I have printed this calibration cube and measured its sides:
Where can I enter the necessary size compensation in Bambu Studio to get a more precise printed cube?
I would advice against calibration cubes for trying to improve dimensional accuracy.
This video explains why in an excellent way:
1 Like
Thanks, I have seen the video but that procedure requires a non-free model which I have not bought yet. I thought I could at least have something “passable”, not perfect, with an old fashioned calibration cube.
My question still stands however, once we find out the size compensations - in whichever way - where do we enter them in?
If all sides appear to be differently off, you’ll probably have to scale the model in the individual axis by the percentage that you’ve calculated using the scale tool.
I use this one for ABS
https://www.printables.com/model/375254-shrinkage-tool
I wouldn’t such a small block to base calculations on.
Sighhh… there are a lot of people on the Internet who overthink X-Y calibration. It’s all BS there is no sense in the claims that one model or the next provides for better calibration. There is a much simpler - and free - method of calibration for dimensions.
If you simply right-click and produce a cube primitive, this is as pure a dimensional object as the slicer software can produce because it involves no interpolation of an incoming model. The cube primitive is a pure mathematical construct. So if you print the default size, which is 25.6mm on each side, you will have an object that the slicer will send to the printer at exactly those dimensions. From there, you can measure what the printer produced versus what the slicer told the printer to produce and adjust accordingly.
Two tricks I might recommend:
-
Since Bambu does not have calibration support for the Z axis, there is no benefit to printing a full cube. Cut or scale the cube at 5 or 10mm and save yourself a lot of time and filament because you can only calibrate X and Y anyway.
-
The second tip is to create varying scales of cubes at 10X increments. My favorite is to make a 100x20x5 and clone the cube and place it in both an X and Y 90 degree and 45 degree offsets. What does this do? It helps diagnose if one of the belts or servo motors is giving you trouble. Remember that at 45 degree, you’re isolating one server motor at a time.
If you want to get really fancy, you can place text on each one labeling the orientation. Then save this as “Calibrate X-Y.3mf”. If your using Orca slicer, you can even pin it in the start menu in Windows. Bambu Studio does not support this but Orca does.
5 Likes
Thanks @Olias I will try your approach.
My question still stands however: once we find out the size compensations - in whichever way - where do we enter them in?
Say I printed the 25.6mm cube, measure it and find a -0.3 mm deviation on the X axis and a +0.4 mm deviation on the Y axis, what compensation I need to enter and where?
The outer X-Y offset can be found in Global/Quality under X-Y Contour. There is a Object setting too if you want to get more granular with an individual object like let’s say a dowel for a specific model. If you’re doing trial and error calculations, there is an advantage to using to using cloning and then to change the settings by object. That will allow you to print multiple variations at once and save time.
Note that there are two settings. The Contour setting is solely for the outer dimensions. For interior or enclosed sections, you want to change X-Y Hole Compensation. Negative numbers will decrease and positive will increae.
3 Likes
Here is a model that works the same as the paid one, but is free:
1 Like
What you typically see as dimensional inaccuracy is the shrinking of the material when cooling down. inaccurate extrusion width can skew your measurment.
If there are really differences between X and Y then I would try to fix the mechanics.
OrcaSlicer allows to enter one compensation value for shrinking in the material profile that applies to X and Y.
You should always take an Inside and outside measurement to negate any influence from inaccuracy of the extrusion width.
And make the measured length as big as possible to reduce the influence of measurement errors.
1 Like
What do you mean by an inside and an outside measurement?
You should measure the outside dimensions of the test object as well as between walls. If say your printer is overextruding so that loops are 0,05mm wider than intended, then the outside measure will be 0,1mm too large although this has nothing to do with printer esteps or shrinking. On the other hand, internal measurements will be 0,1mm too small. So if you take both and use the average, any influence from over or under extrusion cancels out.
1 Like