is the hole pattern locked to the basic dimensions, meaning there is no variance allowed ? or could the each hole be shifted in any direction as long as it remained within the 0.2 tolerance. For example , @4:41 each hole shifted together, but could one hole go to the left , and one to the right meaning they deviate from each other but do not exceed 0.2 position.
“Composit Position” appears to be meaningless when the part is fixed to the left in the assembled state and cannot be translated or rotated. So, is “composit position” used when parts can move or rotate slightly in the assembled state? I am curious in what cases “composit position” is applied to part drawings.
Composite position is often used on large plates or structures where many other parts connect to it. The location of each mating component doesn’t matter, but the holes in the pattern must be located to each other to let each part bolt up.
How would I interpret the lower tolerance frame in composite tolerance if B was the axis of a Center diameter and C was a timing hole, only A and B are specified in the lower tolerance frame? Does that mean I can translate in XYZ and rotate around Z?
Yes, you're right, it can translate XYZ and rotate in Z. Your datum B reference doesn't do anything in the lower frame. The lower frames of composite position constrain in rotation only. Your secondary axis is not constraining rotation so it adds nothing to the constraints. If the lower frame had ref to ABC, then it can only translate XYZ (fully locked in rotation)
This is hard to explain on a message. You need each holes X and Y deviation data from the true position. All hole XY are plotted on a graph (called a paper gage). The hole centers are "best fit" into a circle. This circle represents the position tolerance zones to each other. This is detailed in my GeoTol Pro 2020 book pages 12-28 to 12-29.
So why not just have standard dims with large tols from edges and put the basic positional tols between the hole patterns. I was doing it that way 42 years ago to BS 308 ( british standard ) Is this only ASME - what does ISO / DIN / JIS do? Having just said that - I do understand the principle and it's always good not to allow individual interpretations...Thank for the video.
Yep, thats how the older versions of ASME Y14.5 did it (1973, I believe). But plus/minus tolerancing for locating features comes with its problems: does the large dimensional tolerance apply to only the first hole or the set? What is the order of indexing the datum features (primary, secondary, tertiary). You end up with square vs round tol zones with plus/minus. ISO would use a similar spec for this particular example but instead with two separate frames.
If I made a composite FCF and had a M (maximum material condition modifier) called out in the first frame, do I HAVE to also add that to the second or third frame?
No, you never "have to" add an MMC modifier. It is just an option to add "bonus tolerance" if function allows. Functionally, I have found the upper frame usually does not have the MMC modifier. The top number in composite is a just a large tolerance for the location of the pattern. However, the lower frame is usually calculated using the fixed or floating fastener formula (MMC hole - MMC pin). Therefore, MMC modifiers make functional sense in the lower frame.
The CMM can "best fit" the hole locations to their true positions by releasing the constraints to the datum reference frame. The X/Y deviations collected from the top control can also be plotted on graph paper and best fit manually. This was called a "paper gage" in the old days.
These are two separate sets of tolerance zones (two requirements) that the 4 holes must meet simultaneously. The upper 0.6 tolerance zones are fixed in location relative to each other and the datum reference frame. The lower 0.2 tolerance zones are fixed to each other but unlocked to the DRF (allowed to translate). Tolerance zones don't control other tolerance zones. Tolerance zones instead control the features. You could pass one set and fail the other.
The Composite Controls actually add for a "Flexible way of Opening-up & Relaxing a Tolerance Zone." Scott Neimann is Great! Tom Vanderloop, Author, Teacher & Manufacturing/Fabrication-Welding Consultant
Best explanation of composite position tolerances on the net.
thank you for really clearly explanation ❤❤
Отличная подача материала!
That's the best explanation i've seen
Beautifully Explained 🙂
Very nice video, congrats fom México
Holy shit, this is so good!!!
is the hole pattern locked to the basic dimensions, meaning there is no variance allowed ? or could the each hole be shifted in any direction as long as it remained within the 0.2 tolerance. For example , @4:41 each hole shifted together, but could one hole go to the left , and one to the right meaning they deviate from each other but do not exceed 0.2 position.
The theoretical tolerance zones are locked to the basic dimensions. The hole axes may shift within the dia 0.2 tolerance zones.
Very good explanation thank you very much
“Composit Position” appears to be meaningless when the part is fixed to the left in the assembled state and cannot be translated or rotated.
So, is “composit position” used when parts can move or rotate slightly in the assembled state?
I am curious in what cases “composit position” is applied to part drawings.
Composite position is often used on large plates or structures where many other parts connect to it. The location of each mating component doesn’t matter, but the holes in the pattern must be located to each other to let each part bolt up.
Amazing explanation 😀
Make more video.All the best.
How would I interpret the lower tolerance frame in composite tolerance if B was the axis of a Center diameter and C was a timing hole, only A and B are specified in the lower tolerance frame? Does that mean I can translate in XYZ and rotate around Z?
Yes, you're right, it can translate XYZ and rotate in Z. Your datum B reference doesn't do anything in the lower frame. The lower frames of composite position constrain in rotation only. Your secondary axis is not constraining rotation so it adds nothing to the constraints. If the lower frame had ref to ABC, then it can only translate XYZ (fully locked in rotation)
Would you please instruct how TO INSPECT either on CMM or Any method on 2nd section of composite ? Thanks
This is hard to explain on a message. You need each holes X and Y deviation data from the true position. All hole XY are plotted on a graph (called a paper gage). The hole centers are "best fit" into a circle. This circle represents the position tolerance zones to each other. This is detailed in my GeoTol Pro 2020 book pages 12-28 to 12-29.
So why not just have standard dims with large tols from edges and put the basic positional tols between the hole patterns. I was doing it that way 42 years ago to BS 308 ( british standard ) Is this only ASME - what does ISO / DIN / JIS do? Having just said that - I do understand the principle and it's always good not to allow individual interpretations...Thank for the video.
Yep, thats how the older versions of ASME Y14.5 did it (1973, I believe). But plus/minus tolerancing for locating features comes with its problems: does the large dimensional tolerance apply to only the first hole or the set? What is the order of indexing the datum features (primary, secondary, tertiary). You end up with square vs round tol zones with plus/minus. ISO would use a similar spec for this particular example but instead with two separate frames.
Best vdo
Thanks❤
Thank you!
How would you gage the FRTZF? 4 pins of 11.8mm diameter?
yes, but 11.72 pins (MMC - Position tol). The pins would also need to be perpendicular to a plane
If I made a composite FCF and had a M (maximum material condition modifier) called out in the first frame, do I HAVE to also add that to the second or third frame?
No, you never "have to" add an MMC modifier. It is just an option to add "bonus tolerance" if function allows. Functionally, I have found the upper frame usually does not have the MMC modifier. The top number in composite is a just a large tolerance for the location of the pattern. However, the lower frame is usually calculated using the fixed or floating fastener formula (MMC hole - MMC pin). Therefore, MMC modifiers make functional sense in the lower frame.
Mr Geo you look like spiderman 3 tobey
"I'm gonna put some GD&T in your eye." 😂
Thank you for your video. How do we measure the lower one with cmm?
The CMM can "best fit" the hole locations to their true positions by releasing the constraints to the datum reference frame. The X/Y deviations collected from the top control can also be plotted on graph paper and best fit manually. This was called a "paper gage" in the old days.
@@GeoTolPro thank you very much!
The 0.2 can go out of 0.6 or not? If yes can’t meet the first 0.6. How can I understand that?
These are two separate sets of tolerance zones (two requirements) that the 4 holes must meet simultaneously. The upper 0.6 tolerance zones are fixed in location relative to each other and the datum reference frame. The lower 0.2 tolerance zones are fixed to each other but unlocked to the DRF (allowed to translate). Tolerance zones don't control other tolerance zones. Tolerance zones instead control the features. You could pass one set and fail the other.
@@GeoTolPro Got it，Thank you for your answer！
The Composite Controls actually add for a "Flexible way of Opening-up & Relaxing a Tolerance Zone."
Scott Neimann is Great!
Tom Vanderloop, Author, Teacher & Manufacturing/Fabrication-Welding Consultant
Do we have sample exercise about these??
Our GeoTol Pro 2020 book has lots of exercises.
I love the B joke😄😄😄😄
Bee joke is good!
th-cam.com/video/D3-uTr0aZ1Q/w-d-xo.html looooooooooooooool :D