Gopinath K
Mechanical
can anyone explain easiest method to calculate min gap
again i am confused with shift calculation
again i am confused with shift calculation
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minimum wall thickness of the four holes to the O.D. of the part.
- Thread starter Gopinath K
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So pick a start and end point, one on a hole surface and the other on the OD of the part that sets the min gap calculation. You can think of the start point being fixed, and then you work through the stack up in a way that pushes the end point toward the start point. Pro tip, rotate the part 45° so that way you can just deal with x,y coordinates.
Start with that and post where you need specific help.
Start with that and post where you need specific help.
Gopinath K,
This is not a trivial problem, so it is difficult to explain it in a short post. It requires a tolerance stackup calculation that would include 9 or 10 entries, with bonus tolerance and datum feature shift effects. Probably something that would be covered on the second day of a tolerance stackup course.
BTW there are problems with the relative scale of the features in the part view. The 4 holes look too large relative to the middle hole, and the diameter of feature B is drawn much smaller than it should be. The wall thickness would be much larger than it looks in the part view. I believe that the diameter of B was supposed to be 2.990 - 3.000 instead of 4.990 - 5.000.
The figure looks like it was done by James Meadows - are you working from one of his books?
Evan Janeshewski
Axymetrix Quality Engineering Inc.
This is not a trivial problem, so it is difficult to explain it in a short post. It requires a tolerance stackup calculation that would include 9 or 10 entries, with bonus tolerance and datum feature shift effects. Probably something that would be covered on the second day of a tolerance stackup course.
BTW there are problems with the relative scale of the features in the part view. The 4 holes look too large relative to the middle hole, and the diameter of feature B is drawn much smaller than it should be. The wall thickness would be much larger than it looks in the part view. I believe that the diameter of B was supposed to be 2.990 - 3.000 instead of 4.990 - 5.000.
The figure looks like it was done by James Meadows - are you working from one of his books?
Evan Janeshewski
Axymetrix Quality Engineering Inc.
That center hole has quite the diameter range to it. Makes one wonder what CAD system was bludgeoned in the making of that example.
The better question is - what are the odds of getting within 0.XX inches of that minimum wall thickness for a run of 1000 parts, if the variations allowed have uniform distributions.
The better question is - what are the odds of getting within 0.XX inches of that minimum wall thickness for a run of 1000 parts, if the variations allowed have uniform distributions.
I guess the OP has no problem with the answer itself (he has the correct answer), but he has issues with understanding the answer. Therefore, he come here for an "easier" and why not "the easiest method to calculate min gap". ![[banghead]](/data/assets/smilies/banghead.gif "[banghead] [banghead]")
Well, I just have to say "Welcome to the GD&T world" of calculations.
I guess if there is one, the author (James M.) would have showned it, right![[hairpull3]](/data/assets/smilies/hairpull3.gif "[hairpull3] [hairpull3]")
We can explain it to you, but we cannot understand it for you.
Some efforts are needed, required and recommended.
Well, I just have to say "Welcome to the GD&T world" of calculations.
I guess if there is one, the author (James M.) would have showned it, right
We can explain it to you, but we cannot understand it for you.
Some efforts are needed, required and recommended.
Maybe - I see no allowance for form error, such as a flat spot on the OD.
The advantage of Monte Carlo variation analysis is that it doesn't overestimate the likelihood of a problem or overlook unanticipated contributors.
If the goal is to maintain a wall, specify it as an explicit requirement so all the participants know it rather than requiring a Ouija board to figure out what was important.
The advantage of Monte Carlo variation analysis is that it doesn't overestimate the likelihood of a problem or overlook unanticipated contributors.
If the goal is to maintain a wall, specify it as an explicit requirement so all the participants know it rather than requiring a Ouija board to figure out what was important.
CheckerHater
Mechanical
Gopinath K,
If you prefer graphical representation of the solution, please consider the following:
1) Visualize the gauge to check middle hole wrt outside of the part (shown in red).
2) Visualize the gauge to check smaller holes wrt center hole (shown in blue).
3) Visualize part that will satisfy both gauges and at the same time having outside wall as thin as possible (shown in black).
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
If you prefer graphical representation of the solution, please consider the following:
1) Visualize the gauge to check middle hole wrt outside of the part (shown in red).
2) Visualize the gauge to check smaller holes wrt center hole (shown in blue).
3) Visualize part that will satisfy both gauges and at the same time having outside wall as thin as possible (shown in black).
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
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Gopinath K
Mechanical
Perfect
Thanks to all for your support
Thanks to all for your support
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