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Author Topic: Laser cross hair tool position.  (Read 41365 times)

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Re: Laser cross hair tool position.
« Reply #20 on: March 31, 2009, 04:39:48 PM »
I dont get it- how do you align the cross hair to  the machine spindle? How do you use this?

Offline Greolt

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Re: Laser cross hair tool position.
« Reply #21 on: March 31, 2009, 05:32:43 PM »
Ron

The laser cross is mounted so that it projects exactly parallel with the Z axis travel.

The offset from the spindle centreline is known and consistent.

So in practice the cross is manually aligned with a point of feature on the job or table by jogging.

Then usually by use of a button script the spindle centreline is moved to take up that position.

My experience is, precision is only about 0.02" so obviously it won't fill every setup need.

These lasers cost only a few bucks.  Perhaps more money could buy greater precision.

Greg

Offline Sam

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Re: Laser cross hair tool position.
« Reply #22 on: March 31, 2009, 06:30:24 PM »
I *think* that with the use of a filter, the laser will put out a much finer line, therefore allowing for greater accuracy. I know I have seen them, but how much of a bonus is achieved I don't know.
"CONFIDENCE: it's the feeling you experience before you fully understand the situation."

Offline RICH

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Re: Laser cross hair tool position.
« Reply #23 on: March 31, 2009, 09:07:24 PM »
Hey Guys,
I ordered two of those lasers. Delivery is by boat, so should be here in about
3 or four weeks.  ;D
Should be fun to play with.
RICH

Offline Tweakie.CNC

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Re: Laser cross hair tool position.
« Reply #24 on: April 01, 2009, 02:50:08 AM »
Hi Guys,

I only use the laser pointer on a router where precision is not an issue however, a polarizing filter is still essential. The actual beam width, as far as I can measure, is 0.3mm but our perception of coherent laser light is something different. The surface finish of the work is a determining factor here and highly reflective surfaces produce a sharp and fine image whereas sawn wood produces just the opposite. On Traffolite, engraving laminate, I am confident I could achieve a repositioning accuracy (on an engraved line or edge) of better than 0.2mm.

In reality I align my router work to a pencil line (how accurate is that ?) but this laser device saves so much time and makes positioning so easy that it is now an essential part of the machine.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Tweakie.CNC

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Re: Laser cross hair tool position.
« Reply #25 on: April 01, 2009, 05:58:04 AM »
One thing that should perhaps be mentioned in this thread is the danger associated with using lasers.

These little cross hair pointers are rated at 5 mW max output but prolonged staring into the reflected beam may well cause irreversible eye damage. For tool setting the beam is only viewed for a few seconds and the worst that could happen here is perhaps a bit of after vision - a lot less damaging than looking into the sun for example.

For the measurements that I made in the above posting I wore protective goggles but these are rated for the 1064 nm YAG  laser that I am currently working on and they are only rated at Factor 4 for the 650 nm wavelength of the red pointers. If you are going to spend a lot of time staring at cross hair pointers please invest in a pair of glasses/goggles first - they also remove a lot of the fuzziness and make the beam appear much sharper.

Tweakie.   
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Laser cross hair tool position.
« Reply #26 on: April 01, 2009, 10:38:49 PM »
Is that why you say...‘Do not look into the laser with your remaining eye’  ?

Offline Tweakie.CNC

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Re: Laser cross hair tool position.
« Reply #27 on: April 02, 2009, 02:02:58 AM »
Bad joke perhaps but I am glad that somebody looks at my website.  :)

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline RICH

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Re: Laser cross hair tool position.
« Reply #28 on: April 02, 2009, 10:05:11 AM »
Tweakie,
Recieved the laser yesterday. As noted before before, fine for rough work, but won't be good for anythiing requring accuracy. Tried filtering, helped some some but not a lot. Camera when using Copycat still beats it by
a long shot.
RICH

BTW for $5 I'll find somethinig to do wiith it.

Offline Tweakie.CNC

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Re: Laser cross hair tool position.
« Reply #29 on: April 02, 2009, 11:26:30 AM »
Sorry to hear that you wasted $5 and that it is no good Rich.

As said in the posting above I have a beam width of less than 0.3mm and this is brilliant for a router but not for a mill perhaps.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.