CR-10 v2 runout sensor cover and mount for direct drive extruders

Why this mount exists

I run lots of large prints on this machine and so for me, the runout sensor is essential. While the runout sensor is perfectly usable many Hemera mounts, I didn't like using the default mount with it for two reasons. 

First, with the factory mount that there'd be quite a lot of filament between the sensor and the extruder entry. Second, I didn't like that the filament could end up bending around the z-axis lead screw closest to the sensor.

With this simple mount you can put the runout sensor directly above the filament entry point on the Hemera extruder. It may position fine for other extruders but I have no way of checking that though if this mount sounds like what you're after but doesn't quite fit your setup, get in touch and I'll make a variant to work for you.

How to use it

I've provided two variations of this mount. One orients the runout sensor along the x axis, the other along the y axis. You might find one or other works better for you depending on what you've chosen to mount your extruder - the one I'm using (and pictured here) is the y axis version.

There's also a cover for the underside of the sensor. You'll need four M4 nuts which you can use with the bolts that mount the sensor onto the z axis mount plate. Once the cover's fitted the sensor unit will friction fit into the mount. You can then friction fit the mount onto the top plate that covers the x axis' rollers.

You will of course need an extension cable that's long enough to take the runout sensor the entire length of your printer's x axis. You can buy one or make one as I did here - all I did was pry the latches of each pin out from both connectors, put the pins from a cable I had lying around into the connectors (noting orientation!), hot glued the pins in place and put a protective sheath on the cable. It's hacky but it was cheap and it works.

Printing the parts

I've attempted to model each variant of the holder with ease of printing in mind. The y axis version has a little extension on the left that I felt would help increase the surface area to help with the friction fit on the roller plate, but it probably isn't necessary. Both variants hold just fine though.

Print your preferred holder with the open part of the runout sensor facing up.

Print the sensor cover with the M4 nut gaps facing up.

Print each with whatever wall and infill settings you like. I printed mine with 1.2mm walls and 5% infill using PETG which I found gave me a strong enough pair of parts.

Summary of other parts

1. For the sensor cover: Four M4 nuts
2. For the runout sensor: An extension cable long enough to let the runout sensor travel the full length of the x axis. The cable needs 3 pins - buy one or make one.