Qidi Plus 4 - One Killer Feature, A Few Big Flaws

The Qidi Plus 4 has one killer feature everyone is going to copy (including Bambu Lab). But it also has a few major flaws that prevent it from reaching its full potential. In this video I discuss what sets this printer apart and how it compares to its predecessors: the Q1 Pro and the X-3 series.

*Disclosure: Some of the above links are affiliate links. If you purchase through my links I will earn a small commission. *

00:00 Intro
00:49 Disclosure
01:08 Aesthetics
01:38 Improvements: What Makes It Better?
02:29 Printhead & Hotend Specs
03:19 Filament Cutter - Qidi Box
03:55 Extruder
04:31 Chamber Heater
05:05 Fire Hazard!
05:32 Other Features
06:05 Web Interface & Mobile App
06:38 Firmware (Klipper)
06:47 Camera Monitoring
07:10 Sponsor (PCBWay)
07:45 Spool Holder
08:00 Nozzle Wiper / Purge Chute
08:19 Bed Levelling / Tramming
08:27 Bed Mesh: What Were They Thinking!?
09:02 Input Shaping: Graph Comparison
10:11 The Big Lie Everyone Tells
10:42 Print Tests: PLA
11:22 Califlower
11:48 Print Tests: PETG
12:14 No More VFAs!
13:03 Print Tests: ABS
13:21 Clogging Issues
13:58 There’s a Trend Here..
14:36 More Print Tests
14:55 QidiSlicer / OrcaSlicer
15:33 Print Quality Fixes
15:50 Conclusions

[ygkd]

RE: belt pitch.

EDIT 2: Did a deep dive into this topic to further educate myself. VFAs have two sources: motor mechanical resonance and the polygonal effect of the belt on the pulley (the belt follows a non-circular path around the pulley because the teeth are harder than the sections in between, so it doesn’t have a constant bending radius). The polygonal effect results in a jerkiness of movement, inducing periodic vibrations (jitter) at the print head, appearing as vertical lines on the print matching the belt pitch. Switching to a 1.5mm pitch belt from the usual 2mm will reduce the prominence of the polygon effect. So this is the real reason why the 1.5 belts are better. That being said, the mechanical resonance of the motor (MRR) is the bigger contributor to VFA. This is speed dependent. Every printer has a different natural frequency at which the motor resonance is maximized. By restricting speed to be outside this range (lower or higher) we can limit the prevalence of VFAs. Qidi achieves this with a setting in the slicer called resonance avoidance.

Leaving the original comment for context but I now know this explanation is incorrect.


EDIT: The Plus 4 pulleys appear to have the same diameter as the Q1 Pro I compared it to. So now I'm thinking the difference is in the belt width (9mm v.s. 6mm) or the fact that a finer pitch belt will have more teeth in contact for an equivalent pulley diameter, resulting in less backlash.

[markusgranberg]

Finer pitch on belts does not improve the position accuracy in this application. And the move distance/ motor step is based on the driving pulley diameter.

[Garage]

The ceramic heatbreak nozzle has fixed like 99% of heat creep clogging in the community's experience. Anyone with the stainless heatbreak version can ask for a free replacement. Also just a quick note that for absolute maximum quality on this and many core XY machines you should orient long straight parts 35-45 degrees rotated so it prints diagonal across the bed. :)

[Desmond-k]

Thanks a lot for sharing this in-depth video! I’ve had the Plus 4 on my shopping list for a while now, and I’m really drawn to its enclosed chamber. It’s perfect for me since I frequently print with different materials. However, I’ve also heard about some electrical system issues, and those critical flaws you mentioned in your video have definitely made me think twice about its value for money. Lately, there’s been a lot of talk in the community about the T1Pro. From what I’ve seen, it seems to offer good speed and solid customer support, so it’s definitely on my radar. This Black Friday, I’ll probably be deciding between Qidi and FLSUN. Both brands seem to offer good deals, and I’m excited to see what they have in store.

[andreask.]

Are you sure that the belt pitch results in more precise movement? Smaller gears should give you more precision. I don't see how the belt would achieve this. 🤔

[DaKaN]

Did you remove the plastic film on the camera lens? seems so cloudy

[thorstenjaczek]

I have the Plus 4 for some time now and use the QIDI Studio (Orca based). Because of the higher Voltage (220V) in most of Europe we do not have the SSR problem. I love this printer and it prints faster and cleaner than my Ender 5 Plus. QIDI has a pretty good customer service and helped me as I couldn't connect the printer with the App and Fluidd.
Nice and quiet printer.

[grasstreefarmer]

There seems to be some misunderstanding on the role of belt pitch. Belt pitch width and depth affects transmission power, it does not play a roll in precision of motion. Precision in stepper motor systems comes from the step angle of the motors.
If you consider a 2mm pitch width belt on a 20 tooth pulley its 40mm of belt motion per rotation of the pulley. If you increase the number of teeth on the belt, and the teeth on the pulley it will still be 40mm of belt motion if the pulley is the same diameter as the 20 tooth pulley.
The smallest unit of belt motion you can achieve comes down to how small a rotation angle unit you can command or resolve. Larger pulleys produce more belt motion and smaller ones produce less for each rotation.
This is why in printer config files you won't see any reference to belt pitch and instead see rotation distance, step angle and micro steps.

1.5mm pitch belts would seem to just make it harder to find replacement parts instead of the very common 2mm pitch standard. I also wonder, but don't know for sure, if the smaller pitch could mean they are more prone to skipping.

[Gunner]

would love to know what your filament storage is at 5:06sec mark when you are showing the off gasing issue during heat up.

[investandgrow]

What printer do you recommend that does it all under 1500

[cluebin]

For the PETG spool holder comparison test, it would have been good to do one on a Bambu printer since that is the gold standard for this class of printers. The Prusa MK4 is ancient history at this point and nobody watching this is likely contemplating buying one of those.

[jesuismika]

Would love to see a print comparison between the plus4 X1C and P1S. Make it easier to understand for new buyers.

[colinward]

Thanks for the great review! You included much more detail about the good & the bad, including upgrades must useres are already doing. Noce job!

[jdhurrell]

This printer was #1 on my list until I started hearing more about the overheating issues on that circuit board. I don’t want to risk burning my house down.

[brandonberkmortel]

My qidi plus 4 has been going strong for a month now. Nothing but amazing quality prints.

[williamdery]

Got my Plus 4 one month ago, have not got it to work ---terrible support--will not keep temp. up ---goes up to 220 then goes back down to 140, when bed temp get to 60 head temp goes to 0. still have not got response from tech support
Is there any support in US?

[normanguiver]

Hi more questions than answers. I am one of many with Zortrax + printers looking for a new printer to print nylon. I sent Qidi a .stl and the support team were terrific and they printed it but the material was damp so didn't print well so I don't know what it is capable of. Any experience of it?

[anthonylong]

Im waiting on the Qidi Box to see how good that is and I am also waiting on Flashforge who are also releasing a multicolor unit and new 5M printer in the next month...Its between those two which i get for a Christmas present to myself

[Bespoke-Rodriguez]

Would you be able to provide a list of settings for the best quality prints? Speed is not an issue as I prefer quality over speed. Thank you.

[leaftye]

I'm not crazy about new nozzle. It was already difficult finding different types of nozzles until Trianglelabs made a v6 adapter. Being able to use all sorts of nozzle materials or even just hardened tips, coated nozzles, and high flow cht-type interiors are great options to have. Iirc, it was about half a year before a cht-type Qidi 0.4 nozzle was available, and then several more months before other diameters were available. How long will that take for the Plus 4? I guess that, the normal and safety revisions, and the release of their AMS, is another reason to wait to buy a Plus 4.