Connecting Generic z Probe to Arduino controller

Easel
1

I’ve used Easel with good results, running a grbl controller running 1.1e

When I tried connecting the Z probe, (to SCL and ground), and ran the setup, it succesfully detected contact between the plate and the spindle.

However, whenever I try to run the probe (both testing and before a carve), the same happens:

a) the Spindle will move downwards less than 1mm
b) the spindle will move up some 30mm

With no contact detected

I ran teh advanced probe settings, set the plate thickness, played with several combinations of rate, height and distance, still the same behaviour.

Any pointers?

1 Like
2

What’s the command you’re sending to probe?

3

Easel’s default 38.2.
Using another SW (CNCJS) I tried also with 38.3, with same behavior.

4

Sounds like possibly noise related?
Post your settings.

1 Like
5

Could be… but, wouldn’t that be happening upon touch (spindle to plate, I mean)? They never come even close to touching…

6

noise will make it think it had touched.

7

After the 38.2
What’s the feedrate? Probe distance/direction? Are you retracting after the probe? All of this info will help.
A screenshot of your CNCjs probe settings would suffice.
I tend to guess the same as @Phantomm that your probe is sending a false trigger.
Is this on an x-carve? X-controller?

8

This is a screen shot of CNCjs:

image

And this is the code actually sent:

image
image722×576 30.8 KB

Result is the same with 38.2 and 38.3: Spindle will move downward less than 1mm, and then (without even touching the plate) will move upward 30mm (or so).

9

Odd…

Just out of curiosity, tried with 38.4 and 38.5. They worked.

Now, I’m lost…

10

G38.4 and G38.5 working; with failures on G38.2 and G38.3; support the idea of a false trigger.

Try this filter on your probe input:

Probe_Filter
Probe_Filter840×188 1.39 KB

11

Thanks! Will try that filter tomorrow!

Marino

12

You guys ROCK!

The RC filter did the trick

Marino

1 Like
13

Marino, which way did you face the capacitor? Am I correct in reading the diagram right that the capacitor goes inline between the resistor and probe input?

15

Ok so it’s like a 3way connection that splits off through the capacitor to ground?

16

Think think I got it working. I did what you suggested by splitting off the probe input to the capacitor then to ground and I haven’t gotten any noise yet. Thanks for the help.

17

Please excuse me for not answering before, But my CNC gave me hell today (broken cable in one of the steppers, and installing limit switches, spend the whole day).

I see you got it worked out, but anyways, what I did was to place the resistor in series with the input’s line. The capacitor is connected to ground deriving from the resistor (it doesn’t matter which side).

I was worried for the limit switches, specially whe they didn’t work at first (it was a collection of stupid mistakes), but in the end, they worked perfectly, God knows why…

Thanks to all!

Marino

18

It does matter which side. Glad yours is working, but the circuit you used doesn’t function the same as the original configuration.

19

Sorry for the lousy drawing, I grabed the first piece of paper I came accross with.

IMG_20180415_121409
IMG_20180415_1214093968×2976 2.41 MB

Can you draw something Like I did to show me the right way (I’m an amateur in terms of electronics, and I was very confident that was what you showed): I understood the touch plate to be a switch, and it made sense to place the filter on the Arduino’s input side… Where did I go wrong?

Thanks for the support, man!

Marino

20

This is a better way to do it. Some routers have the spindle/collet grounded.

Marino_Probe_Filter

22

Larry’s drawings remind me thos from Forrest Mims (the guy who wrote the workbooks for Radio Shack’s Electronic Lab)…