Self-centering probing of a 3D curve

[[Ma...]]

I have this nice task here of measuring the tilt angle of oil grooves.

Unfortunately, I can't get it to work. In the 3D curve element, there is no self-centering probing, or are there other simpler solutions? I would appreciate any advice.

[[Ri...]]

Any reason you are wanting to use a Curve? 

 

If you are wanting to just measure that diameter, you could just perform Self-Centering Points at various heights and then use a Recall for a Cylinder. 

 

If you want to try something that may or may not work, create a Line that is at least at the correct start and stop locations, perform a Self-Centering Scan, and then Recall Feature Points into a Cylinder. 

[[Ma...]]

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He is asking to report that groove angle ( 32° +-1° )

Unfortunately it's helix - I faced something similar, yet not found solution. Perhaps there could be formula to get that angle if you use at least 2 touch points with self-centering and probe R > 1.8

Something found https://math.stackexchange.com/questions/4473891/angle-of-rotation-between-two-points-on-cylindrical-helix

Edited November 21, 2024

[[Ri...]]

Oops. Yeah, I didn't see the top of his post. 

 

Invert it then. Perform the Self-Centering Line like I was talking about, and then Recall Feature Points into the 3d-Curve. 

[[Kl...]]

Selfcentering is only available inside standard element, like circle, line, and cylinder.

Measure 8 sections inside cylinder and recall points to use it inside curve.

By using rotary table its easier, only one stylus is necessary, because the sections is rotated to the stylus.

Otherwise you have to use 8 stylus or split some section into subsections according to the stylus.

[[Ri...]]

Well that was much simpler and more elegant than what I originally thought. Haha. 

[[Cl...]]

Could this be an application for the Lift Curve?

[[Ma...]]

Thank you very much for the tip Klaus-Dieter Hermann-Kessler, I'll try it out right away. Let's see if I can do it 😉 

[[Ma...]]

Ok now i have other problems

In my standard settings for the self-centering touch, Fz is specified as -200mn. If I run the program like this, the machine goes into collision because it touches somewhere in Z and moves in the minus direction.
If I change it to +200mn, the machine moves to the correct Z height but hits the part too hard in X. Without self-centering, the stylus travels cleanly along a helical path but does not hit exactly the middle of the oil groove

 

[[Ma...]]

This is the result without rotary table.

[[Ri...]]

Considering this is a 3d self-centering, I wouldn't use the Own Selection - I'd leave it on the Probe In Normal Direction setting. 

With your current settings, it is applying all of the force downward, which is not what you want. 

The Direction of force without rotary table is correct. 

[[Ma...]]

As can be seen from the green actual points, the problem is that the Stylus always slips out of the groove. No matter the diameter of my measuring ball, the self-centering does not work.

Does this have something to do with the probing force in the vectors?

I had another idea:  i used the rotary table to create a self-centering point at the start and end of each groove and then connect the start and end points with a 2d-line. The problem here was that the points were always in the same place. So the line just went straight down. I had no angle/helix

[[Kl...]]

Hallo Mathias,

kontaktiere mich bitte über den Softwaresupport (Hotline) in Oberkochen.

Die kennen mich aus meiner Zeit bei IMT.

Gruss

Klaus