Hey everyone. I’ve been mentioning this project for a little bit and I was thinking that it’s time to start posting my results. Hope you all like it!
Proximity Sensors are nice, but how accurate are they?
We have the Capacitive sensor that can be used on anything with a current, which is good, however it detects electrical current which means different readings for different print bed temperatures. This type of probe can also have different readings based on the ambient temperature in the room and may be affected by dust in the air…
We have the inductive sensor which is limited to metal print beds, is also affected by the amount of current running through its sensing area, can also be affected by ambient temperature and dust as well, and is at least 3x the cost
and we have the mechanical sensors that can be as simple as a microswitch or as complex as the BL Touch sensor (also 3x the cost of the capacitive sensor) . They can sense on any surface but are they really accurate?
With no experience, I can’t say anything about the BL Touch, but the common microswitch was highly inaccurate, and was also affected by the temperature of my print bed…
So, here’s my solution!
An optical sensor!
This uses a LM393 Dual Differential Comparator IC and will output in Digital and/or Analog
This type of sensor with my probe design can detect distance on any surface with high speed and accuracy, and is not affected by current, print bed temperature, ambient temperature, dust, or humidity.
I’ve designed this to be used as a Z stop probe, however this can be used as an endstop with the simple implementation of a spring and a design tweek.
So now the fun stuff:
List of Parts:
1x Optical Sensor
1x Step down Buck converter
2x M3 x 12mm screw
1x M3 x 15mm screw
1x small washer
1x #14 gauge body piercing (one end chucked into a drill and sanded down to form a cylinder)
Jumper Cable Pin Header Connectors
you will need All printed parts from this post
Also you will need this equipment:
A Soldering Iron
Wire Cutters and maybe Wire Strippers
Heat Shrink Tubing
And when you’re finished it should look something like this:
I even have a video found here: (I am having serious problems uploading files to this forum)