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Zlatko Kursar
01-13-2014, 10:37 AM
I made some modification on my Shenhui and now I have more control with calibration.

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George M. Perzel
01-13-2014, 4:42 PM
Zlatko;
Interesting- we could use a few more words of explanation.
Thanks
Best Regards,
George
Laserarts

Zlatko Kursar
01-14-2014, 9:01 AM
George,

I am very poor with words because my english is not very good:D.
Problem was that mirrors and head was not in line so it was impossible to get laser beam in center in all position.
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I also made modification on second mirror so now I have more control on move it up/down and left/right
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Mirror 2 and head was not in same level so it was impossible to get beam in center on both side.
Now I can move head up/down and left/right like on original.
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Also I was unable to get straight beam with third mirror.
Now I can rotate all head and I have straight cut.
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Now in all position I have laser beam in center of head.

Dave Sheldrake
01-14-2014, 9:41 AM
You're English is fine Zlatko and a LOT better than my Croatian :)

Nice mod and seems to work well :) good stuff :)

cheers

Dave

George M. Perzel
01-14-2014, 2:52 PM
Thanks Zlatko;
Good explanantion- If you think Dave's Croation is bad you should here mine!
Best Regards,
George
Laserarts

Martin James
01-16-2014, 11:24 PM
Can someone tell me if it would be a better way to address this type of problem by remounting the tube to get it closer to the 90? thanks marty

Zlatko Kursar
01-17-2014, 8:10 AM
Martin, I think that 90 between tube and first mirror is not critical because with this mirror you can direct beam in any direction. But first and second (and third) mirror must be in same level - horizontal and vertical.

Alexa Ristow
01-17-2014, 9:51 AM
I have found that I could never get the beam 100% centered on the Head and stable across all 4 corners until I had the courage to start adjusting the tube mounts. If the beam is note centered on the first mirror, then it tends to drift left to right or up and down at the 4 corners. Whether or not the tube is 90 to the mirror is not as important as making sure the first mirror contact is dead center.

Regards,

Norman

George M. Perzel
01-17-2014, 11:59 AM
Zlatko;
I am very interested in your red dot beam setup-any explanation and or drawings would be helpful. Thanks
Best Regards,
George
Laserarts

Zlatko Kursar
02-11-2015, 9:10 AM
After my wife burned red dot pointer :mad: because she had forgotten to bring this down, I made a new modification.
I insert the switch that shuts off power to the laser power unit if the pointer lifted.

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Bill George
02-11-2015, 9:25 AM
After my wife burned red dot pointer :mad: because she had forgotten to bring this down, I made a new modification.
I insert the switch that shuts off power to the laser power unit if the pointer lifted.

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Since I don't own the same brand of laser machine, is that drop down laser pointer OEM or something you designed? Either way I like it!

Zlatko Kursar
02-12-2015, 2:43 AM
This is 3 USD for 5 pcs laser pointers :D

Bill George
02-12-2015, 7:39 AM
This is 3 USD for 5 pcs laser pointers :D

Got the Laser, just the mounting is what I have to do. My carriage is different but I have a small machine shop to make one to fit.

Joseph Shawa
01-03-2017, 1:57 PM
Seems it would have been better to mount this on the second mirror so as to keep inertia lower on head.

Kev Williams
01-03-2017, 4:27 PM
These things move so slow I doubt the extra weight would make much difference...

more than once I've taped small bottles of Testors paint to the top plate on the laser head of my LS900- makes a great paint mixer! ;)

Rich Harman
01-03-2017, 6:55 PM
Can someone tell me if it would be a better way to address this type of problem by remounting the tube to get it closer to the 90? thanks marty

No, mounting the tube at exactly 90 degrees will not help. You could literally mount the tube at any wacky angle, as long as the beam is centered on the first mirror, the first mirror can steer the beam where it needs to go. However you may need to raise or lower the tube and/or first mirror so that all three mirrors are on the same plane. I've noticed that the Chinese workers do not care too much if the beam is centered in all the mirrors, only that the beam hits part of the mirror. On my machines I have had to adjust the heights of the mirrors so that the beam is centered on all of them.

Kev Williams
01-04-2017, 12:59 AM
Just my way of doing things, but I'm not so concerned with the beam hitting dead center, anywhere between DC and halfway to the mirror's edges is fine with me...

What does concern me is that where the beam hits each mirror NEVER CHANGES throughout the full X-Y movement.

My alignment procedure is pretty simple--NOTE that some machines like my GCC have 4 mirrors (the GCC's laser is mounted in the bottom of the machine). In these machines the first 2 mirrors are stationary, and when discussing the alignment of the gantry mirrors, I consider mirror 2 to be the "first" mirror... :)

That said--

First, slew the Y axis to move the second mirror as close to the first mirror as possible, and test fire. Now, move the second mirror as far as possible from the first mirror, and test fire. A little off center is fine, more important is that the beam MUST hit the exact same spot when nearest AND farthest from mirror 1. If not, adjust the FIRST mirror ONLY until it does. When you nail it, mirror 1 is now perfectly aligned. NOTE that nothing you now do to mirror 2 can change the beam path from mirror 1.

Once the 1-2 mirror alignment is dead-on, now do the same for mirrors 2 & 3. --which is more tricky because you have to check and align all 4 corners. I test the farthest XY coordinate from the first mirror first--example, if your first mirror is on the left side of the machine, the farthest XY would be the bottom right corner-- then, move the X only to the bottom left corner. Align these 2 positions first, by adjusting ONLY the 2nd mirror. Get the beam to hit the same spot on mirror 3 in both corners. Once you get that to happen, now slew up to the top left and right corners, and see if you're lucky enough to have the beam still hit the same spot(s). Tweak mirror 2 until all 4 corners are dead on, or at least very close.

From there it's just a matter of moving mirror 3 so it fires as straight down as possible, and as close to the lens center as possible.

FWIW, on my LS900, the beam hits both the 2nd and 3rd mirrors towards the 2 o'clock position, about 2mm from center. The beam hits the lens about 1.5mm off center at the 5 o'clock position looking straight down. No cone so dead-center thru the lens isn't an issue. It's been aligned like this for about 7 years. The trick is, the laser hits the mirrors and lens at these positions no matter where the lens head is in the 24x24" table area, so the engraving and cutting results are identical everywhere on the table.

I've thought about trying to center the beam to everything, but since it ain't broke... :D

Joseph Shawa
01-04-2017, 12:34 PM
The only other simple thing that is really, REALLY, is important is that the height of the beam as it leaves mirror 1 is at the same height that you want it to enter into your cutter head.

Rich Harman
01-04-2017, 4:18 PM
Just my way of doing things, but I'm not so concerned with the beam hitting dead center, anywhere between DC and halfway to the mirror's edges is fine with me...

There is the advantage to a non-centered beam, when the mirror gets worn you can rotate to present "new" surface to the beam.

I do feel it is important that the beam be centered in the last mirror. If it isn't then you will need to steer the beam towards the center of the lens - causing the beam to not be perpendicular to the cutting surface.