I think there is a small mistake in your explanation. Your MMC (maximum material condition), only includes the size of the hole, but not the the form. That would actually just be the MMS (maximum material size). To get the full MMC envelope, you also need to add the value of that perpendicularity (subtracting it here, since we are talking abouit a hole), as the hole can, and is allowed to be both at the maximum material size AND to also have that .010 perpendicularity to A in addition, which would decrease the MMC envelope even more. So MMC should be 1.237 here.

@user-nh7gk1bw7d

10 ай бұрын

Hello Alex, you brought up a good point. I also agree with you that the perpendicularity need to be taken into acount. However there is no MAXIMUM material condition applied to the perpendicularity. So I belive MMC should be somewhere between 1.147 to 1.247,most likely 1.153=(1.250-0.003-(0.1-2×0.003))

@Gdandtbasics

10 ай бұрын

Thanks for the great comment! The original question is only focused on the envelope of perfect form that we adhere to when discussing Rule #1 and that is solely reliant on the limits of size (MMC and LMC). So we are ignoring the perpendicularity for this discussion. However as you pointed out, during design of this part we definitely need to consider other boundaries as well. The boundary that gets created when we consider the effects of orientation/location as well as the size and form of the feature is called the Inner Boundary and for this example that would be a boundary of Ø1.243 inches. If the maximum material condition modifier were applied to the feature control frame this boundary would be referred to as the virtual condition.

@AlexLapugean

10 ай бұрын

@@user-nh7gk1bw7d Yes, it's not there, but this is just an example I assume, to show how that would apply here, in this case, the MMC modifier would go on the perpendicularity tolerance.

@AlexLapugean

10 ай бұрын

@@Gdandtbasics Well sure, but you need to put the (M) modifier somewhere, it only makes sense to the perpendicularity, you cannot apply it to the linear dimension itself. So honestly, I see no way to exclude the perpendicularity without making it confusing, except of course putting a 0 value, which would force perfect form at the maximum material size. I think something that would work as you explained it would actually be the envelope requirement. That would be applied to the dimension itself, and force a perfect form at the maximum size, without having any link to the perpendicularity.

@sem7207

10 ай бұрын

​@@AlexLapugean In the end of your last response you have the answer to your own argument. It works for the envelope principle and the envelope priniciple is actually what the topic was.