Design Z Axis End Stops Best Practices

Hi all !! smiling smiley

What is the most preferred End Stop for Z axis ? ( taking under consideration accuracy,better bed levelling, less maintenance and cost )

Should Z Axis End Stop be fixed or should be adjustable what are the pros and cons for both the systems ?

[www.thingiverse.com]

This.

On a non-delta printer, if you have a Z-probe (also called a proximity sensor), then you don't need a Z end stop at all.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
On a non-delta printer, if you have a Z-probe (also called a proximity sensor), then you don't need a Z end stop at all.

A proximity sensor is a magnet and a hall sensor, right? How would RAMPS/Marlin work with such an analog sensor?
I think, I have some laying around, would be nice to know how to implement it.
Olaf

Quote
o_lampe

Quote
dc42
On a non-delta printer, if you have a Z-probe (also called a proximity sensor), then you don't need a Z end stop at all.

A proximity sensor is a magnet and a hall sensor, right? How would RAMPS/Marlin work with such an analog sensor?
I think, I have some laying around, would be nice to know how to implement it.
Olaf

There are lots of different sorts of Z probe designs, including modulated IR, differential IR (I sell these, see [miscsolutions.wordpress.com]), inductive, capacitive, and servo- or solenoid-deployed microswitch probe. I think there are a few people using Hall sensors, but it wouldn't be my choice.

Edited 1 time(s). Last edit at 05/10/2015 05:46AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have a broken thumb throttle from my e-bike laying here.
It sends out a very smooth linear signal ,depending on the distance between magnet and hall sensor.
Wouldn´t it be beneficial, if Marlin would "see the endstop coming" and reduce z-speed during z-home procedure, until a programmed value is matched?
It could even tell the precise distance.

I don´t know if any of the above mentioned sensors send an analog signal?
-Olaf
Sorry, if I hijacked the thread....

Edited 1 time(s). Last edit at 05/10/2015 07:20AM by o_lampe.

Quote
o_lampe
I have a broken thumb throttle from my e-bike laying here.
It sends out a very smooth linear signal ,depending on the distance between magnet and hall sensor.
Wouldn´t it be beneficial, if Marlin would "see the endstop coming" and reduce z-speed during z-home procedure, until a programmed value is matched?

RepRapFirmware for Duet electronics does exactly that.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42

RepRapFirmware for Duet electronics does exactly that.

Wow awesome, but I couldn´t find a hint about z-axis sensors...

5 Extruders would suit fine for my full-color "hedgehog" hotend....yumm
[forums.reprap.org]

Olaf

Quote
o_lampe
Wow awesome, but I couldn´t find a hint about z-axis sensors...

My differential IR sensor provides a quasi-analog output compatible with Duet electronics, to indicate 4 different states: sensor a long way from the bed, sensor approaching trigger height, sensor at/below trigger height, and sensor saturated by ambient IR (which normally means that bright sunlight is reflecting directly into the sensor).

I have made capacitive sensor and ultrasonic height sensors with an analog outputs in the past. There is also a recent thread on the Ormerod forum about a home-made inductive sensor with analog output.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].