Methods and Equipment for Measuring Nozzle Wear

Bambu Lab H2 Series
1

I understand nozzle wear can be measured using a microscope. Is there alternative (i.e. cheaper) equipment that can be used?

Also, I just change nozzles every 3 months or when things start to go wrong in a manner that implies it might be related to the nozzle. Are there actual signs one can look for, fancy gcode programs that can emit a line you can measure, etc?

Thanks in advance for replies.

2

First question is how do nozzles wear? Studies have shown that it’s not an overall increase of bore diameter, but a combination of the tip scrubbing over material that’s already been extruded, and probably the very immediate edge of the nozzle bore opening being eroded away.

Any strategy for measuring wear needs to work on at least one of those two wear points, and ideally both.

3

Nozzles are consumables. A measuring equipment can be expensive and not worthwhile. If one uses abrasive filaments a lot, watching for signs of printing quality issue that cannot be explained by other factors should work.

BTW, changing nozzles every 3 months seems a lot. Did you notice printing quality deteriorate every 3 months or is this a preventive measure?

4

Well, you could always employ Six Sigma’s tools to chart performance degradation, but unless you are running a print farm and squeezing every penny, just do what you are doing and replace based on hours of print time.

While Six Sigma methods don’t cost anything in themselves, the investment in time is another matter.

5

I am not certain it is exactly 3 months, but it is preventative

when the printer sends the reminder for maintenance, i look at the month number and decide what to do based on that, but i dont always do it as soon as the prompt comes up.

6

Two good ideas here, both have some potential.

  1. It may be possible to extrude a single-layer pattern and visually inspect - perhaps with a cheal USB microscope - to see signs of irregular extrusion that would indicate a worn nozzle opening.

Would require reference images and training to identify “good” versus “bad”.

This could be added to the print start G-code so it happens every time, then it would be a matter of chosing to look at it or not.

  1. Bambu already does assign an “abrasiveness value” to filament types, it can be found in the filament properties under “Required nozzle HRC” and ranges from 0-500.

Currently, Studio uses this to determine if a hardened nozzle is required for a given print, and it seems the value is either “3” meaning not required or “40” meaning “required” - unfortunately I don’t see any other values, even for something like PLA Glow.

Nevertheless, a rough wear value could be calculated in the slicer by factoring in layer height, the aforementioned nozzle hardness number, and the total length of extrusion the print requires. Since nozzles don’t carry unique IDs (except on H2C) , it wouldn’t really be possible to track per-nozzle wear, but it would be possible for the printer to say “hey, this print equals 150 wear points” and then users could track that for nozzles if they wish.

7

I replace on hours, for my A1 fleet it has been 2500 for the stock and 5000 after. I’ve crashed and bent a few early, but never had one noticably wear out.

I wore out an ender brass nozzle once so noticably that you could fit larger things like mechanical pencil leads into the orifice. Commonly 0.5mm.