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.

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.

My pleasure. You are very welcome!

Thank you, Roi!

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

Cool. I'm glad this is helpful!

I want quick calculation because in interviews they usually ask to calculate bend line

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.

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.

It probably could. Try doing a google image search, and you will probably find a bunch of examples.

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.

You are welcome!

How wonderful of you to say so! Thank you!

Good catch. Yes, I agree with you.

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.

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!

(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.

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.

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.

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

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.

Thank you!

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.

You are very welcome! I am glad this helped!

That is really good to hear. You are so very welcome!!

I am glad to hear that. Thank you!

You are very welcome!

Thank you very much!

Thank you so much.

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.

You are very welcome!

You are very welcome!

You are welcome. Good idea. Go for it!

Thank you, Hector!

You are welcome!

Thank you for sharing your experience there. That is very cool!

Thank you!

You are very welcome! I am sorry, but I have not made videos for the other form tolerances.

Thank you!

May it serve you well into the future.

Thank you, Rich!