Magnetic Z-Probe Connector (V1)

This is the first iteration of my own magnetic Z-Probe connector. When building my Lowrider V4 CNC machine (https://docs.v1e.com/lowrider/) the common method seems to be to tuck the wires for the Z-Probe somewhere alongside the spindle while the machine is operating. I decided I would rather have the option to quickly and easily completely remove the Z-Probe wires while the machine is in operation to avoid being caught in any way. This is a rough working design that I have been using for the past year on my Lowrider V3, though I plan on making a cleaner version in the future.

The basic principle is to have two sets of opposing magnets on each side of the connector to ensure correct orientation of the connection. 

Materials Required:

-[2x] 6x1mm Pogo Pins (https://a.co/d/3N8c1Q2)

-[2x] 0.25mm Contact Pads (trimmed from scrap material using side cutters)

-[5x] 8x3mm Magnets (https://a.co/d/1wMd3cd) (One for attaching the signal to the spindle, and 4 for the pogo and contact pad connectors)

-Your choice of Z-Probe (Aluminum, small ruler, feeler gauge, etc.)

-Wiring

On one connector side there are two metal contact pads which connect to the signal and ground for the Z-Probe. I used a thin strip of metal (about 0.25mm thick) which I used side cutters to cut out of an old battery contact I had laying around, and then soldered a wire to each pad and crimped a JST connector to the other end of the wires. The JST allows the “pad contact” to easily be removed and reinstalled for maintenance purposes. 

I then used two “Pogo Pins” and soldered wires to the bottom non-spring side. These wires connect to the magnetic “signal” connector which attaches to the spindle, and the other to whatever Z-Probe you are using. 

Each assembly can then be inserted and glued into its appropriate holder. I also glued in two opposing pairs of magnets (for example, the contact pad side has one north pole and one south pole exposed).

From here, it is a simple method of quickly attaching the magnetic connectors, probing to your material, then quickly removing all the probe wires before starting your cut job.


I have also included my files for my magnetic spindle connector. This can be made by slightly roughing up the back of one of the magnets with either sandpaper or any sharp object able to slightly scratch the surface. When soldering, it is important to note that heating these magnets for longer periods of time quickly weakens their magnetic potential. Because of this it is best to use a higher heat and be as quick as possible when pre-tinning your magnet and then soldering the wire to it. Another important note is that your soldering iron tip contains, well… iron. This can make it very tricky to solder to due to the magnet grabbing the soldering iron. Make sure your magnet is well secured so that you can remove heat from the magnet as soon as possible without pulling the magnet along with the iron.