This is a laser tube mount specifically designed for the K40 class of laser machines. It's designed to provide maximum lateral and vertical adjustment in the small space that's available, while still providing a reasonably secure mount for the tube. This mount is tiny compared to some of the others out there, but it fits and allows for far greater adjustment. This is even more important on these "high quality" little machines that are nowhere near square. If you push on the top of the mount it will flex a little, depending on the plastic used in the print. I used PETG, which is pretty rigid. Of course the sheet metal the mounts bolt to will flex when pushed as well. Just don't push on it.
The mount is adjusted by loosening the two top frame bolts that hold the top clamp between the mount frames. A socket is used to turn the adjuster nut. If loosening the nut, it's best to apply some pressure to the tube clamp to push the tube in the opposite direction. This probably won't be necessary for the vertical adjustment as the weight of the tube will allow the tube to drop down as the nut is loosened. Once the painstaking process of mirror alignment is done, tighten the two top bolts to lock the mount in place. It doesn't have to be so tight that the frames bend. Just tighten enough to secure the tube clamp between the frames so they don't move.
The 2 top frame bolts and the 2 bottom bolts that clamp the mount frame and base together are #8 bolts 2.5" long. The frame to case mount holes are designed for #8 socket head bolts, but a dremel can be used to cut the sides off regular screw heads and allow it to drop into the slots. One can also just use a washer if you don't care about it dropping into the slot, but this could prevent the tube from adjusting low enough. The bottom screws can be 3/4" #8, or whatever will fit in the holes. There should be plenty of slot space to slide the mount back and forth quite a bit.
The Tube-ClampA requires two #4 socket head screws. The length of which depends on how much travel you need. I had 1" long screws, which worked fine for the lateral adjuster. The vertical screw in my case needed to be at least 1/2" longer. Use a nut to secure the screw to the clamp, as is shown in the picture. We don't want this screw moving around in the clamp. Also, make sure that the screw head does not protrude past the surface of the clamp (and into the tube). The two clamp halves require (4) 3/4" long #4 screws. I had designed the Tube-ClampA to accept melt in nuts (which I need to order), so the holes on that clamp are a bit larger. I used regular nuts and they worked fine. Only tighten these screws enough to keep the clamp from rattling around on the tube. The clamp should freely spin on the tube, but not so much that the tube will slide under it's own weight should you tip the machine. If it's too tight it could break the tube, especially when the glass expands from the tube heating up. Hopefully there's enough cooling that the tube doesn't get much past room temperature anyway.
The adjuster brackets just snap into place. Push the tube far enough to recess the protruding screw to make it easier to snap the adjuster into place. It's much easier when the screw isn't sticking out and getting in the way. The ends will slide into the slot on the side of the mount and they should slide freely in the slots. The assembly order I used was to bolt the 2 frame pieces to the frame base with 2 #8 bolts. Then screw the clamp halves together on the tube. Then drop a couple screws into the slots at the bottom of the frame and slide it into the tube cavity. Put some bubble wrap under the tube to keep it from banging around. It should be an easy drop in, with some handling of the tube to make room for the mount. Then slide the clamp between the mount frames and add the 2 top #8 bolts and snap the adjusters into place. Put a washer and nut on the adjuster screws to finish it off.
Designed in Fusion 360. File is attached if you want to tweak it.
UPDATE (Tube-ClampA-UPDATED.stl and Tube-ClampB-UPDATED.stl):
Changed the two hole clamps to a single hole to make it easier to get the nut one.
Extended the bolt depth of the vertical clamp adjustment screw an additional 5 mm to add additional vertical travel when using the same screw length as the horizontal adjustment screw.
PETG pretty much always requires supports