[La...] Posted September 4, 2020 Share Posted September 4, 2020 A little background on our CMMs: We do not have gear or pcm. What would be the best method for to determine the pitch location(s) in order to get the distances for Bbls 3 and 4? It seems to me that I would need a macro to determine where the pitch line would be...only problem, I don't know how to create such a macro. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/ Share on other sites More sharing options...
[SH...] Posted September 4, 2020 Share Posted September 4, 2020 🙄 Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76692 Share on other sites More sharing options...
[Ri...] Posted September 4, 2020 Share Posted September 4, 2020 As long as you know the ball size you could use Curve, and then the Circle in Contour Feature. If you don't have Curve, but it is possible to replicate the size of the ball, you could do a direct measurement with self-centering points. If those are just lines, I believe you could also use the tangent function, and drop a tangent nominal circle between the two lines. This doesn't work if this is an involute tooth as the flanks aren't straight they are curved. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76694 Share on other sites More sharing options...
[Ma...] Posted September 4, 2020 Share Posted September 4, 2020 Is it some type of thread? Anyway - tip diameter seems like not bigger then 1mm ( 0,039" ) to scan it as curve Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76696 Share on other sites More sharing options...
[Cl...] Posted September 4, 2020 Share Posted September 4, 2020 Construct > tangent. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76698 Share on other sites More sharing options...
[SH...] Posted September 4, 2020 Share Posted September 4, 2020 Please sign in to view this quote. He want to check the pitchcircle diameter and radius, how does circle in Contor best-fit and tangent circle work??.That line does not pass through the centre of the circle or the minimum point of the circle.... Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76700 Share on other sites More sharing options...
[Cl...] Posted September 4, 2020 Share Posted September 4, 2020 Contour in best fit uses 2d curves to construct nominal circles. The Tangent option uses two lines to essentially do the same thing.Then you just use caliper distance (Maximum) to get the .310 dimension. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76702 Share on other sites More sharing options...
[SH...] Posted September 4, 2020 Share Posted September 4, 2020 I think OP asking about 3and 4 not 12. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76704 Share on other sites More sharing options...
[La...] Posted September 4, 2020 Author Share Posted September 4, 2020 These are not threads, teeth that are directly opposite each other. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76706 Share on other sites More sharing options...
[SH...] Posted September 4, 2020 Share Posted September 4, 2020 What is the profile of the teeth, involute or cycloidal ?? Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76708 Share on other sites More sharing options...
[Ma...] Posted September 4, 2020 Share Posted September 4, 2020 I would ask author of topic which diameters of tips he have. If he can not touch min. diameter of part, then 3 and 4 is useless to measure. For ex. threads are precisely measured only with wires and micrometer. No one asks to measure middle diameter of threads. So what's purpose of 3 and 4 dimension? OK no threads, but tooths. Are you capable of scan whole curve? How are defined 3 and 4? Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76710 Share on other sites More sharing options...
[To...] Posted September 4, 2020 Share Posted September 4, 2020 Is your machine only tactile? Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76712 Share on other sites More sharing options...
[La...] Posted September 10, 2020 Author Share Posted September 10, 2020 We continue to have problems with data for this part. Maybe this view will help with ideas. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76714 Share on other sites More sharing options...
[La...] Posted September 10, 2020 Author Share Posted September 10, 2020 Please sign in to view this quote. I would think it has to be involute. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76716 Share on other sites More sharing options...
[Mi...] Posted September 10, 2020 Share Posted September 10, 2020 Are you sure that's not just the midpoint of the tip and root of each tooth? It is drawn as a centerline. If it is that simple, just measure the tips as a plane and the roots as a plane, then add a symmetry construction. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76718 Share on other sites More sharing options...
[La...] Posted September 10, 2020 Author Share Posted September 10, 2020 Please sign in to view this quote. I take it you are referring to the CMM. Yes, we have an XT Gold scanning head. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76720 Share on other sites More sharing options...
[Ün...] Posted September 10, 2020 Share Posted September 10, 2020 Is the measurement number 3 and 4 the section circle or the average of the top and bottom of the tooth Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76722 Share on other sites More sharing options...
[La...] Posted September 10, 2020 Author Share Posted September 10, 2020 Please sign in to view this quote. This may not answer your question exactly, but the values for the teeth and the space between two teeth at .100 are both .0490 from the center of the part. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76724 Share on other sites More sharing options...
[La...] Posted September 10, 2020 Author Share Posted September 10, 2020 Please sign in to view this quote. I wish it was the midpoint! I tried to explain in my previous post. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76726 Share on other sites More sharing options...
[Mi...] Posted September 10, 2020 Share Posted September 10, 2020 Please sign in to view this quote. Here's a crazy idea - measure both sides of the valley as lines, then recall feature points into a circle, evaluate as Max Inscribed with diameter constrained. Then either create intersection points (probably too unstable) or do some math. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76728 Share on other sites More sharing options...
[Cl...] Posted September 10, 2020 Share Posted September 10, 2020 Or, measure both sides of the valley as planes. Move the planes half the nominal diameter and intersect them. Use a result element to get the distance between the two intersections + the nominal gage ball diameter, (.310) Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76730 Share on other sites More sharing options...
[Ri...] Posted September 11, 2020 Share Posted September 11, 2020 Please sign in to view this quote. If it is an involute then the pitch diameter is where the pin sets on the flanks. Since the flanks are a cylinder, not a plane your only option is to use Curve and the Circle in contour fit. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76732 Share on other sites More sharing options...
[Da...] Posted September 11, 2020 Share Posted September 11, 2020 I am just learning from you guys about gears, so I am sorry if this is a stupid question, but I am going to ask it anyway. The drawing seems to show bubbles 3&4 are the center line of the teeth to the center line of the part and to each other. Couldn't he just create symmetry planes by taking points in the valleys and on the peaks and then compare them to the center line of the part and to each other? As for bubble 12 it looks like a good place for gage pins and a micrometer. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76734 Share on other sites More sharing options...
[Ri...] Posted September 11, 2020 Share Posted September 11, 2020 Please sign in to view this quote. If it's an involute it isn't a straight-sided tooth. The teeth curve based on the pressure angle. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76736 Share on other sites More sharing options...
[Mi...] Posted September 11, 2020 Share Posted September 11, 2020 Please sign in to view this quote. I thought that too, but I think it's actually the point at which the gauge pin contacts the tooth. It's probably "faked in" on the drawing (since it's not drawn as an involute, either), so it doesn't look quite right, but that's what they're going for. Link to comment https://qualityforum.zeiss.com/topic/14594-pitch-location/#findComment-76738 Share on other sites More sharing options...
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