[Ja...] Posted Wednesday at 12:15 AM Share Posted Wednesday at 12:15 AM Let me know how you would treat or measure the lower segment of .06. We were discussing today about strategies and this instance come up. Some of us were siding with 3 results with all holes going back to 1 hole. And the rest of us were siding with 4 results as in hole 1 to hole 2, and hole 2 to hole 3 and so on. This is just a sketch that was brought up today, let me know your thoughts. Thanks in advance. Link to comment Share on other sites More sharing options...
[Ri...] Posted Wednesday at 04:02 AM Share Posted Wednesday at 04:02 AM As drawn, that is not a composite tolerance. I'm not certain if that is just a mistake or not. https://www.gdandtbasics.com/composite-position-vs-multiple-single-segment-tolerances/ Here is some more information on composite tolerances. In a composite tolerance evaluation, you do not call one of the holes "zero" and then reference the error of the other holes in relation to the first hole. The holes are to translate/rotate per their DRF, to minimize the error as equally as possible across the entire pattern. Link to comment Share on other sites More sharing options...
[Ma...] Posted Wednesday at 06:53 AM Share Posted Wednesday at 06:53 AM Please sign in to view this username. thanks for a link - that video had better explanation then their text 😄 So for author - there are two TP callouts - each act like the other one does not exists. So one TP for pattern with ABC and another one pattern for A. Link to comment Share on other sites More sharing options...
[Cl...] Posted Wednesday at 11:17 AM Share Posted Wednesday at 11:17 AM Isn't the lower tier essentially checking perpendicularity to -A-? Link to comment Share on other sites More sharing options...
[Mi...] Posted Wednesday at 01:03 PM Share Posted Wednesday at 01:03 PM This is a pattern of holes so OP Both options are wrong. But also as mentioned, that picture is Multiple Single Segment, not Composite. You will have 2 Position Characteristics set to Best Fit of Bore Pattern: Top one with all 3 Datums filled out, Rotation and Translation turned off. Bottom one with only A, Rotation and Translation allowed. Unless you're using the new GD&T Engine then it would handle that better... Link to comment Share on other sites More sharing options...
[To...] Posted Wednesday at 01:09 PM Share Posted Wednesday at 01:09 PM Please sign in to view this quote. In the OP's example, is there an actual difference? I would apply the same solution for a composite variation. Link to comment Share on other sites More sharing options...
[Mi...] Posted Wednesday at 01:20 PM Share Posted Wednesday at 01:20 PM Please sign in to view this quote. In my current sleep deprived state I don't see a difference in that particular stackup between Composite and Multiple single segment no... I thought that but was hesitant to say it. Link to comment Share on other sites More sharing options...
[To...] Posted Wednesday at 01:23 PM Share Posted Wednesday at 01:23 PM Please sign in to view this quote. LOL. Link to comment Share on other sites More sharing options...
[Ja...] Posted Thursday at 02:54 PM Author Share Posted Thursday at 02:54 PM Hope none of you had to deal with the Midwest storm yesterday it was crazy for us, and that video was top notch. As pointed out earlier my apologies, there is a drawn mistake please see below as this was supposed to be a composite: I know that the lower segment controls the location/ rotation in this case to the hole pattern but is there a real good way to program this if not hole to hole or a 0 hole? Link to comment Share on other sites More sharing options...
[Da...] Posted Friday at 12:08 PM Share Posted Friday at 12:08 PM Please sign in to view this quote. That's exactly what it is; simple perpendicularity. It's a feature normal to A, with A being the only datum. That's all it could ever be. Link to comment Share on other sites More sharing options...
[Wo...] Posted Friday at 12:20 PM Share Posted Friday at 12:20 PM David, I don't think it's just the perpendicularity since this is a pattern of holes. Top tier is a regular Position callout, but the bottom is checking the position of holes to each other allowing for rotation and translation. Link to comment Share on other sites More sharing options...
[Cl...] Posted Friday at 12:30 PM Share Posted Friday at 12:30 PM Wojciech. If that where the case wouldn't the holes have basic dimensions to one another, rather than doing the subtraction of the existing basics? Link to comment Share on other sites More sharing options...
[Wo...] Posted Friday at 12:40 PM Share Posted Friday at 12:40 PM To be honest, I'm not sure if existence of basic dimensions affects how the features are evaluated to DRF. Link to comment Share on other sites More sharing options...
[To...] Posted Friday at 01:04 PM Share Posted Friday at 01:04 PM The lower tier basically consists of four 0.06 diameter cylindrical tolerance zones that are "X" long, and are perpendicular to Datum feature A, whose locations are calculated from the basic dimensions. The axes of all four 5 diameter cylinders must fall within the abovementioned cylinders at a group. So, yes, it is checking perpendicularity to A but it is also checking the location of the 4 holes as a group to each other with no connection to B or C. Link to comment Share on other sites More sharing options...
[Mi...] Posted Friday at 01:09 PM Share Posted Friday at 01:09 PM Please sign in to view this quote. Tom is completely correct here, what's being missed is this is a Pattern of holes. You're not going to make 5 Position Characteristics for the top level and 5 for the bottom. You'll be making 1 Bore Position for the top - Set to Best Fit of Bore Pattern, Rotation and Translation turned off, all 3 Datums filled out. Then the second level is the same thing, except with Rotation and Translation allowed, but only Datum -A- Filled out. Link to comment Share on other sites More sharing options...
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