CNC Z Axis Pointer

thingiverse

For positioning your spindle when CNC cutting. This pointer holder is for (reasonably) accurately finding the workpiece zero point before you start cutting. It doesn't find the Z zero, just the X and Y axis reference point. There are 3 versions, one for 3mm or 1/8" collets, one for 6mm or 1/4" and one replaces the ER11A compression nut completely 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 pointer and, after aligning it, you can drive all around your work area able to see where the spindle centre is. You can check your material is big enough too. There is a tricky part, aligning the laser pointer, 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. *I don't suggest turning the spindle on unless you can set the rotation speed to a low value. Turn by hand to check the dots accuracy.* You can see that it's not perfect, if you run the spindle it will draw a circle around the zero spot and this circle can be quite small and easy to us for finding working zero. 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 for it using 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. I included a version that takes a 6mm pan head screw for 6mm or 1/4" collets, it's a few mm longer to account for the thicker screw head and the thicker back section. I also included a version where it replaces an ER11A compression nut and collet. Just screw your ER11A out and screw this one in. It is quite long when the laser pointer has been inserted (70mm) and the screw adds about 20mm. To insert the device into the spindle you will need about 90mm of z-axis clearance. If you need a shorter version then I have one of those too, see the [shorter Z axis pointer thing.](https://www.thingiverse.com/thing:5251829)