GD&T Position Tolerance Lesson 1 - NO MATH
ฝัง
- เผยแพร่เมื่อ 28 ส.ค. 2024
- Thanks for taking the time to watch what is quickly becoming the most popular GD&T channel on TH-cam. The ad revenue alone doesn't begin to cover the time and effort that goes into making this content. Please help keep this channel going with a per-video subscription to my Patreon account:
/ quintcrispin
Or consider a purchase of my study guide: (it's 50% off right now)
www.build2lrn....
Or a one-time donation to my PayPal account:
qcrispin@gmail.com
Thanks and good luck learning GD&T
- Quint
As a student going in to the second term of Machine Manufacturing Technology at PCC, I can honestly say that this video series is and will be like gold. The faculty members should consider having these added to the GD&T syllabus. Thank you!
Quint, these videos are absolutely amazing. I swear I've been checking TH-cam every 6 months for the last 6-8 years looking for good GD&T tutorials. Please keep going. There is so much to cover and you are doing an incredible job. I would gladly support your videos on Patreon or something if you keep pumping them out.
One of the best explanation on virtual condition. we TH-cam community thank you wholeheartedly for this amazing work!
I followed each and every video of yours & learned the basic GD &T clearly without spending a penny, thank you Quint for this post. I wish Our would have explaining skills like You.
Thank you for putting these videos together. I'm watching the first one now and plan on watching all of them.
Your explanations are by far the best and easiest explanation I have ever seen! Thank you for making this video!
I finally understand what the heck is a [basic dimension] and why it's confusing.
0.) You still use the +/- tolerance for the hole feature "for size". So, if hole is too large or too small it's rejected. Now, we continue to the issue of "position".
1.) Basic dimensions is really a "short cut" to move the horizontal and vertical datum reference edges/surfaces to a single coordinate point[x], [y].
2.) It's a "shortcut for calculation" and presenting the tolerance zone "for the hole center=hole coordinate" as a simple "datum point" and the tolerance circle.
3.) However, you still need a pin gauges and you still need to measure the x and y from the gauge to the datum edges for x and y.
The amount of effort put into this series is insane. Most people would have just done some nearly-good-enough computer animations. What a great thing to have made.
Thank you, Quint! This is nice and simple, perfect for those of us who get lost when you leave too much to intuition
Really appreciate your effort put in to do this video. It gives a far better understanding on Position Tol
Wow this really made virtual conditions hit home with me. Great video thank you
I have to do a training session on GD&T, specifically position and bonus tolerancing for people with no real background in it and I think this is going to be a big help. thanks for doing these!
you prolly dont care but if you are bored like me atm then you can watch all of the latest series on InstaFlixxer. I've been binge watching with my girlfriend for the last weeks =)
@Grayson Jeremy Yea, been using Instaflixxer for since december myself :D
The best explanation I've found of GD&T. Great videos! Already subscribed! (Going to binge watch this series now)
I like what you show at 12:27. That is exactly the virtual condition for an internal feature(hole).
Big diameter(that encircles red and gray circles)=drill hole feature range
Red diameter=diameter from tolerance of straightness, circularity, true position,...etc. This in effect "takes up hole space".
Gray circle=virtual "pin gauge" that can fit.
Thus: Diameter(virtual condition, gage pin diameter) = hole diameter(MMC) - diameter(of slop like straightness tol)
The hole analogy is a little "counter-intuitive" than the scenario of external features, because it get's smaller.
For the external feature it's more intuitive, which is virtual condition = diameter@mmc(largest) + diameter(of slop)
Cool. I have been highlighted. This means I'm on the right track. There's no one at work who knows this stuff, so I can only rely on our friendly educated cyber community. Keep on.
Thats some quality video. I'll definitely suggest to my juniors.
Awesome visual representation
No math....Very well explained thank you..
Clearly explained!
Thank you!
Beautifully and clearly explained the concept Thank you for that
Thanks Teacher🙏
Great efforts 👍 thank you for video
Sir, I'll take my hat off to salute you. This video is gold
really great explanation...no one can explain in such manner... thanks sir
there are many vieos about GD and T and i cant understand a sinlge of them, but i do understand after seeing this video, good job man
Really clear descriptions! Thanks!
Fantastic video! Thanks for taking the time to share your knowledge.
100 points for preparation, good video. Thank you sir
your explanation method is very easy and understandable, thank you ,
Nice work with the explanation dude, thanks a lot for that.
really appreciate your work man
clearly explained
Informative and well demonstrated.
With the addition of the tolerance zone (bull's eye) to get the size of the hole, you lose the press fit nature of your parts. Correct???
Thank you for making this video!
Thank you very much for explaining in that manner.
Thank you sir .You have thoroughly explained the concept.
I'm going to watch all of the videos 🙂.
Good one...Thanks a Lot !
That was nice explanation.
you're the best
super sir
awesome
Amazing!!
Thank you
Thank you!!
So if I am not mistaken, shaft diameter + position tolerance = virtual condition and Bore diameter - position tolerance = virtual condition? Also, I am assuming the hole and the peg shares the same position tolerance at the dead center location. Is it possible to have two different position tolerances? Finally, does the term virtual condition simply means that that there is a theoretical or invisible point where the peg and hole makes contact? Sorry Im self learning.
thanks a lot
Way too long explanation!!!!! Simplyfiet!!!!😥😥😥😥
Amazing video, very informative. Are you able to do one on one GD & T training through skype. I know it wouldnt be free but I really need to get a clear understanding of how GD & T operates. Thank you in advance
One thing that I find that helps is to read "older" GD&T textbooks, because when it was first introduced in 84 they really tried to illustrate very useful sketches. In addition, really focus on terms and definitions. All the more recent textbooks try to "optimize" the written english language to be "lawyer tight"...which doesn't help beginners visualize a full/accurate mental picture.
Thank u lot for Ur valuable work 👮
If the pegs and holes hits their theoretical true positions (center center of bull-eyes), then will the fit be loose?
Hi, I have a question
I have a sketch of a structure composed of three sheets metal, one of them is used as based, and the others are above of this one, separates for a specific distance, these two have an orifice plate with the same diameter and they are concentrics. When the welding is applied to the structure, then the assembly will have distortions, and the two orifices plates won’t be exactly concentrics. I would like to know if there exist a minimum tolerance when you're going to apply welding between hole to hole? For any assembly with the same specifications. Something like a table, a thumb rule, handbook or any document that specify some specific tolerance.
nice explaining, how do you find/ calculate the virtual circel ?
Diameter of virtual circle = diameter of hole(MMC...the smallest) - diameter of slop(like straightness tol value at mmc). This may sound confusing, but if you draw everything out...but especially the gage pin(virtual condition) that will fit it will make sense.
Thanks!
How do you calculate the "bullseye" size?
I have used tolerances for límits and fits and I choose them base on what the book says now how do you decide the geométric tolerance for something? Is there like a rule or something?
can someone can clarify why moving the hole relative to the peg makes the zone smaller?
Can you please message me, i need to teach this to my juniors since this is not included in our syllabus. Some help will be appreciated. Thank you.
super
did you consider the size tolerance of the hole and post?
So the position tolerance within a GD&T control frame is from one side of the bulls-eye to the other? Or from the middle of the bulls-eye (theoretical dead center) to the outer edge of the bulls-eye?
@@quintgdt8751 Why do they put the diameter of lets say .030 into a control frame if the part can only move from the theoretical center to the outer edge of the bulls-eye ( .015 ) in all directions? So a person always divides the location tolerance in half when measuring for quality control?
@@quintgdt8751 Right that is what I am doing now. I am putting a hole in a part and I will have to calculate the side of the hole to the edge of the part to find out if I am within the .030 which is in the tolerance control frame. And you are saying that number is the amount of movement BOTH ways from the center. Or the diameter. Even though the part is only allowed to move .015 in all directions to be in tolerance.
Great
Later after half part was very confusing!
18:33
Thats what she said.
incase if it is with a numerical example it will be clear
If you can commit to a range as stated at min 9:07, what if variation makes it so you cannot commit to that range? You couldn't commit to a bullseye but some how magically you CAN commit to a range that assures being acceptable?
@@quintgdt8751 Not yet, is my answer in that video?
@@quintgdt8751 I'm just trying to get to the heart of the explanation. Essentially what prevents going outside of any tolerance. What if the drill is accidentally set to repeatedly be on out outside edge of the bullseye? Then you'd still have many outside the red due to variability. And so on no matter how large the red bullseye is. Do you kind of understand my question? Thanks
Quint Crispin Rather than use GD&T on parts to make things fit, why not use it on the parts of the machines that cut and drill. Then you could just use basic dimensions on all drawings. Big money saver.
@@quintgdt8751 Oh right! I think what would help would be a video of sketch concept to CAD to manufacturing to verification of a part with a hole to show how position is verified and with another feature that requires A,B C datums. Showing how tolereances fail but GD&T succeeds in reducing scrap, etc.
How does one come up with the position tolerance itself? I know there is
limits and fits for holes and shafts are there charts one can use to
come up with the position tolerance itself thanks.
@@quintgdt8751 Thanks, If i may ask a fallow up question have you ever heard of using formula like the fixed-fastner and floating-faster formulas to get a simple position tolerance provided one already figured out the limit and fit. here is the formulas i'm referring to
images.slideplayer.com/36/10590168/slides/slide_73.jpg
My experience in mfg is trial and error, but companies don't always learn and apply correction. My best case experience is as follows: 1.) R&D being so preoccupied with function of product assumes best case scenario of all the fastener joint position/hole sizes with tight tolerances. 2.) We get the actual parts/they don't fit/we break out the drills. 3.) If we have some time, we may actually carefully measure all the first article parts. 4.) The measurement data can now be easily calculated for average or mean deviation and compared to the drawing dimensions. 5.) Next time we design position and hole size we have a "real tolerance" to apply.
I hope the voice is not by Kevin Conroy's Bruce Wayne...😂
Are you colour blind?
Or am I? 🤨
Quint Crispin oh ok, didn’t realise. Thanks for the response. This made a lot of sense and works really well (the video I mean)
Thank you