This article is a different method to align your laser machine without firing your laser beam every time you do a adjustment.
You need a laser pointer to do this with battery or other power source.
Doing this prevents any damages to the mirror or residue from the tape causing issues with your optics.
The idea is to mount the pointer inside the laser head and align the mirrors until the point reaches the 1st mirror.
After this – you should perform the regular alignment just to confirm this backward alignment.
I need to give credit to Royden James coming up with the idea and a product to use. More about his module a bit further down you can download.
Put a piece of tape over the hole coming out of the laser tube chamber
Test fire your machine quickly so you get a burn mark on the tape.
You can now turn off your machine completely.
Remove the lens from your laser head
Install the led-pointer inside the laser head.
Royden James version
This is a better one if you want to make one you can re-use, it has built in battery and a smaller pointer with a switch for quick and good alignment.
Click this link to Onshape to download Roydens version with description and parts needed.
Move the laser head to bottom right
Turn on your laser pointer and adjust your mirror on the laser head until you hit center on mirror 2.
Move the laser head to bottom left
The dot should now still be in the middle of mirror 2
If its not – follow the details below.
If the dot is to the left – your laser head needs to move closer to the gantry
If the dot is to the right – your laser head needs to move away from your gantry
If the dot is above center – your laser head needs to be lowered – or the 2nd holder lifted
If the dot is below center – your laser head needs to be lifted – or the 2nd holder lowered.
After you do any of adjustments, always always move the laser head to bottom right position and align the dot in center on mirror 2 before testing in bottom left position again.
Do not skip this, seriously – don´t!
Repeat until you have the dot hitting center i both left and right positions.
You now have the X-movement aligned and horizontal.
Now with the laser head aligned, you can have it in bottom right, left or middle position, does not matter. You need it in bottom though!
Adjust mirror 2 until you hit the burned spot on the tape over the hole.
Move the gantry to the top and see how the dot moved.
If the dot is to the left – your 2nd mirror holder needs to move further right
If the dot is to the right – your 2nd mirror holder needs to move further left
If the dot is above center – your 2nd mirror holder needs to be lowered
If the dot is below center – your 2nd mirror holder needs to be lifted
As usual – after adjustment you need to move the gantry to bottom position and look at the dot – adjust mirror 2 until you hit the burned spot again.
Repeat until you hit the burned dot in both bottom and top position of the gantry.
You are now done without firing the laser.
You can now follow this alignment guide to confirm that your alignment is well done!