Probing without the magnet on an Elite?

[Alphonse (Alan)]

My OneFinity Elite is equipped with a spindle motor that is earth grounded. With my original Journeyman I could probe without the magnet because the spindle was grounded and the probing circuit was satisfied with the earth ground of the spindle.

Is it possible to do some magic and eliminate the magnet for probing on the Masso equipped Elite? BTW, I have tried probing without the magnet (by mistake ) and discovered it doesn’t work!

EDIT: There is a similar thread on the Masso Forum but with no real answer for totally eliminating the magnet (gnd). https://forums.masso.com.au/threads/onefinity-probe-plate-no-magnet.3952/

[adamfenn28 (Adam Fenn)]

One way it just to use a 3D probe, like this: https://www.youtube.com/watch?v=wqhJUIPHDhY&t=6s

I suspect that’s a solution you’re considering though. You could also remove the magnet and wire that lead to the frame. Assuming we’re talking about the same spindle, and not a new one with ceramic bearings, that should work.

[Alphonse (Alan)]

Thanks Adam, my spindle is a Mechatron and it doesn’t have ceramic bearings. So, for example, the magnet attached to a frame bolt of the OneFinity works. That does help eliminate the risk of not attaching the magnet everytime. The better solution might be to cut the magnet off and put a more secure frame connection on that lead.

I am wondering about bonding the OF frame with a G3 ground. This was suggested on the Masso forum but there seems to be some concern about mixing the grounding/bonding between the spindle and the G3 controller.

I have not looked into the 3D probe too much. I have seen it and was reminded of a Heimer 3D-Taster.

[Alphonse (Alan)]

I cut the magnet off and replaced it with a connector which is now secured to the frame of the Onefinity.

It works and eliminates the risk of knocking the magnet off the frame. Now I no longer need to worry about fooling with a magnet.

[Gman (Mark Fettback)]

Alan is very correct just make sure the frame is grd and all is good

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Alan,

@Aiph5u

Ground the machine in accordance with the regulations!

The machine in which the motor spindle is installed must be grounded separately for each moving machine component. Even if, for example, the moving axes of a milling machine are electrically conductively connected to each other via ball screws and linear bearings, this electrical connection is insufficient for the protective earth connection and must be supplemented by a separate earth connection for each axis in accordance with VDE regulations. A protective conductor test must be carried out individually before commissioning.

– Source: Mechatron HFS Series High-Frequency Spindle Operating Manual

@Aiph5u

To not only prevent EMI but also to comply EN/IEC 60204-1 safety standard, the machine should be electrically bonded and grounded. Here the links with the relevant information on how to do this:

• Proper Grounding; How have you grounded your frame?
• Material and Tools needed to ground your Onefinity CNC
• Static electricity in a router

• Make using XYZ touch plate probing without magnet work after upgrading to a spindle

Regarding bonding and grounding the machine chassis, the CNC Controller and the VFD control cabinet, of course all grounds have to be put together. It is recommended to put all grounds together in one point, which usually is the ground of the control cabinet (VFD earth symbol).

@Aiph5u

– Source: Omron MX2 User’s Manual

An example for a ground loop is if your cable TV provider grounds their cable in their distributor board out there a few miles down the road and then it is grounded again in your house at your cable TV wall outlet or in the receiver. This can produce a lot of hum that deteriorates the signal. This is because in an unbalanced line, ground participates in signal flow (=ground is a circuit conductor that completes the circuit back to the source here). The solution here would be galvanic isolation. I have an isolation transformer as a sheath current filter in front of my cable receiver, and I have much better signal quality since then.

[tbeaulieu (Todd Beaulieu)]

Just stick the magnet on the frame. That’s what I did. Works perfectly.