Another way to align lasers ?

**pascalp** · 2015-07-30 14:14:24

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Topic: Another way to align lasers ?

I was trying to find a place for my scan beside my printer.

During a calibration, while playing with lasers I found that my plate was a kind of mirror and reflect light.

At first glance It make me smile, then It make me thinking ...
The laser out of alignment with the plate make the reflected light at angle (twice the error) with the direct lightning. So direct and reflect intricated could indicate a perfect alignment ?!

A close-up with lasers aligned and centered on the center point of the plate.

When the plate is perdendicular with the wall/backplate the 2 lines are //. But this is not mandatory, if I dont miss, It works equally well as I only consider direct and reflected light.

I just made a try with my plate not aligned with wall to check and I found that one of my laser have rotate , not to much but my method seems to be accurate.

Lasers are firmly held, BUT the internal screen move/rotate
Some really light (really light) taps on the arm give

I hope that a drop of cyano could cure the problem wiich affect both of my lasers.

**n2ri** · 2015-07-31 02:59:31

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From: St Louis MO USA area
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Re: Another way to align lasers ?

cool. also instructions say to dull plate with med-fine sand paper to prevent reflective double vision so to speak once aligned. so tight areas get scanned correctly.

another thing I always wondered is, if one laser was on a bit higher horizontal plane (about a half inch or so) than the other would that help with say scanning over hangs on object being scanned. where both lasers on exact same plane would not see top/bottom of such shapes? or would this need to be another pair of lasers/cameras set on vertical plane from top/bottom focused in center of scan area?

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs

**pascalp** · 2015-07-31 08:40:08

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Re: Another way to align lasers ?

I need to re-read instructions, I've missed the dulling advice.
When scanning, I use the cover that came with the kit and didn't notice any obvious reflections. I'll pay attention next time.

**n2ri** · 2015-08-01 06:07:27

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Re: Another way to align lasers ?

most lasers work best with dull black surfaces. when I used laser thermometers in my HVAC career I had to put black tape on grills to get best readings. makes sense as light is absorbed in dark colors and reflected on lite colors.

some scanners use grids for alignment I have seen. but not sure on this one.

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs

**pascalp** · 2015-08-02 10:20:38

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Re: Another way to align lasers ?

I'm quite satisfied of the reflect alignment method, really sensitive. I found that my plate had a little bit of wobble. I've used the old table coupler. The upgrade version is better, but I'll print-it with a tighter hole. The axe hole appear to be 5.25mm on the STL, with my printer a 5.05 will give a better fit and even a bit of reaming isn't a problem.

I've began to cure my lasers problem.
The culprit

The lens is only held by pressure between laser body and cap while a dab of glu join laser and cap.
Too few glu, glu soften by hot weather, gluing fragilized while turning laser held by the holder during alignment process, and the lens became free to rotate under tic-tic of the stepper.

I've re-glued the cap with a bit of loctite on the side of the cap, nothing between lens and cap.

I began to get results with simple model.

1.9M, right laser.

Just a little more "sophisticated" shape and threshold, lighting will need more attention.

Real difficulty arose with a not so complicated glossy model.
With repaired laser, dual scan was possible. L & R 1.9M scan, light wasn't equal on both side.

Will probably need, fine tuned multiple scans and worked and merged with meshlab to get a fine result.

Globally I'm really satisfied of the Atlas3D. Hardware work, operator will have to master software.

**pascalp** · 2015-08-02 21:53:03

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Re: Another way to align lasers ?

I've moved my scanner, now it's aligned with window, both sides are equally lightened.

I've followed Pirvan and is CD box. Not exactly the same print, just a cross with an horizontal ligne at 3.25"

Not too far ...

Another way to align lasers ?

Posts: 6

1 Topic by pascalp 2015-07-30 14:14:24

Topic: Another way to align lasers ?

2 Reply by n2ri 2015-07-31 02:59:31 (edited by n2ri 2015-07-31 03:01:59)

Re: Another way to align lasers ?

3 Reply by pascalp 2015-07-31 08:40:08

Re: Another way to align lasers ?

4 Reply by n2ri 2015-08-01 06:07:27

Re: Another way to align lasers ?

5 Reply by pascalp 2015-08-02 10:20:38 (edited by pascalp 2015-08-02 10:33:30)

Re: Another way to align lasers ?

6 Reply by pascalp 2015-08-02 21:53:03 (edited by pascalp 2015-08-02 21:57:35)

Re: Another way to align lasers ?

Posts: 6