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View Full Version : Alignment. Houston, we have a problem.



Joseph Shawa
09-19-2016, 12:46 AM
My beam is hitting DEAD CENTER on the opening to mirror 3 from ALL corners. Cannot see even a little difference in location of burn.

After reflection off of Mirror 3 the beam goes VERTICALLY down the right side of the empty tube NOT THE CENTER.

If I adjust the mirror so that beam is centered on tape at the exit (no cone) then the beam is not vertical and will go out to the left.(visible at a couple of inches.

If I adjust the mirror so that the unfocused beam is aligned vertically (hits same spot when table is up or down) then the beam is about 4mm off center to the right (25mm mirror).

If I place a lens in the tube with the mirror set like this (vertical) , the beam exits NO LONGER vertical but off to the left.

If I adjust the mirror so that the beam with the lens is vertical then the focused beam hits the side of the cone. So I cannot use air assist.

Do I need to hit mirror 3 at a different place? I just cannot figure this one out logically.

Same thing with different focal length lenses.

This is why I thought my tube was shot right out of the gate. I am an expert on alignment now.

I ordered a new head but I question whether it will work. Something is goofy.

Anyone?


So having worked on it for, WAAYY to long, I have decided that if I keep this head then the beam needs to come in at the top of the opening at mirror 3 so that it reflects down nearer to the middle. Funny how we strive to get the beam centered in the mirrors and this time it has been the problem. I'll try it and report back.


















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Joseph Shawa775 560 0130 (tel:775%20560%200130)

Scott Marquez
09-19-2016, 2:29 AM
You are correct, you need to hit mirror 3 above center.
Rabbit laser has an alignment resource on their website that shows this.
Scott

Joseph Shawa
09-19-2016, 2:42 AM
Thanks for the reply, Scott. I'll check out Rabbit.
The bummer is that I have to raise the whole tube and work forward.
This probably has been the reason for inconsistent power as some of the beam has been getting cut off and the cone was getting hot.
I'd have to say this is a poor design feature and something I've not heard a word about.

alan corder
09-19-2016, 5:50 AM
An excellent video here, https://www.youtube.com/watch?v=8DjK7zeSDCQ helped me a lot.

Joseph Shawa
09-21-2016, 12:58 PM
I have decided that if I keep this head then the beam needs to come in at the top of the opening at mirror 3 so that it reflects down nearer to the middle. Funny how we strive to get the beam centered in the mirrors and this time it has been the problem. I'll try it and report back.


Well, I FINALLY figured out how to remedy the problem.

Once I got my beam entering high through the opening on the head to M3 the beam was STILL getting cut off somehow.
Well it turns out that the opening is actually not indicative of the actual path to the mirror. There is a lip onto which the mirror seats and that needed to go. Easy.
The main hole was STILL lower than the top of the mirror and to get the beam to hit high I had to grind out the path. It is now more of an oval at the top.

VIOLLA!!

I have an unimpeded path from M2 through the head orifice and onto M3. I believe it could still go higher because the vertical beam through the tube vs the mirror are not exactly the same so I think it is still off to the right a bit, but once I made adjustments I can hit directly in the center of two spots 8 inches different in height.

Did some cutting on 1mm plastic with the new alignment and it RIPPED through the jobs.

Checked the alignment the next morning and whatdoyouknow still spot on. I guess there is no evil magic in Chinese machines, just an occasional poorly made part.

Very happy now.


















--
Joseph Shawa775 560 0130 (tel:775%20560%200130)





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