M2 Auto-Leveling Kit (Beta)

[PcS]

You should not get head collisions. I can run G 28 again after G29 and nothing happens other than a correct homing. Z probe or not. If the plate is high in the center. Either way you will end up with that little bow.

[Bratag]

You should not get head collisions. I can run G 28 again after G29 and nothing happens other than a correct homing. Z probe or not. If the plate is high in the center. Either way you will end up with that little bow.

So the sequence of events for my collision was

Run G28 - correctly homes to the center of the bed.
Run G29 - runs through the auto level - finishes and the bed stays high
Run G28 - bed homes to X/Y , then as per the config file it did a -4 on the Z before homing - now because the bed was already at the Z-stop - when it tried to move to the center to home it rammed the print head into the bed.

As long as the print bed drops before you run the second G28 all is well.

[PcS]

I think I deleted the -4.....can't remember now. But I do know I ran a g28 again after a g29 with no issue. I will confirm those things again tonight and let you know.

[Tim]

Not that anybody else is going to try implementing the auto-leveling with random hardware purchased through Amazon, but for the record, the 2mm proximity sensor does NOT work with the Zebra plate. However, it does work on a strip of copper tape, so I think the problem is the thickness of the Zebra plate above the copper layer, not the Zebra plate itself.

I ordered the 2mm proximity sensor because it was the only one I could find that could be ordered through Amazon Prime; the 4mm sensor is on order but ships from China with at least a week's lead time. But the sensor dimensions are all the same, so I can use this one for testing how it can mount with the dual extruder assembly getting in the way.

[Jules]

Not that anybody else is going to try implementing the auto-leveling with random hardware purchased through Amazon, but for the record, the 2mm proximity sensor does NOT work with the Zebra plate......

Well, crud! Thanks Tim, it does help to know.

[N5QM]

Not that anybody else is going to try implementing the auto-leveling with random hardware purchased through Amazon, but for the record, the 2mm proximity sensor does NOT work with the Zebra plate. However, it does work on a strip of copper tape, so I think the problem is the thickness of the Zebra plate above the copper layer, not the Zebra plate itself.

I ordered the 2mm proximity sensor because it was the only one I could find that could be ordered through Amazon Prime; the 4mm sensor is on order but ships from China with at least a week's lead time. But the sensor dimensions are all the same, so I can use this one for testing how it can mount with the dual extruder assembly getting in the way.

Tim,

I ordered this one yesterday and it is scheduled for delivery tomorrow, via prime shipping...

http://www.amazon.com/gp/product/B008FZ9UNA

[Tim]

I ordered this one yesterday and it is scheduled for delivery tomorrow, via prime shipping...

Hmm, I missed that one somehow.

Jules---I have not determined that the 4mm sensor will not work with the Zebra plate; on the contrary, the fact that the sensor I got worked on a piece of copper tape suggests that it will. It's just that the non-metallic part of it is too thick for the 2mm sensor. Measuring on the edge of the plate, the Zebra has about 1mm between the top and the copper layer, but it's too close to call it definitive.

[Bratag]

I ordered this one yesterday and it is scheduled for delivery tomorrow, via prime shipping...

Hmm, I missed that one somehow.

Jules---I have not determined that the 4mm sensor will not work with the Zebra plate; on the contrary, the fact that the sensor I got worked on a piece of copper tape suggests that it will. It's just that the non-metallic part of it is too thick for the 2mm sensor. Measuring on the edge of the plate, the Zebra has about 1mm between the top and the copper layer, but it's too close to call it definitive.

While its not an apples to apples comparison. The sensor that shipped with the beta kit was perfectly capable of triggering with a good 4mm between it and the plate. Now that might be because the MIC6 plate is a beefy chunk of metal, but it does give hope that you could have something between the metal and the sensor and still be good.

[Tim]

Now that might be because the MIC6 plate is a beefy chunk of metal, but it does give hope that you could have something between the metal and the sensor and still be good.

Since it's really easy to test the sensor by connecting it to a 9V battery and watching the indicator LED on top, I did a quick test trying to detect a metal ruler through a bunch of pages in my notebook. That test worked as long as the thickness of the pages was less than about 1.5mm. It makes sense that anything you stick between the sensor and the target will have a different dielectric than air, and that's going to change the inductance, and consequently the detection distance.

I think my 2mm sensor is just short of working with the Zebra plate. However, I want a couple of mm of margin, anyway.

[Jules]

...Jules---I have not determined that the 4mm sensor will not work with the Zebra plate; on the contrary, the fact that the sensor I got worked on a piece of copper tape suggests that it will. It's just that the non-metallic part of it is too thick for the 2mm sensor. Measuring on the edge of the plate, the Zebra has about 1mm between the top and the copper layer, but it's too close to call it definitive.

Whew! Is the new M2 one a 4mm sensor? (Missed that bit. All happy again!)