Spindle Camera

[Bob La Londe]

I decided I needed a spindle camera to measure a job for modifications. I used to have one, but it was flaky and needed work, and mostly I just couldn't find it. So... I bought a decent resolution USB camera to make my own.

I struggled for hours trying to figure out how I wanted to make the mount for it so I could get adjust to be both concentric and parallel with the spindle. I was thinking maybe a 3 point spring loaded adjuster riding on a ball bearing to adjust parallel. Kind of like the adjuster on a transit level. Then a base plate mounted in a socket with four adjuster screws. Like Set-Tru or Run-Tru adjustable lathe chuck. I might do all of that someday, but I realized I didn't need to do any of that to measure my job.

As long as I can zoom in and get good enough resolution and focus the camera can be cattywampus and it doesn't matter. Measurements are relative. As long as I don't raise or lower the head while taking my sightings it will be fine. Just zero at a good reference point, and then rezero at that same reference point with an edge finder before I make the modifications, and I'll be within a couple thousandths. This is a hack job modification. Even I probably won't notice if that's all the further off it is.

I just slapped a round stud on the back of the camera and stuck it in a tool holder.

I know from experience a camera setup is good to about .001-.0015 and I get better than .002 with the edge finder so I should be all good. Just take my measurements write the code, and hack away.

[Bob La Londe]

The camera view screen you see overlaid on the control screen is an integrated plug-in written by Klause Dietz. I'm not sure if I spelled his name correctly, if I did not I apologize. It is a free plug-in available off of his website.

If you would like to do something like this with other software controls that don't have a compatible plug in, there are standalone programs that will do this sort of thing and you can plug the camera into a standalone laptop or other computer that's nearby. In theory this sort of application is not limited to CNC mills. You could use it on a manual milling machine and just read the dros when your independent software on your separate laptop computer shows crosshairs lined up where you want them.

I found two independent programs that are not control software dependent available for this sort of application. One is about $40 from a guy who makes a little inexpensive spindle camera, and the other is free. If somebody wants to find them they can, but I'm not going to go back and find the links for you. Both appear to be windows only. I didn't try either of them as the Dietz plug-in works very well with Mach3. I may try the independent software in the future if I want to use this camera on one of the other machines in the shop.

[Paul Alciatore]

That looks interesting.

I have pondered having a spindle camera that functions as an edge finder. The resolution is there as you seem to have experienced. With proper choice of camera and lens, you can achieve 0.001" resolution. I was thinking in terms of getting a naked PC board style camera and machining the mount for it.

As for alignment, I thought of just X-Y adjustment screws. If the camera/lens mount is carefully machined then the angular alignment should be OK. Perhaps a permanent shim or two at the PC board's corners if that is found to be needed. The X-Y adjustment screws would be used to put the cross hairs of the camera on the mill's spindle axis.

It is nice to see that the camera's image can be combined with the DRO/CAM screen.

[Rich Carlstedt]

Bob, I am confused .
Not with you, but electronic applications, so bare with me because You have me considering doing the same thing, but I lack electronic Moxy.
1.Where does the cross hair (grid) come from ? Is it a built in camera function ? or a software application? or is it a taped on Mylar over the screen ?

2. For general measurement , the center of the cross hair is irrelevant ( I think ?) but is very important for finding centers for the spindle ?
I believe Instead of using a edge finder , could you not use a Rotary Table located by a spindle plug , and then mount the camera to the spindle and by rotating the table confirm the cameras center location or adjust it to match the RT rotation.

3 What do I need software for? does not the camera have a USB plug and the screen display automatically ?

4. Do not know digital cameras..is Parallex an issue ? ( If so, then only moving the axis and DRO's will give accurate position)

I ask because I grind small profile tools and use a pocket comparator to measure, but it would be great to have a computer screen with a grid and create my own full size comparator. And also use it on the mill for measuring engraved plates .

Rich

[skunkworks]

Very cool - A guy I know has been playing around with vision... (I have just a little bit)

[Bob La Londe]

Bob, I am confused .
Not with you, but electronic applications, so bare with me because You have me considering doing the same thing, but I lack electronic Moxy.
1.Where does the cross hair (grid) come from ? Is it a built in camera function ? or a software application? or is it a taped on Mylar over the screen ?

In my case from the software or from the software plugin. think there are some microscope cameras that have a crosshair function, but it may also be built into their software. One user ont he other thread said they made a mechanical (marked mylar?) crosshair, but I don't have confidence in that myself.

2. For general measurement , the center of the cross hair is irrelevant ( I think ?) but is very important for finding centers for the spindle ?

Yes. For general measurement its irrelevant, but I have located points by aligning both crosshairs simultaneously with known square edges.

I believe Instead of using a edge finder , could you not use a Rotary Table located by a spindle plug , and then mount the camera to the spindle and by rotating the table confirm the cameras center location or adjust it to match the RT rotation.

I'm not sure I understand that, but I can locate center of cross hairs relative to center of rotation, at a particular height by simply rotating the spindle. For general measurement its irrelevant, but for edge finding relative to the spindle it would be very important. I'm not sure what functional improvement interceding a rotary table would add.

3 What do I need software for? does not the camera have a USB plug and the screen display automatically ?

If you have a mechanical crosshair you are correct. You could any application or monitor that displays your camera video.

4. Do not know digital cameras..is Parallex an issue ? ( If so, then only moving the axis and DRO's will give accurate position)

Your are measuring by the location of only one pixel (in theory) so I don't think it would be any issue. You place it on your reference point or edge, zero that DRO, align it to the feature, and read the DRO.

I ask because I grind small profile tools and use a pocket comparator to measure, but it would be great to have a computer screen with a grid and create my own full size comparator. And also use it on the mill for measuring engraved plates .

I think with some work these are reasonable objectives, except that your grid size would be relative. I think you need measure point to point by moving the table/spindle relative to the work piece. That's really a little beyond the scope of what I was thinking.

Rich

I think the best accuracy that can be achieved is still only going to be a few thousandths of an inch with this method.

[MikeHenry]

1.Where does the cross hair (grid) come from ? Is it a built in camera function ? or a software application? or is it a taped on Mylar over the screen ?

Rich,

This USB microscope has a built-in cross-hairs as well as on-board monitor and HDMI port for use with a stand-alone monitor that might be a help to aging eyes. It looks like it would be fairly easy to work up a custom mount if you want to install it on a machine, though the base unit is fairly heavy. This guy did a review of the scope that mentions the cross-hair features, starting at about 9 minutes in to the video. It might be better suited for use as a bench top comparator, perhaps with an XY stage in the base.

https://www.youtube.com/watch?v=_QamUtQci7c&t=349s:

https://www.amazon.com/dp/B07VK52X9C...roduct_details

Finally here's someone that mounted one on a Luthy tool grinder:

https://www.instagram.com/p/B9CsBbeo_vq/

[Bob La Londe]

Basically with a spindle mounted camera or a side head mounted camera you are turning your milling machine into a crude comparator. If you make a bi adjustable Mount or do an insanely good / lucky job of making it you can also use it for an edge finder. My first spindle camera made a fair edge finder. I found if I always set it exactly the same height off the stock I didn't have to align everything perfectly I just had to three point align it. I guess if I mounted it permanently on a tool holder, and measured it as a tool height like any other tool, I might be able to do that fairly easily. Set it at exactly the same height every time.

[Bob La Londe]

The other trick, is to take a measurement, rotate it 180°, measure again and split the difference.

For the job I set this one up for I'm just going to lock the spindle and take my measurements. Then when I'm done writing my code file and ready to make the modifications I'll use a regular edge finder to locate the part.