Bed microswitch connection Maestro

Dugee

Converting a MPMD to a Meastro board, done all my config, just need to start getting the wiring ready.

For bed levelling, this uses 3 microswitches, one at each tower.

To wire these am I connecting them in parallel and connecting them to the E0 pins, STOP and GND?

Then using Mode 4 with M574 E0 S1 to configure the switches?

I couldn't see any reference to multiple bed switches other than the FSR through the JohnSL board, that I don't have........

thanks in advance.

PuterPro

My first thought is wire in series ...

In parallel is there's any difference between the towers it gets triggered when the first one home gets there which leaves the others out of sync.

I have a Cartesian with dual axis, I run the motors independently by separating the Axis' (Z & U) and home them separately.

There's a bunch of CoreXY guys around, they may have a better answer.

dc42

By MPMD do you mean Monoprice Mini Delta? If so, connect them to the X, Y and Z endstop inputs. The one connected to the X endstop input must be on the tower that is driven by the X motor output, and similarly for Y and Z. See https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwareDeltaPrinter, in particular the bit about testing motors and endstops individually near the end.

Dugee

@dc42 I have read through that, but am still confused. This is my first go at upgrading anything like this so I might be misunderstanding.

I have 3 high end optical endstops that I was going to wire in to x, y, and z endstops. If I put the 3 bed switches in as x, y, z, low endstops, where do I wire the high end stops to?

I thought that, conceptually, the switch arrangements for the MPMD were closer to the Johnsl FSR system, but with 3 tactile switches instead of FSRs. This is why I had thought that E0, along with mode 4 z probe was the way to go. I had considered that the nozzle pushing down on the bed would trigger the one of the switches as part of the calibration routine.

Apart from waiting for a better psu to arrive this has been my only problem with this upgrade. The documentation has need great and most answers I have found there. I am doing this as a learning thing so I guess the aim is being achieved!

dc42

I didn't realise tbat the MPMD had bed switches as well as tower endstops. If they are NC switches, I agree that you can connect them in series to the E0 endstop connector.

Dugee

why series and not parallel - is there a reason I require all of them to be triggered and not just 1?

I'll go ahead and wire them in series though.

ta

dc42

I said wire them in series if they are NC (normally closed) switches, i.e. the contacts are closed until the nozzle pushes the bed. If they are normally open switches, wire them in parallel.

Dugee

@dc42 gotcha. Understand.

Dugee

@dugee turns out the switches are normally open so I'll be wiring in parallel.

Once I get this up and running I'll try and put a guide together in case anyone else plans on this board swap.

Dugee

by way of an update, whilst I understand it is not the preferred way to do it, with these switches wired in parallel I get a z probe response from each of the switches as they are pressed in turn, giving me exactly what I had hoped for. At some point I may investigate changing this to an NC switch, but for now, all good.

I set them up using the z-probe connector, not E0 using M558 P5 H5 I1 F120 T6000, inverting the switch position and at the moment it works. Havent got to calibration yet but the z probe is showing when pressed.
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Just need to work out why me end stops aren't working.

(The only reason to have the switches as normally closed is prevent movement if there is a loose connection. With normally closed switches that would trigger immediately, while normally opened would never trigger. However that may be reason enough to change, IDK.)