In a prior post I talked about my 3D Printing Journey. One thing I talked about was trying to set the E axis steps for the P3Steel because the extruder was having an issue and was clicking while it was feeding the filament. I have finally got back to tuning the P3Steel.
I thought it would be a good idea to check what were the settings for the Prusa Mk3x. This should give me a good baseline since I am using the same z stepper motors and the other stepper motors are very similar. The extruder setup came from parts for an Mk3 using the Bondtech gears. By using Pronterface and connecting to the Mk3x, I will be able to use the Marlin M503 command to see what the settings are. Then I will edit the Marlin files for the P3Steel and set the appropriate values to match.
Issuing the M503 command I can see that the default axis steps per unit values for the Mk3x are Y=100, Y=100, Z=400, and E=280. First I did the classic extrusion test where you make a mark 120mm from where the filament goes into the extruder. You then extrude 100mm of filament. You next check to see how much was extruded by by checking your mark at 120mm with the point where the filament goes into the extruder. Ideally the distance should now be 20mm. If you have less than you are under extruding. If you have more, then you are over extruding.
Well when I first did the test, that 120mm mark disappeared into the extruder and filament kept feeding into it for a while. So I then marked off 3 segments of 100mm each and ran the test again. Well, two of those marks disappeared into the extruder. I was able to see how much was extruded.
I edited the Marlin Configuration.h file to make a change to the E value for the default axis steps per unit. I compiled the firmware and loaded it to the P3Steel. Each time I make a change to the firmware, I change the output name of the printer (“P3Steel-1.8”). That way I not it has changed. When I ran the test again, the same thing happened. A lot more than 100mm of filament was pulled in. On the printer you can check the configuration settings. The value that I thought I changed was the same.
The settings for the P3Steel were Y=100, Y=100, Z=400, and E=1900. The value for the E value wasn’t 280 like I had set it to. A little bit of head scratching here. What happened I thought. Well the magic of EEPROM happened. Even though the name changed, the changes I made were now part of the default settings and not the current settings. So in the LCD menu for the printer, I loaded the default settings and my change was there. I then saved the settings to the EEPROM to make sure they would stay there. I marked 120mm on the filament and ran the test again by feeding 100mm in to the extruder. I measured what was left and it was 20mm. So it was a success.
Quick note here. In my prior post when I was trying to work on the extruder clicking issue, I had changed the E value to 575. It seemed to have helped, but I did not run an extrusion test, nor did I check the axis steps value for the E. More than likely it was still 1900.
In tuning a 3D printer, in addition to the E step calibration, there are a number of other things that should be looked at. Updating your firmware can help issues with know problems. So check with the kit supplier (Prusa, etc.) or with the project that produces your firmware (Marlin, Klipper, etc.).
Check the mechanical components of your 3D printer. Make sure all the fasteners are tight. The belts should be tight (but not too tight). The pulleys for your belts shouldn’t move on the motor shafts (check and tighten the set screw). If you have wheels on your 3D printer, make sure they are properly tightened to prevent wobble and wear. Regular lubrication is needed on any of your lead screws, guide rods, or other bearings to keep the parts moving without friction. SuperLube synthetic grease is good for this.
Print shifts to the left or right can be caused by a loose belt or a broken pulley or a free spinning pulley on the X axis. Print shifts to the front or rear can be caused by the same issues but on the Y axis. I had an issue once on a print where on the last few layers, the print shifted to the left right a bit. I was able to use the print ok, but the guide pulley on the X axis broke which caused the shift. Sticking leads screws or friction on the guide rods can cause layer issues due to the Z not moving smoothly.
The stepper motors of the 3D printer can cause EMI or RFI interference issues. I seem to be having that with the output on the LCD screen for my P3Steel. The cables aren’t shielded at all. One possible solution is to get some snap on ferrite filter cores for the LCD cables.