[Magnum164]

Can someone explain one thing to me -- how does a regular camera or microscope get height information?

You can't this can only give you 2D dimensions. For height you would have to lay the part on the side and get the 2D dimensions for the side. No different than measuring the part with a ruler, just more accurate.

That is why I have my microscribe as well, for those times when I need to do the complete part and not just the 2D top or bottom.

[cnczoner]

Well that certainly clears up a lot -- I was scratching my head on this for a while.

So what's the point then? a low-cost flat-bed scanner take very nice images of flattish parts, or a regular digital camera gets proper images of other parts. I still can't see the reason for putting a camera on a cnc mill, unless you want to ensure that there's no perspective distortion (though for that, I just move the camera as far back as possible and zoom in as much as possible).

[Magnum164]

Well that certainly clears up a lot -- I was scratching my head on this for a while.

So what's the point then? a low-cost flat-bed scanner take very nice images of flattish parts, or a regular digital camera gets proper images of other parts. I still can't see the reason for putting a camera on a cnc mill, unless you want to ensure that there's no perspective distortion (though for that, I just move the camera as far back as possible and zoom in as much as possible).

There are several different reasons. The main one being Accuracy. Sure you can scan it in but I think you can get better accuracy with this method. Read the linked articles and they will give more detail.

For me, I will use the camera more for aligning things on the mill more than anything.

[NEATman]

Z axis measurement with a microscope...
I think I had read somewhere here on CNCzone how someone had projected a laser line at a downward 45 degree angle. Let's assume that the laser line is projected from the right side of the camera downward to the left. When the Z level was high, the line would appear on the left of the screen, when it is at the "0" Z level, the line would be centered on the screen, and when the Z was low, the line would appear on the right of the screen. I'm not sure if this was used for measurements, or just as a reference.

Anyone try out that slim metal tube camera?

Keith

[cnczoner]

Z axis measurement with a microscope...
I think I had read somewhere here on CNCzone how someone had projected a laser line at a downward 45 degree angle. ...
Keith

This I've seen, and makes full sense. Though I suspect there'd be a problem with some surfaces where being at an angle would block the light from getting to low spots on the surface, such as a CPU heatsink. I'm wondering if we can use a laser pointed straight down with an optical sensor for "depth" calculation (like sonar, but with a very precise position)?

Cheers,
-Neil.

[Magnum164]

This I've seen, and makes full sense. Though I suspect there'd be a problem with some surfaces where being at an angle would block the light from getting to low spots on the surface, such as a CPU heatsink. I'm wondering if we can use a laser pointed straight down with an optical sensor for "depth" calculation (like sonar, but with a very precise position)?

Cheers,
-Neil.

using lasers or even digital cameras for 3D surfacing is all really part of a 3D scanner. For me before going through that much trouble i would probably invest in a scanner. If I can find the link when I get home I can post, but there is cheap software and plans on building your own.