Pairing BitZero with modified cheap Z probe for easier zeroing on the spoilboard / bed

[woodchip_breath (Cormac McCarthy)]

There may be a way to do this with the BitZero alone but I have not figured it out. The BitZero is made for zeroing on the corner of the stock as far as I can tell, and its uneven bottom prevents the probe from lying flat on the bed.

I have been thinking about using one of these cheap Z probes for this purpose for a while, but I was thinking about splicing it into the BitZero wiring. A few days ago I did some shower thinking and came up with this plan.

I bought a Z probe from Amazon, there are many to choose from. Here is the one I got: RATTMMOTOR CNC Probe Tool Setter Cnc Milling Z-Axis Tool Setting Touch Plate Probe Mach3 Router Milling Cnc Engraving Machine Auto-Check Instrument Setting Probe - Amazon.com

I peeled the red lead away from the black lead with my hands. If one isn’t familiar, this is easy to do as the wires are separated by the insulation. I cut the wires at a decent length away from the probe and only left the black wire, which is connected to the metal cylinder.

I stripped the end from the black wire and press fitted a 8mm magnet into a 3d printed holder. That print is linked here. It is an OpenSCAD source file but the designer has a few ready-made STL files. One can customize that source file to accommodate any size of magnet. I had to print a couple of them to get the fit right.

EDIT: Here is that Thingiverse link for the magnet wire lead: Wire Magnets by CuriousTech - Thingiverse

Now, I connect the BitZero magnet to the bit holder as shown and also connect the magnet from the FrankenZProbe, and by the miracle of continuity, the new probe will also trigger the machine.

See the image below.

If anyone is interested and the OpenSCAD is a bit tricky, I can help with that. I could also print you a model, but unfortunately, it might take a few tries. One would be better off to find a friend or a maker space. The print should only take a few minutes as it is very small.

As far as implementing this into your CNC software, I’m not certain. I use CNCjs and it is fairly versatile. I just modified my BitZero script.

Maybe someone will find this useful. Honestly, I just like making gadgets like this.

[gdon_2003 (Guy Donham)]

The BitZero does have two levels. The one is for putting on the corner but if you simply sit it on the spoilboard and select Z probe only the software and controller know how to compensate for the height difference. A lot of people only zero on the corner but I often center in the center of my project and set z zero on the bottom of material (spoilboard). Be sure in CM you tell it if you have v1 or v2 BitZero. I think the current default is v2 which is what you picture above.

[woodchip_breath (Cormac McCarthy)]

@gdon_2003 What you say makes sense.

I don’t have an easy way to run a Windows machine in my basement near the Shapeoko so I don’t use Carbide Create. I previously owned a 3018 and had the Raspberry Pi hooked to it for CNCjs, so I just migrated that to the Shapeoko. I don’t have the benefit of those built-in scripts so I have used the ones that the CNCjs creator has made with a few alterations.

I could put the BitZero on the near corner of the spoilboard and take the Z zero from there. I actually hadn’t thought of that (not sure why!). I have been getting the X and Y zero from the top left near corner of the stock and then jogging maybe 20 mm to the front and right to use this new probe.

I thought I had figured out an easy way to get the Z zero of the bed but I suppose I just found another way to skin the cat.

I think this thing will still come in handy and I didn’t have to modify the BitZero or the Shapeoko in any way, which was a goal when I first had the idea.

[woodchip_breath (Cormac McCarthy)]

Following up in case anyone else tries this hack out for themselves:

My device will not work as shown in the photo. The new device magnetic lead must be in contact with the BitZero flat metal surface and not attached to the router bit / housing. The continuity must be between the BitZero touch pad and the new device touch pad.

Since the magnet is not attracted to the BitZero, I stuck it to a large ferrous metal washer. I just place this washer on the BitZero and that makes the connection. This should be tested to make sure the Carbide3D logo lights up when the bit touches the new device.

I explained this more than necessary, but I would hate to see someone break a bit by being a little hasty.

I did find this probe useful when surfacing a cupped piece of wood. I wanted the highest spot so I could judge my first surfacing height. I put this probe in the middle and very easily got a Z zero without resorting to the good old paper test.