[To...] Posted July 29, 2020 Share Posted July 29, 2020 Hey Gang, I need to measure 2 surfaces on a torus feature and need to report the out diameter. If I measure it as a circle, I can't guarantee I am on the equator. I am considering measuring it as a torus or freeform surface and then recalling the points into a circle or cylinder and evaluating the diameter using Outer Tangential, in hopes of finding the highest points on the apex. I'd like to hear your thoughts and ideas. . Link to comment Share on other sites More sharing options...
[To...] Posted July 29, 2020 Author Share Posted July 29, 2020 I have to do the same thing on another torus but this one has more surface area. . Link to comment Share on other sites More sharing options...
[Ri...] Posted July 29, 2020 Share Posted July 29, 2020 Could of thoughts: First one would be, could you scan a curve from the top to bottom of the Torus, report the max point (which would give you the equator), and then use that point to measure your circle at the equator? Second, could you do a curve distance where you measure the two ends from top to bottom? There seems to be a lot of ways you could attempt this. Link to comment Share on other sites More sharing options...
[Mi...] Posted July 29, 2020 Share Posted July 29, 2020 I would try an OTE cylinder, but constrain the normal direction in the evaluation methods (if that's even possible; I can't remember for sure off the top of my head). Link to comment Share on other sites More sharing options...
[Ri...] Posted July 29, 2020 Share Posted July 29, 2020 On your second one, could you just not do a result element calculation difference between the d1 + d2? Or are you trying to actual measure it? I've had to measure a lot of ball races, and for me, the best thing that worked was measuring a circle on the short arc side to grab the Z location, and then measuring the equator with the known Z value. Link to comment Share on other sites More sharing options...
[To...] Posted July 29, 2020 Author Share Posted July 29, 2020 Please sign in to view this quote. The diameter tolerance is +.0000"/-.0001". Can't afford stackup of error. Thanks for the tip. I did consider that but was wondering about location accuracy of short arcs at equator. Will certainly give it a shot. Link to comment Share on other sites More sharing options...
[Ri...] Posted July 29, 2020 Share Posted July 29, 2020 Please sign in to view this quote. Holy cow, Batman! Tell them their best bet is a XXX class ring gage. Lol. Link to comment Share on other sites More sharing options...
[Cl...] Posted July 29, 2020 Share Posted July 29, 2020 Maybe create a symmetry between the top and bottom planes. Create a circle at that Z location? Link to comment Share on other sites More sharing options...
[To...] Posted July 29, 2020 Author Share Posted July 29, 2020 Please sign in to view this quote. We're trying to sell Yasda CNC Mill and are doing a test cut to show the machine can make the part. I'm using our Prismo Ultra to prove the machine can make the part. I'm guessing customer probably has gages but I don't know if anyone asked. lol Link to comment Share on other sites More sharing options...
[Ke...] Posted July 29, 2020 Share Posted July 29, 2020 Usually, when I have to measure a diameter at the equator of a torus, I measure the feature as a taurus, and put it in a secondary alignment (filling in X, Y, Z origins only). Then, I measure the diameter as a circle path, using the secondary alignment at it's origin. This usually gets me within 1 micron of a calculated diameter, based on the torus (using D1 & D2), of a well formed part. Given the small area that you are looking to measure, I would consider using an L1 evaluation (In my experience, it usually gives you a more accurate size, when there isn't a lot of surface to evaluate), at least for the torus, to get your location Link to comment Share on other sites More sharing options...
[Cl...] Posted July 29, 2020 Share Posted July 29, 2020 What exactly is the "L1" evaluation? Link to comment Share on other sites More sharing options...
[To...] Posted July 29, 2020 Author Share Posted July 29, 2020 Please sign in to view this quote. Ditto.... I see it in the evaluation window but not sure what it means. I did find something in the help. Thanks. Link to comment Share on other sites More sharing options...
[Ke...] Posted July 29, 2020 Share Posted July 29, 2020 The way I understand it, L1 (least absolute value) is a simpler (more direct) calculation method than LSQ. I did a comparison between LSQ & L1, vs measuring with a a linear trace on a MarSurf LD 260. LSQ consistently gave larger results, while there was good correlation between L1 evaluation and the Mahr. Link to comment Share on other sites More sharing options...
[Ri...] Posted July 29, 2020 Share Posted July 29, 2020 I believe the L1 also takes the location aspect out of the equation with evaluating the radius. Link to comment Share on other sites More sharing options...
[Br...] Posted July 29, 2020 Share Posted July 29, 2020 Just another idea to try- what if you measure the torus as a torus, then instead of recalling, measure it again as a circle feature with a formula that captures the Z value of the torus. Link to comment Share on other sites More sharing options...
[To...] Posted July 30, 2020 Author Share Posted July 30, 2020 Please sign in to view this quote. Ken suggested making an alignment from the torus and then measuring the circle from that alignment, which I am going to try. Though I think Richard's suggestion of XXX ring gages would produce the most reliable proof. I just didn't think about this early enough to get them on order. Link to comment Share on other sites More sharing options...
[Ja...] Posted July 30, 2020 Share Posted July 30, 2020 What if we use cylindrical probe? Link to comment Share on other sites More sharing options...
[To...] Posted July 30, 2020 Author Share Posted July 30, 2020 Please sign in to view this quote. Hmmmm I think we might have a winner .... Link to comment Share on other sites More sharing options...
[SH...] Posted July 30, 2020 Share Posted July 30, 2020 Please sign in to view this quote. Waw, what a brain you have!!! Link to comment Share on other sites More sharing options...
[Ri...] Posted July 30, 2020 Share Posted July 30, 2020 Too many variables in using Cylinder probes. Wouldn't be so bad if the tolerance allowed for it. Link to comment Share on other sites More sharing options...
[SH...] Posted July 30, 2020 Share Posted July 30, 2020 I appreciated his out of box thinking, his suggestion may be rejected.. Link to comment Share on other sites More sharing options...
[Ri...] Posted July 30, 2020 Share Posted July 30, 2020 Please sign in to view this quote. There is no such thing as a bad idea. Link to comment Share on other sites More sharing options...
[Mi...] Posted July 30, 2020 Share Posted July 30, 2020 Please sign in to view this quote. Pretty sure I've had a few 😕 Link to comment Share on other sites More sharing options...
[An...] Posted July 31, 2020 Share Posted July 31, 2020 See attached.Contribution_31_07_2020.xlsm Link to comment Share on other sites More sharing options...
[To...] Posted July 31, 2020 Author Share Posted July 31, 2020 Please sign in to view this quote. Do you have any dialog or opinion to go along with your work? I am assuming you're trying to communicate that minimal error arises with slight location offset. Link to comment Share on other sites More sharing options...
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