Lasers as measuring/locating devices

[Swede]

The use of lasers in all facets of industry has exploded. You'd think there'd be all sorts of cool stuff for the home shop guy that use lasers... but there aren't.

Browsing eBay, I saw an ad for "Laser edge finder". It is what you'd expect, a diode laser in the spindle. I guess you could find an edge with it, but I can't imagine it being more than about 0.004" accurate; not good enough.

Then, there's the laser line-making devices, that can send out a beautifully straight and bright line on any flat surface. They are cheap, just a few bucks. I've seen them on circular saws. Is there any application for a mill, for example? I've thought of mounting one on my band saw, but I couldn't make it work very well.

Finally measuring. Apparently the technology is too expensive, but why can't we have laser indicators that can measure distances to 0.000,000,002" or some ridiculous value?

Who is using a laser in their shop right now?

 

[danstir]

I use a laser pointer on my mill. It's a round column mill and when I have to change the height and don't want to lose my reference I make sure it is pointed at a line drawn on the far wall while re-tightening the column. Not my idea, I got it off a board somewhere.

 

[dalem9]

I have a laser it is a peice of junk. But I do like the point it at the wall idea. May have a use for it after all Thanks Dale

 

[Blogwitch]

I have a laser spotter on my new drill press. Once set to the correct position for length of drill being used it is fairly good for drilling pre-marked holes, but I wouldn't call it super accurate, but plenty good enough for a drill press.

It shows it rather well if you click the last of the small pictures.

http://www.charnwood.net/shop/product/16mm-capacity-pillar-drill?cid=125


John

 

[ShopShoe]

I would have a potential caution. A few years ago I was involved in teaching computer classes and laser pointers were all the rage. It seemed like a good idea for the instructor to be able to stand behind the student and point the laser at the relevant part of the screen. Then, someone pointed out that a stray reflection could end up in someone's eye. Drastic cutback in laser-pointer use after that.

Could a shiny piece of work reflect a laser back into someone's eye? In woodworking this is probably not an issue, but with metal ???

--ShopShoe

 

[purpleknif]

We do a lot of re-building where I work and we had a Laser salesman in to demonstrate his wares. After 2 hours of set up his laser couldn't produce repeatable measurements. so. we still use the "old school" methods for alignment. Take from this what you will.

 

[Tin Falcon]

laser mice are pretty much the standard for computer pointing devices . the laser is reflected off the table mouse pad whatever and it is converted into movement. I have wondered why are similar devised not used for inexpensive dros seems like any surface would work as a reference even mount the sensor inside the machine. Maybe my thinking to simplistic.
Tin

 

[GailInNM]

Not for the home shop YET, but the last two high end machining centers installed at the manufacturing plant that I am retired from have laser tool measuring. Every time a tool is loaded from the tool magazine a laser measures the diameter of the tool and the tool length offset and corrects the program to the value for that tool. If a tool goes out of programmed limits it can select an alternate tool from the magazine and flag the out of limits tool to be changed by the operator and the control updated that it has been changed. No preset-measuring a tool is required so strictly an operator is required. The laser does all the measuring that a tool room or machinist would have done in the past.

Laser interferometers are routinely used to calibrated high end CNC machine tools.

None of this is cheap but is is a big cost saver in a commercial environment. Thirty years ago CNC was very expensive and and beyond the reach of any hobby machinist. Today .with inflation factored in, the cost is probably 10 percent of what they were then and they outperform the tools of 30 years ago. As the technology matures laser measuring will slowly find its way into the home shop in a viable way.
Gail in NM

 

[tattoomike68]

Back in 1993 I worked for the US Army Corps of Engineers as a hydro graphic surveyor. Even then we could shoot miles and get a good measurement.

In 10 miles we could hold less then 1 foot of error. Our best at the time was 1 part error in 650,000 ratio.

The river dredges were all set from laser control points on banks to the barge and tugs to keep the machine in place.

I may have hated that job but I did get to use radar, infra red, lasers and sonar to measure things, I did learn to map river bottoms, huge piles of rock or a whole mountain. My dumb ass did not ever bring a fishing pole.
Civil Engineering sucks, when I quit I was done measuring dirt.

I would have loved to do what GailInNM did .

 

[Jeremy_BP]

I use lasers as optical endstops for all sorts of things. I also use them as pointers.
I've made small laser range sensors, but was never able to get much more than 0.01" repeatability. However, I could probably do better with better data filtering.

Tin: Laser mice wouldn't do to well for a DRO. So far, all the one's I've ever messed with have used a laser to create a reference on a surface, and use a 16x16px camera to detect movement. Fun to play with, but not very accurate at all.

 

[Swede]

I think a lot of the macro-scale stuff lasers were ready to do in the 1990's have been replaced by cheaper GPS-based technology.

I'd still love to see a laser-based DRO... I guess it's possible but too expensive.

 

[arnoldb]

IMHO the technology to make laser DROs are available and cheap as well -if one is prepared to follow a different way of thinking.

If I consider the density at which information is stored at on optical discs (CDs/DVDs) and the accuracy and speed at which those can be read, it should be neither expensive nor too difficult to make a "linear" scale that is optically encoded for reading, and processing the data can be very efficiently and cheaply done with low-cost programmable ICs.

The biggest cost associated with this hare-brained idea of mine would be to find and use suitably temperature-stable material (and I don't see why the metallic layers needed can't be deposited on glass) and a way of preventing damage to the scale or dirtying it up. Another issue would be coping with vibration.

One of the biggest advantages I can see with using a laser-encoded system as described above is that true reference points can be encoded in the scale itself, overcoming some of the problems of using quadrature encoders.

;D Just had to lay my egg as well ;D

Kind regards, Arnold

 

[Jeremy_BP]

You could even do a quadrature encoder with laser references.

 

[firebird]

Hi

I have a laser edge finder and wouldn't live without it now. I bought it maybe 5 years ago when they were about £40.00 and came with the polarizer lens. They are considerably more expensive now. I would say I can get within .002 which for the most part is more than accurate enough for the work I do. very rarely now do I get the DTI out. Lasers are extremely easy to use as well, just line up the dot and zero the dial or DRO, you don't have to halve anything. I agree you would think now that there would be some cheap kit available.

Cheers

Rich