Hi Dean, I’m viewing your videos from The Netherlands and I’m a little late to the party as I’ve been designing and drawing machines for more than 30 years. And I really must say this, that you are the first one to ever make sense of GD&T to me (and probably a lot of other people 😂). Thank you so much for your videos!
Hi Dean I work for an automotive company and I just wanted to tell you that your videos are excellent and are super helpful. The way you explain everything so clearly is amazing. Keep up the great work. Thank you for all the videos.
Hi! Thanks so much! I’m glad you find my explanations helpful. I really try to explain the material instead of just present what is in Y14.5 Which auto company do you work for?
Thank you so much! I really appreciate your comment. I made this lecture on my own, as opposed to repeating what has already been written in textbooks etc.. I’m glad you find it helpful.
Hello Mr dean I'm from Tunisia, I don't understand very well the English language but your style is easy. Thank you so much for those videos.they are very helpful . Thank you a gain.
Great video! For your section discussing two diameters that lie in the same theoretical axis I believe the datum should be identified as A-B in the first datum box. Splitting the indicates that A is primary and B is secondary.
For total runout, so you have to take readings at 1 cross section at a time before moving infinity to the next cross section? For total runout, you actually take continuous readings along the entire length of the part rather than at discrete cross sections. Here’s how it works: Setup: Mount the part on a rotating fixture and position the dial indicator so that its probe touches the surface of the part. Zero the Indicator: Rotate the part to a starting position and set the dial indicator to zero. Take Continuous Readings: As the part rotates, move the dial indicator along the length of the part, continuously recording the readings. This way, you capture the surface variation along the entire length of the part. The goal is to measure the total variation in the surface as the part rotates and the indicator moves along its length. The Full Indicator Movement (FIM) for total runout is the difference between the maximum and minimum readings observed during this process. This method ensures that you account for any surface irregularities along the entire length of the part, providing a comprehensive assessment of its geometric accuracy.
Does this concept of FIM also apply to total runout? Yes, the concept of Full Indicator Movement (FIM) also applies to total runout, but with some differences. While circular runout measures the variation in a single cross-sectional plane, total runout measures the variation along the entire length of the part’s surface as it rotates. Here’s how it works: Setup: Mount the part on a rotating fixture and position the dial indicator so that its probe touches the surface of the part. Zero the Indicator: Rotate the part to a starting position and set the dial indicator to zero. Take Readings: Rotate the part and move the dial indicator along the length of the part, taking readings at multiple points along the surface. For example, if you take readings at several points along the length of the part and get the following dial indicator readings (in thousandths of an inch): 0.000" +0.003" +0.005" +0.004" +0.002" -0.001" -0.004" -0.003" Calculate FIM: Determine the maximum and minimum readings. In this example, the maximum reading is +0.005" and the minimum reading is -0.004". The FIM is the difference between these two values: FIM=Max Reading−Min Reading=+0.005"−(−0.004")=0.009" So, the FIM for total runout in this example is 0.009 inches. If this FIM is within the specified total runout tolerance, then the part is considered satisfactory. Total runout provides a more comprehensive assessment of the part’s surface variation along its entire length, making it a stricter and more inclusive measure compared to circular runout.
For the last example, if FIM .007 inches is less than the circular runout tolerance everyone's happy? Exactly! If the Full Indicator Movement (FIM) of 0.007 inches is less than the specified circular runout tolerance, then the part meets the required standards, and everyone should be satisfied with the result.
So does a specific cross section does not matter with total runout? Copilot Sent by Copilot: Correct, for total runout, the focus is on the entire length of the part rather than specific cross sections. The dial indicator is moved along the length of the part while it rotates, capturing continuous readings. This method ensures that any surface irregularities along the entire length are accounted for, providing a comprehensive measure of the part’s geometric accuracy.
Does the full indicator movement have to be less than the circular runout torlerance in order it to be call satisfactory? Copilot Sent by Copilot: Yes, for a part to be considered satisfactory, the full indicator movement (FIM) must be within the specified circular runout tolerance. Circular runout measures the variation in the surface of a rotating part, and FIM is the total variation observed when the part is rotated 360 degrees around its datum axis12. If the FIM exceeds the specified tolerance, the part does not meet the required standards and is considered unsatisfactory3.
Hi Dean, thanks for the excellent video. At 10:10 the image shown, has the datum included in two separate compartments instead it should be shown in the same compartment with a dash in between. Is the understanding correct? Also I saw the run out tolerance applied to an axis of the datum feature what does that infer?
Hi, so the term axial runout is not used in the ASME standard, but in general engineering parlance it means parallel to axis of rotation and radial means perpendicular to axis of rotation when it comes to calculating stresses etc… For runout in ASME terms, a radial runout is the surface of revolution(the surface of a cylinder), and axial runout is a plane perpendicular to the axis of rotation (the face of a cylinder)
Hi, thanks so much! The requirement for total runout is that the surface of the part must lie between two concentric cylinders separated by the total runout tolerance. To get a tolerance zone of two coaxial cones, to control a taper, profile of a surface can be used.
Hi, I recently made a video about datums: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MxvJ9aWbiY8.html I’m eventually going to make a second video dealing with more advanced topics.
If you wanted to check the total runout on 2 different sized attached cylinders on the same axis datum, could you attach your feature control frame to the dimension that designates the axis datum or would you just make a leader for each feature?
Hi Dean, I don’t get the difference between a surface datum (cylinder, cone) and a diameter axis. Does it make a difference ? Both times you would put a piece in a chuck, v-block etc. and measure the runout on the surface ?
