CNC Alignment Laser

thingiverse

For positioning your spindle when CNC cutting. This laser device is for (reasonably) accurately finding the job zero point before you start cutting. It doesn't find the Z zero, just the X and Y axis reference point. It's not difficult to find the X and Y home spot using a bit with a sharp point (V-bit) but you have to lower it till it is close to the surface to get reasonable accuracy. Can be a tedious procedure. This holder accepts a cheap laser module (head) that you can buy online for less than $0.35 each. They have a lens and current limiting resistor. Because this design uses 2 1.5V LR44 batteries, your laser needs to be the 3V version, mine was a 5V version and I had to reduce the 91ohms resistor. With the laser in your spindle (not spinning) you can move around your work area knowing where the centre of the spindle is. You can check that your material is big enough for the job. There is a tricky part, aligning the laser module, they are not particularly well aligned when you buy them, for that you should buy a "boresight laser" but then you're talking much higher costs and a delay while some online shop ships it. Print with any material, open side up with no support. Maybe you like to use a brim for better adhesion for the tall print. I just use hairspray (on the print bed) I use 1/8th" bits so I designed the **first version** to use a 3mm screw about 20mm long for the spindle collet chuck to hold onto, include a nut and washer to align properly and hold it securely. This replaces a 1/8th or 3mm tool. With the **second version** the lid can also be used as a hex socket wrench if you have a 17mm ER11A collet chuck like my Stepcraft HF spindle otherwise use the flat lid. A 3mm machine screw goes through the lid and this is what the chuck holds onto. If your spindle has a 1/4" or 6mm chuck then you will need to screw this size onto the 3mm screw. With the **3rd version** the ER11A clamping nut is removed completely and the ER11 cap version will screw in in its place. This will only work if you have an ER11A collet chuck with the 14mmx 0.75mm thread (not the ER11 version which has a different thread) There are a few alternatives for this type of alignment, some are fixed to your CNC spindle holder but offset so you need to use a macro to calculate the spindle's actual position. Others use 2 line lasers to form a cross at the spindle position, these are large permanent devices added to your spindle mount but are always there, just a flick of a switch away from seeing the spindle's position. My other thing, [Z-Axis Pointer](https://www.thingiverse.com/thing:5247220) is a simpler design, a bit longer and trickier to align but quick to print and try. If you own a Stepcraft CNC I suggest a look at the [Stepcraft Laser Cross Pointer](https://www.thingiverse.com/thing:5320061) I was using my alignment laser to see how much the laser dot moved when raising the spindle, sure enough about 1.5mm of movement in the x axis as the spindle went up about 80mm. Turns out my Z-axis travel was fine but the spindle was mounted slightly off vertical. Probably wouldn't matter on shallow cuts but not so good on a deeper one.