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 thefirst 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 thesecond 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 the3rd 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 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

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.

Print Settings

Printer Brand:

Creality

Printer: 

Ender 3

Rafts:

No

Resolution: 

.2

Infill:

20%

Filament:

Amz PLA

White

Notes:

To print the socket lid I used supports and printed with the threaded section on the bed.

To print the ER11A version, use super high resolution because the thread is quite fine, only 0.75mm thread pitch. I printed mine with the fine thread on the bed (no supports necessary but a brim may be needed for bed adhesion)

IMPORTANT

To print the battery cup you will have to use Vase mode (in Cura this is "Spiralize Outer Contours" under "Special modes") because the cup is only one layer thick. If you use any other mode the printer will leave blobs at the seam which you will have to sand off.

Post-Printing

Screw the lid onto the body, it may be tight after printing so add some oil or a smear of grease to help. If it's too tight, clean out the threads with a sharp pointer or knife. I cut the sliver of partial thread at the start back a bit to help engagement and stop it folding over.

Once it starts work it a bit, to and fro, until it moves freely enough to undo easily but tight enough to be secure when in use.

Insert the 3mm screw, a washer and a nut through the lid. Tighten firmly, this has to be perpendicular to the lid else the pointer won't align easily.

Check your laser works from 2 LR44 batteries. If not, the resistor needs to be reduced, I soldered 75 ohms in parallel with the 91 ohms on the module. You don't want it bright, this makes the dot look big on the workpiece.

To make contact with the batteries I used some solder braid but any fine wire will do as well. You can use the wires that come on the module.

One wire (from the resistor) does through the hole in the bottom of the cup where it will contact the front of the battery, the positive wire (red) goes up the outside of the cup where it gets pressed onto the back of the batteries by the lid.

The Z-Axis pointer is designed to hold the lens end of the laser and allow the back to be positioned with 3 3mm set screws, thus enabling aligning the laser. The laser must go all the way to the bottom.

Push the module into the body and insert the 3 set screws (M3 set screws, 4mm long) to hold it in place lightly. Look through the holes for the set screw and make sure you don't screw into the PCB slot, this could short out the power to the laser.

Insert the battery cup, routing the black wire through the hole in the bottom and lay it flat so that the bare wire will contact the front of the batteries or fold it over the edge to make contact with the side of the top battery as shown in the picture. The other wire gets pushed to the side by the cup, there should be a channel for the wire.

Now your laser will be working but the dot will be big. Put some tape over the end and pierce a small hole in it. This will reduce the intensity and dot diameter.

Adjust the set screws till the laser does not draw a circle when you put it in the spindle and turn it by hand. You can also do this with a hand drill which turns slowly. Dont' be tempted to turn it on unless your spindle runs slowly. Mine self destructed.

For storage, just insert an insulator like some paper or tape between the wire and battery or between the 2 batteries.

Pictures below

Side contact with top battery

Storage

Running the spindle to fast

Category: Machine Tools