Calibrating my Ender 3 V2 after modding to Direct Drive

Temp tower after modding printer.

Now that I have the direct drive setup on my Ender 3 V2, it is time to get the printer adequately calibrated. At the end of my previous post, I included a picture of a temp tower. Structurally it was a good print, but there were some problems, especially with the burnt filament throughout the temp tower. Now that I have my hardware mods completed(for now), I have gone through and done some essential calibration. This post will highlight some of the calibration steps I’ve done.

Checked all screws and connections

I had done this step before. But I thought it would be worthwhile to do this again. Any action I do later will do nothing to improve prints if I have a loose screw somewhere. I didn’t find any loose screws this time, which is good. I’d rather spend a few minutes checking all screws and have no problems further down the calibration process caused by something simple like a loose screw.

I also checked all connections while testing screws. I have made many changes to the printer and moved most of the electronics to outside the enclosure. Fortunately, I did not find any loose connections. But again, it is better to make sure then find out later time was wasted troubleshooting something caused by a loose connection.

Checked the belt tensions

For the x and y belts, I checked them by plucking them with my small hex wrench. If they give a slight twang, I call them good. I did have to tighten my x-gantry belt slightly. That isn’t surprising. As part of putting the direct drive on, I had to remove the hot end assembly from the x-gantry. When I hooked all of that back up, I might have forgotten to re-tighten the belt.

Checked the wheels and lead screw

First, I made sure there was no wobble in the bed. Had there been wobble in the bed, I could have fixed this with the eccentric nut. I also ensured all of the wheels under the bed were smoothly moving while I moved the bed along the y-axis. I find this to be more of an art than science, but I make sure the bed can freely move as I push it, yet can’t move independently.

The eccentric nut for the y-gantry is directly above the wheel on the front right (as you look at it from the front). Turn this nut until the bed wobble is gone.

For the other wheels on the printer I did the same. Each of the wheels moved freely, but not too freely. I knew these would be good since I had just adjusted them yesterday.

Finally, I checked the lead screw. The lead screw seemed good. I chose not to lubricate my lead screw at this time, but I did inspect it to make sure there were no apparent issues.

PID Tuning

Anytime a change to the hotend is done, a PID tuning should be completed. Technically I haven’t changed my hot end at all, even with all the mods I’ve done lately. But since buying this particular printer, I have yet to do a PID tuning that I remember. Plus, I plan to print filaments that I typically print at about 240C. So I wanted to be sure to do my PID tuning at that temperature.

Below are the necessary steps I used to do my PID tuning from the terminal in Octoprint. I also should note I take any filament out of the hot end while doing the PID tuning. I know some people like to leave it there. But I’ve found it can burn filament and cause small clogs doing so.

  • M503 – The M503 command tells the printer to show current settings saved in memory. In this case, I wanted the current PID settings for my hotend. My current settings were: Recv: echo: M301 P22.11 I1.92 D63.79.
  • M303 E0 S240 C10 – With his command, I told the printer to do a PID autotune (M303) on my hotend (E0) at 240C (S240) and repeat the autotune ten times (C10). At this time, I like to watch the hotend heat up and cool down in the temperature tab of Octoprint. The final values given to me were:
    Recv: #define DEFAULT_Kp 24.65
    Recv: #define DEFAULT_Ki 2.09
    Recv: #define DEFAULT_Kd 72.62
  • M301 P24.65 I2.09 D72.62 – This commend sent the new PID settings to the printer.
  • M500 – This command writes the new PID settings to memory.
  • M503 – I usually do the M503 one more time to ensure the PID settings were changed correctly.

Below is a screenshot of what PID tuning looks like in Octoprint.

PID tuning.

This is the most considerable change in PID tuning I’ve had on my printers. It makes me wonder if I should have done it when I got it out of the box. Yes, I am PID tuning at a much higher temp, which will have an impact. But still, I wonder.

Calibrating the extruder

I knew for sure I would have to calibrate the e-steps. I installed a new extruder stepper motor and changed out the stock extruder assembly for an all-metal one. I have a hunch the burning filament I was seeing in my temp tower came from my e-steps being way off.

If someone wants, I can do a whole post on calibrating the e-steps. I basically just extruded 100mm, measured the difference, and adjusted my e-steps accordingly (original e-steps*100/measurement). After saving my new e-steps of 97, I am almost dead on when I extrude 100mm now.

Test print

Now that my printer was calibrated, it was time to print the temp tower again. I could tell right away this one was printing better.

I did end up changing filament. For the first temp tower, I was using white PETG from Sunlu. That roll was almost at the end when I started this, and calibrating my e-steps used the last of it. The temp tower below is grey PETG from Duramic 3D. If I order PETG off Amazon, that is what I usually get. I must admit, though, that I am probably done ordering PETG off of Amazon. I see better deals and better selections of filament going directly to filament manufacturers now. Plus, printing samples from various subscription boxes have given great leads on good filament sources.

Before I ramble too much.. here is the post-calibration temp tower:

SONY DSC

This temp tower obviously printed much better. As with the previous one, it printed from 230C to 250C, with the base at 240C. The print had very little stringing and one weird artifact at the top of the 245C level. I think the 1mm retraction at 30mms seems to work well with this direct drive setup.

So far, I’m pleased.

So far, I am happy with the PrinterMods.com direct drive setup. I’m still on the fence about keeping it installed, though. I may end up throwing a MicroSwiss all-metal hotend on this printer. And if I do that, I will want to use the MicroSwiss direct drive. I’ll give it a few weeks, though, and see how I like this setup.

Song of the Day: Paint it Black

Ok, usually I try to tie my song of the day into the post. Well, I just wanted to share this great version of Paint it Black by War, with Eric Burdon on vocals.

Bonus Song: Tobacco Road

Another great track from Eric Burdon and War.

One comment

Leave a Reply