FELIXprinters Pro Series Installation and user guide

How to fix z-sensor triggered
9 February
2018
Revision 4
FELIX Pro 1

How to fix z-sensor triggered
9 February 2018
1
FELIX Pro 1
www.FELIXprinters.com
Introduction
1Introduction
The FELIX Pro 1 features automatic calibration. This calibration heavily relies on the probe switch, which is
integrated in the hot-end flexure.
This flexure touches two contacts internally in the extruder assembly. When touching the bed this flexure
deforms and the contact is broken between one of the two contacts. The printer-controller detects at that
moment that the current active hot-end touches the bed.
Under normal circumstances this mechanism works properly. However, there are some cases where the probing
mechanism can be falsely triggered. In this how to, we’ll explain the mechanism in a bit more detail and also
show you what to do when an error occurs.

How to fix z-sensor triggered
9 February 2018
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FELIX Pro 1
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Inner workings of the probe mechanism
2Inner workings of the probe mechanism
In short: The probe mechanism basically consists of a spring and a switch. When the spring (the flexure) deforms,
the electrical contact gets broken. That is registered as a “z sensor triggered!” event.
If you see a “z sensor triggered!” message when the printer is idle, it means that one or both of the switches
have broken the electrical contact.
To make the probing mechanism as reliable as possible we did the following:
-Make sure the flexure has a pre-tension so it always pushes itself against the round contact pin
-Tune the pre-tension in such a way that the probe triggered event happens when pushing the extruder
with a defined force
-Use a magnet as the second electrical contact, so the flexure is “sucked” firmly into the print head.
-Treat the contacting surfaces and edges of the flexure so they are smooth, ensuring good contact.
Complete extruder assembly
Zoomed in view of left extruder assembly
Zoomed in view of flexure/probe
mechanism. Top part of hot-end
hidden from view
When the hot-end touches the bed
the flexure deforms and the green
indicated points (which are
mounted on the hot-end) move
upwards. The top green point moves
away from the electrical contact
and it gets detected by the printer.
Electrical contacts
spoints

How to fix z-sensor triggered
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Step by step troubleshooting:
3Step by step troubleshooting:
3.1 Check if z-sensor triggered goes away after heating both nozzles.
In some cases, cooled down filament in the not-used extruder(s) pulls the flexure mechanism slightly upwards,
causing a (sometimes constant) false trigger. To check if this is the case, heat both extruders to at least 180°C.
Check if the message has disappeared once both extruders have reached their target temperature. The latest
firmware releases automatically heat the extruders to 150°C when performing probing actions, but you can still
sometimes can see the “triggered” message when the heads are cold.
3.2 Are the hot-ends fully pushed backwards against the contact points?
During transport sometimes the flexure can be detached from the back contact point (the magnet). This can
be easily fixed by pulling the hot-end out and then pushing it backwards. You can usually feel the flexure
making contact with the magnet in the back of the print head, sometimes with an audible click.
3.3 Detect which hot-end gives problems
If the message does not go away, please check next step.
Pull down both hot-ends and
check if the z-sensor triggered
message goes away.
This example we use a
screwdriver to pull the both hot-
ends down. You can also use
tweezers for instance

How to fix z-sensor triggered
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Step by step troubleshooting:
3.4 Dirt between contact points.
Another cause for errors can be dust, corrosion or chips of plastic or metal that are stuck between vital electrical
contact areas of the print head. The debris can build up over time.
To correct this, the following can be attempted:
Remove the hot ends (see the manual for the procedure).
Attention: Handle the hot ends with care, they are sensitive and can be deformed rather easily when they are
outside the print head!
Clean the metal surfaces that are indicated in the pictures below with detergent and a Q-tip. They should be
perfectly free of dust, debris, metal filing, grease, ….
In the print head itself there are also areas of attention:

How to fix z-sensor triggered
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Step by step troubleshooting:
The electrical contact areas are indicated with red arrows. They need to be spotless.
3.5 Flexure deformed
As mentioned before, the flexure is a spring. We calibrate it with a certain pre-tension so that we have a reliable
electric contact. To check if the spring dimensions are still correct, you need a caliper to measure the distance
as indicated in the picture below.
Distance must be
between 4.55 and 4.60
mm

How to fix z-sensor triggered
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Step by step troubleshooting:
The screws which mount the flexure onto the hot-end should be properly fastened. If you can see that part of
the flexure can rotate around these screws, they need to be fastened.
If the distance is too small, the pretension of the spring will be too high. This will result in a first layer which is
squashed to much on the bed.
If the distance is too large, the pretension will not be enough to make electric contact and the sensor will
constantly be triggered. This is the most likely cause for the z-sensor triggered message.
To fix this issue, the flexure need to be deformed until the desired distance (indicated gap of 4.55 to 4.60mm) is
reached. If deforming goes very easily it could indicate that both or one of the torx screws mounting the flexure
onto the hot-end are loose. Please fix them otherwise tuning the flexure is no use.
To properly measure, make
sure not to deform the
flexure.

How to fix z-sensor triggered
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Step by step troubleshooting:
3.6 Wire breakage/ loose contact
Worst case (and not a very likely thing to happen) is that the cables are broken or mounted contacts are loose.
Wiggle the cables to see if the message “z-sensor triggered” appears or disappears.
Check if contact eye is loose
Check if this screw
is not loose

How to fix z-sensor triggered
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FELIX Pro 1
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Step by step troubleshooting:
If you are unable to continue or have any questions, you can check at the support section of our website or
you can contact us directly:
Website: www.felixprinters.com/support
Email: [e-mail]
Telephone: [phone]
Address: Zeemanlaan 15, 3401MV IJsselstein, The Netherlands
Kind regards,
FELIXprinters