Video není dostupné.
Omlouváme se.
GD&T ASME Y14.5 Fundamental Rule “A”
Vložit
- čas přidán 2. 05. 2021
- I discuss fundamental rule “A” from ASME Y14.5.
This rule specifies which dimensions require tolerances..
Spoiler alert......all dimensions require a tolerance.
I describe where to find tolerances if they are not directly applied to a dimension.
This is a great explanation! I remember once as a young engineer I prepared a drawing and called out that I wanted the hole diameter to be clearance for 1/4-20 on a part. I put it in a note and thought I was all set. Lucky for me, I had a boss / mentor who saw the "drawing" before I sent it to the shop. He explained to me that it was the engineers job to specify the size and location of the holes... Since then I've become a machine shop owner and a professor. When a student screws up a tolerance spec it might lower their grade. They learn a lesson about doing better work, and I learn a lesson about doing better teaching. When a customer screws up, and we don't see it and call them to ask for an updated drawing, the question becomes who is responsible for the $25,000.00 mistake... (You can really put the decimal place any where you want in that number.) In my experience as a job shop owner is, I cannot make it right I loose the customer. It is important to realize the person receiving the drawing is also responsible for knowing if they understand it and if it is clear.
Hi,
I totally agree. Any extra work in the design phase pays dividends when the part goes out to be made. Another phrase I really emphasize in preparing drawings is “read what you require”. I can’t expect students to read standards like ASME B1.1 Unified Inch Screw Threads in it’s entirety, but I hope they at least know where the relevant passages are in machinery’s handbook.
Thanks for the thoughtful comment.
Thank you, for us the self though, having reliable information is critical. Appreciate your time to make the video.
Great to hear! Thanks for leaving comment.
I can't stop praising your video, it is super informative and pragmatic. Thanks a lot for making this video..Thumb Up!!
Awesome to hear, I’m glad you found my video helpful!
I'm trying to understand how does fundamental rule A apply to the following - typically tapped holes have some portion of the diameter left by the hole drilled before tapping, somewhat deeper than the thread. Does "Each feature shall be toleranced" mean it is mandatory to specify the tap drill depth (not the depth of thread!) dimension and tolerance? And what about the size tolerance for that portion of the hole, and the location tolerance for this feature? It's a separate feature and not part of the thread after all. Or maybe some of this is defined in the standards that define the threads? What part of it is up to the drawing maker to specify to truely have "each feature" toleranced?
Great explanation😊
Thanks so much!
Well done Prof O'Dell
Thanks for the support!
Great explanation Sir,,
Thankyou!
Dean, thank you for all these great videos. GD&T is a tough language to learn. Your videos are helping a lot.
I went ahead and bought ASME Y14.5 - 2018. I'm now going through it one chapter at a time. I also just finished the AGI Fundamentals and Advanced GD&T courses. I also own version 29 of The Machiner's Handbook.
But, what I don't have is a Machinist's background.
Question: Do you have any videos that would provide information on the type of tolerances that someone could easily get with different manufacturing processes? For example, when drilling a hole with a drill press and a sharp drill bit, what kind of +- should I expect to get there? How about the Perpendicularity for such drilled hole?
Another one would be: when specifying a Flatness tolerance for a surface, what kind of flatness tolerance is easily achievable and which are more difficult for machinists?
I think such a video would help someone get a feel for what can be built by a machinist.
Thanks in advance. Keep making these videos. It's just great.
6:53 I have a question on the drawing here, how can you qualify the datum A on the drawing? Thanks
Could we have the cola drinking bit in speedy motion as a permanent feature of your videos?
Thanks for the support! I’d consider it, but I think Coca Cola already owes me for the product placement. I will have to send them a bill for putting their product in front of tens of viewers.
The cola bit is so flashy that they won’t pay up, don’t you think?