AZ-axis point cloud

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Tomis
Posts: 5
Joined: Tue May 30, 2017 6:24 pm

AZ-axis point cloud

Post by Tomis »

Hello
We are building camshaft grinding machine and now we are middle of point cloud mess.
I found this awesome program and tried it with my point cloud. It is probed with mach3 and is point cloud from camshaft.
A axis is 0-360 deg and Z is ~ 0 - -20mm
I tried to make it proper with apply transformation so that i could save it to STL and then open it with Bobcad-cam.
Now all I have is only something like this: }
I would really appreciate tips, thanks.
0,-21.6935
0.2,-21.6935
0.4,-21.692
0.6,-21.6915
0.8,-21.691
1,-21.6905
1.2,-21.6895
1.4,-21.688
1.6,-21.687
1.8,-21.689
2,-21.69
2.2,-21.6895
2.4,-21.6895
2.6,-21.689
2.8,-21.6895
3,-21.6905
3.2,-21.689
.......
daniel
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Re: AZ-axis point cloud

Post by daniel »

CloudCompare only 'expects' (loads) 2D or 3D point cloud with coordinates expressed in a Cartesian coordinate system.

Here you have angular coordinates on the first dimension and Cartesian ones on the second dimension (if I understand well). So you have to first transform them outside of CC if you want to be able to process them in CC.

It should be easy with any software such as Matlab or even Excel. Should be something like :
X = cos(A) * Z
Y = sin(A) * Z

(not sure what's the geometry of your assembly).
Daniel, CloudCompare admin
Tomis
Posts: 5
Joined: Tue May 30, 2017 6:24 pm

Re: AZ-axis point cloud

Post by Tomis »

Thanks
I just cannot understand how to continue with this?
Something wrong?
Y= sin(A) * Z

Image
daniel
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Re: AZ-axis point cloud

Post by daniel »

Well, actually the exact equation would depend on your actual assembly. How are the sensors linked together?
Daniel, CloudCompare admin
Tomis
Posts: 5
Joined: Tue May 30, 2017 6:24 pm

Re: AZ-axis point cloud

Post by Tomis »

Hi

Well here is a sample video of how different probing head could affect. Point cloud is probed with grinding stone diameter probe and it is Z and rotating axle is A.
Just wondering perhaps we did probing at the wrong direction because Z0 is lathe chuck's surface now. Just to have one rigid point.
Now we cannot calculate camshafts base radius. If camshaft center would be Z0 then it could be calculated...

https://www.youtube.com/watch?time_cont ... O37yVG10co
daniel
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Re: AZ-axis point cloud

Post by daniel »

Do you know what is the distance between the probe 'zero' (what you call Z0 I guess) and the rotation center?
Daniel, CloudCompare admin
Tomis
Posts: 5
Joined: Tue May 30, 2017 6:24 pm

Re: AZ-axis point cloud

Post by Tomis »

I think it is -60 because lathe chuck is 120mm but not measured exactly yet.
If we measure the exact value then we could probably use lathe chuck surface. It is easier to zero the Z axle to that because grinding stone wears etc.
Tomis
Posts: 5
Joined: Tue May 30, 2017 6:24 pm

Re: AZ-axis point cloud

Post by Tomis »

So do you think it is possible to have this kind of point cloud to show like it is?
daniel
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Re: AZ-axis point cloud

Post by daniel »

Can you send me the complete cloud / measurements?
Daniel, CloudCompare admin
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