Prototype red line/cross alignment pointer

Community Laser Talk
1

I’ve been meaning to work on replacing the red dot pointer with a cross-style pointer for 3 reasons;

  • The alignment on the red dot changes if the distance to the target changes
  • The mounting bracket isn’t very sturdy or solid and moves/shifts often
  • It’s hard to see the dot if the nozzle is really close to the work surface

The pre-made and modeled ones I’ve found are made for the K40 or other device, are flimsy, or don’t work for other reasons.

I’ve combined a tube mount with a 3D printed bracked to address the issues:

  • Aluminum clamp doesn’t have 3D-printed imperfpections and is a solid mount to the laser head tube.
  • Less material used, and the arms are (or can be modified to be) far enough away from the head to show the line even if the nozzle is close to the surface
  • X/Y lines are easier to see and, if aligned correctly, give a visual X/Y alignment for objects on the bed
  • Z/object distance doesn’t matter (if aligned correctly).

I’m going to try to do the physical install tomorrow. OpenSCAD model file included for anybody interested in playing with it. I’ve parametized all the settings, so it can be adjusted for different environments.

laser_mount_scad.txt
(2.6 KB)

laser_clamp
laser_clamp.png1190×599 9.74 KB

lmount_bottom
lmount_bottom.jpg960×540 47.1 KB
lmount_top
lmount_top.jpg2789×2789 769 KB

2

“More work needed,” but that’s what prototyping is for, right?

There is still not perfect mechanical alignment. I’m either going to need to fudge the design, or build some form of alignment mechanism into it.

laser_guide
laser_guide.jpg960×821 108 KB

3

Redo with using the laser to cut acrylic in order to give the opportunity to adjust.

1/2" cast acrylic and 3/16" extruded from the scrap pile at my now-goto acrylic supply shop. 20mm tube clamp from Amazon. Misc 3mm screws and hardware to assemble.

Assembled, aligned, and then used acrylic glue to lock everything into place. Pointer stays aligned even if Z moves and the X/Y are good for 8" or so of alignment before the beam cuts off. I can get to about 3mm off the surface and still see the lines under the laser head.

l_pointer
l_pointer.jpg960×720 85.3 KB
l_mount
l_mount.jpg960×720 140 KB
pointer_clamp.lbrn (57.1 KB)

1 Like
4

I use similar appearing lasers on my cross beam pointer setup. Were you able to obtain lasers with focusing adjustment rings snug enough that they do not shift over time?! I have bought multiple sets and the adjustment rings have so much play in them that they end up shifting/moving due to the back and forth movement of the head. I tried snugging them up with teflon plumbers tape but that did not work well. Thread lock is a possibility but I am afraid it might not react well with the plastic parts or might not be reversible with the plastic parts.

5

Were you able to obtain lasers with focusing adjustment rings snug enough that they do not shift over time?! I have bought multiple sets and the adjustment rings have so much play in them that they end up shifting/moving due to the back and forth movement of the head.

I’ve used vinyl electrical tape and hot glue. Both have worked for me. Electrical tape is easier to remove.

1 Like