Qidi Plus 4

I purchased a Qidi Plus4 for my new company for some small-time manufacturing and prototyping, but like most things I feel a need to tinker a little bit.

Resources

The Plus4 Community Wiki on Github is a great resource. The downside is there's quite a lot here you can rabbit hole into, but overall there are some good "out of the box" things to consider.

When I first got my printer, I updated to the v1.6.0 firmware and then implemented these changes below

Basic additions

The first one is the CLEAR_NOZZLE With Conditional Purging and Wiping macro changes - when I'm not changing filaments and/or I'm doing back-to-back printing, the purge at least is not necessary and a bit of a waste - so I've used this to address that.

The second is the Better Chamber Temperature Readings alteration, which averages the reading from the GD32 in the hotend with the temperature probe in the chamber to improve the accuracy.

I also noted the stepper drivers get quite warm - about 90 to 95c - ultimately they are still within their design specs but I cannot resist a bit more cooling - especially with the chamber temps able to get quite warm. So I've printed the Hex Mainboard Cover for 92mm fan, installed the larger fan and duct work, and then applied the Adaptive Main Board Cooling Configuration to allow the fan to run at a lower duty cycle.

Finally, re-enabling the SCREWS_TILT_CALCULATE macro allows me to get the bed quite near square before applying any bed meshing - this uses the inductive probe to get a very good bed level compared to using a feeler gauge

Tuning

Since I have better cooling for the drivers, I also implemented the Stepper Motor Tweaks, although I haven't noticed any real difference.

Finally, I re-adjusted the belt tension from the factory as per the How to adjust belt tension on the Qidi Plus 4 guide. This resulted in much higher max accels before excessive smoothing after tunning the input shaper test. I don't want the belts too tight to cause premature wear, but I did find them a little bit loose until doing this.

My Own Tweaks

I have done two tweaks:

The first is a Step Drift Fix that may or may not improve repeated probing. The more I've read about the issue over on the various places (linked in the readme) the more I actually think this one doesn't do anything meaningful. However, I found it also didn't break anything either, so for now I've left it on the printer as is.

Finally, I set up a Stock Probe Compensation macro that aims to improve the speed at which prints start. Since I will be using this printer for low-volume production and prototyping, I will frequently find myself doing back-to-back prints. While the startup procedure from Qidi is quite reliable, it is also quite slow. This project is still a work in progress as of May 2025 as it's not particularly easy to model the behavior of the inductive probe and its compensation as a function of both the chamber and bed temperatures. I don't need it to be perfect, just at least on par for good first layers with the manufacturer procedure.