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Margaret Robertson
เข้าร่วมเมื่อ 5 พ.ค. 2017
วีดีโอ
How to find and use Google Shared Drive
มุมมอง 17211 หลายเดือนก่อน
How to find and use Google Shared Drive
MD20c offset dwg in CAD w cutting plane line
มุมมอง 74ปีที่แล้ว
MD20c offset dwg in CAD w cutting plane line
Welcome video syllabus and using Moodle MD 2023
มุมมอง 125ปีที่แล้ว
Welcome video syllabus and using Moodle MD 2023
How to find and use Google Shared Drive
มุมมอง 2002 ปีที่แล้ว
How to find and use Google Shared Drive
Please tell me the manual maths calculation also ❤oh dear❤
There's more detail about that in two videos, "ME02d keyways - help for assignment 2 - smaller shaft and hub" and "ME02e keyways - help for assignment 2 - larger shaft and hub."
That is so nice for you to share this amazing vedio. Is the PDF handout still available?
How kind. You are very welcome! I'm sorry--I looked but I cannot find it.
Hello Margaret, thank you for lucid explanation. Really appreciate your work. I have a doubt. Flatness tolerance zone is two parallel planes seperated by flatness tolerance value and its location is not fixed. But where does the tol zone exactly lie? (since we dont have datum for it) In other words, in the table example, where does the top plane of tolerance zone lie? Lower plane will be at distance of tolerance value, but confused as where does the top plane lie. Hope you've understood what I am trying to ask.
Thank you, and you are welcome. Imagine the tolerance zone as a set of 2 sheets of clear glass, stuck together and floating in space. The set of 2 sheets of glass can be located anywhere and they can be tipped at any angle, as long as they are completely inside the size tolerance. In the table example, the top of the set of glass sheets could be located as high as 31". Or the bottom of the set of glass sheets could be located as low as 29". As long as they don't stick outside the size tolerance zone, they're correct. You're controlling only how flat is the surface, no matter how high or low it is and no matter at what angle it is oriented.
@@margaretrobertson8848 Thank you for replaying. What I have understood is - Tol zone should not violate MMC /LMC boundary. But still my question is - where does top plane of tolerance lie in the available space? Is it like that top plane is tangential to topmost peaks of surface variations ( off course not violating MMC boundary) and lower plane is at distance of tol value from top plane. I have similar kind of query when we apply perpendicularity tolerance to surface. Here tol zone will be two parallel planes separated by tol value and perpendicular to given datum but again WHERE??
@@adityabhargav1830 Flatness controls form only; it doesn't have a datum. So the tol zone can lie ANYWHERE within the MMC/LMC boundary. And you are right, the plane would be found by being tangent to surface peaks. It is not easy to inspect. Perpendicularity does use a datum. It is easier to inspect.
@@margaretrobertson8848 Thank you for clarifying my doubt. So is it okay to consider the same when we apply perpendicularly or angularity to surface? - tol zone within MMC LMC boundary and top tol plane tangential to highest peaks of surface variations
@@adityabhargav1830 Yes. And perpendicularity and angularity are inspected relative to a datum.
Your video is so quality in every second, thanks. I have a question, Is there a situation that we can only use angle but not angularity.
Thank you. You can always use regular dimensioning without GDT, like dimensioning an angle, and you can put a tolerance on your dimension or let it use the tolerance in the title block. But that gives you a fan-shaped tolerance zone. If you want better control across the whole surface, and with a tolerance zone that stays the same thickness throughout, you can add an angularity control.
Thank you!
Thank you!
My pleasure. You are very welcome!
Great video Margaret! You explain this so well and so patiently. Thank you!
Thank you, Roi!
Madam, it is very good teaching GD&T. 2:37 How to make gaga pin for whole pattern hole with pin gage dia .237, do have to still keep the centre main gage pin at (vc) .988.Because mentioned B at M in FCF of pattern hole. So at inspection can make both pin on single gage datum A ,at a time. Kindly reply.
Thank you. Yes--the six holes are specified at MMC and datum B for those holes is also specified at MMC, so you would make the center gage pin at VC of .988, and you would make six gage pins for the holes at their VC (MMC of .245 minus tolerance of .008 = .237).
@@margaretrobertson8848 thank you for your kind reply
I loved 10:10 and 10:31 and got a little giggle! Trying to do wood working for this to make a giant pinion door with 9 teeth and a rack with 9 teeth. And this is helping a lot.
Cool. I'm glad this is helpful!
I loved 10:10 and 10:37 and got a little giggle! Trying to do wood working for this to make a giant pinion door with 9 teeth and a rack with 9 teeth. And this is helping a lot.
Thanks for the video! As a fellow Oregonian who lives in the Cascade foothills I use this method as well. Every evening cool air comes down to the valley from 6000' and flows through my N/S orientated house. Only had to use the heat pump last summer during the weeks where the wildfire smoke was in the hazardous category.
I tried this formula but correct for only 90degree angle not for other angles to find exact bend line
I want quick calculation because in interviews they usually ask to calculate bend line
What would be the Circumference formula for different angle other than 90 degree?like 45degree,122.5degree etc
Good question. Circumference / (360/angle). For example, 360/45 = 8. That is, 45 degrees is 1/8 of a circle. So for a 45 degree angle, it's circumference/8.
Im curious about closing the windows during daytime. If we close the windows, wouldnt there would be no air circulation?
Can you show real world application of this to multistorey compact houses in hot cities. Thanks.
You need to be in the kind of hot climate where it is markedly colder at night. So, a desert climate is perfect, and a tropical climate is not. It will work in a temperate climate, too, if the urban heat island effect isn't too great. Then you want thermal mass to absorb heat: concrete, stone, etc. Try doing an internet search under "night ventilation" or "night flushing." See if you can get "Heating, Cooling, Lighting: Sustainable Design Strategies, 5th ed." by Lechner from your library. It's super helpful.
I wonder if this can be applied to multi story smaller, compact houses in the city. Wish you can show samples. Thanks.
It probably could. Try doing a google image search, and you will probably find a bunch of examples.
"Hall of Shame" award. I'm glad that exists, and I remember certain parts of San Francisco that were similar. Too hot in the summer, too cold in the winter, and people barely used those areas.
Hi Margaret, if a feature was respected with a compound datum A-B, does that mean the feature needs to be within the tolerance zone from datum A and datum B at the same time ? The purpose of using datum A-B instead of using datum A and datum B separately is making sure neither of them has precedence over the other?
Yes. The two datums are used together is if they are all one datum. You can imagine a line that connects the centers of A and B, and that is in effect the datum. You use compound datums with parts that rotate. The inspector puts the part into an adjustable gage.
thanks
You are welcome!
I just found your channel today and I'm in love. You cover so many subjects that are of interest to me. It's a real treasure trove!
How wonderful of you to say so! Thank you!
Thank you
can I suggest the break lines at 11.57 don't truly represent the distance between the previous and next tooth down the line , they show the distance as at the end of your rack.we always used this " cutting " technique when drawing long axles and shafts on an A4 format .sometimes several break lines at different diameters were needed for the lathe operator to turn the piece .I like the explanations all the same.
Good catch. Yes, I agree with you.
Hoping for your contact info because I need someone to help me design a rack and pinion gear system...
Hi Louis - I am afraid that is beyond something I can do. Have you looked at the video "ME05 rack & pinion gears?" It's rather general, but could get you started.
I'm sorry, this video was years ago, but I need to clarify. I am very confused as to why the unit for deadload of joist is in psf. Thank you!
The problem (from a textbook, by Onouye) gives the dead loads of each kind of element in pounds per square foot. He is saying that if you look at a section of joists in this building, every square foot of that will weigh 3 pounds. You could think of the "joists" section as being a solid slab of joist material. The joists are 2 feet apart, so each lineal foot of joist carries TWO square feet of weight. You might want to have a look at the video "Struc24d load tracing - tributary area quiz;" at the beginning it might give a little more detailed explanation--for the rafters instead of the joists, but it is the same approach.
Actually, what would be of more help is the video "Struc24b tributary area." It is rather short, and it shows you how the tributary width, or load strip, is always halfway between supports.
Thank you for your big help, ma'am Margaret! I didn't thought I would get a response right away! I'll get to the video that you said. Thank you very much!
@@eliesebanta8145 You are very welcome! I hope that it helps!
Landing is requires at every 30’ according to addag
(Or every 40' for slopes 1:16 to 1:20) Thank you very much for taking the time to comment. I will correct this.
@@margaretrobertson8848 thank you. I was unaware of that. Would you please let me know where I can find that information in ADA. Thanks again.
@@Mytraism It is a little indirect. ADAAG 2010, section 4.8.2 says "The maximum rise for any run shall be 30 in (see Fig. 16)." Then FIg. 16, "Components of a Single Ramp Run and Sample Ramp Dimensions" shows a table. For a slope of 1:12 to < 1:16 with a max rise of 30 in, it notes max horizontal projection of 30 ft. For a slope of 1:16 to < 1:20, it notes max horizontal project of 40 ft. If you calculate how long is the base of a triangle with a height of 30 in. and a slope of 1:16, you get a length of 480 in. or 40 ft.
@@margaretrobertson8848 thanks so much. I was totally unaware of that!
@@Mytraism They don't make it obvious. And thank you again for your help, too.
Max allowable riser is 7”, thread is Min 11 in interior applications according to Ibc
Thank you. I had some old data in there that I should have changed by now.
@@margaretrobertson8848 I like your lectures a lot. I have looked at half of them today and will look at the other parts soon. 7 3/4” risers are used in residential single family and are allowed by IRC.
@@Mytraism Yes. Thank you for your very kind words!
@@margaretrobertson8848 I also wanted to mention that I find your selection of contemporary building examples to explain ADA ramps really helpful. I learnt a lot from it. I also didn’t know how much of ADA is geared towards wheelchair users and not enough towards others with other types of physical challenges. The definition of disability you presented was the first time I had ever seen. I am looking for more lectures on sustainability design. If you know of any resources that I could use please let me know.
5:03, based on the rule 1#, the form must perfect at MMC, why we still can make the tolerance of the pin's OD(±.002) tighter than the perpendicularity which is called out by .006. Hoping for your answer,thanks in advance.
Perfect form at MMC is the size of the envelope, the hole within which the pin must fit. The pin can be smaller, and it can tip. As long as it fits within the hole, that is all that matters.
Hello, MMC has a benefit to get an extra tolerance, at which situation we must use w/o MMC?
Bonus tolerance only happens when a geometric tolerance is applied at MMC, that is, when there is an M in the feature control frame. When an actual part is any size other than MMC, you get a bonus tolerance. The amount which the actual size departs from MMC is the amount of bonus tolerance you get.
@@margaretrobertson8848 thanks for the feedback
how to specify the tolerances on tooth thickness in spur gear case ?
Give tooth thickness in a gear cutting data table. (Machinist will use that to set up the gear-cutting machine.) You can give tolerance in drawing title block, in a separate note, or directly on the tooth thickness in the data table. Standards for selecting tolerance classes are in American Gear Manufacturers Association (AGMA) handbooks.
Your GD&T videos are really great, if you had separated the viedos form other courses, you would have got more viewers.
Thank you!
Hi, why circularity cannot be applied with a MMC modifier ?
Good question. Because circularity is a surface control, which means it is applied regardless of feature size. It is measured by contacting the surface, which requires specialized equipment. That is why it is not used often.
Thank you so much! I have a set old permit drawings, trying to understand and figure out what I want to do with my backyard, this is amazing video!!
You are very welcome! I am glad this helped!
i love you this has helped me so much!!! thank you
That is really good to hear. You are so very welcome!!
useful
I am glad to hear that. Thank you!
Thank you madam for detailed explanation. It helps a lot.
You are very welcome!
Great explanation i understand very well thank you ( my English is not good but you made the information come to me 👍)
Thank you very much!
Thanks
So yay haha ⛰️🤖 💭
your channel is a gift! thank you for sharing all the lessons!🥰
Thank you so much.
Thank you for this video. I am in an online school for GM and they don’t do the best job explaining the material and no class room videos or nothing. You helped me a lot! Will save this for reference. ❤
You are so very welcome! It is really good to hear that this helped you with your class! I hope you have found some of the other videos about various mechanical drawing topics--there are a whole bunch of them.
Thank you for this. Finally an easy explanation of aluminium grades
You are very welcome!
So simplified and clear. Thank you!
You are very welcome!
Thanks 🙏 May I recommend creating playlists for your videos?
You are welcome. Good idea. Go for it!
Great info.
Thank you, Hector!
Thank you
You are welcome!
I visited Zion N.P. in summer 2002 or so and was fascinated by the cool air coming down from the towers into the visitor center. They are downdraft cooling towers. There are pads at the top that are sprayed with water. The cool moist air then sinks down the chimney and into the center. I stood next to the "fireplace" opening and felt this wonderful cool air coming out. I live in PA where it's too humid for that method to work.
Thank you for sharing your experience there. That is very cool!
What this "inch" stuff you speak of? I'm kidding... great video
Thank you!
Thank you so much Mam. Your videos are very much useful to learn GD&T basic concpets and put it practice in our regular work. Could you please share your videos on GD&T Straightness, Circularity & Cylindricity as I have seen GDT Flatness video only in Form tolerances category. Appreciate your great work and keep up the good work!
You are very welcome! I am sorry, but I have not made videos for the other form tolerances.
thank you Margaret Robertson
Great information
Thank you!