Big Red z-probe modification details

[Blake Samuels]

We installed a new z-probe to big red last night. The pink one.

Mechanically it went on the head in a similar way. The body of the probe was much longer and protrudes below the head which is probably desirable. In the event of a crash, the probe should be pushed upwards by some distance before force is applied directly to head assembly. Might reduce damage to head and beam. However risk of damage to z-probe is probably increased since it could get stuck in honeycomb and on machine restart, snapped off when it tries to drive home.

Electrically the old probe was a simple switch. It was supplied with ground and signal. The controller input is pull up.

The new probe is a powered device with a signal output. It takes 24V and GND. Our wires are brown (24V), black (signal) and blue (GND).

Testing by plugging it into the controller showed that connecting to the pin with wire marked ELT+ (pin 1) allowed the z datum to work with our new probe (that pin alone). However we note that pin 1 and pin 3 were connected together with the existing switch so that both z-axis positive limit and z-axis "original' (origin) were connected. We kept it connected like this in final install. Extract from the manual p44 below.

Maybe for x and y axis, the "positive limit" can be different to "origin". e.g. origin is what you find when doing datum but limit is what you enforce when user/job is moving head around. I can't see that as relevant for z though.

To get the 24V power to the head, we reused the 5V cable that was going to the laser pointer (laser pointer long since removed). We note that a beam combiner would be a better device for showing  where the laser will cut.

There was a small 1A 5V plastic coated black power supply that supplied this 5V and a GND to the head assembly. We removed this 5V supply from the electronics area of the laser cutter. It had no other uses than the laser pointer.

We connected the wire that was formerly for 5V supply to head to 24V output on the X3 block along with existing z probe ground and signal. The GND (from 5V pointer) was left disconnected at both ends and taped off. 

The colours of the wires were coincidentally the same at the head end so connections were: brown (24V), black (signal) and blue (GND).

All joints were soldered and heatshrinked.

RCD tripped out during the works. It was a larger one towards top right of cabinet and was unlabelled. We put a label "lasers" on it.

Please post other things if they come to mind!

[Fletcher Boyd]

With a new z-probe comes new height adjustment details. The new drop height is 11.3mm. That means we're actually at a reasonable distance between the probe and the head :)

--
You received this message because you are subscribed to the Google Groups "Artifactory Laser Subcommittee" group.
To unsubscribe from this group and stop receiving emails from it, send an email to artifactory-la...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/artifactory-laser/CAPC%2Bwzt6oBZdJcd6LxtoQUuEcvfn7%2B3Nb-duDR_JzR9fDuWkcQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.