GD&T ASME Y14.5 Bonus Tolerance vs Datum Shift

I show what MMC modifiers mean in different areas of the feature control frame.
I discuss the difference between bonus tolerance and datum shift according to ASME Y14.5
#ASME

[@robertchurchill3485]

I've taken a lot of instruction on G,D&T but this video is exceptional.

[@RDeanOdell]

Thanks so much! I’ve endured some GD&T training as well that I didn’t enjoy, so I try to do it a little different than the typical presentation.

[@robertchurchill3485]

@@RDeanOdell You are so welcome. Specifically, the explanation on the inspection criteria is vitally important and left out of a lot of instruction.

[@robertacevedo449]

Your videos are.the best it allows a machinist An example of how to check parts.thank you

[@RDeanOdell]

Thank you so much! I’m so happy to provide information that people like yourself find helpful at work.

[@robertballerstedt5688]

Great video, this concept has given me trouble off and on for years. I would like to see an example with a pattern of holes utilizing datum shift- perhaps a pipe flange with clearance holes lining up with either fixed or floating fasteners.

[@xpatrickxbateman76x]

Excellent videos keep it up, love them. Thanks.

[@RDeanOdell]

Thanks so much! Great to hear!

[@dennisluchtefeld8156]

Would be great if you could do a 3 hole part where MMC of one hole has datum shift allowable for both B and C, where B and C are diameters of two of the holes.

[@pinoypyroguy]

Very good Information. SUBS !!!!

[@adwaibowlekar3943]

Great explanation

[@RDeanOdell]

Thanks!

[@darshandg9747]

great explanation. how to calculate the datum shift value happened in this case?

[@FrankLu-w7w]

If i design a hole in the inspection gauge, and put the part on the gauge, then use a 0.95 pin to inspection the position, how about the diameter foe the hole in the gauge, thanks in advance for your reply😊

[@rogeliogarcia1913]

Excellent explanation. Thank you

[@RDeanOdell]

You are welcome! Thanks for watching.

[@kotamanohar8561]

nice explanation sir

[@RDeanOdell]

Thanks!

[@sanaznekooei2436]

Hello, thank you for the video. One question: why is MMC necessary for datum B? fixing the part with "two plates" having their maximum distance (virtual condition), so that all producted parts can fit in is not clear by itsself?

[@RDeanOdell]

Hi, so design-wise you could get the same outer boundary with MMB or RMB. For inspection, RMB dictates the use of some kind of collapsing planes, like a centering vise. MMB can be simulated with a fixed gage, but can also be checked the same way as RMB (although some tolerance may be given up this way)

[@michaeldkendall1592]

Thank you for the videos, very helpful. Have you ever seen a non-coaxial compound datum with a material modifier? Why would that be necessary? Thank you.

[@darrylg6766]

I understand how datum shift works when inspecting a part to a datum at MMC, but how does it work to a datum at LMC?? that is confusing me.

[@RDeanOdell]

Hi, it’s not possible to use hard gages if the Datum is referenced at LMB. The LMC limit is inside the part. It can be calculated with a CMM. I’d say it’s main use is for the designer to communicate design intent. It can be inspected as if it was specified RMB, with the slight chance that an acceptable part may be rejected.

[@darrylg6766]

Thanks for the clarification!@@RDeanOdell

[@rajkumarmurugesan4325]

Very useful

[@RDeanOdell]

Thanks!

[@Traveler360d]

Please make a vide explaining: Feature and feature of size

[@rageisyourweapon]

Great explanation and example Dean. Are you affiliated in any way with the Y14.5 or Y14.5.1 standards committees?

[@RDeanOdell]

Thanks so much! I’m not affiliated with any of the committees. I’d be thrilled to be a part of one, but I have no idea how to go about joining.

[@kelvin4845]

how to calculate the 0.3 tolerance if not given

[@ntsclasses7702]

Hi Dean,
Good morning!
I have a query on Datum Shift. Do you know how much percentage of Datum Shift can use in an assembly?

[@trandangbk77]

I have 1 question, is datum allowed to tilt instead of shift? E.g if the callout is 1.0|A|B(M), assume A is a plane, the we are only able to shift with B. But what happens if the callout is 1.0|B(M)?

[@raghavendrapalekar6739]

Can you please make more videos like this on MMb or LMb considering on one drawing...

[@RDeanOdell]

Hi, I’m working on a video where I address different datum reference frames, some of which use MMB as secondary and tertiary datum references.

[@raghavendrapalekar6739]

@@RDeanOdell please waiting for your upload...

[@emregungor2969]

not well understand.. not enough explanation. datum shift is mostly used with patterns !

[@robertballerstedt5688]

I think you have the same idea, just multiple fixed pins instead of a single pin in the gage

[@derekdoane1765]

Isnt the M modifer in the datum frame called MMB not MMC?

[@RDeanOdell]

Yeah it is. I’m not a robot so I occasionally call the symbol by its name and not its function in the feature control frame.

[@LeHung-er2id]

with position, why it need datum A?

[@RDeanOdell]

Great question! Datum A controls the perpendicularity of the holes. During inspection, both sides of the part should be checked to determine the tilt of the axis of each hole.

[@pratikacharekar7255]

Will it give any bonus tolerance due to MMB ?

[@RDeanOdell]

Hi. No additional bonus tolerance can result from datum features specified at MMB. Datum shift is available, but isn’t the same as bonus tolerance.