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What is the function of a feature, which is specified by profil ISO 22081?

Hole 8.4, 2x 5 and slot at „B“ (two integral features) are fits at the same time against primary A.

2:05 I’m afraid the basic datum system A I B M I C doesn‘t follow function. The solution is A I B-C. MMC is not required.

希望冰衡中国继续上传教程！

thats a very dificult topic

Thank very much for this video. But in standard ISO 22081 it states that the only general tolerance can be the geometric surface profile tolerance . It does not mention the position tolerance. So is it also possible to create general geometrical tolerances in the drawing that differ from the surface profile tolerances? For example for a transmission shaft, put a general circular run-out with referred to the main axis ? In this way it is possible to continue using size dimension ?

Welcome back bro

Hi, I am having a hard time understanding why surface profile is used but not flatness? can you elaborate more on this? Many Thanks ! I learnt alot from your videos !

很多老闆/老師/設計者，都不了解幾何公差要先將特徵分成一般公差（沒有+-多少的那一種）及特註公差（有+-多少有基準等等），還要在藍圖右下角標示一般公差的要求（像 .X=+-0.5. /.XX=+-0.3. / .XXX=+-0.1),現在只能説大混戰，用嘴巴決定了品質，越混越回去

5:21 In this situation, instead of 0.3, what should be the value? 0.2 or 0.1 or 0.05?

我以為第一行是指孔徑大小+/-0.2 而第二行是中心相對位置不可超越0.4mm, 第三行是軸心的平行不可偏差0.2

Best video on the basic topic Ive seen yet! Thank you so much. When do you apply geometric tolerance principles to this example, the next video?

This is ignorant of ASME Y14.5 Rule 1: Envelope Principle. 2.7.1 Variations of Form (Rule #1: Envelope Principle) The form of an individual regular feature of size is controlled by its limits of size to the extent prescribed in the following paragraphs and illustrated in Fig. 2-6. (a) The surface or surfaces of a regular feature of size shall not extend beyond a boundary (envelope) of per- fect form at MMC. This boundary is the true geometric form represented by the drawing. No variation in form is permitted if the regular feature of size is produced at its MMC limit of size unless a straightness or flatness tolerance is associated with the size dimension or the Independency symbol is applied per para. 2.7.3. See Fig. 2-7. In other words, it’s implied that full form MMC boundary needs to checked on simply features of size with no other modifiers specified. Two point check will lead to misreported false data. Please do not post more misinformation online. It adds to the confusion.

love your video. thanks so much.

各位年輕人，幾何公差用在工廠，用心在工廠的工作再看幾何公差的資料才會有心得

幾何公差有很多基本觀念,以下請思考： 幾何公差在製造中的角色？到底是作甚麼用的？誰最該懂幾何公差？ 幾何公差是在製造零件（detail part)時，為保證後續組裝的順利，加諸於最低層零件的外形尺寸限制,也是機製件完工後，進入機工檢驗站品檢員放行零件的依據；你可以發現，幾何公差主要用於機工件，而且是最低層的零件，sheet metal 件，膠合件等幾何公差就少很多，因為這些零件不能算是剛體，也就是這些零件用幾何公差去控制零件尺寸是作不到的；如果你是老闆一定要注意幾何公差會大大的影嚮製造成本，尤其產品圖是你自己設計的，設計員不懂的幾何公差，加工成本會增加，設計員濫標幾何公差，操機員會造反，不懂裝配的方法，最終成品會一直出不來，設計員茫然不知是他的藍圖有問題，所以設計員是最該懂幾何公差而且要負責後續組裝的程序，當老闆一定要知道組織的功能，安排正确的人在正確位置上，賦與正確的組織功能，製造才能順利，不要一直駡人，算東算西，操弄人性搞政治 最後提一下組裝，在組裝時，有 I 件 R 件的概念，I件就是直接裝配，I 件上所有的尺寸都是作到直接裝配的狀態，不再有任何加工動作，像飛機發動機零件，幾乎是 I 件，R件就會有鑽孔/加大孔徑/修邊的加工動作，像有些人在飛彈或飛機蒙皮上直接標示 final size的孔徑，這就很明顯的嫩或混；幾何公差不是不好，但要懂它，不要濫用它；要懂裝配，因為機製件作出來是為了裝配，幾何公差是一種限制，老闆要怕它，設計員要懂它，不要濫用（像基本尺寸），尤其要負責藍圖上的東西，包括次組合的裝配都是你的責任，不要推說只要按 3D就沒問題了，大家知道嗎？ 3D在CAD/CAM上可以準到小數下22位左右，而且沒有幾何公差

怎麼透過判斷是同向還是反向去套用增減環?如果同向比較少 反向比較多 那哪個是增環哪個是減環 如果增減環反過來填寫出來的值會是 -16.5

Yeah, we usually forget orientation in stackup tolerance

There are some videos without sub, I can not understand fully. Hope you give us more videos in feature. Really like them, thank you

Your videos are really practical and informative

Wonderful. Simple but effective teaching. Thank you so much for spreading knowledge. Keep it up. 😊

Can any one please clarify my doubt if all the dimension are in positive tolerance that means 27+17+16+20 then the sum of all will be 80 but the over all length is 74.5+/- 1.5 only that means 76

買老師的課程有問題可以請教老師嗎

老師講得蠻好的，增減環和公差是以中心值加減公差，最後經過計算可以得到

请徐老师继续上传视频。

Nb

Hi Kraig. Great information. Thank you. I am familiar with the use of UZ modifier when it comes to Line Profile or Surface Profile. But how about with a True Position? In my company we use an ISO standard and we see more and more True Position with UZ called out on prints. For instance: TP of a plane |0.1 UZ +0.05|E (Plane datum E). I understand the theory behind it but I cant find a way to program it in our Zeiss CMM using Calypso. Any help is highly appreciate.

Thanks

看懂了吗？

Good job

Come backkkk

In the tolerance stackup table, there is mistake. In tolerance column there should be +/-0.2mm but you kept +/-0.4mm.

Hai sir i have one doubt in case for uz value will be negative means how could we calculate, Eg: uz - 0.1

请上传更多视频！

請教 Page 8, 答案是 "存在干涉" 是嗎?

Great video. Example needed. How will tolerance be modified by B hole and C slot both at MMC.

老师有一个疑问麻烦指点一下：如果测量带方向的话，最下层这个0.1体现在两个圆心相对位置是±0.05还是±0.1？

Thank you, this is extremely helpful.

Good presentation. Easy to understand. 👍

Thanks Kraig, suppose while manufacturing these two hole and shaft , regarding hole AME chart and Shaft AME Chart which one is correct combination ,if it is bolt means need little clearance , If both are at MMC chance to meet interference . could you any clarification.

請說中文，謝謝您

照圖例看起來，輪廓度跟圓度差了上下0.5? 這樣輪廓度並不包含圓度吧? 不過輪廓度比圓度更嚴格倒是真的

Thanks for well described

Great content! 🙌 I would appreciate more knowledge like this, thank you!!

Thank you sir, very interesting. While using positional tolerance attached with MMC(M), suppose the part is produced at MMC , means there is no departure to LMC ,not permitting bonus ,so in that condition how will be the function of fit effecting at assembly with mating part. Is there clearance fit or transition fit. Also how to mention location clearance fit (H7/h6) and Push fit (H7/k6) with dimensions. kindly reply.

Thank you for this video. Very useful.

I can't understand the phrase to choose 8.8 dia?

Kindly a request , could you do this lesson in English. Very interesting.

Not clear sir

Can't find the excel sheet in comment section