio. Its good to know that you got something out of this video!

[@adelelamrani9245]

Infinity MFG thank you so much we need more professors like you can you do more videos on this topic showing more tolerance and dimensioning and charts and explain tbe signs like for ex the m or L and stuff like that and practice problems would be nice

[@tejasjadhav5660]

Hello sir, very good & important information

[@haroldsimpson8422]

Doc, no matter how many tines I watch this same video, I continue to get value from it. Thank you sir, had you would have been my instructor back when I was undergraduate and graduate school I probably would have gotten my PHd.

[@infinitymfg5397]

Thanks. Comments like this are very motivational.

[@danielpipersburgh1740]

Very Helpful!!! I have my final tomorrow! Thank you so so SO much!!!!

[@infinitymfg5397]

Thanks for watching!

[@felipeperez-rp3rd]

I have a question about the theoretically exact dimensions, tolerances can be applied

[@srinivassomenahalli9457]

Very Informative -Thank you so much for this information please share additional videos on CMM Basics and measurements

[@infinitymfg5397]

Thanks for watching.

[@lisaliisforthebirds1918]

I noticed the holes are not dimensioned from the datum surfaces. Wouldn't you want them to be?

[@massgass9131]

i mocked up my resume to get an inspecting job..and it worked...now I'm going into this job not really knowing anything until i watched this..definately needed the 3,2,1, rule

[@infinitymfg5397]

LMAO! Good luck!

[@carlosvalverde2928]

English isn't my native tongue and I understood this better than my mechanical drawing classes

[@infinitymfg5397]

Thanks! That's awesome!

[@abhinavmalviya1]

Just what I needed! Highly informative video. Thank you so much.

[@infinitymfg5397]

Thanks! Its awesome to know that this was helpful to someone.

[@SH-bl9wh]

Big thanks. You have good teaching attributes. Liked. Subbed. Commented. Looking forward to see all your other videos.

[@StevenHaggis]

Silly question, but what is the diameter of the holes please?

[@prakhars440]

Nice explained

[@Kenneth_H_Olsen]

How come the thumb rule axis, has Y axis on the index finger ( pointy finger), and X axis on the thumb. But the drawings provided, and on usual 3D programs Y is the vertical axis ? Y axis should be thumb , X should be index finger. and Z the ring finger . What is the benefit of schematic inconsistancy ?

[@bigbfromaz]

Radar Blue the letters X, Y, and, Z are just Letters that we refer to in order to label 3 axes in 3D space. If you learn and understand the concepts, the letters you use to define the axes often become irrelevant. For example, when I make a design and make the drawing for it, I primarily use the labels A, B, and C to define the datum features that restrict the 6 degrees of freedom in the part. When I send it to a shop for manufacturing, they may load the parts in their machines in whatever orientation they choose to manufacture the part in. The machines will have X, Y and Z axes labeled, but more often than not during the manufacturing process, the part will not be oriented so that it identically match the machine’s X, Y, and Z axes. However, as long as the part is fixtured in the machine in a way that replicates or simulates the A, B, and C datum reference frame, it can be made correctly and repeatably. Once the part is outside of the machine, we can then measure the part itself to determine the part’s own A, B, and C datum reference frame and the other dimensions that result. If we both had CMMs to measure the part with, you may set yours up in a completely different orientation relative to the machine’s own X, Y, and Z axis. But, as long as we both establish our datum using the same A, B, and C scheme, we will get the same results when measuring the part.

[@Kenneth_H_Olsen]

@@bigbfromaz I understand ! I have worked with 3D software onscreen, animation art . And relative new to Mechanics, have never operated a CNC (or CMM) only manual lathe. The Datum are loaded into the software, and the Machine determines what is X, Y, Z . Thanks for a rich reply .

[@gototcm]

Dumb question. How do you know the dimensions are in inches and not metric?

[@infinitymfg5397]

Not a dumb question at all. Inches VS metric can usually be found in the title blocks of a drawings. See this video for help: kzbin.info/www/bejne/g2nJcnlmrbKreNU

[@lovefoolish2019]

a technician once told me if the plan doesn’t specify, that metric units rarely have more than one decimal place and that english measurements usually have 2 or more decimal places

[@stevencoons450]

You are using first angle projection not third angle....very confusing...totally distracted me.

[@femiosusa510]

Thank you.

[@diygarygaming]

This is why college degrees are becoming irrelevant.

[@infinitymfg5397]

Oh my goodness, I hope not! I still need to pay some bills! LOL!

[@thrashingmetal]

they teach it in college

[@Pawel_Szczudlo]

Very clear. Very precise. Without any unecessary additions. I will follow this channel closely

[@infinitymfg5397]

Thank you! Welcome to the channel.

[@stephenfischer5322]

Very informative and well done! I'm looking forward to your other videos for more information

[@sushantkumar2631]

this is the best ever video on gd and t ..i have ever seen on you tube.........thank you 10000 times for that

[@raghavendrapalekar6739]

Make videos on modifiers please

[@infinitymfg5397]

That is a good idea

[@littlehercules5716]

Thank you

[@subtle_info]

I really appreciate your effort and resources you provide thank you for making this video

[@infinitymfg5397]

Thanks for taking the time to watch and comment.

[@JOSECHAPAH]

Great video! Thank you very much, greetings from Mexico

[@infinitymfg5397]

Wow! Thanks! And thanks for watching!

[@ayushpatil4001]

Thank you . Extremely helpful.

[@silvius__5539]

Why 3A 3B 3C ON THE SKETCH? Shouldn't be : A1 A2 A3 / B1 B2 / C1 ?

[@nikj4351]

this person got so clear voice

[@infinitymfg5397]

Thanks!

[@Lisa-nz9bq]

Very well explained. Thank you for the upload Sir.

[@foadsf]

Your Twitter link is not correct. Would you be kind to fix it?

[@syrussmith6757]

First off, I'd like to thank you for making such an informative video! Could you please elaborate on the 3-2-1 rule a bit? Isn't the block still capable of moving along the "+" directions of all of the 3 axes? I mean, fixture 1 stops the block from moving along the "-" direction of the Y axis, but it can still slide in the "+" direction, right?

[@Andrew-eg3xn]

I am confused about this also.

[@sxoutz]

i believe you have to imagine the constraints being mirrored so the movement is limited on both sides!

[@vincefeldman7424]

Thank you very much for the videos! Can you please explain how the drawing defines the diameter of the circle?

[@jojiran]

No hole DIA ?This will not fly in the Auto industry

[@peteraguilar7181]

question when using an insert do I use MMC for hole?

[@agankachu09]

Why is the Z-axis not vertical to the horizontal plane?? In segment 9:09 I see Y-axis vertical to the horizontal plane. Is this a North American thing? Isn't Z-axis always perpendicular to the horizontal plane? I had a tough time getting my point across to an engineer in Ontario, Canada. I could make out he came from the Auto-CAD world (2D) where X-axis and Y-axis goes along the Length and Height of the monitor screen and Z-axis comes towards you - the operator. This is incorrect per me. There has to be some standard. To me Z-axis always directed towards the sky.

[@infinitymfg5397]

The orientation of the z-axis isn't tied to 'horizontal' or 'vertical' per-se. Typically, X-Y-Z and the left hand rule are centered on the concept of following the device (tool spindle, inspection probe, etc) That is what dictates the Z-axis, the X and Y axis depict travel relative to that. This is why you can have machines that are 'horizontal' and 'vertical', they are telling you the orientation of the spindle.

[@robertshreffler6155]

the teacher mentions Right hand rule in video, but L H rule in reply? the way I learned R H rule is simple, cross the X towards the Y and the Z will unscrew out of the plane. So that way you can place the XY plane at any orientation, and you expect Z to unscrew out of it. Take a look at a CAD screen and watch the results as spelled out here!

[@hildaguzman6287]

Please help i am having the worst trouble figuring out how too get all the dimensions on excel symbol font to create an inspection reports for my shop :( what font is it ??

[@infinitymfg5397]

I'm not familiar with this function in excel.

[@SaxyBerto]

Good explanation. The only comment I have is your orthographic projection is 1st angle projection. North America 3rd angle projection is most commonly used.

[@raghuram5977]

such a awesome explanation .. really I learned something what I need. But i have a doubt like . How profile tolerance get effect by MMC ?? I have seen in some blue prints asking profile with MMC !! seeking for your answer.

[@infinitymfg5397]

Hi Raghu, Thanks for watching and commenting. There are two modifiers that use the same symbol, 'Maximum Material Condition' and 'Maximum Material Boundary'; they use the symbol of an upper case 'M' in a circle. A profile tolerance is subject to MMB, this means that a surface is being treated as a boundary or datum feature (secondary or tertiary). This gives information to the engineer on how to design the gauge (datum simulator) so that the maximum material is accounted for. You can get more information on this from "Ultimate GD&T Pocket Guide" - 2nd edition on page 38.

[@raghuram5977]

Hi sir, So how bonus tolerance will add to the profile tolerance when some features called for profile with MMC.

[@tommywiseguy]

Even though the 3-2-1 rule is common for establishing a coordinate system, it does not satisfy ASME 14.5 for a DRF. In your example, you would need to use 3 perpendicular planes. Datum A feature would locate on the 3 highest points, Datum B feature would locate against the 2 highest points and Datum C feature would locate against the single highest point on that surface.

[@gulshangore7292]

very helpful video, but i wanna know the practical use of gd&t. plz share a kind of video in which i can learn gd&t practically through engineering drawings.

[@infinitymfg5397]

That's a good idea. I wanted to lay a foundation of the basic rules and then add to the series by apply it to a practical example. thanks for watching and the feedback!

[@mayureshkange6729]

Very informative video..!!! Thanks for posting it

[@infinitymfg5397]

Thanks for watching!

[@DavidBrown-xe9mk]

Datum Scheme is simple. Typically A|B|C = X|Y|Z X= FORE/AFT Y= CROSSCAR AND Z = ZED(UP/DOWN). Understand this first along with this video and you will get very basic knowledge. The fun stuff comes with datum targets, local alignments, and theoretical datum assignment for parts that are NOT round, flat, or square for example: an airplane blade or a shaving razor. Its called Curve.

[@JohnDoe_toetag]

Your audio is whacked. Stop fidgeting around or move the mic. Have to agree with other commenter. Your dimensions are not tied to your datums. Seems very strange. If this is your “go to” sample, it is ripe for improvement.

[@JitendraKumar-io4hv]

Please provide same as hindi best lacture

[@laxboi97]

you kinda sound like salman khan!

[@makismastro7533]

Sir ,the datums A , B, C are planar surfaces of the equipment.which has to be used for simulation.The points 3, 2,1 are the minimum ponits of contacts which the part shall have when it sets up on the inspection ot manufacturing equipment .This is what you are saying or I am wrong?thanks.

[@frink32]

Brilliant Dr. Cummings! Subbed and learning more!

[@infinitymfg5397]

Thanks for watching!

[@bucaddy]

I don't agree with the 3-2-1 rule, or maybe I misunderstood it's implementation. When measuring, you should consider the entire plane as datum A. If you only establish the plane off of three points and not simulated contact with a perfect plane, one of the three points could fall into a local peak / valley imperfection on the surface.

[@akashsaxena192]

is it always necessary to set the part for machining w.r.t datums because sometimes for example in case of a bearing journal and shoulder we machine them together while holding some other features but in drawings we still give perpendicularity for shoulder wrt the journal, probably a similar video for parts like a casing with bearing could solve my doubt.

[@peterwalter2034]

So exactly how far away are the holes from Datums B & C? Shouldn't the dimensions be referenced from those 2 datums?

[@ajaywantphull1434]

Good basic knowledge but can you please provide some knowledge regarding datums in relation to net pads resting, 4 way and 2 way for stamping perspectives

[@thirumoorthi.c604]

HI, In geometric tolerance, what is the definition of ø 0.06? is it plus or minus 0.2 ? or other?

[@MarcusWolschon]

Having the tolerance zone in imperial units instead of standard metric AND not having a unit on it looks very error prone. 0.06mm would be a perfectly reasonable tolerance.