Bracket for Using a Digital Caliper to Level Your Bed Prior to “Automatic Levelling”
This bracket allows you to use a digital calliper to level your bed before performing “automatic levelling”. The idea is to use a simple tool that you probably already have to achieve very precise measurements. The main role of the bracket is to provide a stable mounting point for the calliper, allowing you to take repeatable measurements.
Materials:
Digital calliper
Double-sided tape (the thinner the better – I used 0.2 mm)
Some filament (in my case, PETG)
Printing:
Print it on its side.
Once printed, chamfer the highlighted edges using a sharp knife to ensure any poor first layer does not interfere with the fit of the bracket.
Assembly
Using double-sided tape, attach the bracket to the back of your calliper. (I chose to mount the calliper upside down, as I wanted to make adjustments when bed is positioned close to the print head, since this is the point where the first layer is printed.)
How to Use
Press “Return to Home” on your printer and wait until the process is complete.
Then move the gantry backwards along the +Y axis until it is positioned above the bed screws.
Clip the bracket with the attached calliper onto the gantry.
Lower the calliper until it just touches the bed. Do not press with force, as the bed will flex and this will give a false reading.
Zero the calliper.
Lift the calliper from the bed (while keeping it attached to the gantry) and move the gantry forwards along the –Y axis until it is positioned above a mounting screw.
Lower the calliper again and check the reading:
Negative – this corner of the bed is higher; you need to lower it.
0.00 – this corner is level with your baseline.
Positive – this corner is lower; you need to raise it.
Adjust the height using the screws under the bed:
Clockwise – the bed will lower.
Anticlockwise – the bed will rise.
Clip the bracket to the other side of the print head and repeat the above steps.
Tips & Tricks
Make sure you keep your base value unchanged. In other words, do not re-zero or turn off the calliper.
When attaching the calliper to the bracket, it does not need to be perfectly aligned. “Close enough” is sufficient, as the goal is to obtain repeatable results rather than absolute precision.
I took my measurements with the build plate in place so I could probe directly above the bed screws. If you do not probe in this exact area, your base measurements will change once you adjust any of the remaining three corners.
Reduce the contact area between the calliper and the bed plate. I used cap head screws in a magnetic bracket, but you could also glue in a small plastic disc or another small object.
When mounting the calliper on the left-hand side of the gantry, make sure it is not trapped between the chain guide for the PTFE tube and the cable.
You do not need to use a calliper with a broken screen. Use one that is easier to read, such as a model without cracked glass.
Roni
