# Re indexing round column mills the easy way



## gonzo (Nov 7, 2021)

I have mounted the guts out of a laser pointer using a plug in power supply in lieu of battery.
This I mounted vertically on the front of the pully guard.
Then I mounted a stiff member onto the top of the round column.
The stationary member now has a .040 hole drilled in it that lines up with the laser beam when the head is in the proper position.
When the head is in the proper position the laser shines on the ceiling.
Now i can realign my mill head most effectively in short order.


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## tweinke (Nov 7, 2021)

Very interesting! I like it, simple and effective!


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## slow-poke (Nov 7, 2021)

How accurate is this?


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## gonzo (Nov 7, 2021)

It's difficult to get a number on it but it is certainly much more accurate than anything else I have tried.
By the way I only used a .040 hole because it was the smallest bit i had. No doubt a smaller hole would yield more accurate results.


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## woodchucker (Nov 7, 2021)

just be careful of that laser. Even just looking at the dot (not in your eyes) can affect them. I worked on a friends laser for a while. I made an attachment for his laser.. He owned an audio business, where they did big venues. He needed to know where each speaker hit. They knew the cone of each speaker so the laser needed to mimic that cone visibly so he could make sure he was getting coverage with each speaker. Over time I found myself getting sick of the high intensity light while calibrating the device. 

on another note, it was my first real machining job. I thought it came out great for a novice.


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## Lo-Fi (Nov 7, 2021)

woodchucker said:


> Over time I found myself getting sick of the high intensity light while calibrating the device.



Interesting... Could you elaborate? I made myself a laser centering device for my mill, but haven't really used it as I then had reservations (that may be unfounded) about looking at laser light reflected off shiny metal.


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## francist (Nov 7, 2021)

Neat idea, and other than the actual electronic component, nicely low-tech.

I guess if one wanted to lessen the potential for reflection into the eyes, at least for the nearest metal part that the beam shines through, a film vial or something similar with the bottom cut out would make a nice little tunnel to shield the reflection. The laser won’t care if it shines through a tunnel before it passes through the alignment hole, but your eyes would be shielded from reflection as it does. You’d still see the dot on the ceiling, but that may not be as reflective as the metal beam part.

-frank


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## woodchucker (Nov 7, 2021)

Lo-Fi said:


> Interesting... Could you elaborate? I made myself a laser centering device for my mill, but haven't really used it as I then had reservations (that may be unfounded) about looking at laser light reflected off shiny metal.


his was a high powered green laser. he needed the high power because he used it in big conference centers.
I found myself getting nauseous and headaches. I had to ask him for the glasses that came with it. It helped but in the close qtrs of my basement it was still too much.  It took a few days to get back to normal each time I worked with it. I also remember having spots and dark spots.  it's been quite a few years 10/2014 to be exact, so a little sketchy on full details. even on a black background super bright.


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## woodchucker (Nov 7, 2021)

I have a laser on my drill press... it's a red laser. I use it occasionally, and I have one on my compound miter saw.. red also.
Both are low powered and fine.   Just cautioning because I saw how much light that was throwing off, and it's green. 
Not sure if the green are more powerful, but it's worth noting.  If you are going to be using for long periods, the glasses are a good idea.

This year I bought a green laser Huepar crossline self leveling laser for tile work. it didn't come with glasses, so I used some brown glasses I had to work with. It made it easier to work with it.  

My caution was not being a safety nazi, just trying to make you aware of some of the side effects.


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## Hawkeye (Nov 7, 2021)

I have a laser pointer mounted on the front of my mill, aimed at a piece of kite string on the far wall, about 10 1/2' away. Even if the dot ended up 1/16" off centre (it usually doesn't), inverse sine calculation shows that it would only be off by 0.027 degrees.


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## Lo-Fi (Nov 8, 2021)

Thanks @woodchucker , appreciate it. No sense in being reckless with eyesight!


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## higgite (Nov 8, 2021)

slow-poke said:


> How accurate is this?





gonzo said:


> It's difficult to get a number on it but it is certainly much more accurate than anything else I have tried.



It is a neat idea, but as wide as the reflection pattern is on the peep sight bar, I’d be surprised if it’s all that accurate. But, I was wrong once before.  It should be easy enough to indicate for repeatability. My OCD (anal is such a harsh term) wouldn't let me not do that.

Tom


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## RJSakowski (Nov 8, 2021)

I had looked into the laser target on a far wall as a means of  mill/vise alignment before and rejected it.  Diode laser beams have an inescapable beam divergence.  For lasers that I have used. this amounted to about .05º.  Better optics as in lasers used for gun sights could improve on that.  My mill has a distance of around 10.5" from the column axis to the spindle axis.  which would lead to an uncertainty of around .009" in the x axis position.  The width of the target will add to this uncertainty.  Another factor adding to the uncertainty is the parallelness of the column axis to the plumb line.


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## Hawkeye (Nov 8, 2021)

The target is, as mentioned, a piece of white kite string (very thin) hanging from a screw, with a weight on the end. There is a black cloth behind it for contrast. The 10 1/2' distance is measured from the centre line of the column, not the spindle. Since any lateral movement is around the column, the laser is aiming relative to the column. Before changing the elevation of the head, I look at the laser dot on the string. When I realign the head, I try to duplicate the appearance of the dot on the string. It's been working for me for some years now.


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## scottdube (Jun 13, 2022)

Brilliant!


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