Some people are having problems printing the Willys MB RC Gear box. I believe this is due to an improper printer and/or filament calibration.
Here is my procedure for calibrating my filament profile. I do this every time I open a new roll of filament.
Warning: I use Prusaslicer therefore this procedure is precisely for PrusaSlicer. I’m certain you can do the same in any slicer that you may use, but you will need to figure out how.
Now, if you know how to do this procedure in another slicer, feel free to contact me and provide the steps and screen captures, I will create a specific Document for your slicer. This will help others.
Step 1 Download the files #
Download this file. It contains an excel spreadsheet and two stl files that are used in this procedure.
Step 2 Filament size #
Although we buy 1.75mm diameter filament, it is never 1.75mm and it varies along the roll. So my first step is too measure the diameter with a micrometer. You can use a digital caliper as well, but do not put to much pressure, you will flatten de filament and make a false reading.
Now write that measure in the spreadhseet in the filament size column. Take 7 different measure along at least 7 feet of filament.
Once you have 7 different measures, note the date, brand of filament and filament average size.
Step 3 Create Filament profile #
In Prusaslicer under the Filament settings tab, start a new profile by selecting the Generic PLA. Make sure the Extrusion Multiplier is set to 1
Change the Diameter with the value calculated in the previous step. Make sure you set the temperature to your preference for that brand of filament. Change the name with something relevant and save the profile.
Step 4 Generate GCODE for the Cube in Vase Mode #
You will now Print the 40x40x40 cube file you downloaded.
Under the Print Settings Tab, check the Spiral Vase checkbox. This will ensure it prints the cube with only one wall thickness. Since I do this every time I open a new roll, I saved the Printer Profile as seen in the black circle. That is not a requirement, but you might as well do it instead of changing the settings every time.
Then Slice the Cube and export the Gcode
Step 5 Measure the wall thickness #
IMPORTANT: Prusaslicer prints 0.45mm thick wall. I have no clue whether this is standard with every slicer out there. So if you are using something else. Find this information otherwise this whole shebang might just be wrong. If you find it is something else, than replace de target value 0f 0.45mm in the spreadsheet with the proper value for your slicer/printer.
Back to our regular program, You first need to print the cube. Then you will measure each wall at 4 different places, for a total of 16 measurements. I do some sort of plus sign on every face and I don’t measure right on the corner where it may be thicker.
Write down each measure in the spreadsheet. As you can see above, the walls are thicker than the target. My printer is therefore over extruding this filament.
Now write down the Extruder Multiplier on the right side and save the file.
Head back to your Filament Profile in PrusaSlicer and change the Extruder Multiplier with the computed value and save the profile
Step 7 Print the Bearing Calibration Confirmation STL file #
Slice the Bearing Calibration Confirmation stl file (not in vase mode) and print it. Test with a 10-15-4mm bearing.
You should be able to push the bearing in the calibration part with your fingers. You should not burst a vein on your forehead while pushing.
Flip the part, the bearing should remain in place and not drop out of the part.
Finally, you should be able to push the bearing out with your fingers. I used my little finger to get the bearing out of this part.
If this is not your case, it’s a waste of time to print the Willys gear box, it won’t work. Recalibrate until you have a proper calibrated printer/filament.
Again, if you have the knowledge to do this in another slicer, please contact me to share, I will create this same exact article for that slicer. Thanks!
