40W CO2 Laser - mirror alignment HELL

[slow_rider]

I finally got new mirrors for my brand new CO2 laser which I own for 2 months now and couldn't not finish a single cut with (thank you Chinese factory for not caring at all!!!).
In the process of replacing many things in the machine, I also wanted to remove the air intake adapter. In order to remove it the XY table needed to go out as well. Yesterday I tried to re-align to mirrors and after about 2 hours in I understood that it simply can not be done because when I move the table (Y) axis and point drift in one direction more than I can adjust with the screws to center it in the mirror. So my guess is that the table is not moving in a straight line in 45 degrees against the 1st mirror. Do I need to re-position the XY table?

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[buddydog]

Always a bad idea to mod more than one thing at a time BUT about ten minutes in on this video maybe will help you. Not my video but a good procedure:

[slow_rider]

I've actually made a huge step forward yesterday... I ended up leaving the mirrors as they are and moved the XY table + mount for the 1st mirror. After about 2 hours I had a pretty good alignment. Now It is almost perfect, top left is a bit off but I should be able to adjust that as well. If the machine was not made like a huge pile of S$$T it would have been easier!

[miketola]

Check your X axis. It must 90 degrees angle. Some machines its wrong.

[slow_rider]

The X axis is not traveling at 90 degrees in relation to the Y axis, 100% sure. That's why I can't get a perfect calibration on all corners.

[miketola]

Its normal issue. Just turn it right. Loose your belt and fix it. Turn it right, you can hear when belt jump over.

[slow_rider]

I need to take 2 or 3 days off from tuning this... it took several days until I got everything to work. I also had to change the tube, do some fixing on the control boards (diodes exploded WTF) and figure out how to attach the PWM display board to the MOSHI board - actually needed to cut a wire so it will work. Also new power supply and new mirrors because the original ones were scratched in two places... I've cut a new panel for the machine and Now I cut something to hold a USB-B connector as I am sure the long cable's weight will eventually cause damage to the card that has the USB connector on it...

Thanks for the advice, as soon as I have my mental powers back I am doing that.

[miketola]

Alot of work :-)

[buddydog]

Welcome to the $20,000 laser for $500 "kit"club! Once you get it right they work pretty good. You will need air assist and a movable table and then read Miketola's posts on focal length and optimizing path. It is amazing what 25 watts (your actual power with these rigs) can do.

[automationtechinc]

you can check the video to see if it will help from here

Hobby 40W CO2 LASER ENGRAVING CUTTING MACHINE ENGRAVER, Support and Ship from USA | Automation Technology Inc

or check this professional machine

CO2 Laser Cutter and Engraver With Auto Focus, 60W, 20? X 12? | Automation Technology Inc

[slow_rider]

By the way I have a question: Can I accurately position an object for engraving? For example, lets say I have a box 2" by 2" and I want to engrave something dead center. How can I position it and other identical boxes in a way that the engraving will be exactly at the same spot?

[buddydog]

By the way I have a question: Can I accurately position an object for engraving? For example, lets say I have a box 2" by 2" and I want to engrave something dead center. How can I position it and other identical boxes in a way that the engraving will be exactly at the same spot?

To do multiple parts sometimes I use the same drawing and draw a box outlining the part (medallion,stamp etc) and delete the center and cut out the box or circle, and then the next part fits in the box etc and is positioned correctly. I have used cardboard as a positioning system successfully. Be sure and tape it so it can't move! Oh when your done making the form be sure and delete the box and add the engraving back into the program! I often keep two copies of a program, one with the box cutout and one with just the engraving.

I did an outboard motor gasket a week ago and it was much to large to fit the machine so it had to be done in two setups with the extra rolled under the table.