Inquiry on Scanning Z Probe

R006

hey,

I am currently using a Duet 3 MB6HC and am interested in integrating a scanning Z probe with my setup.

I plan to use a longer wire to connect the scanning Z probe to the IC. Are there any potential issues with using longer wires in this setup?
Could you provide recommendations on wire type, shielding, or any best practices to minimize potential issues?
Could you provide details on the accuracy of the scanning Z probe?
Additionally, what is the operating temperature range for the scanning Z probe?

link: https://docs.duet3d.com/en/Duet3D_hardware/Duet_3_family/Duet_3_Scanning_Z_Probe

droftarts

@R006 For the cable between the SZP board and coil, we use a 4-core FFC cable, with 0.50mm pitch, opposite side contacts. We supply 5cm and 15cm cables, and I've seen a 20cm cable in the kits that come with Mellow Fly toolboards. I'm not sure how much longer you can go than that before there are issues with interference; I don't have any longer ones to test with.

Accuracy is limited by two factors:

noise in the reading, which limits the resolution. On the test machine this varies from about +/- 1.2um at 4mm distance from the bed to +/- 3um at 6mm distance. Some of this noise may be caused by vibration of the machine.
Like all inductive sensors, it is temperature-sensitive. So the absolute accuracy depends on how well you calibrate it for changes in temperature of the bed and/or the sensor. There is a thermistor on the sensor to help with this.

We suggest a maximum ambient temperature of 75°C, and an absolute maximum board temperature of 85°C. The coil can likely cope with higher temperatures than this, having no active components. Our FFC cables are rated at 80°C, but you can get FFC cables that are rated to 105°C from Molex.

Ian